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mm/huge_memory: refactor copy_huge_pmd() non-present logic
Right now we are inconsistent in our use of thp_migration_supported():
static inline bool thp_migration_supported(void)
{
return IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION);
}
And simply having arbitrary and ugly #ifdef
CONFIG_ARCH_ENABLE_THP_MIGRATION blocks in code.
This is exhibited in copy_huge_pmd(), which inserts a large #ifdef
CONFIG_ARCH_ENABLE_THP_MIGRATION block and an if-branch which is difficult
to follow
It's difficult to follow the logic of such a large function and the
non-present PMD logic is clearly separate as it sits in a giant if-branch.
Therefore this patch both separates out the logic and utilises
thp_migration_supported().
No functional change intended.
Link: https://lkml.kernel.org/r/6eaadc23ed512d370ede65561e34e96241c54b9d.1762812360.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Chris Li <chrisl@kernel.org>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Gregory Price <gourry@gourry.net>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Mathew Brost <matthew.brost@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Wei Xu <weixugc@google.com>
Cc: xu xin <xu.xin16@zte.com.cn>
Cc: Yuanchu Xie <yuanchu@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Lorenzo Stoakes
committed by
Andrew Morton
Andrew Morton
parent
aa62204cb6
commit
e244d82d02
109
mm/huge_memory.c
109
mm/huge_memory.c
@@ -1699,6 +1699,62 @@ void touch_pmd(struct vm_area_struct *vma, unsigned long addr,
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update_mmu_cache_pmd(vma, addr, pmd);
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}
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static void copy_huge_non_present_pmd(
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struct mm_struct *dst_mm, struct mm_struct *src_mm,
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pmd_t *dst_pmd, pmd_t *src_pmd, unsigned long addr,
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struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma,
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pmd_t pmd, pgtable_t pgtable)
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{
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swp_entry_t entry = pmd_to_swp_entry(pmd);
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struct folio *src_folio;
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VM_WARN_ON(!is_pmd_non_present_folio_entry(pmd));
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if (is_writable_migration_entry(entry) ||
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is_readable_exclusive_migration_entry(entry)) {
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entry = make_readable_migration_entry(swp_offset(entry));
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pmd = swp_entry_to_pmd(entry);
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if (pmd_swp_soft_dirty(*src_pmd))
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pmd = pmd_swp_mksoft_dirty(pmd);
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if (pmd_swp_uffd_wp(*src_pmd))
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pmd = pmd_swp_mkuffd_wp(pmd);
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set_pmd_at(src_mm, addr, src_pmd, pmd);
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} else if (is_device_private_entry(entry)) {
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/*
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* For device private entries, since there are no
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* read exclusive entries, writable = !readable
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*/
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if (is_writable_device_private_entry(entry)) {
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entry = make_readable_device_private_entry(swp_offset(entry));
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pmd = swp_entry_to_pmd(entry);
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if (pmd_swp_soft_dirty(*src_pmd))
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pmd = pmd_swp_mksoft_dirty(pmd);
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if (pmd_swp_uffd_wp(*src_pmd))
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pmd = pmd_swp_mkuffd_wp(pmd);
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set_pmd_at(src_mm, addr, src_pmd, pmd);
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}
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src_folio = pfn_swap_entry_folio(entry);
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VM_WARN_ON(!folio_test_large(src_folio));
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folio_get(src_folio);
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/*
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* folio_try_dup_anon_rmap_pmd does not fail for
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* device private entries.
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*/
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folio_try_dup_anon_rmap_pmd(src_folio, &src_folio->page,
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dst_vma, src_vma);
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}
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add_mm_counter(dst_mm, MM_ANONPAGES, HPAGE_PMD_NR);
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mm_inc_nr_ptes(dst_mm);
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pgtable_trans_huge_deposit(dst_mm, dst_pmd, pgtable);
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if (!userfaultfd_wp(dst_vma))
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pmd = pmd_swp_clear_uffd_wp(pmd);
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set_pmd_at(dst_mm, addr, dst_pmd, pmd);
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}
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int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm,
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pmd_t *dst_pmd, pmd_t *src_pmd, unsigned long addr,
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struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma)
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@@ -1744,59 +1800,12 @@ int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm,
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ret = -EAGAIN;
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pmd = *src_pmd;
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#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
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if (unlikely(is_swap_pmd(pmd))) {
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swp_entry_t entry = pmd_to_swp_entry(pmd);
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VM_WARN_ON(!is_pmd_non_present_folio_entry(pmd));
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if (is_writable_migration_entry(entry) ||
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is_readable_exclusive_migration_entry(entry)) {
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entry = make_readable_migration_entry(swp_offset(entry));
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pmd = swp_entry_to_pmd(entry);
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if (pmd_swp_soft_dirty(*src_pmd))
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pmd = pmd_swp_mksoft_dirty(pmd);
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if (pmd_swp_uffd_wp(*src_pmd))
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pmd = pmd_swp_mkuffd_wp(pmd);
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set_pmd_at(src_mm, addr, src_pmd, pmd);
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} else if (is_device_private_entry(entry)) {
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/*
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* For device private entries, since there are no
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* read exclusive entries, writable = !readable
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*/
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if (is_writable_device_private_entry(entry)) {
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entry = make_readable_device_private_entry(swp_offset(entry));
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pmd = swp_entry_to_pmd(entry);
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if (pmd_swp_soft_dirty(*src_pmd))
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pmd = pmd_swp_mksoft_dirty(pmd);
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if (pmd_swp_uffd_wp(*src_pmd))
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pmd = pmd_swp_mkuffd_wp(pmd);
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set_pmd_at(src_mm, addr, src_pmd, pmd);
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}
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src_folio = pfn_swap_entry_folio(entry);
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VM_WARN_ON(!folio_test_large(src_folio));
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folio_get(src_folio);
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/*
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* folio_try_dup_anon_rmap_pmd does not fail for
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* device private entries.
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*/
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folio_try_dup_anon_rmap_pmd(src_folio, &src_folio->page,
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dst_vma, src_vma);
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}
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add_mm_counter(dst_mm, MM_ANONPAGES, HPAGE_PMD_NR);
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mm_inc_nr_ptes(dst_mm);
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pgtable_trans_huge_deposit(dst_mm, dst_pmd, pgtable);
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if (!userfaultfd_wp(dst_vma))
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pmd = pmd_swp_clear_uffd_wp(pmd);
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set_pmd_at(dst_mm, addr, dst_pmd, pmd);
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if (unlikely(thp_migration_supported() && is_swap_pmd(pmd))) {
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copy_huge_non_present_pmd(dst_mm, src_mm, dst_pmd, src_pmd, addr,
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dst_vma, src_vma, pmd, pgtable);
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ret = 0;
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goto out_unlock;
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}
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#endif
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if (unlikely(!pmd_trans_huge(pmd))) {
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pte_free(dst_mm, pgtable);
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