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901b3290bd
1402 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
David Hildenbrand
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3523a37e65 |
mm: provide vm_normal_(page|folio)_pmd() with CONFIG_PGTABLE_HAS_HUGE_LEAVES
Patch series "mm: replace follow_page() by folio_walk". Looking into a way of moving the last folio_likely_mapped_shared() call in add_folio_for_migration() under the PTL, I found myself removing follow_page(). This paves the way for cleaning up all the FOLL_, follow_* terminology to just be called "GUP" nowadays. The new page table walker will lookup a mapped folio and return to the caller with the PTL held, such that the folio cannot get unmapped concurrently. Callers can then conditionally decide whether they really want to take a short-term folio reference or whether the can simply unlock the PTL and be done with it. folio_walk is similar to page_vma_mapped_walk(), except that we don't know the folio we want to walk to and that we are only walking to exactly one PTE/PMD/PUD. folio_walk provides access to the pte/pmd/pud (and the referenced folio page because things like KSM need that), however, as part of this series no page table modifications are performed by users. We might be able to convert some other walk_page_range() users that really only walk to one address, such as DAMON with damon_mkold_ops/damon_young_ops. It might make sense to extend folio_walk in the future to optionally fault in a folio (if applicable), such that we can replace some get_user_pages() users that really only want to lookup a single page/folio under PTL without unconditionally grabbing a folio reference. I have plans to extend the approach to a range walker that will try batching various page table entries (not just folio pages) to be a better replace for walk_page_range() -- and users will be able to opt in which type of page table entries they want to process -- but that will require more work and more thoughts. KSM seems to work just fine (ksm_functional_tests selftests) and move_pages seems to work (migration selftest). I tested the leaf implementation excessively using various hugetlb sizes (64K, 2M, 32M, 1G) on arm64 using move_pages and did some more testing on x86-64. Cross compiled on a bunch of architectures. This patch (of 11): We want to make use of vm_normal_page_pmd() in generic page table walking code where we might walk hugetlb folios that are mapped by PMDs even without CONFIG_TRANSPARENT_HUGEPAGE. So let's expose vm_normal_page_pmd() + vm_normal_folio_pmd() with CONFIG_PGTABLE_HAS_HUGE_LEAVES. Link: https://lkml.kernel.org/r/20240802155524.517137-1-david@redhat.com Link: https://lkml.kernel.org/r/20240802155524.517137-2-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Janosch Frank <frankja@linux.ibm.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matthew Wilcox <willy@infradead.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Barry Song
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9f101bef40 |
mm: swap: add nr argument in swapcache_prepare and swapcache_clear to support large folios
Right now, swapcache_prepare() and swapcache_clear() supports one entry only, to support large folios, we need to handle multiple swap entries. To optimize stack usage, we iterate twice in __swap_duplicate(): the first time to verify that all entries are valid, and the second time to apply the modifications to the entries. Currently, we're using nr=1 for the existing users. [v-songbaohua@oppo.com: clarify swap_count_continued and improve readability for __swap_duplicate] Link: https://lkml.kernel.org/r/20240802071817.47081-1-21cnbao@gmail.com Link: https://lkml.kernel.org/r/20240730071339.107447-2-21cnbao@gmail.com Signed-off-by: Barry Song <v-songbaohua@oppo.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: David Hildenbrand <david@redhat.com> Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Chris Li <chrisl@kernel.org> Cc: Gao Xiang <xiang@kernel.org> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kairui Song <kasong@tencent.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yosry Ahmed <yosryahmed@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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David Hildenbrand
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394290cba9 |
mm: turn USE_SPLIT_PTE_PTLOCKS / USE_SPLIT_PTE_PTLOCKS into Kconfig options
Patch series "mm: split PTE/PMD PT table Kconfig cleanups+clarifications". This series is a follow up to the fixes: "[PATCH v1 0/2] mm/hugetlb: fix hugetlb vs. core-mm PT locking" When working on the fixes, I wondered why 8xx is fine (-> never uses split PT locks) and how PT locking even works properly with PMD page table sharing (-> always requires split PMD PT locks). Let's improve the split PT lock detection, make hugetlb properly depend on it and make 8xx bail out if it would ever get enabled by accident. As an alternative to patch #3 we could extend the Kconfig SPLIT_PTE_PTLOCKS option from patch #2 -- but enforcing it closer to the code that actually implements it feels a bit nicer for documentation purposes, and there is no need to actually disable it because it should always be disabled (!SMP). Did a bunch of cross-compilations to make sure that split PTE/PMD PT locks are still getting used where we would expect them. [1] https://lkml.kernel.org/r/20240725183955.2268884-1-david@redhat.com This patch (of 3): Let's clean that up a bit and prepare for depending on CONFIG_SPLIT_PMD_PTLOCKS in other Kconfig options. More cleanups would be reasonable (like the arch-specific "depends on" for CONFIG_SPLIT_PTE_PTLOCKS), but we'll leave that for another day. Link: https://lkml.kernel.org/r/20240726150728.3159964-1-david@redhat.com Link: https://lkml.kernel.org/r/20240726150728.3159964-2-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Reviewed-by: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Borislav Petkov <bp@alien8.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Muchun Song <muchun.song@linux.dev> Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Xu <peterx@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Zi Yan
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2a28713a67 |
memory tiering: introduce folio_use_access_time() check
If memory tiering mode is on and a folio is not in the top tier memory, folio's cpupid field is repurposed to store page access time. Instead of an open coded check, use a function to encapsulate the check. Link: https://lkml.kernel.org/r/20240724130115.793641-3-ziy@nvidia.com Signed-off-by: Zi Yan <ziy@nvidia.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Zi Yan
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40b760cfd4 |
mm/numa: no task_numa_fault() call if PTE is changed
When handling a numa page fault, task_numa_fault() should be called by a process that restores the page table of the faulted folio to avoid duplicated stats counting. Commit |
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Ram Tummala
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4cd7ba16a0 |
mm: fix old/young bit handling in the faulting path
Commit |
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Linus Torvalds
|
7a3fad30fd |
Random number generator updates for Linux 6.11-rc1.
-----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEq5lC5tSkz8NBJiCnSfxwEqXeA64FAmaarzgACgkQSfxwEqXe A66ZWBAAlhXx8bve0uKlDRK8fffWHgruho/fOY4lZJ137AKwA9JCtmOyqdfL4Dmk VxFe7pEQJlQhcA/6kH54uO7SBXwfKlKZJth6SYnaCRMUIbFifHjjIQ0QqldjEKi0 rP90Hu4FVsbwQC7u9i9lQj9n2P36zb6pn83BzpZQ/2PtoVCSCrdSJUe0Rxa3H3GN 0+nNkDSXQt5otCByLaeE3x7KJgXLWL9+G2eFSFLTZ8rSVfMx1CdOIAG37WlLGdWm BaFYPDKMyBTVvVJBNgAe9YSqtrsZ5nlmLz+Z9wAe/hTL7RlL03kWUu34/Udcpull zzMDH0WMntiGK3eFQ2gOYSWqypvAjwHgn3BzqNmjUb69+89mZsdU1slcvnxWsUwU D3vphrscaqarF629tfsXti3jc5PoXwUTjROZVcCyeFPBhyAZgzK8xUvPpJO+RT+K EuUABob9cpA6FCpW/QeolDmMDhXlNT8QgsZu1juokZac2xP3Ly3REyEvT7HLbU2W ZJjbEqm1ppp3RmGELUOJbyhwsLrnbt+OMDO7iEWoG8aSFK4diBK/ZM6WvLMkr8Oi 7ioXGIsYkCy3c47wpZKTrAapOPJp5keqNAiHSEbXw8mozp6429QAEZxNOcczgHKC Ea2JzRkctqutcIT+Slw/uUe//i1iSsIHXbE81fp5udcQTJcUByo= =P8aI -----END PGP SIGNATURE----- Merge tag 'random-6.11-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random Pull random number generator updates from Jason Donenfeld: "This adds getrandom() support to the vDSO. First, it adds a new kind of mapping to mmap(2), MAP_DROPPABLE, which lets the kernel zero out pages anytime under memory pressure, which enables allocating memory that never gets swapped to disk but also doesn't count as being mlocked. Then, the vDSO implementation of getrandom() is introduced in a generic manner and hooked into random.c. Next, this is implemented on x86. (Also, though it's not ready for this pull, somebody has begun an arm64 implementation already) Finally, two vDSO selftests are added. There are also two housekeeping cleanup commits" * tag 'random-6.11-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random: MAINTAINERS: add random.h headers to RNG subsection random: note that RNDGETPOOL was removed in 2.6.9-rc2 selftests/vDSO: add tests for vgetrandom x86: vdso: Wire up getrandom() vDSO implementation random: introduce generic vDSO getrandom() implementation mm: add MAP_DROPPABLE for designating always lazily freeable mappings |
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Jason A. Donenfeld
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9651fcedf7 |
mm: add MAP_DROPPABLE for designating always lazily freeable mappings
The vDSO getrandom() implementation works with a buffer allocated with a
new system call that has certain requirements:
- It shouldn't be written to core dumps.
* Easy: VM_DONTDUMP.
- It should be zeroed on fork.
* Easy: VM_WIPEONFORK.
- It shouldn't be written to swap.
* Uh-oh: mlock is rlimited.
* Uh-oh: mlock isn't inherited by forks.
- It shouldn't reserve actual memory, but it also shouldn't crash when
page faulting in memory if none is available
* Uh-oh: VM_NORESERVE means segfaults.
It turns out that the vDSO getrandom() function has three really nice
characteristics that we can exploit to solve this problem:
1) Due to being wiped during fork(), the vDSO code is already robust to
having the contents of the pages it reads zeroed out midway through
the function's execution.
2) In the absolute worst case of whatever contingency we're coding for,
we have the option to fallback to the getrandom() syscall, and
everything is fine.
3) The buffers the function uses are only ever useful for a maximum of
60 seconds -- a sort of cache, rather than a long term allocation.
These characteristics mean that we can introduce VM_DROPPABLE, which
has the following semantics:
a) It never is written out to swap.
b) Under memory pressure, mm can just drop the pages (so that they're
zero when read back again).
c) It is inherited by fork.
d) It doesn't count against the mlock budget, since nothing is locked.
e) If there's not enough memory to service a page fault, it's not fatal,
and no signal is sent.
This way, allocations used by vDSO getrandom() can use:
VM_DROPPABLE | VM_DONTDUMP | VM_WIPEONFORK | VM_NORESERVE
And there will be no problem with OOMing, crashing on overcommitment,
using memory when not in use, not wiping on fork(), coredumps, or
writing out to swap.
In order to let vDSO getrandom() use this, expose these via mmap(2) as
MAP_DROPPABLE.
Note that this involves removing the MADV_FREE special case from
sort_folio(), which according to Yu Zhao is unnecessary and will simply
result in an extra call to shrink_folio_list() in the worst case. The
chunk removed reenables the swapbacked flag, which we don't want for
VM_DROPPABLE, and we can't conditionalize it here because there isn't a
vma reference available.
Finally, the provided self test ensures that this is working as desired.
Cc: linux-mm@kvack.org
Acked-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
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Christoph Hellwig
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cd1e0dac3a |
mm: unexport vmf_insert_mixed_mkwrite
vmf_insert_mixed_mkwrite is only used by the built-in DAX code. Link: https://lkml.kernel.org/r/20240702072327.1640911-1-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alistair Popple <apopple@nvidia.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Kefeng Wang
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28bdacbcb3 |
mm: move memory_failure_queue() into copy_mc_[user]_highpage()
Patch series "mm: migrate: support poison recover from migrate folio", v5.
The folio migration is widely used in kernel, memory compaction, memory
hotplug, soft offline page, numa balance, memory demote/promotion, etc,
but once access a poisoned source folio when migrating, the kernel will
panic.
There is a mechanism in the kernel to recover from uncorrectable memory
errors, ARCH_HAS_COPY_MC(eg, Machine Check Safe Memory Copy on x86), which
is already used in NVDIMM or core-mm paths(eg, CoW, khugepaged, coredump,
ksm copy), see copy_mc_to_{user,kernel}, copy_mc_{user_}highpage callers.
This series of patches provide the recovery mechanism from folio copy for
the widely used folio migration. Please note, because folio migration is
no guarantee of success, so we could chose to make folio migration
tolerant of memory failures, adding folio_mc_copy() which is a #MC
versions of folio_copy(), once accessing a poisoned source folio, we could
return error and make the folio migration fail, and this could avoid the
similar panic shown below.
CPU: 1 PID: 88343 Comm: test_softofflin Kdump: loaded Not tainted 6.6.0
pc : copy_page+0x10/0xc0
lr : copy_highpage+0x38/0x50
...
Call trace:
copy_page+0x10/0xc0
folio_copy+0x78/0x90
migrate_folio_extra+0x54/0xa0
move_to_new_folio+0xd8/0x1f0
migrate_folio_move+0xb8/0x300
migrate_pages_batch+0x528/0x788
migrate_pages_sync+0x8c/0x258
migrate_pages+0x440/0x528
soft_offline_in_use_page+0x2ec/0x3c0
soft_offline_page+0x238/0x310
soft_offline_page_store+0x6c/0xc0
dev_attr_store+0x20/0x40
sysfs_kf_write+0x4c/0x68
kernfs_fop_write_iter+0x130/0x1c8
new_sync_write+0xa4/0x138
vfs_write+0x238/0x2d8
ksys_write+0x74/0x110
This patch (of 5):
There is a memory_failure_queue() call after copy_mc_[user]_highpage(),
see callers, eg, CoW/KSM page copy, it is used to mark the source page as
h/w poisoned and unmap it from other tasks, and the upcomming poison
recover from migrate folio will do the similar thing, so let's move the
memory_failure_queue() into the copy_mc_[user]_highpage() instead of
adding it into each user, this should also enhance the handling of
poisoned page in khugepaged.
Link: https://lkml.kernel.org/r/20240626085328.608006-1-wangkefeng.wang@huawei.com
Link: https://lkml.kernel.org/r/20240626085328.608006-2-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Jane Chu <jane.chu@oracle.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jiaqi Yan <jiaqiyan@google.com>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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David Hildenbrand
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ee86814b05 |
mm/migrate: move NUMA hinting fault folio isolation + checks under PTL
Currently we always take a folio reference even if migration will not even be tried or isolation failed, requiring us to grab+drop an additional reference. Further, we end up calling folio_likely_mapped_shared() while the folio might have already been unmapped, because after we dropped the PTL, that can easily happen. We want to stop touching mapcounts and friends from such context, and only call folio_likely_mapped_shared() while the folio is still mapped: mapcount information is pretty much stale and unreliable otherwise. So let's move checks into numamigrate_isolate_folio(), rename that function to migrate_misplaced_folio_prepare(), and call that function from callsites where we call migrate_misplaced_folio(), but still with the PTL held. We can now stop taking temporary folio references, and really only take a reference if folio isolation succeeded. Doing the folio_likely_mapped_shared() + folio isolation under PT lock is now similar to how we handle MADV_PAGEOUT. While at it, combine the folio_is_file_lru() checks. [david@redhat.com: fix list_del() corruption] Link: https://lkml.kernel.org/r/8f85c31a-e603-4578-bf49-136dae0d4b69@redhat.com Link: https://lkml.kernel.org/r/20240626191129.658CFC32782@smtp.kernel.org Link: https://lkml.kernel.org/r/20240620212935.656243-3-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Tested-by: Donet Tom <donettom@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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David Hildenbrand
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4b88c23ab8 |
mm/migrate: make migrate_misplaced_folio() return 0 on success
Patch series "mm/migrate: move NUMA hinting fault folio isolation + checks under PTL". Let's just return 0 on success, which is less confusing. ... especially because we got it wrong in the migrate.h stub where we have "return -EAGAIN; /* can't migrate now */" instead of "return 0;". Likely this wrong return value doesn't currently matter, but it certainly adds confusion. We'll add migrate_misplaced_folio_prepare() next, where we want to use the same "return 0 on success" approach, so let's just clean this up. Link: https://lkml.kernel.org/r/20240620212935.656243-1-david@redhat.com Link: https://lkml.kernel.org/r/20240620212935.656243-2-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Donet Tom <donettom@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Kefeng Wang
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2f9f085436 |
mm: memory: rename pages_per_huge_page to nr_pages
Since the callers are converted to use nr_pages naming, use it inside too. Link: https://lkml.kernel.org/r/20240618091242.2140164-5-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: David Hildenbrand <david@redhat.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Kefeng Wang
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530dd9926d |
mm: memory: improve copy_user_large_folio()
Use nr_pages instead of pages_per_huge_page and move the address alignment from copy_user_large_folio() into the callers since it is only needed when we don't know which address will be accessed. Link: https://lkml.kernel.org/r/20240618091242.2140164-4-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: David Hildenbrand <david@redhat.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Kefeng Wang
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5132633ee7 |
mm: memory: use folio in struct copy_subpage_arg
Directly use folio in struct copy_subpage_arg. Link: https://lkml.kernel.org/r/20240618091242.2140164-3-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Kefeng Wang
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78fefd04c1 |
mm: memory: convert clear_huge_page() to folio_zero_user()
Patch series "mm: improve clear and copy user folio", v2. Some folio conversions. An improvement is to move address alignment into the caller as it is only needed if we don't know which address will be accessed when clearing/copying user folios. This patch (of 4): Replace clear_huge_page() with folio_zero_user(), and take a folio instead of a page. Directly get number of pages by folio_nr_pages() to remove pages_per_huge_page argument, furthermore, move the address alignment from folio_zero_user() to the callers since the alignment is only needed when we don't know which address will be accessed. Link: https://lkml.kernel.org/r/20240618091242.2140164-1-wangkefeng.wang@huawei.com Link: https://lkml.kernel.org/r/20240618091242.2140164-2-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: David Hildenbrand <david@redhat.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Barry Song
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9ae2feaced |
mm: use folio_add_new_anon_rmap() if folio_test_anon(folio)==false
For the !folio_test_anon(folio) case, we can now invoke
folio_add_new_anon_rmap() with the rmap flags set to either EXCLUSIVE or
non-EXCLUSIVE. This action will suppress the VM_WARN_ON_FOLIO check
within __folio_add_anon_rmap() while initiating the process of bringing up
mTHP swapin.
static __always_inline void __folio_add_anon_rmap(struct folio *folio,
struct page *page, int nr_pages, struct vm_area_struct *vma,
unsigned long address, rmap_t flags, enum rmap_level level)
{
...
if (unlikely(!folio_test_anon(folio))) {
VM_WARN_ON_FOLIO(folio_test_large(folio) &&
level != RMAP_LEVEL_PMD, folio);
}
...
}
It also improves the code's readability. Currently, all new anonymous
folios calling folio_add_anon_rmap_ptes() are order-0. This ensures that
new folios cannot be partially exclusive; they are either entirely
exclusive or entirely shared.
A useful comment from Hugh's fix:
: Commit "mm: use folio_add_new_anon_rmap() if folio_test_anon(folio)==
: false" has extended folio_add_new_anon_rmap() to use on non-exclusive
: folios, already visible to others in swap cache and on LRU.
:
: That renders its non-atomic __folio_set_swapbacked() unsafe: it risks
: overwriting concurrent atomic operations on folio->flags, losing bits
: added or restoring bits cleared. Since it's only used in this risky way
: when folio_test_locked and !folio_test_anon, many such races are excluded;
: but, for example, isolations by folio_test_clear_lru() are vulnerable, and
: setting or clearing active.
:
: It could just use the atomic folio_set_swapbacked(); but this function
: does try to avoid atomics where it can, so use a branch instead: just
: avoid setting swapbacked when it is already set, that is good enough.
: (Swapbacked is normally stable once set: lazyfree can undo it, but only
: later, when found anon in a page table.)
:
: This fixes a lot of instability under compaction and swapping loads:
: assorted "Bad page"s, VM_BUG_ON_FOLIO()s, apparently even page double
: frees - though I've not worked out what races could lead to the latter.
[akpm@linux-foundation.org: comment fixes, per David and akpm]
[v-songbaohua@oppo.com: lock the folio to avoid race]
Link: https://lkml.kernel.org/r/20240622032002.53033-1-21cnbao@gmail.com
[hughd@google.com: folio_add_new_anon_rmap() careful __folio_set_swapbacked()]
Link: https://lkml.kernel.org/r/f3599b1d-8323-0dc5-e9e0-fdb3cfc3dd5a@google.com
Link: https://lkml.kernel.org/r/20240617231137.80726-3-21cnbao@gmail.com
Signed-off-by: Barry Song <v-songbaohua@oppo.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Tested-by: Shuai Yuan <yuanshuai@oppo.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Chris Li <chrisl@kernel.org>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
||
|
Barry Song
|
15bde4abab |
mm: extend rmap flags arguments for folio_add_new_anon_rmap
Patch series "mm: clarify folio_add_new_anon_rmap() and __folio_add_anon_rmap()", v2. This patchset is preparatory work for mTHP swapin. folio_add_new_anon_rmap() assumes that new anon rmaps are always exclusive. However, this assumption doesn’t hold true for cases like do_swap_page(), where a new anon might be added to the swapcache and is not necessarily exclusive. The patchset extends the rmap flags to allow folio_add_new_anon_rmap() to handle both exclusive and non-exclusive new anon folios. The do_swap_page() function is updated to use this extended API with rmap flags. Consequently, all new anon folios now consistently use folio_add_new_anon_rmap(). The special case for !folio_test_anon() in __folio_add_anon_rmap() can be safely removed. In conclusion, new anon folios always use folio_add_new_anon_rmap(), regardless of exclusivity. Old anon folios continue to use __folio_add_anon_rmap() via folio_add_anon_rmap_pmd() and folio_add_anon_rmap_ptes(). This patch (of 3): In the case of a swap-in, a new anonymous folio is not necessarily exclusive. This patch updates the rmap flags to allow a new anonymous folio to be treated as either exclusive or non-exclusive. To maintain the existing behavior, we always use EXCLUSIVE as the default setting. [akpm@linux-foundation.org: cleanup and constifications per David and akpm] [v-songbaohua@oppo.com: fix missing doc for flags of folio_add_new_anon_rmap()] Link: https://lkml.kernel.org/r/20240619210641.62542-1-21cnbao@gmail.com [v-songbaohua@oppo.com: enhance doc for extend rmap flags arguments for folio_add_new_anon_rmap] Link: https://lkml.kernel.org/r/20240622030256.43775-1-21cnbao@gmail.com Link: https://lkml.kernel.org/r/20240617231137.80726-1-21cnbao@gmail.com Link: https://lkml.kernel.org/r/20240617231137.80726-2-21cnbao@gmail.com Signed-off-by: Barry Song <v-songbaohua@oppo.com> Suggested-by: David Hildenbrand <david@redhat.com> Tested-by: Shuai Yuan <yuanshuai@oppo.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Chris Li <chrisl@kernel.org> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yosry Ahmed <yosryahmed@google.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Barry Song
|
20dfa5b7ad |
mm: set pte writable while pte_soft_dirty() is true in do_swap_page()
This patch leverages the new pte_needs_soft_dirty_wp() helper to optimize a scenario where softdirty is enabled, but the softdirty flag has already been set in do_swap_page(). In this situation, we can use pte_mkwrite instead of applying write-protection since we don't depend on write faults. Link: https://lkml.kernel.org/r/20240607211358.4660-3-21cnbao@gmail.com Signed-off-by: Barry Song <v-songbaohua@oppo.com> Suggested-by: David Hildenbrand <david@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Chris Li <chrisl@kernel.org> Cc: Kairui Song <kasong@tencent.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Yosry Ahmed
|
b2d1f38b52 |
mm: swap: remove 'synchronous' argument to swap_read_folio()
Commit [1] introduced IO polling support duding swapin to reduce swap read latency for block devices that can be polled. However later commit [2] removed polling support. Commit [3] removed the remnants of polling support from read_swap_cache_async() and __read_swap_cache_async(). However, it left behind some remnants in swap_read_folio(), the 'synchronous' argument. swap_read_folio() reads the folio synchronously if synchronous=true or if SWP_SYNCHRONOUS_IO is set in swap_info_struct. The only caller that passes synchronous=true is in do_swap_page() in the SWP_SYNCHRONOUS_IO case. Hence, the argument is redundant, it is only set to true when the swap read would have been synchronous anyway. Remove it. [1] Commit |
||
|
Barry Song
|
c18160dba5 |
mm: swap: reuse exclusive folio directly instead of wp page faults
After swapping out, we perform a swap-in operation. If we first read and
then write, we encounter a major fault in do_swap_page for reading, along
with additional minor faults in do_wp_page for writing. However, the
latter appears to be unnecessary and inefficient. Instead, we can
directly reuse in do_swap_page and completely eliminate the need for
do_wp_page.
This patch achieves that optimization specifically for exclusive folios.
The following microbenchmark demonstrates the significant reduction in
minor faults.
#define DATA_SIZE (2UL * 1024 * 1024)
#define PAGE_SIZE (4UL * 1024)
static void *read_write_data(char *addr)
{
char tmp;
for (int i = 0; i < DATA_SIZE; i += PAGE_SIZE) {
tmp = *(volatile char *)(addr + i);
*(volatile char *)(addr + i) = tmp;
}
}
int main(int argc, char **argv)
{
struct rusage ru;
char *addr = mmap(NULL, DATA_SIZE, PROT_READ | PROT_WRITE,
MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
memset(addr, 0x11, DATA_SIZE);
do {
long old_ru_minflt, old_ru_majflt;
long new_ru_minflt, new_ru_majflt;
madvise(addr, DATA_SIZE, MADV_PAGEOUT);
getrusage(RUSAGE_SELF, &ru);
old_ru_minflt = ru.ru_minflt;
old_ru_majflt = ru.ru_majflt;
read_write_data(addr);
getrusage(RUSAGE_SELF, &ru);
new_ru_minflt = ru.ru_minflt;
new_ru_majflt = ru.ru_majflt;
printf("minor faults:%ld major faults:%ld\n",
new_ru_minflt - old_ru_minflt,
new_ru_majflt - old_ru_majflt);
} while(0);
return 0;
}
w/o patch,
/ # ~/a.out
minor faults:512 major faults:512
w/ patch,
/ # ~/a.out
minor faults:0 major faults:512
Minor faults decrease to 0!
Link: https://lkml.kernel.org/r/20240602004502.26895-1-21cnbao@gmail.com
Signed-off-by: Barry Song <v-songbaohua@oppo.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Chris Li <chrisl@kernel.org>
Cc: Kairui Song <kasong@tencent.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
||
|
Baolin Wang
|
43e027e414 |
mm: memory: extend finish_fault() to support large folio
Patch series "add mTHP support for anonymous shmem", v5.
Anonymous pages have already been supported for multi-size (mTHP)
allocation through commit
|
||
|
Chuanhua Han
|
508758960b |
mm: swap: entirely map large folios found in swapcache
When a large folio is found in the swapcache, the current implementation requires calling do_swap_page() nr_pages times, resulting in nr_pages page faults. This patch opts to map the entire large folio at once to minimize page faults. Additionally, redundant checks and early exits for ARM64 MTE restoring are removed. Link: https://lkml.kernel.org/r/20240529082824.150954-7-21cnbao@gmail.com Signed-off-by: Chuanhua Han <hanchuanhua@oppo.com> Co-developed-by: Barry Song <v-songbaohua@oppo.com> Signed-off-by: Barry Song <v-songbaohua@oppo.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Chris Li <chrisl@kernel.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: David Hildenbrand <david@redhat.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Gao Xiang <xiang@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kairui Song <kasong@tencent.com> Cc: Khalid Aziz <khalid.aziz@oracle.com> Cc: Len Brown <len.brown@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Yosry Ahmed <yosryahmed@google.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Chuanhua Han
|
4c3f966436 |
mm: swap: make should_try_to_free_swap() support large-folio
The function should_try_to_free_swap() operates under the assumption that swap-in always occurs at the normal page granularity, i.e., folio_nr_pages() = 1. However, in reality, for large folios, add_to_swap_cache() will invoke folio_ref_add(folio, nr). To accommodate large folio swap-in, this patch eliminates this assumption. Link: https://lkml.kernel.org/r/20240529082824.150954-6-21cnbao@gmail.com Signed-off-by: Chuanhua Han <hanchuanhua@oppo.com> Co-developed-by: Barry Song <v-songbaohua@oppo.com> Signed-off-by: Barry Song <v-songbaohua@oppo.com> Acked-by: Chris Li <chrisl@kernel.org> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Gao Xiang <xiang@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kairui Song <kasong@tencent.com> Cc: Khalid Aziz <khalid.aziz@oracle.com> Cc: Len Brown <len.brown@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Yosry Ahmed <yosryahmed@google.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Barry Song
|
29f252cdc2 |
mm: introduce arch_do_swap_page_nr() which allows restore metadata for nr pages
Should do_swap_page() have the capability to directly map a large folio, metadata restoration becomes necessary for a specified number of pages denoted as nr. It's important to highlight that metadata restoration is solely required by the SPARC platform, which, however, does not enable THP_SWAP. Consequently, in the present kernel configuration, there exists no practical scenario where users necessitate the restoration of nr metadata. Platforms implementing THP_SWAP might invoke this function with nr values exceeding 1, subsequent to do_swap_page() successfully mapping an entire large folio. Nonetheless, their arch_do_swap_page_nr() functions remain empty. Link: https://lkml.kernel.org/r/20240529082824.150954-5-21cnbao@gmail.com Signed-off-by: Barry Song <v-songbaohua@oppo.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Chris Li <chrisl@kernel.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Chuanhua Han <hanchuanhua@oppo.com> Cc: David Hildenbrand <david@redhat.com> Cc: Gao Xiang <xiang@kernel.org> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kairui Song <kasong@tencent.com> Cc: Len Brown <len.brown@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Yosry Ahmed <yosryahmed@google.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Mateusz Guzik
|
3577dbb192 |
mm: batch unlink_file_vma calls in free_pgd_range
Execs of dynamically linked binaries at 20-ish cores are bottlenecked on the i_mmap_rwsem semaphore, while the biggest singular contributor is free_pgd_range inducing the lock acquire back-to-back for all consecutive mappings of a given file. Tracing the count of said acquires while building the kernel shows: [1, 2) 799579 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@| [2, 3) 0 | | [3, 4) 3009 | | [4, 5) 3009 | | [5, 6) 326442 |@@@@@@@@@@@@@@@@@@@@@ | So in particular there were 326442 opportunities to coalesce 5 acquires into 1. Doing so increases execs per second by 4% (~50k to ~52k) when running the benchmark linked below. The lock remains the main bottleneck, I have not looked at other spots yet. Bench can be found here: http://apollo.backplane.com/DFlyMisc/doexec.c $ cc -O2 -o shared-doexec doexec.c $ ./shared-doexec $(nproc) Note this particular test makes sure binaries are separate, but the loader is shared. Stats collected on the patched kernel (+ "noinline") with: bpftrace -e 'kprobe:unlink_file_vma_batch_process { @ = lhist(((struct unlink_vma_file_batch *)arg0)->count, 0, 8, 1); }' Link: https://lkml.kernel.org/r/20240521234321.359501-1-mjguzik@gmail.com Signed-off-by: Mateusz Guzik <mjguzik@gmail.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Bang Li
|
6faa49d1c4 |
mm: use update_mmu_tlb_range() to simplify code
Let us simplify the code by update_mmu_tlb_range(). Link: https://lkml.kernel.org/r/20240522061204.117421-4-libang.li@antgroup.com Signed-off-by: Bang Li <libang.li@antgroup.com> Reviewed-by: Lance Yang <ioworker0@gmail.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Chris Zankel <chris@zankel.net> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
David Hildenbrand
|
fce831c920 |
mm/memory: cleanly support zeropage in vm_insert_page*(), vm_map_pages*() and vmf_insert_mixed()
For now we only get the (small) zeropage mapped to user space in four
cases (excluding VM_PFNMAP mappings, such as /proc/vmstat):
(1) Read page faults in anonymous VMAs (MAP_PRIVATE|MAP_ANON):
do_anonymous_page() will not refcount it and map it pte_mkspecial()
(2) UFFDIO_ZEROPAGE on anonymous VMA or COW mapping of shmem
(MAP_PRIVATE). mfill_atomic_pte_zeropage() will not refcount it and
map it pte_mkspecial().
(3) KSM in mergeable VMA (anonymous VMA or COW mapping).
cmp_and_merge_page() will not refcount it and map it
pte_mkspecial().
(4) FSDAX as an optimization for holes.
vmf_insert_mixed()->__vm_insert_mixed() might end up calling
insert_page() without CONFIG_ARCH_HAS_PTE_SPECIAL, refcounting the
zeropage and not mapping it pte_mkspecial(). With
CONFIG_ARCH_HAS_PTE_SPECIAL, we'll call insert_pfn() where we will
not refcount it and map it pte_mkspecial().
In case (4), we might not have VM_MIXEDMAP set: while fs/fuse/dax.c sets
VM_MIXEDMAP, we removed it for ext4 fsdax in commit
|
||
|
David Hildenbrand
|
11b914ee9e |
mm/memory: move page_count() check into validate_page_before_insert()
Patch series "mm/memory: cleanly support zeropage in vm_insert_page*(), vm_map_pages*() and vmf_insert_mixed()", v2. There is interest in mapping zeropages via vm_insert_pages() [1] into MAP_SHARED mappings. For now, we only get zeropages in MAP_SHARED mappings via vmf_insert_mixed() from FSDAX code, and I think it's a bit shaky in some cases because we refcount the zeropage when mapping it but not necessarily always when unmapping it ... and we should actually never refcount it. It's all a bit tricky, especially how zeropages in MAP_SHARED mappings interact with GUP (FOLL_LONGTERM), mprotect(), write-faults and s390x forbidding the shared zeropage (rewrite [2] s now upstream). This series tries to take the careful approach of only allowing the zeropage where it is likely safe to use (which should cover the existing FSDAX use case and [1]), preventing that it could accidentally get mapped writable during a write fault, mprotect() etc, and preventing issues with FOLL_LONGTERM in the future with other users. Tested with a patch from Vincent that uses the zeropage in context of [1]. [1] https://lkml.kernel.org/r/20240430111354.637356-1-vdonnefort@google.com [2] https://lkml.kernel.org/r/20240411161441.910170-1-david@redhat.com This patch (of 3): We'll now also cover the case where insert_page() is called from __vm_insert_mixed(), which sounds like the right thing to do. Link: https://lkml.kernel.org/r/20240522125713.775114-2-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Illia Ostapyshyn
|
0ba5e806e1 |
mm/vmscan: update stale references to shrink_page_list
Commit
|
||
|
Andrew Bresticker
|
ab1ffc86cb |
mm/memory: don't require head page for do_set_pmd()
The requirement that the head page be passed to do_set_pmd() was added in commit |
||
|
Kefeng Wang
|
cfdd12b482 |
mm: fix possible OOB in numa_rebuild_large_mapping()
The large folio is mapped with folio size(not greater PMD_SIZE) aligned
virtual address during the pagefault, ie, 'addr = ALIGN_DOWN(vmf->address,
nr_pages * PAGE_SIZE)' in do_anonymous_page(). But after the mremap(),
the virtual address only requires PAGE_SIZE alignment. Also pte is moved
to new in move_page_tables(), then traversal of the new pte in the
numa_rebuild_large_mapping() could hit the following issue,
Unable to handle kernel paging request at virtual address 00000a80c021a788
Mem abort info:
ESR = 0x0000000096000004
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x04: level 0 translation fault
Data abort info:
ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
CM = 0, WnR = 0, TnD = 0, TagAccess = 0
GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
user pgtable: 4k pages, 48-bit VAs, pgdp=00002040341a6000
[00000a80c021a788] pgd=0000000000000000, p4d=0000000000000000
Internal error: Oops: 0000000096000004 [#1] SMP
...
CPU: 76 PID: 15187 Comm: git Kdump: loaded Tainted: G W 6.10.0-rc2+ #209
Hardware name: Huawei TaiShan 2280 V2/BC82AMDD, BIOS 1.79 08/21/2021
pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : numa_rebuild_large_mapping+0x338/0x638
lr : numa_rebuild_large_mapping+0x320/0x638
sp : ffff8000b41c3b00
x29: ffff8000b41c3b30 x28: ffff8000812a0000 x27: 00000000000a8000
x26: 00000000000000a8 x25: 0010000000000001 x24: ffff20401c7170f0
x23: 0000ffff33a1e000 x22: 0000ffff33a76000 x21: ffff20400869eca0
x20: 0000ffff33976000 x19: 00000000000000a8 x18: ffffffffffffffff
x17: 0000000000000000 x16: 0000000000000020 x15: ffff8000b41c36a8
x14: 0000000000000000 x13: 205d373831353154 x12: 5b5d333331363732
x11: 000000000011ff78 x10: 000000000011ff10 x9 : ffff800080273f30
x8 : 000000320400869e x7 : c0000000ffffd87f x6 : 00000000001e6ba8
x5 : ffff206f3fb5af88 x4 : 0000000000000000 x3 : 0000000000000000
x2 : 0000000000000000 x1 : fffffdffc0000000 x0 : 00000a80c021a780
Call trace:
numa_rebuild_large_mapping+0x338/0x638
do_numa_page+0x3e4/0x4e0
handle_pte_fault+0x1bc/0x238
__handle_mm_fault+0x20c/0x400
handle_mm_fault+0xa8/0x288
do_page_fault+0x124/0x498
do_translation_fault+0x54/0x80
do_mem_abort+0x4c/0xa8
el0_da+0x40/0x110
el0t_64_sync_handler+0xe4/0x158
el0t_64_sync+0x188/0x190
Fix it by making the start and end not only within the vma range, but also
within the page table range.
Link: https://lkml.kernel.org/r/20240612122822.4033433-1-wangkefeng.wang@huawei.com
Fixes:
|
||
|
David Hildenbrand
|
384a746bb5 |
Revert "mm: init_mlocked_on_free_v3"
There was insufficient review and no agreement that this is the right
approach.
There are serious flaws with the implementation that make processes using
mlock() not even work with simple fork() [1] and we get reliable crashes
when rebooting.
Further, simply because we might be unmapping a single PTE of a large
mlocked folio, we shouldn't zero out the whole folio.
... especially because the code can also *corrupt* urelated memory because
kernel_init_pages(page, folio_nr_pages(folio));
Could end up writing outside of the actual folio if we work with a tail
page.
Let's revert it. Once there is agreement that this is the right approach,
the issues were fixed and there was reasonable review and proper testing,
we can consider it again.
[1] https://lkml.kernel.org/r/4da9da2f-73e4-45fd-b62f-a8a513314057@redhat.com
Link: https://lkml.kernel.org/r/20240605091710.38961-1-david@redhat.com
Fixes:
|
||
|
Linus Torvalds
|
de7e71ef8b |
mm: simplify and improve print_vma_addr() output
Use '%pD' to print out the filename, and print out the actual offset within the file too, rather than just what the virtual address of the mapping is (which doesn't tell you anything about any mapping offsets). Also, use the exact vma_lookup() instead of find_vma() - the latter looks up any vma _after_ the address, which is of questionable value (yes, maybe you fell off the beginning, but you'd be more likely to fall off the end). Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Linus Torvalds
|
61307b7be4 |
The usual shower of singleton fixes and minor series all over MM,
documented (hopefully adequately) in the respective changelogs. Notable
series include:
- Lucas Stach has provided some page-mapping
cleanup/consolidation/maintainability work in the series "mm/treewide:
Remove pXd_huge() API".
- In the series "Allow migrate on protnone reference with
MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's
MPOL_PREFERRED_MANY mode, yielding almost doubled performance in one
test.
- In their series "Memory allocation profiling" Kent Overstreet and
Suren Baghdasaryan have contributed a means of determining (via
/proc/allocinfo) whereabouts in the kernel memory is being allocated:
number of calls and amount of memory.
- Matthew Wilcox has provided the series "Various significant MM
patches" which does a number of rather unrelated things, but in largely
similar code sites.
- In his series "mm: page_alloc: freelist migratetype hygiene" Johannes
Weiner has fixed the page allocator's handling of migratetype requests,
with resulting improvements in compaction efficiency.
- In the series "make the hugetlb migration strategy consistent" Baolin
Wang has fixed a hugetlb migration issue, which should improve hugetlb
allocation reliability.
- Liu Shixin has hit an I/O meltdown caused by readahead in a
memory-tight memcg. Addressed in the series "Fix I/O high when memory
almost met memcg limit".
- In the series "mm/filemap: optimize folio adding and splitting" Kairui
Song has optimized pagecache insertion, yielding ~10% performance
improvement in one test.
- Baoquan He has cleaned up and consolidated the early zone
initialization code in the series "mm/mm_init.c: refactor
free_area_init_core()".
- Baoquan has also redone some MM initializatio code in the series
"mm/init: minor clean up and improvement".
- MM helper cleanups from Christoph Hellwig in his series "remove
follow_pfn".
- More cleanups from Matthew Wilcox in the series "Various page->flags
cleanups".
- Vlastimil Babka has contributed maintainability improvements in the
series "memcg_kmem hooks refactoring".
- More folio conversions and cleanups in Matthew Wilcox's series
"Convert huge_zero_page to huge_zero_folio"
"khugepaged folio conversions"
"Remove page_idle and page_young wrappers"
"Use folio APIs in procfs"
"Clean up __folio_put()"
"Some cleanups for memory-failure"
"Remove page_mapping()"
"More folio compat code removal"
- David Hildenbrand chipped in with "fs/proc/task_mmu: convert hugetlb
functions to work on folis".
- Code consolidation and cleanup work related to GUP's handling of
hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2".
- Rick Edgecombe has developed some fixes to stack guard gaps in the
series "Cover a guard gap corner case".
- Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the series
"mm/ksm: fix ksm exec support for prctl".
- Baolin Wang has implemented NUMA balancing for multi-size THPs. This
is a simple first-cut implementation for now. The series is "support
multi-size THP numa balancing".
- Cleanups to vma handling helper functions from Matthew Wilcox in the
series "Unify vma_address and vma_pgoff_address".
- Some selftests maintenance work from Dev Jain in the series
"selftests/mm: mremap_test: Optimizations and style fixes".
- Improvements to the swapping of multi-size THPs from Ryan Roberts in
the series "Swap-out mTHP without splitting".
- Kefeng Wang has significantly optimized the handling of arm64's
permission page faults in the series
"arch/mm/fault: accelerate pagefault when badaccess"
"mm: remove arch's private VM_FAULT_BADMAP/BADACCESS"
- GUP cleanups from David Hildenbrand in "mm/gup: consistently call it
GUP-fast".
- hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault path to
use struct vm_fault".
- selftests build fixes from John Hubbard in the series "Fix
selftests/mm build without requiring "make headers"".
- Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the
series "Improved Memory Tier Creation for CPUless NUMA Nodes". Fixes
the initialization code so that migration between different memory types
works as intended.
- David Hildenbrand has improved follow_pte() and fixed an errant driver
in the series "mm: follow_pte() improvements and acrn follow_pte()
fixes".
- David also did some cleanup work on large folio mapcounts in his
series "mm: mapcount for large folios + page_mapcount() cleanups".
- Folio conversions in KSM in Alex Shi's series "transfer page to folio
in KSM".
- Barry Song has added some sysfs stats for monitoring multi-size THP's
in the series "mm: add per-order mTHP alloc and swpout counters".
- Some zswap cleanups from Yosry Ahmed in the series "zswap same-filled
and limit checking cleanups".
- Matthew Wilcox has been looking at buffer_head code and found the
documentation to be lacking. The series is "Improve buffer head
documentation".
- Multi-size THPs get more work, this time from Lance Yang. His series
"mm/madvise: enhance lazyfreeing with mTHP in madvise_free" optimizes
the freeing of these things.
- Kemeng Shi has added more userspace-visible writeback instrumentation
in the series "Improve visibility of writeback".
- Kemeng Shi then sent some maintenance work on top in the series "Fix
and cleanups to page-writeback".
- Matthew Wilcox reduces mmap_lock traffic in the anon vma code in the
series "Improve anon_vma scalability for anon VMAs". Intel's test bot
reported an improbable 3x improvement in one test.
- SeongJae Park adds some DAMON feature work in the series
"mm/damon: add a DAMOS filter type for page granularity access recheck"
"selftests/damon: add DAMOS quota goal test"
- Also some maintenance work in the series
"mm/damon/paddr: simplify page level access re-check for pageout"
"mm/damon: misc fixes and improvements"
- David Hildenbrand has disabled some known-to-fail selftests ni the
series "selftests: mm: cow: flag vmsplice() hugetlb tests as XFAIL".
- memcg metadata storage optimizations from Shakeel Butt in "memcg:
reduce memory consumption by memcg stats".
- DAX fixes and maintenance work from Vishal Verma in the series
"dax/bus.c: Fixups for dax-bus locking".
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Merge tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull mm updates from Andrew Morton:
"The usual shower of singleton fixes and minor series all over MM,
documented (hopefully adequately) in the respective changelogs.
Notable series include:
- Lucas Stach has provided some page-mapping cleanup/consolidation/
maintainability work in the series "mm/treewide: Remove pXd_huge()
API".
- In the series "Allow migrate on protnone reference with
MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's
MPOL_PREFERRED_MANY mode, yielding almost doubled performance in
one test.
- In their series "Memory allocation profiling" Kent Overstreet and
Suren Baghdasaryan have contributed a means of determining (via
/proc/allocinfo) whereabouts in the kernel memory is being
allocated: number of calls and amount of memory.
- Matthew Wilcox has provided the series "Various significant MM
patches" which does a number of rather unrelated things, but in
largely similar code sites.
- In his series "mm: page_alloc: freelist migratetype hygiene"
Johannes Weiner has fixed the page allocator's handling of
migratetype requests, with resulting improvements in compaction
efficiency.
- In the series "make the hugetlb migration strategy consistent"
Baolin Wang has fixed a hugetlb migration issue, which should
improve hugetlb allocation reliability.
- Liu Shixin has hit an I/O meltdown caused by readahead in a
memory-tight memcg. Addressed in the series "Fix I/O high when
memory almost met memcg limit".
- In the series "mm/filemap: optimize folio adding and splitting"
Kairui Song has optimized pagecache insertion, yielding ~10%
performance improvement in one test.
- Baoquan He has cleaned up and consolidated the early zone
initialization code in the series "mm/mm_init.c: refactor
free_area_init_core()".
- Baoquan has also redone some MM initializatio code in the series
"mm/init: minor clean up and improvement".
- MM helper cleanups from Christoph Hellwig in his series "remove
follow_pfn".
- More cleanups from Matthew Wilcox in the series "Various
page->flags cleanups".
- Vlastimil Babka has contributed maintainability improvements in the
series "memcg_kmem hooks refactoring".
- More folio conversions and cleanups in Matthew Wilcox's series:
"Convert huge_zero_page to huge_zero_folio"
"khugepaged folio conversions"
"Remove page_idle and page_young wrappers"
"Use folio APIs in procfs"
"Clean up __folio_put()"
"Some cleanups for memory-failure"
"Remove page_mapping()"
"More folio compat code removal"
- David Hildenbrand chipped in with "fs/proc/task_mmu: convert
hugetlb functions to work on folis".
- Code consolidation and cleanup work related to GUP's handling of
hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2".
- Rick Edgecombe has developed some fixes to stack guard gaps in the
series "Cover a guard gap corner case".
- Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the
series "mm/ksm: fix ksm exec support for prctl".
- Baolin Wang has implemented NUMA balancing for multi-size THPs.
This is a simple first-cut implementation for now. The series is
"support multi-size THP numa balancing".
- Cleanups to vma handling helper functions from Matthew Wilcox in
the series "Unify vma_address and vma_pgoff_address".
- Some selftests maintenance work from Dev Jain in the series
"selftests/mm: mremap_test: Optimizations and style fixes".
- Improvements to the swapping of multi-size THPs from Ryan Roberts
in the series "Swap-out mTHP without splitting".
- Kefeng Wang has significantly optimized the handling of arm64's
permission page faults in the series
"arch/mm/fault: accelerate pagefault when badaccess"
"mm: remove arch's private VM_FAULT_BADMAP/BADACCESS"
- GUP cleanups from David Hildenbrand in "mm/gup: consistently call
it GUP-fast".
- hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault
path to use struct vm_fault".
- selftests build fixes from John Hubbard in the series "Fix
selftests/mm build without requiring "make headers"".
- Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the
series "Improved Memory Tier Creation for CPUless NUMA Nodes".
Fixes the initialization code so that migration between different
memory types works as intended.
- David Hildenbrand has improved follow_pte() and fixed an errant
driver in the series "mm: follow_pte() improvements and acrn
follow_pte() fixes".
- David also did some cleanup work on large folio mapcounts in his
series "mm: mapcount for large folios + page_mapcount() cleanups".
- Folio conversions in KSM in Alex Shi's series "transfer page to
folio in KSM".
- Barry Song has added some sysfs stats for monitoring multi-size
THP's in the series "mm: add per-order mTHP alloc and swpout
counters".
- Some zswap cleanups from Yosry Ahmed in the series "zswap
same-filled and limit checking cleanups".
- Matthew Wilcox has been looking at buffer_head code and found the
documentation to be lacking. The series is "Improve buffer head
documentation".
- Multi-size THPs get more work, this time from Lance Yang. His
series "mm/madvise: enhance lazyfreeing with mTHP in madvise_free"
optimizes the freeing of these things.
- Kemeng Shi has added more userspace-visible writeback
instrumentation in the series "Improve visibility of writeback".
- Kemeng Shi then sent some maintenance work on top in the series
"Fix and cleanups to page-writeback".
- Matthew Wilcox reduces mmap_lock traffic in the anon vma code in
the series "Improve anon_vma scalability for anon VMAs". Intel's
test bot reported an improbable 3x improvement in one test.
- SeongJae Park adds some DAMON feature work in the series
"mm/damon: add a DAMOS filter type for page granularity access recheck"
"selftests/damon: add DAMOS quota goal test"
- Also some maintenance work in the series
"mm/damon/paddr: simplify page level access re-check for pageout"
"mm/damon: misc fixes and improvements"
- David Hildenbrand has disabled some known-to-fail selftests ni the
series "selftests: mm: cow: flag vmsplice() hugetlb tests as
XFAIL".
- memcg metadata storage optimizations from Shakeel Butt in "memcg:
reduce memory consumption by memcg stats".
- DAX fixes and maintenance work from Vishal Verma in the series
"dax/bus.c: Fixups for dax-bus locking""
* tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (426 commits)
memcg, oom: cleanup unused memcg_oom_gfp_mask and memcg_oom_order
selftests/mm: hugetlb_madv_vs_map: avoid test skipping by querying hugepage size at runtime
mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_wp
mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_fault
selftests: cgroup: add tests to verify the zswap writeback path
mm: memcg: make alloc_mem_cgroup_per_node_info() return bool
mm/damon/core: fix return value from damos_wmark_metric_value
mm: do not update memcg stats for NR_{FILE/SHMEM}_PMDMAPPED
selftests: cgroup: remove redundant enabling of memory controller
Docs/mm/damon/maintainer-profile: allow posting patches based on damon/next tree
Docs/mm/damon/maintainer-profile: change the maintainer's timezone from PST to PT
Docs/mm/damon/design: use a list for supported filters
Docs/admin-guide/mm/damon/usage: fix wrong schemes effective quota update command
Docs/admin-guide/mm/damon/usage: fix wrong example of DAMOS filter matching sysfs file
selftests/damon: classify tests for functionalities and regressions
selftests/damon/_damon_sysfs: use 'is' instead of '==' for 'None'
selftests/damon/_damon_sysfs: find sysfs mount point from /proc/mounts
selftests/damon/_damon_sysfs: check errors from nr_schemes file reads
mm/damon/core: initialize ->esz_bp from damos_quota_init_priv()
selftests/damon: add a test for DAMOS quota goal
...
|
||
|
Matthew Wilcox (Oracle)
|
737019cf6a |
mm: optimise vmf_anon_prepare() for VMAs without an anon_vma
If the mmap_lock can be taken for read, we can call __anon_vma_prepare() while holding it, saving ourselves a trip back through the fault handler. Link: https://lkml.kernel.org/r/20240426144506.1290619-5-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Jann Horn <jannh@google.com> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Matthew Wilcox (Oracle)
|
a373baed5a |
mm: delay the check for a NULL anon_vma
Instead of checking the anon_vma early in the fault path where all page faults pay the cost, delay it until we know we're going to need the anon_vma to be filled in. This will have a slight negative effect on the first fault in an anonymous VMA, but it shortens every other page fault. It also makes the code slightly cleaner as the anon and file backed fault handling look more similar. The Intel kernel test bot reports a 3x improvement in vm-scalability throughput with the small-allocs-mt test. This is clearly an extreme situation that won't be replicated in any real-world workload, but it's a nice win. https://lore.kernel.org/all/202404261055.c5e24608-oliver.sang@intel.com/ Link: https://lkml.kernel.org/r/20240426144506.1290619-3-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: Jann Horn <jannh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Matthew Wilcox
|
e0ffb29bc5 |
mm: simplify thp_vma_allowable_order
Combine the three boolean arguments into one flags argument for readability. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: David Hildenbrand <david@redhat.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Kefeng Wang
|
6ed31ba392 |
mm: memory: check userfaultfd_wp() in vmf_orig_pte_uffd_wp()
Add userfaultfd_wp() check in vmf_orig_pte_uffd_wp() to avoid the
unnecessary FAULT_FLAG_ORIG_PTE_VALID check/pte_marker_entry_uffd_wp() in
most pagefault, note, the function vmf_orig_pte_uffd_wp() is not inlined
in the two kernel versions, the difference is shown below,
perf date,
perf report -i perf.data.before | grep vmf
0.17% 0.13% lat_pagefault [kernel.kallsyms] [k] vmf_orig_pte_uffd_wp.part.0.isra.0
perf report -i perf.data.after | grep vmf
lat_pagefault -W 5 -N 5 /tmp/XXX
latency before after diff
average(8 tests) 0.262675 0.2600375 -0.0026375
Although it's a small, but the uffd_wp is a new feature than previous
kernel, when the vma is not registered with UFFD_WP, let's avoid to
execute the new logical, also adding __always_inline attribute to
vmf_orig_pte_uffd_wp(), which make set_pte_range() only check VM_UFFD_WP
flags without the function call. In addition, directly call the
vmf_orig_pte_uffd_wp() in do_anonymous_page() and set_pte_range() to save
an uffd_wp variable.
Link: https://lkml.kernel.org/r/20240422030039.3293568-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
||
|
Lance Yang
|
96ebdb0320 |
mm/memory: add any_dirty optional pointer to folio_pte_batch()
This commit adds the any_dirty pointer as an optional parameter to folio_pte_batch() function. By using both the any_young and any_dirty pointers, madvise_free can make smarter decisions about whether to clear the PTEs when marking large folios as lazyfree. Link: https://lkml.kernel.org/r/20240418134435.6092-4-ioworker0@gmail.com Signed-off-by: Lance Yang <ioworker0@gmail.com> Suggested-by: David Hildenbrand <david@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Barry Song <21cnbao@gmail.com> Cc: Jeff Xie <xiehuan09@gmail.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yin Fengwei <fengwei.yin@intel.com> Cc: Zach O'Keefe <zokeefe@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Kefeng Wang
|
1f2d8b4421 |
mm: move mm counter updating out of set_pte_range()
Patch series "mm: batch mm counter updating in filemap_map_pages()", v3. Let's batch mm counter updating to accelerate filemap_map_pages(). This patch (of 2): In order to support batch mm counter updating in filemap_map_pages(), move mm counter updating out of set_pte_range(), the folios are file from filemap, and distinguish folios by vmf->flags and vma->vm_flags from another caller finish_fault(). Link: https://lkml.kernel.org/r/20240412064751.119015-1-wangkefeng.wang@huawei.com Link: https://lkml.kernel.org/r/20240412064751.119015-2-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Barry Song
|
ec33687c67 |
mm: add per-order mTHP anon_fault_alloc and anon_fault_fallback counters
Patch series "mm: add per-order mTHP alloc and swpout counters", v6. The patchset introduces a framework to facilitate mTHP counters, starting with the allocation and swap-out counters. Currently, only four new nodes are appended to the stats directory for each mTHP size. /sys/kernel/mm/transparent_hugepage/hugepages-<size>/stats anon_fault_alloc anon_fault_fallback anon_fault_fallback_charge anon_swpout anon_swpout_fallback These nodes are crucial for us to monitor the fragmentation levels of both the buddy system and the swap partitions. In the future, we may consider adding additional nodes for further insights. This patch (of 4): Profiling a system blindly with mTHP has become challenging due to the lack of visibility into its operations. Presenting the success rate of mTHP allocations appears to be pressing need. Recently, I've been experiencing significant difficulty debugging performance improvements and regressions without these figures. It's crucial for us to understand the true effectiveness of mTHP in real-world scenarios, especially in systems with fragmented memory. This patch establishes the framework for per-order mTHP counters. It begins by introducing the anon_fault_alloc and anon_fault_fallback counters. Additionally, to maintain consistency with thp_fault_fallback_charge in /proc/vmstat, this patch also tracks anon_fault_fallback_charge when mem_cgroup_charge fails for mTHP. Incorporating additional counters should now be straightforward as well. Link: https://lkml.kernel.org/r/20240412114858.407208-1-21cnbao@gmail.com Link: https://lkml.kernel.org/r/20240412114858.407208-2-21cnbao@gmail.com Signed-off-by: Barry Song <v-songbaohua@oppo.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Chris Li <chrisl@kernel.org> Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com> Cc: Kairui Song <kasong@tencent.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Yosry Ahmed <yosryahmed@google.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
David Hildenbrand
|
3aeea4fc83 |
mm/memory: use folio_mapcount() in zap_present_folio_ptes()
We want to limit the use of page_mapcount() to the places where it is
absolutely necessary. In zap_present_folio_ptes(), let's simply check the
folio mapcount(). If there is some issue, it will underflow at some point
either way when unmapping.
As indicated already in commit
|
||
|
David Hildenbrand
|
c5541ba378 |
mm: follow_pte() improvements
follow_pte() is now our main function to lookup PTEs in VM_PFNMAP/VM_IO VMAs. Let's perform some more sanity checks to make this exported function harder to abuse. Further, extend the doc a bit, it still focuses on the KVM use case with MMU notifiers. Drop the KVM+follow_pfn() comment, follow_pfn() is no more, and we have other users nowadays. Also extend the doc regarding refcounted pages and the interaction with MMU notifiers. KVM is one example that uses MMU notifiers and can deal with refcounted pages properly. VFIO is one example that doesn't use MMU notifiers, and to prevent use-after-free, rejects refcounted pages: pfn_valid(pfn) && !PageReserved(pfn_to_page(pfn)). Protection changes are less of a concern for users like VFIO: the behavior is similar to longterm-pinning a page, and getting the PTE protection changed afterwards. The primary concern with refcounted pages is use-after-free, which callers should be aware of. Link: https://lkml.kernel.org/r/20240410155527.474777-4-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Fei Li <fei1.li@intel.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Sean Christopherson <seanjc@google.com> Cc: Yonghua Huang <yonghua.huang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
David Hildenbrand
|
29ae7d96d1 |
mm: pass VMA instead of MM to follow_pte()
... and centralize the VM_IO/VM_PFNMAP sanity check in there. We'll now also perform these sanity checks for direct follow_pte() invocations. For generic_access_phys(), we might now check multiple times: nothing to worry about, really. Link: https://lkml.kernel.org/r/20240410155527.474777-3-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Sean Christopherson <seanjc@google.com> [KVM] Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Fei Li <fei1.li@intel.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Yonghua Huang <yonghua.huang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Ryan Roberts
|
3931b871c4 |
mm: madvise: avoid split during MADV_PAGEOUT and MADV_COLD
Rework madvise_cold_or_pageout_pte_range() to avoid splitting any large folio that is fully and contiguously mapped in the pageout/cold vm range. This change means that large folios will be maintained all the way to swap storage. This both improves performance during swap-out, by eliding the cost of splitting the folio, and sets us up nicely for maintaining the large folio when it is swapped back in (to be covered in a separate series). Folios that are not fully mapped in the target range are still split, but note that behavior is changed so that if the split fails for any reason (folio locked, shared, etc) we now leave it as is and move to the next pte in the range and continue work on the proceeding folios. Previously any failure of this sort would cause the entire operation to give up and no folios mapped at higher addresses were paged out or made cold. Given large folios are becoming more common, this old behavior would have likely lead to wasted opportunities. While we are at it, change the code that clears young from the ptes to use ptep_test_and_clear_young(), via the new mkold_ptes() batch helper function. This is more efficent than get_and_clear/modify/set, especially for contpte mappings on arm64, where the old approach would require unfolding/refolding and the new approach can be done in place. Link: https://lkml.kernel.org/r/20240408183946.2991168-8-ryan.roberts@arm.com Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: Barry Song <v-songbaohua@oppo.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Barry Song <21cnbao@gmail.com> Cc: Chris Li <chrisl@kernel.org> Cc: Gao Xiang <xiang@kernel.org> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Lance Yang <ioworker0@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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|
Ryan Roberts
|
a62fb92ac1 |
mm: swap: free_swap_and_cache_nr() as batched free_swap_and_cache()
Now that we no longer have a convenient flag in the cluster to determine if a folio is large, free_swap_and_cache() will take a reference and lock a large folio much more often, which could lead to contention and (e.g.) failure to split large folios, etc. Let's solve that problem by batch freeing swap and cache with a new function, free_swap_and_cache_nr(), to free a contiguous range of swap entries together. This allows us to first drop a reference to each swap slot before we try to release the cache folio. This means we only try to release the folio once, only taking the reference and lock once - much better than the previous 512 times for the 2M THP case. Contiguous swap entries are gathered in zap_pte_range() and madvise_free_pte_range() in a similar way to how present ptes are already gathered in zap_pte_range(). While we are at it, let's simplify by converting the return type of both functions to void. The return value was used only by zap_pte_range() to print a bad pte, and was ignored by everyone else, so the extra reporting wasn't exactly guaranteed. We will still get the warning with most of the information from get_swap_device(). With the batch version, we wouldn't know which pte was bad anyway so could print the wrong one. [ryan.roberts@arm.com: fix a build warning on parisc] Link: https://lkml.kernel.org/r/20240409111840.3173122-1-ryan.roberts@arm.com Link: https://lkml.kernel.org/r/20240408183946.2991168-3-ryan.roberts@arm.com Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Barry Song <21cnbao@gmail.com> Cc: Barry Song <v-songbaohua@oppo.com> Cc: Chris Li <chrisl@kernel.org> Cc: Gao Xiang <xiang@kernel.org> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Lance Yang <ioworker0@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Baolin Wang
|
d2136d749d |
mm: support multi-size THP numa balancing
Now the anonymous page allocation already supports multi-size THP (mTHP), but the numa balancing still prohibits mTHP migration even though it is an exclusive mapping, which is unreasonable. Allow scanning mTHP: Commit |
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Baolin Wang
|
6b0ed7b3c7 |
mm: factor out the numa mapping rebuilding into a new helper
Patch series "support multi-size THP numa balancing", v2. This patchset tries to support mTHP numa balancing, as a simple solution to start, the NUMA balancing algorithm for mTHP will follow the THP strategy as the basic support. Please find details in each patch. This patch (of 2): To support large folio's numa balancing, factor out the numa mapping rebuilding into a new helper as a preparation. Link: https://lkml.kernel.org/r/cover.1712132950.git.baolin.wang@linux.alibaba.com Link: https://lkml.kernel.org/r/cover.1711683069.git.baolin.wang@linux.alibaba.com Link: https://lkml.kernel.org/r/8bc2586bdd8dbbe6d83c09b77b360ec8fcac3736.1711683069.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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|
Barry Song
|
68dbcf4899 |
mm: alloc_anon_folio: avoid doing vma_thp_gfp_mask in fallback cases
Fallback rates surpassing 90% have been observed on phones utilizing 64KiB CONT-PTE mTHP. In these scenarios, when one out of every 16 PTEs fails to allocate large folios, the remaining 15 PTEs fallback. Consequently, invoking vma_thp_gfp_mask seems redundant in such cases. Furthermore, abstaining from its use can also contribute to improved code readability. Link: https://lkml.kernel.org/r/20240329073750.20012-1-21cnbao@gmail.com Signed-off-by: Barry Song <v-songbaohua@oppo.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Acked-by: Yu Zhao <yuzhao@google.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: David Hildenbrand <david@redhat.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Rientjes <rientjes@google.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Itaru Kitayama <itaru.kitayama@gmail.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yang Shi <shy828301@gmail.com> Cc: Yin Fengwei <fengwei.yin@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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|
York Jasper Niebuhr
|
ba42b524a0 |
mm: init_mlocked_on_free_v3
Implements the "init_mlocked_on_free" boot option. When this boot option
is enabled, any mlock'ed pages are zeroed on free. If
the pages are munlock'ed beforehand, no initialization takes place.
This boot option is meant to combat the performance hit of
"init_on_free" as reported in commit
|
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|
Peter Xu
|
239e9a90c8 |
mm: introduce vma_pgtable_walk_{begin|end}()
Introduce per-vma begin()/end() helpers for pgtable walks. This is a preparation work to merge hugetlb pgtable walkers with generic mm. The helpers need to be called before and after a pgtable walk, will start to be needed if the pgtable walker code supports hugetlb pages. It's a hook point for any type of VMA, but for now only hugetlb uses it to stablize the pgtable pages from getting away (due to possible pmd unsharing). Link: https://lkml.kernel.org/r/20240327152332.950956-5-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Reviewed-by: Christoph Hellwig <hch@infradead.org> Reviewed-by: Muchun Song <muchun.song@linux.dev> Tested-by: Ryan Roberts <ryan.roberts@arm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andrew Jones <andrew.jones@linux.dev> Cc: Aneesh Kumar K.V (IBM) <aneesh.kumar@kernel.org> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: David Hildenbrand <david@redhat.com> Cc: James Houghton <jthoughton@google.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Mike Rapoport (IBM)" <rppt@kernel.org> Cc: Rik van Riel <riel@surriel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Christoph Hellwig
|
5b34b76cb0 |
mm: move follow_phys to arch/x86/mm/pat/memtype.c
follow_phys is only used by two callers in arch/x86/mm/pat/memtype.c. Move it there and hardcode the two arguments that get the same values passed by both callers. [david@redhat.com: conflict resolutions] Link: https://lkml.kernel.org/r/20240403212131.929421-4-david@redhat.com Link: https://lkml.kernel.org/r/20240324234542.2038726-4-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fei Li <fei1.li@intel.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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|
Christoph Hellwig
|
cb10c28ac8 |
mm: remove follow_pfn
Remove follow_pfn now that the last user is gone. Link: https://lkml.kernel.org/r/20240324234542.2038726-3-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fei Li <fei1.li@intel.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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David Hildenbrand
|
ebb34f78d7 |
mm: convert folio_estimated_sharers() to folio_likely_mapped_shared()
Callers of folio_estimated_sharers() only care about "mapped shared vs. mapped exclusively", not the exact estimate of sharers. Let's consolidate and unify the condition users are checking. While at it clarify the semantics and extend the discussion on the fuzziness. Use the "likely mapped shared" terminology to better express what the (adjusted) function actually checks. Whether a partially-mappable folio is more likely to not be partially mapped than partially mapped is debatable. In the future, we might be able to improve our estimate for partially-mappable folios, though. Note that we will now consistently detect "mapped shared" only if the first subpage is actually mapped multiple times. When the first subpage is not mapped, we will consistently detect it as "mapped exclusively". This change should currently only affect the usage in madvise_free_pte_range() and queue_folios_pte_range() for large folios: if the first page was already unmapped, we would have skipped the folio. [david@redhat.com: folio_likely_mapped_shared() kerneldoc fixup] Link: https://lkml.kernel.org/r/dd0ad9f2-2d7a-45f3-9ba3-979488c7dd27@redhat.com Link: https://lkml.kernel.org/r/20240227201548.857831-1-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com> Acked-by: Barry Song <v-songbaohua@oppo.com> Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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|
Barry Song
|
f238b8c33c |
arm64: mm: swap: support THP_SWAP on hardware with MTE
Commit
|
||
|
Donet Tom
|
f8fd525ba3 |
mm/mempolicy: use numa_node_id() instead of cpu_to_node()
Patch series "Allow migrate on protnone reference with MPOL_PREFERRED_MANY
policy:, v4.
This patchset is to optimize the cross-socket memory access with
MPOL_PREFERRED_MANY policy.
To test this patch we ran the following test on a 3 node system.
Node 0 - 2GB - Tier 1
Node 1 - 11GB - Tier 1
Node 6 - 10GB - Tier 2
Below changes are made to memcached to set the memory policy,
It select Node0 and Node1 as preferred nodes.
#include <numaif.h>
#include <numa.h>
unsigned long nodemask;
int ret;
nodemask = 0x03;
ret = set_mempolicy(MPOL_PREFERRED_MANY | MPOL_F_NUMA_BALANCING,
&nodemask, 10);
/* If MPOL_F_NUMA_BALANCING isn't supported,
* fall back to MPOL_PREFERRED_MANY */
if (ret < 0 && errno == EINVAL){
printf("set mem policy normal\n");
ret = set_mempolicy(MPOL_PREFERRED_MANY, &nodemask, 10);
}
if (ret < 0) {
perror("Failed to call set_mempolicy");
exit(-1);
}
Test Procedure:
===============
1. Make sure memory tiring and demotion are enabled.
2. Start memcached.
# ./memcached -b 100000 -m 204800 -u root -c 1000000 -t 7
-d -s "/tmp/memcached.sock"
3. Run memtier_benchmark to store 3200000 keys.
#./memtier_benchmark -S "/tmp/memcached.sock" --protocol=memcache_binary
--threads=1 --pipeline=1 --ratio=1:0 --key-pattern=S:S --key-minimum=1
--key-maximum=3200000 -n allkeys -c 1 -R -x 1 -d 1024
4. Start a memory eater on node 0 and 1. This will demote all memcached
pages to node 6.
5. Make sure all the memcached pages got demoted to lower tier by reading
/proc/<memcaced PID>/numa_maps.
# cat /proc/2771/numa_maps
---
default anon=1009 dirty=1009 active=0 N6=1009 kernelpagesize_kB=64
default anon=1009 dirty=1009 active=0 N6=1009 kernelpagesize_kB=64
---
6. Kill memory eater.
7. Read the pgpromote_success counter.
8. Start reading the keys by running memtier_benchmark.
#./memtier_benchmark -S "/tmp/memcached.sock" --protocol=memcache_binary
--pipeline=1 --distinct-client-seed --ratio=0:3 --key-pattern=R:R
--key-minimum=1 --key-maximum=3200000 -n allkeys
--threads=64 -c 1 -R -x 6
9. Read the pgpromote_success counter.
Test Results:
=============
Without Patch
------------------
1. pgpromote_success before test
Node 0: pgpromote_success 11
Node 1: pgpromote_success 140974
pgpromote_success after test
Node 0: pgpromote_success 11
Node 1: pgpromote_success 140974
2. Memtier-benchmark result.
AGGREGATED AVERAGE RESULTS (6 runs)
==================================================================
Type Ops/sec Hits/sec Misses/sec Avg. Latency p50 Latency
------------------------------------------------------------------
Sets 0.00 --- --- --- ---
Gets 305792.03 305791.93 0.10 0.18949 0.16700
Waits 0.00 --- --- --- ---
Totals 305792.03 305791.93 0.10 0.18949 0.16700
======================================
p99 Latency p99.9 Latency KB/sec
-------------------------------------
--- --- 0.00
0.44700 1.71100 11542.69
--- --- ---
0.44700 1.71100 11542.69
With Patch
---------------
1. pgpromote_success before test
Node 0: pgpromote_success 5
Node 1: pgpromote_success 89386
pgpromote_success after test
Node 0: pgpromote_success 57895
Node 1: pgpromote_success 141463
2. Memtier-benchmark result.
AGGREGATED AVERAGE RESULTS (6 runs)
====================================================================
Type Ops/sec Hits/sec Misses/sec Avg. Latency p50 Latency
--------------------------------------------------------------------
Sets 0.00 --- --- --- ---
Gets 521942.24 521942.07 0.17 0.11459 0.10300
Waits 0.00 --- --- --- ---
Totals 521942.24 521942.07 0.17 0.11459 0.10300
=======================================
p99 Latency p99.9 Latency KB/sec
---------------------------------------
--- --- 0.00
0.23100 0.31900 19701.68
--- --- ---
0.23100 0.31900 19701.68
Test Result Analysis:
=====================
1. With patch we could observe pages are getting promoted.
2. Memtier-benchmark results shows that, with the patch,
performance has increased more than 50%.
Ops/sec without fix - 305792.03
Ops/sec with fix - 521942.24
This patch (of 2):
Instead of using 'cpu_to_node()', we use 'numa_node_id()', which is
quicker. smp_processor_id is guaranteed to be stable in the
'mpol_misplaced()' function because it is called with ptl held.
lockdep_assert_held was added to ensure that.
No functional change in this patch.
[donettom@linux.ibm.com: add "* @vmf: structure describing the fault" comment]
Link: https://lkml.kernel.org/r/d8b993ea9dccfac0bc3ed61d3a81f4ac5f376e46.1711002865.git.donettom@linux.ibm.com
Link: https://lkml.kernel.org/r/cover.1711373653.git.donettom@linux.ibm.com
Link: https://lkml.kernel.org/r/6059f034f436734b472d066db69676fb3a459864.1711373653.git.donettom@linux.ibm.com
Link: https://lkml.kernel.org/r/cover.1709909210.git.donettom@linux.ibm.com
Link: https://lkml.kernel.org/r/744646531af02cc687cde8ae788fb1779e99d02c.1709909210.git.donettom@linux.ibm.com
Signed-off-by: Aneesh Kumar K.V (IBM) <aneesh.kumar@kernel.org>
Signed-off-by: Donet Tom <donettom@linux.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Huang, Ying <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
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|
Peter Xu
|
1965e933dd |
mm/treewide: replace pXd_huge() with pXd_leaf()
Now after we're sure all pXd_huge() definitions are the same as pXd_leaf(), reuse it. Luckily, pXd_huge() isn't widely used. Link: https://lkml.kernel.org/r/20240318200404.448346-12-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bjorn Andersson <andersson@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David S. Miller <davem@davemloft.net> Cc: Fabio Estevam <festevam@denx.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Konrad Dybcio <konrad.dybcio@linaro.org> Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Cc: Lucas Stach <l.stach@pengutronix.de> Cc: Mark Salter <msalter@redhat.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Shawn Guo <shawnguo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Paolo Bonzini
|
a96cb3bf39 |
Merge x86 bugfixes from Linux 6.9-rc3
Pull fix for SEV-SNP late disable bugs. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
||
|
Paolo Bonzini
|
f7842747d1 |
mm: replace set_pte_at_notify() with just set_pte_at()
With the demise of the .change_pte() MMU notifier callback, there is no notification happening in set_pte_at_notify(). It is a synonym of set_pte_at() and can be replaced with it. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Message-ID: <20240405115815.3226315-5-pbonzini@redhat.com> Acked-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
||
|
David Hildenbrand
|
04c35ab3bd |
x86/mm/pat: fix VM_PAT handling in COW mappings
PAT handling won't do the right thing in COW mappings: the first PTE (or,
in fact, all PTEs) can be replaced during write faults to point at anon
folios. Reliably recovering the correct PFN and cachemode using
follow_phys() from PTEs will not work in COW mappings.
Using follow_phys(), we might just get the address+protection of the anon
folio (which is very wrong), or fail on swap/nonswap entries, failing
follow_phys() and triggering a WARN_ON_ONCE() in untrack_pfn() and
track_pfn_copy(), not properly calling free_pfn_range().
In free_pfn_range(), we either wouldn't call memtype_free() or would call
it with the wrong range, possibly leaking memory.
To fix that, let's update follow_phys() to refuse returning anon folios,
and fallback to using the stored PFN inside vma->vm_pgoff for COW mappings
if we run into that.
We will now properly handle untrack_pfn() with COW mappings, where we
don't need the cachemode. We'll have to fail fork()->track_pfn_copy() if
the first page was replaced by an anon folio, though: we'd have to store
the cachemode in the VMA to make this work, likely growing the VMA size.
For now, lets keep it simple and let track_pfn_copy() just fail in that
case: it would have failed in the past with swap/nonswap entries already,
and it would have done the wrong thing with anon folios.
Simple reproducer to trigger the WARN_ON_ONCE() in untrack_pfn():
<--- C reproducer --->
#include <stdio.h>
#include <sys/mman.h>
#include <unistd.h>
#include <liburing.h>
int main(void)
{
struct io_uring_params p = {};
int ring_fd;
size_t size;
char *map;
ring_fd = io_uring_setup(1, &p);
if (ring_fd < 0) {
perror("io_uring_setup");
return 1;
}
size = p.sq_off.array + p.sq_entries * sizeof(unsigned);
/* Map the submission queue ring MAP_PRIVATE */
map = mmap(0, size, PROT_READ | PROT_WRITE, MAP_PRIVATE,
ring_fd, IORING_OFF_SQ_RING);
if (map == MAP_FAILED) {
perror("mmap");
return 1;
}
/* We have at least one page. Let's COW it. */
*map = 0;
pause();
return 0;
}
<--- C reproducer --->
On a system with 16 GiB RAM and swap configured:
# ./iouring &
# memhog 16G
# killall iouring
[ 301.552930] ------------[ cut here ]------------
[ 301.553285] WARNING: CPU: 7 PID: 1402 at arch/x86/mm/pat/memtype.c:1060 untrack_pfn+0xf4/0x100
[ 301.553989] Modules linked in: binfmt_misc nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_g
[ 301.558232] CPU: 7 PID: 1402 Comm: iouring Not tainted 6.7.5-100.fc38.x86_64 #1
[ 301.558772] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebu4
[ 301.559569] RIP: 0010:untrack_pfn+0xf4/0x100
[ 301.559893] Code: 75 c4 eb cf 48 8b 43 10 8b a8 e8 00 00 00 3b 6b 28 74 b8 48 8b 7b 30 e8 ea 1a f7 000
[ 301.561189] RSP: 0018:ffffba2c0377fab8 EFLAGS: 00010282
[ 301.561590] RAX: 00000000ffffffea RBX: ffff9208c8ce9cc0 RCX: 000000010455e047
[ 301.562105] RDX: 07fffffff0eb1e0a RSI: 0000000000000000 RDI: ffff9208c391d200
[ 301.562628] RBP: 0000000000000000 R08: ffffba2c0377fab8 R09: 0000000000000000
[ 301.563145] R10: ffff9208d2292d50 R11: 0000000000000002 R12: 00007fea890e0000
[ 301.563669] R13: 0000000000000000 R14: ffffba2c0377fc08 R15: 0000000000000000
[ 301.564186] FS: 0000000000000000(0000) GS:ffff920c2fbc0000(0000) knlGS:0000000000000000
[ 301.564773] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 301.565197] CR2: 00007fea88ee8a20 CR3: 00000001033a8000 CR4: 0000000000750ef0
[ 301.565725] PKRU: 55555554
[ 301.565944] Call Trace:
[ 301.566148] <TASK>
[ 301.566325] ? untrack_pfn+0xf4/0x100
[ 301.566618] ? __warn+0x81/0x130
[ 301.566876] ? untrack_pfn+0xf4/0x100
[ 301.567163] ? report_bug+0x171/0x1a0
[ 301.567466] ? handle_bug+0x3c/0x80
[ 301.567743] ? exc_invalid_op+0x17/0x70
[ 301.568038] ? asm_exc_invalid_op+0x1a/0x20
[ 301.568363] ? untrack_pfn+0xf4/0x100
[ 301.568660] ? untrack_pfn+0x65/0x100
[ 301.568947] unmap_single_vma+0xa6/0xe0
[ 301.569247] unmap_vmas+0xb5/0x190
[ 301.569532] exit_mmap+0xec/0x340
[ 301.569801] __mmput+0x3e/0x130
[ 301.570051] do_exit+0x305/0xaf0
...
Link: https://lkml.kernel.org/r/20240403212131.929421-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reported-by: Wupeng Ma <mawupeng1@huawei.com>
Closes: https://lkml.kernel.org/r/20240227122814.3781907-1-mawupeng1@huawei.com
Fixes:
|
||
|
Peter Xu
|
f8572367ea |
mm/memory: fix missing pte marker for !page on pte zaps
Commit |
||
|
Barry Song
|
cd197c3a20 |
mm: prohibit the last subpage from reusing the entire large folio
In a Copy-on-Write (CoW) scenario, the last subpage will reuse the entire
large folio, resulting in the waste of (nr_pages - 1) pages. This wasted
memory remains allocated until it is either unmapped or memory reclamation
occurs.
The following small program can serve as evidence of this behavior
main()
{
#define SIZE 1024 * 1024 * 1024UL
void *p = malloc(SIZE);
memset(p, 0x11, SIZE);
if (fork() == 0)
_exit(0);
memset(p, 0x12, SIZE);
printf("done\n");
while(1);
}
For example, using a 1024KiB mTHP by:
echo always > /sys/kernel/mm/transparent_hugepage/hugepages-1024kB/enabled
(1) w/o the patch, it takes 2GiB,
Before running the test program,
/ # free -m
total used free shared buff/cache available
Mem: 5754 84 5692 0 17 5669
Swap: 0 0 0
/ # /a.out &
/ # done
After running the test program,
/ # free -m
total used free shared buff/cache available
Mem: 5754 2149 3627 0 19 3605
Swap: 0 0 0
(2) w/ the patch, it takes 1GiB only,
Before running the test program,
/ # free -m
total used free shared buff/cache available
Mem: 5754 89 5687 0 17 5664
Swap: 0 0 0
/ # /a.out &
/ # done
After running the test program,
/ # free -m
total used free shared buff/cache available
Mem: 5754 1122 4655 0 17 4632
Swap: 0 0 0
This patch migrates the last subpage to a small folio and immediately
returns the large folio to the system. It benefits both memory availability
and anti-fragmentation.
Link: https://lkml.kernel.org/r/20240308092721.144735-1-21cnbao@gmail.com
Signed-off-by: Barry Song <v-songbaohua@oppo.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Lance Yang <ioworker0@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
||
|
Kefeng Wang
|
5aa598a72e |
mm: memory: fix shift-out-of-bounds in fault_around_bytes_set
The rounddown_pow_of_two(0) is undefined, so val = 0 is not allowed in the
fault_around_bytes_set(), and leads to shift-out-of-bounds,
UBSAN: shift-out-of-bounds in include/linux/log2.h:67:13
shift exponent 4294967295 is too large for 64-bit type 'long unsigned int'
CPU: 7 PID: 107 Comm: sh Not tainted 6.8.0-rc6-next-20240301 #294
Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015
Call trace:
dump_backtrace+0x94/0xec
show_stack+0x18/0x24
dump_stack_lvl+0x78/0x90
dump_stack+0x18/0x24
ubsan_epilogue+0x10/0x44
__ubsan_handle_shift_out_of_bounds+0x98/0x134
fault_around_bytes_set+0xa4/0xb0
simple_attr_write_xsigned.isra.0+0xe4/0x1ac
simple_attr_write+0x18/0x24
debugfs_attr_write+0x4c/0x98
vfs_write+0xd0/0x4b0
ksys_write+0x6c/0xfc
__arm64_sys_write+0x1c/0x28
invoke_syscall+0x44/0x104
el0_svc_common.constprop.0+0x40/0xe0
do_el0_svc+0x1c/0x28
el0_svc+0x34/0xdc
el0t_64_sync_handler+0xc0/0xc4
el0t_64_sync+0x190/0x194
---[ end trace ]---
Fix it by setting the minimum val to PAGE_SIZE.
Link: https://lkml.kernel.org/r/20240302064312.2358924-1-wangkefeng.wang@huawei.com
Fixes:
|
||
|
Barry Song
|
ac96cc4d1c |
mm: make folio_pte_batch available outside of mm/memory.c
madvise, mprotect and some others might need folio_pte_batch to check if a range of PTEs are completely mapped to a large folio with contiguous physical addresses. Let's make it available in mm/internal.h. While at it, add proper kernel doc and sanity-check more input parameters using two additional VM_WARN_ON_FOLIO(). [21cnbao@gmail.com: build fix] Link: https://lkml.kernel.org/r/CAGsJ_4wWzG-37D82vqP_zt+Fcbz+URVe5oXLBc4M5wbN8A_gpQ@mail.gmail.com [david@redhat.com: improve the doc for the exported func] Link: https://lkml.kernel.org/r/20240227104201.337988-1-21cnbao@gmail.com Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Barry Song <v-songbaohua@oppo.com> Suggested-by: David Hildenbrand <david@redhat.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Lance Yang <ioworker0@gmail.com> Cc: Yin Fengwei <fengwei.yin@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
John Hubbard
|
6c1b748ebf |
mm/memory.c: do_numa_page(): remove a redundant page table read
do_numa_page() is reading from the same page table entry, twice, while holding the page table lock: once while checking that the pte hasn't changed, and again in order to modify the pte. Instead, just read the pte once, and save it in the same old_pte variable that already exists. This has no effect on behavior, other than to provide a tiny potential improvement to performance, by avoiding the redundant memory read (which the compiler cannot elide, due to READ_ONCE()). Also improve the associated comments nearby. Link: https://lkml.kernel.org/r/20240228034151.459370-1-jhubbard@nvidia.com Signed-off-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Matthew Wilcox (Oracle)
|
63b774993d |
mm: convert free_swap_cache() to take a folio
All but one caller already has a folio, so convert free_page_and_swap_cache() to have a folio and remove the call to page_folio(). Link: https://lkml.kernel.org/r/20240227174254.710559-19-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Vishal Moola (Oracle)
|
997f0ecb11 |
mm/memory: change vmf_anon_prepare() to be non-static
Patch series "Handle hugetlb faults under the VMA lock", v2. It is generally safe to handle hugetlb faults under the VMA lock. The only time this is unsafe is when no anon_vma has been allocated to this vma yet, so we can use vmf_anon_prepare() instead of anon_vma_prepare() to bailout if necessary. This should only happen for the first hugetlb page in the vma. Additionally, this patchset begins to use struct vm_fault within hugetlb_fault(). This works towards cleaning up hugetlb code, and should significantly reduce the number of arguments passed to functions. The last patch in this series may cause ltp hugemmap10 to "fail". This is because vmf_anon_prepare() may bailout with no anon_vma under the VMA lock after allocating a folio for the hugepage. In free_huge_folio(), this folio is completely freed on bailout iff there is a surplus of hugetlb pages. This will remove a folio off the freelist and decrement the number of hugepages while ltp expects these counters to remain unchanged on failure. The rest of the ltp testcases pass. This patch (of 2): In order to handle hugetlb faults under the VMA lock, hugetlb can use vmf_anon_prepare() to ensure we can safely prepare an anon_vma. Change it to be a non-static function so it can be used within hugetlb as well. Link: https://lkml.kernel.org/r/20240221234732.187629-6-vishal.moola@gmail.com Link: https://lkml.kernel.org/r/20240221234732.187629-2-vishal.moola@gmail.com Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Ryan Roberts
|
c6ec76a2eb |
mm: add pte_batch_hint() to reduce scanning in folio_pte_batch()
Some architectures (e.g. arm64) can tell from looking at a pte, if some follow-on ptes also map contiguous physical memory with the same pgprot. (for arm64, these are contpte mappings). Take advantage of this knowledge to optimize folio_pte_batch() so that it can skip these ptes when scanning to create a batch. By default, if an arch does not opt-in, folio_pte_batch() returns a compile-time 1, so the changes are optimized out and the behaviour is as before. arm64 will opt-in to providing this hint in the next patch, which will greatly reduce the cost of ptep_get() when scanning a range of contptes. Link: https://lkml.kernel.org/r/20240215103205.2607016-16-ryan.roberts@arm.com Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Acked-by: David Hildenbrand <david@redhat.com> Tested-by: John Hubbard <jhubbard@nvidia.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Barry Song <21cnbao@gmail.com> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Morse <james.morse@arm.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <shy828301@gmail.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
David Hildenbrand
|
10ebac4f95 |
mm/memory: optimize unmap/zap with PTE-mapped THP
Similar to how we optimized fork(), let's implement PTE batching when consecutive (present) PTEs map consecutive pages of the same large folio. Most infrastructure we need for batching (mmu gather, rmap) is already there. We only have to add get_and_clear_full_ptes() and clear_full_ptes(). Similarly, extend zap_install_uffd_wp_if_needed() to process a PTE range. We won't bother sanity-checking the mapcount of all subpages, but only check the mapcount of the first subpage we process. If there is a real problem hiding somewhere, we can trigger it simply by using small folios, or when we zap single pages of a large folio. Ideally, we had that check in rmap code (including for delayed rmap), but then we cannot print the PTE. Let's keep it simple for now. If we ever have a cheap folio_mapcount(), we might just want to check for underflows there. To keep small folios as fast as possible force inlining of a specialized variant using __always_inline with nr=1. Link: https://lkml.kernel.org/r/20240214204435.167852-11-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Cc: Yin Fengwei <fengwei.yin@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
David Hildenbrand
|
2b42a7e531 |
mm/memory: factor out zapping folio pte into zap_present_folio_pte()
Let's prepare for further changes by factoring it out into a separate function. Link: https://lkml.kernel.org/r/20240214204435.167852-5-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Cc: Yin Fengwei <fengwei.yin@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
David Hildenbrand
|
d11838ed63 |
mm/memory: further separate anon and pagecache folio handling in zap_present_pte()
We don't need up-to-date accessed-dirty information for anon folios and can simply work with the ptent we already have. Also, we know the RSS counter we want to update. We can safely move arch_check_zapped_pte() + tlb_remove_tlb_entry() + zap_install_uffd_wp_if_needed() after updating the folio and RSS. While at it, only call zap_install_uffd_wp_if_needed() if there is even any chance that pte_install_uffd_wp_if_needed() would do *something*. That is, just don't bother if uffd-wp does not apply. Link: https://lkml.kernel.org/r/20240214204435.167852-4-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Cc: Yin Fengwei <fengwei.yin@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
David Hildenbrand
|
0cf18e839f |
mm/memory: handle !page case in zap_present_pte() separately
We don't need uptodate accessed/dirty bits, so in theory we could replace ptep_get_and_clear_full() by an optimized ptep_clear_full() function. Let's rely on the provided pte. Further, there is no scenario where we would have to insert uffd-wp markers when zapping something that is not a normal page (i.e., zeropage). Add a sanity check to make sure this remains true. should_zap_folio() no longer has to handle NULL pointers. This change replaces 2/3 "!page/!folio" checks by a single "!page" one. Note that arch_check_zapped_pte() on x86-64 checks the HW-dirty bit to detect shadow stack entries. But for shadow stack entries, the HW dirty bit (in combination with non-writable PTEs) is set by software. So for the arch_check_zapped_pte() check, we don't have to sync against HW setting the HW dirty bit concurrently, it is always set. Link: https://lkml.kernel.org/r/20240214204435.167852-3-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Cc: Yin Fengwei <fengwei.yin@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
David Hildenbrand
|
789753e17c |
mm/memory: factor out zapping of present pte into zap_present_pte()
Patch series "mm/memory: optimize unmap/zap with PTE-mapped THP", v3.
This series is based on [1]. Similar to what we did with fork(), let's
implement PTE batching during unmap/zap when processing PTE-mapped THPs.
We collect consecutive PTEs that map consecutive pages of the same large
folio, making sure that the other PTE bits are compatible, and (a) adjust
the refcount only once per batch, (b) call rmap handling functions only
once per batch, (c) perform batch PTE setting/updates and (d) perform TLB
entry removal once per batch.
Ryan was previously working on this in the context of cont-pte for arm64,
int latest iteration [2] with a focus on arm6 with cont-pte only. This
series implements the optimization for all architectures, independent of
such PTE bits, teaches MMU gather/TLB code to be fully aware of such
large-folio-pages batches as well, and amkes use of our new rmap batching
function when removing the rmap.
To achieve that, we have to enlighten MMU gather / page freeing code
(i.e., everything that consumes encoded_page) to process unmapping of
consecutive pages that all belong to the same large folio. I'm being very
careful to not degrade order-0 performance, and it looks like I managed to
achieve that.
While this series should -- similar to [1] -- be beneficial for adding
cont-pte support on arm64[2], it's one of the requirements for maintaining
a total mapcount[3] for large folios with minimal added overhead and
further changes[4] that build up on top of the total mapcount.
Independent of all that, this series results in a speedup during munmap()
and similar unmapping (process teardown, MADV_DONTNEED on larger ranges)
with PTE-mapped THP, which is the default with THPs that are smaller than
a PMD (for example, 16KiB to 1024KiB mTHPs for anonymous memory[5]).
On an Intel Xeon Silver 4210R CPU, munmap'ing a 1GiB VMA backed by
PTE-mapped folios of the same size (stddev < 1%) results in the following
runtimes for munmap() in seconds (shorter is better):
Folio Size | mm-unstable | New | Change
---------------------------------------------
4KiB | 0.058110 | 0.057715 | - 1%
16KiB | 0.044198 | 0.035469 | -20%
32KiB | 0.034216 | 0.023522 | -31%
64KiB | 0.029207 | 0.018434 | -37%
128KiB | 0.026579 | 0.014026 | -47%
256KiB | 0.025130 | 0.011756 | -53%
512KiB | 0.024292 | 0.010703 | -56%
1024KiB | 0.023812 | 0.010294 | -57%
2048KiB | 0.023785 | 0.009910 | -58%
[1] https://lkml.kernel.org/r/20240129124649.189745-1-david@redhat.com
[2] https://lkml.kernel.org/r/20231218105100.172635-1-ryan.roberts@arm.com
[3] https://lkml.kernel.org/r/20230809083256.699513-1-david@redhat.com
[4] https://lkml.kernel.org/r/20231124132626.235350-1-david@redhat.com
[5] https://lkml.kernel.org/r/20231207161211.2374093-1-ryan.roberts@arm.com
This patch (of 10):
Let's prepare for further changes by factoring out processing of present
PTEs.
Link: https://lkml.kernel.org/r/20240214204435.167852-1-david@redhat.com
Link: https://lkml.kernel.org/r/20240214204435.167852-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
||
|
David Hildenbrand
|
d7c0e5f722 |
mm/memory: ignore writable bit in folio_pte_batch()
... and conditionally return to the caller if any PTE except the first one is writable. fork() has to make sure to properly write-protect in case any PTE is writable. Other users (e.g., page unmaping) are expected to not care. Link: https://lkml.kernel.org/r/20240129124649.189745-16-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alexghiti@rivosinc.com> Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Russell King (Oracle) <linux@armlinux.org.uk> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
David Hildenbrand
|
25365e1069 |
mm/memory: ignore dirty/accessed/soft-dirty bits in folio_pte_batch()
Let's always ignore the accessed/young bit: we'll always mark the PTE as old in our child process during fork, and upcoming users will similarly not care. Ignore the dirty bit only if we don't want to duplicate the dirty bit into the child process during fork. Maybe, we could just set all PTEs in the child dirty if any PTE is dirty. For now, let's keep the behavior unchanged, this can be optimized later if required. Ignore the soft-dirty bit only if the bit doesn't have any meaning in the src vma, and similarly won't have any in the copied dst vma. For now, we won't bother with the uffd-wp bit. Link: https://lkml.kernel.org/r/20240129124649.189745-15-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alexghiti@rivosinc.com> Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Russell King (Oracle) <linux@armlinux.org.uk> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
David Hildenbrand
|
f8d937761d |
mm/memory: optimize fork() with PTE-mapped THP
Let's implement PTE batching when consecutive (present) PTEs map consecutive pages of the same large folio, and all other PTE bits besides the PFNs are equal. We will optimize folio_pte_batch() separately, to ignore selected PTE bits. This patch is based on work by Ryan Roberts. Use __always_inline for __copy_present_ptes() and keep the handling for single PTEs completely separate from the multi-PTE case: we really want the compiler to optimize for the single-PTE case with small folios, to not degrade performance. Note that PTE batching will never exceed a single page table and will always stay within VMA boundaries. Further, processing PTE-mapped THP that maybe pinned and have PageAnonExclusive set on at least one subpage should work as expected, but there is room for improvement: We will repeatedly (1) detect a PTE batch (2) detect that we have to copy a page (3) fall back and allocate a single page to copy a single page. For now we won't care as pinned pages are a corner case, and we should rather look into maintaining only a single PageAnonExclusive bit for large folios. Link: https://lkml.kernel.org/r/20240129124649.189745-14-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alexghiti@rivosinc.com> Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Russell King (Oracle) <linux@armlinux.org.uk> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
David Hildenbrand
|
53723298ba |
mm/memory: pass PTE to copy_present_pte()
We already read it, let's just forward it. This patch is based on work by Ryan Roberts. [david@redhat.com: fix the hmm "exclusive_cow" selftest] Link: https://lkml.kernel.org/r/13f296b8-e882-47fd-b939-c2141dc28717@redhat.com Link: https://lkml.kernel.org/r/20240129124649.189745-13-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alexghiti@rivosinc.com> Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Russell King (Oracle) <linux@armlinux.org.uk> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
David Hildenbrand
|
23ed190868 |
mm/memory: factor out copying the actual PTE in copy_present_pte()
Let's prepare for further changes. Link: https://lkml.kernel.org/r/20240129124649.189745-12-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alexghiti@rivosinc.com> Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Russell King (Oracle) <linux@armlinux.org.uk> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Kefeng Wang
|
085ff35e76 |
mm: memory: move mem_cgroup_charge() into alloc_anon_folio()
The GFP flags from vma_thp_gfp_mask() according to user configuration only used for large folio allocation but not for memory cgroup charge, and GFP_KERNEL is used for both order-0 and large order folio when memory cgroup charge at present. However, mem_cgroup_charge() uses the GFP flags in a fairly sophisticated way. In addition to checking gfpflags_allow_blocking(), it pays attention to __GFP_NORETRY and __GFP_RETRY_MAYFAIL to ensure that processes within this memcg do not exceed their quotas. So we'd better to move mem_cgroup_charge() into alloc_anon_folio(), 1) it will make us to allocate as much as possible large order folio, because we could try the next order if mem_cgroup_charge() fails, although the memcg's memory usage is close to its limits. 2) using same GFP flags for allocation and charge is to be consistent with PMD THP firstly, in addition, according to GFP flag returned from vma_thp_gfp_mask(), GFP_TRANSHUGE_LIGHT could make us skip direct reclaim, _GFP_NORETRY will make us skip mem_cgroup_oom() and won't trigger memory cgroup oom from large order(order <= COSTLY_ORDER) folio charging. Link: https://lkml.kernel.org/r/20240122011612.501029-1-wangkefeng.wang@huawei.com Link: https://lkml.kernel.org/r/20240117103954.2756050-1-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Kefeng Wang
|
6b27cc6c66 |
mm: convert mm_counter_file() to take a folio
Now all callers of mm_counter_file() have a folio, convert mm_counter_file() to take a folio. Saves a call to compound_head() hidden inside PageSwapBacked(). Link: https://lkml.kernel.org/r/20240111152429.3374566-11-willy@infradead.org Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Kefeng Wang
|
a23f517b0e |
mm: convert mm_counter() to take a folio
Now all callers of mm_counter() have a folio, convert mm_counter() to take a folio. Saves a call to compound_head() hidden inside PageAnon(). Link: https://lkml.kernel.org/r/20240111152429.3374566-10-willy@infradead.org Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Kefeng Wang
|
eabafaaa95 |
mm: convert to should_zap_page() to should_zap_folio()
Make should_zap_page() take a folio and rename it to should_zap_folio() as preparation for converting mm counter functions to take a folio. Saves a call to compound_head() hidden inside PageAnon(). [wangkefeng.wang@huawei.com: fix used-uninitialized warning] Link: https://lkml.kernel.org/r/962a7993-fce9-4de8-85cd-25e290f25736@huawei.com Link: https://lkml.kernel.org/r/20240111152429.3374566-9-willy@infradead.org Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Kefeng Wang
|
530c2a0da0 |
mm: use pfn_swap_entry_folio() in copy_nonpresent_pte()
Call pfn_swap_entry_folio() as preparation for converting mm counter functions to take a folio. Link: https://lkml.kernel.org/r/20240111152429.3374566-8-willy@infradead.org Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Kefeng Wang
|
21fff064a2 |
mm: memory: use nth_page() in clear/copy_subpage()
The clear and copy of huge gigantic page has converted to use nth_page() to handle the possible discontinuous struct page(SPARSEMEM without VMEMMAP), but not change for the non-gigantic part, fix it too. Link: https://lkml.kernel.org/r/20231229082207.60235-1-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Zi Yan <ziy@nvidia.com> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Kairui Song
|
13ddaf26be |
mm/swap: fix race when skipping swapcache
When skipping swapcache for SWP_SYNCHRONOUS_IO, if two or more threads
swapin the same entry at the same time, they get different pages (A, B).
Before one thread (T0) finishes the swapin and installs page (A) to the
PTE, another thread (T1) could finish swapin of page (B), swap_free the
entry, then swap out the possibly modified page reusing the same entry.
It breaks the pte_same check in (T0) because PTE value is unchanged,
causing ABA problem. Thread (T0) will install a stalled page (A) into the
PTE and cause data corruption.
One possible callstack is like this:
CPU0 CPU1
---- ----
do_swap_page() do_swap_page() with same entry
<direct swapin path> <direct swapin path>
<alloc page A> <alloc page B>
swap_read_folio() <- read to page A swap_read_folio() <- read to page B
<slow on later locks or interrupt> <finished swapin first>
... set_pte_at()
swap_free() <- entry is free
<write to page B, now page A stalled>
<swap out page B to same swap entry>
pte_same() <- Check pass, PTE seems
unchanged, but page A
is stalled!
swap_free() <- page B content lost!
set_pte_at() <- staled page A installed!
And besides, for ZRAM, swap_free() allows the swap device to discard the
entry content, so even if page (B) is not modified, if swap_read_folio()
on CPU0 happens later than swap_free() on CPU1, it may also cause data
loss.
To fix this, reuse swapcache_prepare which will pin the swap entry using
the cache flag, and allow only one thread to swap it in, also prevent any
parallel code from putting the entry in the cache. Release the pin after
PT unlocked.
Racers just loop and wait since it's a rare and very short event. A
schedule_timeout_uninterruptible(1) call is added to avoid repeated page
faults wasting too much CPU, causing livelock or adding too much noise to
perf statistics. A similar livelock issue was described in commit
|
||
|
Jiaxun Yang
|
8fa5070833 |
mm/memory: Use exception ip to search exception tables
On architectures with delay slot, instruction_pointer() may differ
from where exception was triggered.
Use exception_ip we just introduced to search exception tables to
get rid of the problem.
Fixes:
|
||
|
David Hildenbrand
|
e4e3df290f |
mm/memory: fix folio_set_dirty() vs. folio_mark_dirty() in zap_pte_range()
The correct folio replacement for "set_page_dirty()" is
"folio_mark_dirty()", not "folio_set_dirty()". Using the latter won't
properly inform the FS using the dirty_folio() callback.
This has been found by code inspection, but likely this can result in some
real trouble when zapping dirty PTEs that point at clean pagecache folios.
Yuezhang Mo said: "Without this fix, testing the latest exfat with
xfstests, test cases generic/029 and generic/030 will fail."
Link: https://lkml.kernel.org/r/20240122171751.272074-1-david@redhat.com
Fixes:
|
||
|
Linus Torvalds
|
fb46e22a9e |
Many singleton patches against the MM code. The patch series which
are included in this merge do the following:
- Peng Zhang has done some mapletree maintainance work in the
series
"maple_tree: add mt_free_one() and mt_attr() helpers"
"Some cleanups of maple tree"
- In the series "mm: use memmap_on_memory semantics for dax/kmem"
Vishal Verma has altered the interworking between memory-hotplug
and dax/kmem so that newly added 'device memory' can more easily
have its memmap placed within that newly added memory.
- Matthew Wilcox continues folio-related work (including a few
fixes) in the patch series
"Add folio_zero_tail() and folio_fill_tail()"
"Make folio_start_writeback return void"
"Fix fault handler's handling of poisoned tail pages"
"Convert aops->error_remove_page to ->error_remove_folio"
"Finish two folio conversions"
"More swap folio conversions"
- Kefeng Wang has also contributed folio-related work in the series
"mm: cleanup and use more folio in page fault"
- Jim Cromie has improved the kmemleak reporting output in the
series "tweak kmemleak report format".
- In the series "stackdepot: allow evicting stack traces" Andrey
Konovalov to permits clients (in this case KASAN) to cause
eviction of no longer needed stack traces.
- Charan Teja Kalla has fixed some accounting issues in the page
allocator's atomic reserve calculations in the series "mm:
page_alloc: fixes for high atomic reserve caluculations".
- Dmitry Rokosov has added to the samples/ dorectory some sample
code for a userspace memcg event listener application. See the
series "samples: introduce cgroup events listeners".
- Some mapletree maintanance work from Liam Howlett in the series
"maple_tree: iterator state changes".
- Nhat Pham has improved zswap's approach to writeback in the
series "workload-specific and memory pressure-driven zswap
writeback".
- DAMON/DAMOS feature and maintenance work from SeongJae Park in
the series
"mm/damon: let users feed and tame/auto-tune DAMOS"
"selftests/damon: add Python-written DAMON functionality tests"
"mm/damon: misc updates for 6.8"
- Yosry Ahmed has improved memcg's stats flushing in the series
"mm: memcg: subtree stats flushing and thresholds".
- In the series "Multi-size THP for anonymous memory" Ryan Roberts
has added a runtime opt-in feature to transparent hugepages which
improves performance by allocating larger chunks of memory during
anonymous page faults.
- Matthew Wilcox has also contributed some cleanup and maintenance
work against eh buffer_head code int he series "More buffer_head
cleanups".
- Suren Baghdasaryan has done work on Andrea Arcangeli's series
"userfaultfd move option". UFFDIO_MOVE permits userspace heap
compaction algorithms to move userspace's pages around rather than
UFFDIO_COPY'a alloc/copy/free.
- Stefan Roesch has developed a "KSM Advisor", in the series
"mm/ksm: Add ksm advisor". This is a governor which tunes KSM's
scanning aggressiveness in response to userspace's current needs.
- Chengming Zhou has optimized zswap's temporary working memory
use in the series "mm/zswap: dstmem reuse optimizations and
cleanups".
- Matthew Wilcox has performed some maintenance work on the
writeback code, both code and within filesystems. The series is
"Clean up the writeback paths".
- Andrey Konovalov has optimized KASAN's handling of alloc and
free stack traces for secondary-level allocators, in the series
"kasan: save mempool stack traces".
- Andrey also performed some KASAN maintenance work in the series
"kasan: assorted clean-ups".
- David Hildenbrand has gone to town on the rmap code. Cleanups,
more pte batching, folio conversions and more. See the series
"mm/rmap: interface overhaul".
- Kinsey Ho has contributed some maintenance work on the MGLRU
code in the series "mm/mglru: Kconfig cleanup".
- Matthew Wilcox has contributed lruvec page accounting code
cleanups in the series "Remove some lruvec page accounting
functions".
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Merge tag 'mm-stable-2024-01-08-15-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
"Many singleton patches against the MM code. The patch series which are
included in this merge do the following:
- Peng Zhang has done some mapletree maintainance work in the series
'maple_tree: add mt_free_one() and mt_attr() helpers'
'Some cleanups of maple tree'
- In the series 'mm: use memmap_on_memory semantics for dax/kmem'
Vishal Verma has altered the interworking between memory-hotplug
and dax/kmem so that newly added 'device memory' can more easily
have its memmap placed within that newly added memory.
- Matthew Wilcox continues folio-related work (including a few fixes)
in the patch series
'Add folio_zero_tail() and folio_fill_tail()'
'Make folio_start_writeback return void'
'Fix fault handler's handling of poisoned tail pages'
'Convert aops->error_remove_page to ->error_remove_folio'
'Finish two folio conversions'
'More swap folio conversions'
- Kefeng Wang has also contributed folio-related work in the series
'mm: cleanup and use more folio in page fault'
- Jim Cromie has improved the kmemleak reporting output in the series
'tweak kmemleak report format'.
- In the series 'stackdepot: allow evicting stack traces' Andrey
Konovalov to permits clients (in this case KASAN) to cause eviction
of no longer needed stack traces.
- Charan Teja Kalla has fixed some accounting issues in the page
allocator's atomic reserve calculations in the series 'mm:
page_alloc: fixes for high atomic reserve caluculations'.
- Dmitry Rokosov has added to the samples/ dorectory some sample code
for a userspace memcg event listener application. See the series
'samples: introduce cgroup events listeners'.
- Some mapletree maintanance work from Liam Howlett in the series
'maple_tree: iterator state changes'.
- Nhat Pham has improved zswap's approach to writeback in the series
'workload-specific and memory pressure-driven zswap writeback'.
- DAMON/DAMOS feature and maintenance work from SeongJae Park in the
series
'mm/damon: let users feed and tame/auto-tune DAMOS'
'selftests/damon: add Python-written DAMON functionality tests'
'mm/damon: misc updates for 6.8'
- Yosry Ahmed has improved memcg's stats flushing in the series 'mm:
memcg: subtree stats flushing and thresholds'.
- In the series 'Multi-size THP for anonymous memory' Ryan Roberts
has added a runtime opt-in feature to transparent hugepages which
improves performance by allocating larger chunks of memory during
anonymous page faults.
- Matthew Wilcox has also contributed some cleanup and maintenance
work against eh buffer_head code int he series 'More buffer_head
cleanups'.
- Suren Baghdasaryan has done work on Andrea Arcangeli's series
'userfaultfd move option'. UFFDIO_MOVE permits userspace heap
compaction algorithms to move userspace's pages around rather than
UFFDIO_COPY'a alloc/copy/free.
- Stefan Roesch has developed a 'KSM Advisor', in the series 'mm/ksm:
Add ksm advisor'. This is a governor which tunes KSM's scanning
aggressiveness in response to userspace's current needs.
- Chengming Zhou has optimized zswap's temporary working memory use
in the series 'mm/zswap: dstmem reuse optimizations and cleanups'.
- Matthew Wilcox has performed some maintenance work on the writeback
code, both code and within filesystems. The series is 'Clean up the
writeback paths'.
- Andrey Konovalov has optimized KASAN's handling of alloc and free
stack traces for secondary-level allocators, in the series 'kasan:
save mempool stack traces'.
- Andrey also performed some KASAN maintenance work in the series
'kasan: assorted clean-ups'.
- David Hildenbrand has gone to town on the rmap code. Cleanups, more
pte batching, folio conversions and more. See the series 'mm/rmap:
interface overhaul'.
- Kinsey Ho has contributed some maintenance work on the MGLRU code
in the series 'mm/mglru: Kconfig cleanup'.
- Matthew Wilcox has contributed lruvec page accounting code cleanups
in the series 'Remove some lruvec page accounting functions'"
* tag 'mm-stable-2024-01-08-15-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (361 commits)
mm, treewide: rename MAX_ORDER to MAX_PAGE_ORDER
mm, treewide: introduce NR_PAGE_ORDERS
selftests/mm: add separate UFFDIO_MOVE test for PMD splitting
selftests/mm: skip test if application doesn't has root privileges
selftests/mm: conform test to TAP format output
selftests: mm: hugepage-mmap: conform to TAP format output
selftests/mm: gup_test: conform test to TAP format output
mm/selftests: hugepage-mremap: conform test to TAP format output
mm/vmstat: move pgdemote_* out of CONFIG_NUMA_BALANCING
mm: zsmalloc: return -ENOSPC rather than -EINVAL in zs_malloc while size is too large
mm/memcontrol: remove __mod_lruvec_page_state()
mm/khugepaged: use a folio more in collapse_file()
slub: use a folio in __kmalloc_large_node
slub: use folio APIs in free_large_kmalloc()
slub: use alloc_pages_node() in alloc_slab_page()
mm: remove inc/dec lruvec page state functions
mm: ratelimit stat flush from workingset shrinker
kasan: stop leaking stack trace handles
mm/mglru: remove CONFIG_TRANSPARENT_HUGEPAGE
mm/mglru: add dummy pmd_dirty()
...
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Kefeng Wang
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e99fb98d47 |
mm: remove unnecessary ia64 code and comment
IA64 has gone with commit
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David Hildenbrand
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08e7795e24 |
mm/memory: page_try_dup_anon_rmap() -> folio_try_dup_anon_rmap_pte()
Let's convert copy_nonpresent_pte(). While at it, perform some more folio conversion. Link: https://lkml.kernel.org/r/20231220224504.646757-37-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yin Fengwei <fengwei.yin@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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David Hildenbrand
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d8ef5e311d |
mm/rmap: convert page_dup_file_rmap() to folio_dup_file_rmap_[pte|ptes|pmd]()
Let's convert page_dup_file_rmap() like the other rmap functions. As there is only a single caller, convert that single caller right away and remove page_dup_file_rmap(). Add folio_dup_file_rmap_ptes() right away, we want to perform rmap baching during fork() soon. Link: https://lkml.kernel.org/r/20231220224504.646757-34-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yin Fengwei <fengwei.yin@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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David Hildenbrand
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c46265030b |
mm/memory: page_remove_rmap() -> folio_remove_rmap_pte()
Let's convert zap_pte_range() and closely-related tlb_flush_rmap_batch(). While at it, perform some more folio conversion in zap_pte_range(). Link: https://lkml.kernel.org/r/20231220224504.646757-29-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yin Fengwei <fengwei.yin@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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David Hildenbrand
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b832a354d7 |
mm/memory: page_add_anon_rmap() -> folio_add_anon_rmap_pte()
Let's convert restore_exclusive_pte() and do_swap_page(). While at it, perform some folio conversion in restore_exclusive_pte(). Link: https://lkml.kernel.org/r/20231220224504.646757-21-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yin Fengwei <fengwei.yin@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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David Hildenbrand
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ef37b2ea08 |
mm/memory: page_add_file_rmap() -> folio_add_file_rmap_[pte|pmd]()
Let's convert insert_page_into_pte_locked() and do_set_pmd(). While at it, perform some folio conversion. Link: https://lkml.kernel.org/r/20231220224504.646757-9-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Yin Fengwei <fengwei.yin@intel.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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David Hildenbrand
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68f0320824 |
mm/rmap: convert folio_add_file_rmap_range() into folio_add_file_rmap_[pte|ptes|pmd]()
Let's get rid of the compound parameter and instead define explicitly which mappings we're adding. That is more future proof, easier to read and harder to mess up. Use an enum to express the granularity internally. Make the compiler always special-case on the granularity by using __always_inline. Replace the "compound" check by a switch-case that will be removed by the compiler completely. Add plenty of sanity checks with CONFIG_DEBUG_VM. Replace the folio_test_pmd_mappable() check by a config check in the caller and sanity checks. Convert the single user of folio_add_file_rmap_range(). While at it, consistently use "int" instead of "unisgned int" in rmap code when dealing with mapcounts and the number of pages. This function design can later easily be extended to PUDs and to batch PMDs. Note that for now we don't support anything bigger than PMD-sized folios (as we cleanly separated hugetlb handling). Sanity checks will catch if that ever changes. Next up is removing page_remove_rmap() along with its "compound" parameter and smilarly converting all other rmap functions. Link: https://lkml.kernel.org/r/20231220224504.646757-8-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Yin Fengwei <fengwei.yin@intel.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Matthew Wilcox (Oracle)
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c9bdf768dd |
mm: convert swap_readpage() to swap_read_folio()
All callers have a folio, so pass it in, saving two calls to compound_head(). Link: https://lkml.kernel.org/r/20231213215842.671461-11-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Matthew Wilcox (Oracle)
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2853b66b60 |
mm: remove some calls to page_add_new_anon_rmap()
We already have the folio in these functions, we just need to use it. folio_add_new_anon_rmap() didn't exist at the time they were converted to folios. Link: https://lkml.kernel.org/r/20231211162214.2146080-5-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Matthew Wilcox (Oracle)
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96db66d9c8 |
mm: convert ksm_might_need_to_copy() to work on folios
Patch series "Finish two folio conversions". Most callers of page_add_new_anon_rmap() and lru_cache_add_inactive_or_unevictable() have been converted to their folio equivalents, but there are still a few stragglers. There's a bit of preparatory work in ksm and unuse_pte(), but after that it's pretty mechanical. This patch (of 9): Accept a folio as an argument and return a folio result. Removes a call to compound_head() in do_swap_page(), and prevents folio & page from getting out of sync in unuse_pte(). Reviewed-by: David Hildenbrand <david@redhat.com> [willy@infradead.org: fix smatch warning] Link: https://lkml.kernel.org/r/ZXnPtblC6A1IkyAB@casper.infradead.org [david@redhat.com: only adjust the page if the folio changed] Link: https://lkml.kernel.org/r/6a8f2110-fa91-4c10-9eae-88315309a6e3@redhat.com Link: https://lkml.kernel.org/r/20231211162214.2146080-1-willy@infradead.org Link: https://lkml.kernel.org/r/20231211162214.2146080-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Jiajun Xie
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9eab0421fa |
mm: fix unmap_mapping_range high bits shift bug
The bug happens when highest bit of holebegin is 1, suppose holebegin is
0x8000000111111000, after shift, hba would be 0xfff8000000111111, then
vma_interval_tree_foreach would look it up fail or leads to the wrong
result.
error call seq e.g.:
- mmap(..., offset=0x8000000111111000)
|- syscall(mmap, ... unsigned long, off):
|- ksys_mmap_pgoff( ... , off >> PAGE_SHIFT);
here pgoff is correctly shifted to 0x8000000111111,
but pass 0x8000000111111000 as holebegin to unmap
would then cause terrible result, as shown below:
- unmap_mapping_range(..., loff_t const holebegin)
|- pgoff_t hba = holebegin >> PAGE_SHIFT;
/* hba = 0xfff8000000111111 unexpectedly */
The issue happens in Heterogeneous computing, where the device(e.g.
gpu) and host share the same virtual address space.
A simple workflow pattern which hit the issue is:
/* host */
1. userspace first mmap a file backed VA range with specified offset.
e.g. (offset=0x800..., mmap return: va_a)
2. write some data to the corresponding sys page
e.g. (va_a = 0xAABB)
/* device */
3. gpu workload touches VA, triggers gpu fault and notify the host.
/* host */
4. reviced gpu fault notification, then it will:
4.1 unmap host pages and also takes care of cpu tlb
(use unmap_mapping_range with offset=0x800...)
4.2 migrate sys page to device
4.3 setup device page table and resolve device fault.
/* device */
5. gpu workload continued, it accessed va_a and got 0xAABB.
6. gpu workload continued, it wrote 0xBBCC to va_a.
/* host */
7. userspace access va_a, as expected, it will:
7.1 trigger cpu vm fault.
7.2 driver handling fault to migrate gpu local page to host.
8. userspace then could correctly get 0xBBCC from va_a
9. done
But in step 4.1, if we hit the bug this patch mentioned, then userspace
would never trigger cpu fault, and still get the old value: 0xAABB.
Making holebegin unsigned first fixes the bug.
Link: https://lkml.kernel.org/r/20231220052839.26970-1-jiajun.xie.sh@gmail.com
Signed-off-by: Jiajun Xie <jiajun.xie.sh@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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