4490 Commits

Author	SHA1	Message	Date
Linus Torvalds	b7f94fcf55	sched_ext: A fix for v6.14-rc6 ... BPF schedulers could trigger a crash by passing in an invalid CPU to the helper scx_bpf_select_cpu_dfl(). Fix it by verifying input validity. -----BEGIN PGP SIGNATURE----- iIQEABYKACwWIQTfIjM1kS57o3GsC/uxYfJx3gVYGQUCZ9H4tw4cdGpAa2VybmVs Lm9yZwAKCRCxYfJx3gVYGY2PAP95rqNEACvl5uz/HQM+T0WpwGDaIJ3fmKYd3GZY 3XJjhwD/YmKMLmth0xeDLkAtVUNsMp4EjpssKdzi0CJq+Nl4nQw= =OxEw -----END PGP SIGNATURE----- Merge tag 'sched_ext-for-6.14-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext Pull sched_ext fix from Tejun Heo: "BPF schedulers could trigger a crash by passing in an invalid CPU to the scx_bpf_select_cpu_dfl() helper. Fix it by verifying input validity" * tag 'sched_ext-for-6.14-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext: sched_ext: Validate prev_cpu in scx_bpf_select_cpu_dfl()	2025-03-12 11:52:04 -10:00
Shrikanth Hegde	14672f059d	sched/deadline: Use online cpus for validating runtime ... The ftrace selftest reported a failure because writing -1 to sched_rt_runtime_us returns -EBUSY. This happens when the possible CPUs are different from active CPUs. Active CPUs are part of one root domain, while remaining CPUs are part of def_root_domain. Since active cpumask is being used, this results in cpus=0 when a non active CPUs is used in the loop. Fix it by looping over the online CPUs instead for validating the bandwidth calculations. Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Juri Lelli <juri.lelli@redhat.com> Link: https://lore.kernel.org/r/20250306052954.452005-2-sshegde@linux.ibm.com	2025-03-06 10:21:31 +01:00
Zecheng Li	3b4035ddbf	sched/fair: Fix potential memory corruption in child_cfs_rq_on_list ... child_cfs_rq_on_list attempts to convert a 'prev' pointer to a cfs_rq. This 'prev' pointer can originate from struct rq's leaf_cfs_rq_list, making the conversion invalid and potentially leading to memory corruption. Depending on the relative positions of leaf_cfs_rq_list and the task group (tg) pointer within the struct, this can cause a memory fault or access garbage data. The issue arises in list_add_leaf_cfs_rq, where both cfs_rq->leaf_cfs_rq_list and rq->leaf_cfs_rq_list are added to the same leaf list. Also, rq->tmp_alone_branch can be set to rq->leaf_cfs_rq_list. This adds a check `if (prev == &rq->leaf_cfs_rq_list)` after the main conditional in child_cfs_rq_on_list. This ensures that the container_of operation will convert a correct cfs_rq struct. This check is sufficient because only cfs_rqs on the same CPU are added to the list, so verifying the 'prev' pointer against the current rq's list head is enough. Fixes a potential memory corruption issue that due to current struct layout might not be manifesting as a crash but could lead to unpredictable behavior when the layout changes. Fixes: fdaba61ef8 ("sched/fair: Ensure that the CFS parent is added after unthrottling") Signed-off-by: Zecheng Li <zecheng@google.com> Reviewed-and-tested-by: K Prateek Nayak <kprateek.nayak@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20250304214031.2882646-1-zecheng@google.com	2025-03-05 17:30:54 +01:00
Andrea Righi	9360dfe4cb	sched_ext: Validate prev_cpu in scx_bpf_select_cpu_dfl() ... If a BPF scheduler provides an invalid CPU (outside the nr_cpu_ids range) as prev_cpu to scx_bpf_select_cpu_dfl() it can cause a kernel crash. To prevent this, validate prev_cpu in scx_bpf_select_cpu_dfl() and trigger an scx error if an invalid CPU is specified. Fixes: f0e1a0643a ("sched_ext: Implement BPF extensible scheduler class") Cc: stable@vger.kernel.org # v6.12+ Signed-off-by: Andrea Righi <arighi@nvidia.com> Signed-off-by: Tejun Heo <tj@kernel.org>	2025-03-03 07:55:48 -10:00
Linus Torvalds	d203484f25	Prevent cond_resched() based preemption when interrupts are disabled, ... on PREEMPT_NONE and PREEMPT_VOLUNTARY kernels. Signed-off-by: Ingo Molnar <mingo@kernel.org> -----BEGIN PGP SIGNATURE----- iQJFBAABCgAvFiEEBpT5eoXrXCwVQwEKEnMQ0APhK1gFAmfCDDMRHG1pbmdvQGtl cm5lbC5vcmcACgkQEnMQ0APhK1gf+RAAvFNXelLgrNbILZ6ckp/ikWnjCbf2QOIk aCm6JMQm7WrFvgo1u6CM4vQQYZdEqf8+KiEjJJnoq2P4jvYzhO1/1pLfEDNaHeiH GneosmKAwSMR8lgDlw5DXxhXsfeuYYhG5VMe2ia+kyiIA83TUF6hl9jpawWB3dsw +xB6CAg3JLoR2v44E/Mf1PdGaGrF90fYxp+X5RNSqxVXcN54cgVx2G9lHeTIWcnp SjIiWo5mply50de+dxD5dNUB9mj/k+yLQaiuPfUDGo/ZOjFyBnsP5VlD+ySbhkIa Rwdw6olLqXLcX5D5RsPIuePm/XdmAQXr6GXxJjdhtV1oWTP3Bejev3upQ/kxHQ50 DQa+aSTqNx9bNlwphUafCmVo1OZap4mViOSWP7r96HhFwehLGGmkjEaU9eFuUl0P kG+qGq28U+Nnz0r6/pEkwic1B6wbq2x1XRbtJqxXnBcQvMxMgDWNrTIj1ytDcSBb 3Qo0shRrtjH7DN1ly8IBllLQ0wXXI5O6GwjI7absEyEjpdoxFyMsHpaFONlTWRdi NgR2+5MWTxExeWaDRPAJM+THzwucfWVTeZVXJFMRfQnNIBj7TpO3X3Y4xzP9Vl/Y 2HEz8voSDZUVN6Ejxx/am7kb68WpWw46xmj59wWT7nf9SVEEm+R4Pfe3O9+0yvQV V4l6tN4yfEU= =RknP -----END PGP SIGNATURE----- Merge tag 'sched-urgent-2025-02-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fix from Ingo Molnar: "Prevent cond_resched() based preemption when interrupts are disabled, on PREEMPT_NONE and PREEMPT_VOLUNTARY kernels" * tag 'sched-urgent-2025-02-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/core: Prevent rescheduling when interrupts are disabled	2025-02-28 17:00:16 -08:00
Thomas Gleixner	82c387ef75	sched/core: Prevent rescheduling when interrupts are disabled ... David reported a warning observed while loop testing kexec jump: Interrupts enabled after irqrouter_resume+0x0/0x50 WARNING: CPU: 0 PID: 560 at drivers/base/syscore.c:103 syscore_resume+0x18a/0x220 kernel_kexec+0xf6/0x180 __do_sys_reboot+0x206/0x250 do_syscall_64+0x95/0x180 The corresponding interrupt flag trace: hardirqs last enabled at (15573): [<ffffffffa8281b8e>] __up_console_sem+0x7e/0x90 hardirqs last disabled at (15580): [<ffffffffa8281b73>] __up_console_sem+0x63/0x90 That means __up_console_sem() was invoked with interrupts enabled. Further instrumentation revealed that in the interrupt disabled section of kexec jump one of the syscore_suspend() callbacks woke up a task, which set the NEED_RESCHED flag. A later callback in the resume path invoked cond_resched() which in turn led to the invocation of the scheduler: __cond_resched+0x21/0x60 down_timeout+0x18/0x60 acpi_os_wait_semaphore+0x4c/0x80 acpi_ut_acquire_mutex+0x3d/0x100 acpi_ns_get_node+0x27/0x60 acpi_ns_evaluate+0x1cb/0x2d0 acpi_rs_set_srs_method_data+0x156/0x190 acpi_pci_link_set+0x11c/0x290 irqrouter_resume+0x54/0x60 syscore_resume+0x6a/0x200 kernel_kexec+0x145/0x1c0 __do_sys_reboot+0xeb/0x240 do_syscall_64+0x95/0x180 This is a long standing problem, which probably got more visible with the recent printk changes. Something does a task wakeup and the scheduler sets the NEED_RESCHED flag. cond_resched() sees it set and invokes schedule() from a completely bogus context. The scheduler enables interrupts after context switching, which causes the above warning at the end. Quite some of the code paths in syscore_suspend()/resume() can result in triggering a wakeup with the exactly same consequences. They might not have done so yet, but as they share a lot of code with normal operations it's just a question of time. The problem only affects the PREEMPT_NONE and PREEMPT_VOLUNTARY scheduling models. Full preemption is not affected as cond_resched() is disabled and the preemption check preemptible() takes the interrupt disabled flag into account. Cure the problem by adding a corresponding check into cond_resched(). Reported-by: David Woodhouse <dwmw@amazon.co.uk> Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: David Woodhouse <dwmw@amazon.co.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: stable@vger.kernel.org Closes: https://lore.kernel.org/all/7717fe2ac0ce5f0a2c43fdab8b11f4483d54a2a4.camel@infradead.org	2025-02-27 21:13:57 +01:00
Linus Torvalds	e6d3c4e535	sched_ext: A fix for v6.14-rc4 ... pick_task_scx() has a workaround to avoid stalling when the fair class's balance() says yes but pick_task() says no. The workaround was incorrectly deciding to keep the prev taks running if the task is on SCX even when the task is in a sleeping state, which can lead to several confusing failure modes. Fix it by testing the prev task is currently queued on SCX instead. -----BEGIN PGP SIGNATURE----- iIQEABYKACwWIQTfIjM1kS57o3GsC/uxYfJx3gVYGQUCZ79/Ww4cdGpAa2VybmVs Lm9yZwAKCRCxYfJx3gVYGdhUAQDM1AcK7pJUHzayuQCecCxNspGty8nR9T4KeVly 51pA2gEA4sbs6Fj4doVKVyaCunsvFoZ8Tb/utCX716fVnpjMMgY= =yDMV -----END PGP SIGNATURE----- Merge tag 'sched_ext-for-6.14-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext Pull sched_ext fix from Tejun Heo: "pick_task_scx() has a workaround to avoid stalling when the fair class's balance() says yes but pick_task() says no. The workaround was incorrectly deciding to keep the prev taks running if the task is on SCX even when the task is in a sleeping state, which can lead to several confusing failure modes. Fix it by testing the prev task is currently queued on SCX instead" * tag 'sched_ext-for-6.14-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext: sched_ext: Fix pick_task_scx() picking non-queued tasks when it's called without balance()	2025-02-26 14:13:11 -08:00
Tejun Heo	8fef0a3b17	sched_ext: Fix pick_task_scx() picking non-queued tasks when it's called without balance() ... a6250aa251 ("sched_ext: Handle cases where pick_task_scx() is called without preceding balance_scx()") added a workaround to handle the cases where pick_task_scx() is called without prececing balance_scx() which is due to a fair class bug where pick_taks_fair() may return NULL after a true return from balance_fair(). The workaround detects when pick_task_scx() is called without preceding balance_scx() and emulates SCX_RQ_BAL_KEEP and triggers kicking to avoid stalling. Unfortunately, the workaround code was testing whether @prev was on SCX to decide whether to keep the task running. This is incorrect as the task may be on SCX but no longer runnable. This could lead to a non-runnable task to be returned from pick_task_scx() which cause interesting confusions and failures. e.g. A common failure mode is the task ending up with (!on_rq && on_cpu) state which can cause potential wakers to busy loop, which can easily lead to deadlocks. Fix it by testing whether @prev has SCX_TASK_QUEUED set. This makes @prev_on_scx only used in one place. Open code the usage and improve the comment while at it. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Pat Cody <patcody@meta.com> Fixes: a6250aa251 ("sched_ext: Handle cases where pick_task_scx() is called without preceding balance_scx()") Cc: stable@vger.kernel.org # v6.12+ Acked-by: Andrea Righi <arighi@nvidia.com>	2025-02-25 08:28:52 -10:00
Mathieu Desnoyers	02d954c0fd	sched: Compact RSEQ concurrency IDs with reduced threads and affinity ... When a process reduces its number of threads or clears bits in its CPU affinity mask, the mm_cid allocation should eventually converge towards smaller values. However, the change introduced by: commit 7e019dcc47 ("sched: Improve cache locality of RSEQ concurrency IDs for intermittent workloads") adds a per-mm/CPU recent_cid which is never unset unless a thread migrates. This is a tradeoff between: A) Preserving cache locality after a transition from many threads to few threads, or after reducing the hamming weight of the allowed CPU mask. B) Making the mm_cid upper bounds wrt nr threads and allowed CPU mask easy to document and understand. C) Allowing applications to eventually react to mm_cid compaction after reduction of the nr threads or allowed CPU mask, making the tracking of mm_cid compaction easier by shrinking it back towards 0 or not. D) Making sure applications that periodically reduce and then increase again the nr threads or allowed CPU mask still benefit from good cache locality with mm_cid. Introduce the following changes: * After shrinking the number of threads or reducing the number of allowed CPUs, reduce the value of max_nr_cid so expansion of CID allocation will preserve cache locality if the number of threads or allowed CPUs increase again. * Only re-use a recent_cid if it is within the max_nr_cid upper bound, else find the first available CID. Fixes: 7e019dcc47 ("sched: Improve cache locality of RSEQ concurrency IDs for intermittent workloads") Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Gabriele Monaco <gmonaco@redhat.com> Link: https://lkml.kernel.org/r/20250210153253.460471-2-gmonaco@redhat.com	2025-02-18 08:50:36 +01:00
Linus Torvalds	ff3b373ecc	- Clarify what happens when a task is woken up from the wake queue and make ... clear its removal from that queue is atomic -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmexq1MACgkQEsHwGGHe VUq6ghAAoD872KGmQ3YioDZs+FKLpLWvo+6lC2rY+GFQ3oCu4TJfmlsiTGLCyzjv aYwL52diIORD9/Yfn6Sq/ZWkfncoVmwnht+tgVjXeRr3Pb4EnttgWxPRx/xYQizr jgRASpNsRUTr6zNzqEeeQYodIJaInOF5+r26oqYArcN5V9XB9Qaj0+f14UiyB6u+ 53qpEQqQopeLPyG4t59iUfefsaWm2ZIW3EnoWeyI8sRuaapGY/0LHhUAn6vcA++N kuUkliVsk+f/uTNZeJ4zv2uy8DpBXO4kTjmwPVwFz46sJ8RL8P7MOLax7e7fNssw tylwHt4qoLEoB2vg1yMvlUNFMeH85gj8hTyJMsgGtFTbwCH0kLFEoXUz0lfKMS7U A271E1Bumu3OT7FrAnxQahViv02YWG5fcg6R3OidQdSmgoQBIMJwDA2pyKLiq9FL 7mWoNfEqqBWn4O/1qBlf3jCvfFlzXRSSgVzEruoNB93cgzTaQaN5yVgeekMzwJEj NDowmIZRxEN8+lJyMxIGSOGa44aTXu0/+dtehEDeSpsDOXULFc5fpYt4SSa0Jt/F LlgnPGkM1vF0ddG5vDJpGw6B9Dhb82i1oYy2IVwOCkLOXSp2kvLDEI3sqgk5mmlH zFtAV21Zm4jqBke/aF7r+RCYRvDyQkuW0d1+H9okGWLSk7jKauM= =J43o -----END PGP SIGNATURE----- Merge tag 'sched_urgent_for_v6.14_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fix from Borislav Petkov: - Clarify what happens when a task is woken up from the wake queue and make clear its removal from that queue is atomic * tag 'sched_urgent_for_v6.14_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched: Clarify wake_up_q()'s write to task->wake_q.next	2025-02-16 10:38:24 -08:00
Linus Torvalds	04f41cbf03	sched_ext: Fixes for v6.14-rc2 ... - Fix lock imbalance in a corner case of dispatch_to_local_dsq(). - Migration disabled tasks were confusing some BPF schedulers and its handling had a bug. Fix it and simplify the default behavior by dispatching them automatically. - ops.tick(), ops.disable() and ops.exit_task() were incorrectly disallowing kfuncs that require the task argument to be the rq operation is currently operating on and thus is rq-locked. Allow them. - Fix autogroup migration handling bug which was occasionally triggering a warning in the cgroup migration path. - tools/sched_ext, selftest and other misc updates. -----BEGIN PGP SIGNATURE----- iIQEABYKACwWIQTfIjM1kS57o3GsC/uxYfJx3gVYGQUCZ695uA4cdGpAa2VybmVs Lm9yZwAKCRCxYfJx3gVYGeCfAQDmUixMNJCIrRphYsWcYUzlGLZyyRpQEEYFtRMO UC266gD+PUV2UvuO5sAVH8HVnGdOqkXaE/IRG+TC7fQH3ruPlgI= =LFd1 -----END PGP SIGNATURE----- Merge tag 'sched_ext-for-6.14-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext Pull sched_ext fixes from Tejun Heo: - Fix lock imbalance in a corner case of dispatch_to_local_dsq() - Migration disabled tasks were confusing some BPF schedulers and its handling had a bug. Fix it and simplify the default behavior by dispatching them automatically - ops.tick(), ops.disable() and ops.exit_task() were incorrectly disallowing kfuncs that require the task argument to be the rq operation is currently operating on and thus is rq-locked. Allow them. - Fix autogroup migration handling bug which was occasionally triggering a warning in the cgroup migration path - tools/sched_ext, selftest and other misc updates * tag 'sched_ext-for-6.14-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext: sched_ext: Use SCX_CALL_OP_TASK in task_tick_scx sched_ext: Fix the incorrect bpf_list kfunc API in common.bpf.h. sched_ext: selftests: Fix grammar in tests description sched_ext: Fix incorrect assumption about migration disabled tasks in task_can_run_on_remote_rq() sched_ext: Fix migration disabled handling in targeted dispatches sched_ext: Implement auto local dispatching of migration disabled tasks sched_ext: Fix incorrect time delta calculation in time_delta() sched_ext: Fix lock imbalance in dispatch_to_local_dsq() sched_ext: selftests/dsp_local_on: Fix selftest on UP systems tools/sched_ext: Add helper to check task migration state sched_ext: Fix incorrect autogroup migration detection sched_ext: selftests/dsp_local_on: Fix sporadic failures selftests/sched_ext: Fix enum resolution sched_ext: Include task weight in the error state dump sched_ext: Fixes typos in comments	2025-02-14 11:14:24 -08:00
Chuyi Zhou	f5717c93a1	sched_ext: Use SCX_CALL_OP_TASK in task_tick_scx ... Now when we use scx_bpf_task_cgroup() in ops.tick() to get the cgroup of the current task, the following error will occur: scx_foo[3795244] triggered exit kind 1024: runtime error (called on a task not being operated on) The reason is that we are using SCX_CALL_OP() instead of SCX_CALL_OP_TASK() when calling ops.tick(), which triggers the error during the subsequent scx_kf_allowed_on_arg_tasks() check. SCX_CALL_OP_TASK() was first introduced in commit 36454023f5 ("sched_ext: Track tasks that are subjects of the in-flight SCX operation") to ensure task's rq lock is held when accessing task's sched_group. Since ops.tick() is marked as SCX_KF_TERMINAL and task_tick_scx() is protected by the rq lock, we can use SCX_CALL_OP_TASK() to avoid the above issue. Similarly, the same changes should be made for ops.disable() and ops.exit_task(), as they are also protected by task_rq_lock() and it's safe to access the task's task_group. Fixes: 36454023f5 ("sched_ext: Track tasks that are subjects of the in-flight SCX operation") Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com> Signed-off-by: Tejun Heo <tj@kernel.org>	2025-02-13 06:57:33 -10:00
Tejun Heo	f3f08c3acf	sched_ext: Fix incorrect assumption about migration disabled tasks in task_can_run_on_remote_rq() ... While fixing migration disabled task handling, 3296682157 ("sched_ext: Fix migration disabled handling in targeted dispatches") assumed that a migration disabled task's ->cpus_ptr would only have the pinned CPU. While this is eventually true for migration disabled tasks that are switched out, ->cpus_ptr update is performed by migrate_disable_switch() which is called right before context_switch() in __scheduler(). However, the task is enqueued earlier during pick_next_task() via put_prev_task_scx(), so there is a race window where another CPU can see the task on a DSQ. If the CPU tries to dispatch the migration disabled task while in that window, task_allowed_on_cpu() will succeed and task_can_run_on_remote_rq() will subsequently trigger SCHED_WARN(is_migration_disabled()). WARNING: CPU: 8 PID: 1837 at kernel/sched/ext.c:2466 task_can_run_on_remote_rq+0x12e/0x140 Sched_ext: layered (enabled+all), task: runnable_at=-10ms RIP: 0010:task_can_run_on_remote_rq+0x12e/0x140 ... <TASK> consume_dispatch_q+0xab/0x220 scx_bpf_dsq_move_to_local+0x58/0xd0 bpf_prog_84dd17b0654b6cf0_layered_dispatch+0x290/0x1cfa bpf__sched_ext_ops_dispatch+0x4b/0xab balance_one+0x1fe/0x3b0 balance_scx+0x61/0x1d0 prev_balance+0x46/0xc0 __pick_next_task+0x73/0x1c0 __schedule+0x206/0x1730 schedule+0x3a/0x160 __do_sys_sched_yield+0xe/0x20 do_syscall_64+0xbb/0x1e0 entry_SYSCALL_64_after_hwframe+0x77/0x7f Fix it by converting the SCHED_WARN() back to a regular failure path. Also, perform the migration disabled test before task_allowed_on_cpu() test so that BPF schedulers which fail to handle migration disabled tasks can be noticed easily. While at it, adjust scx_ops_error() message for !task_allowed_on_cpu() case for brevity and consistency. Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: 3296682157 ("sched_ext: Fix migration disabled handling in targeted dispatches") Acked-by: Andrea Righi <arighi@nvidia.com> Reported-by: Jake Hillion <jakehillion@meta.com>	2025-02-10 10:40:47 -10:00
Tejun Heo	3296682157	sched_ext: Fix migration disabled handling in targeted dispatches ... A dispatch operation that can target a specific local DSQ - scx_bpf_dsq_move_to_local() or scx_bpf_dsq_move() - checks whether the task can be migrated to the target CPU using task_can_run_on_remote_rq(). If the task can't be migrated to the targeted CPU, it is bounced through a global DSQ. task_can_run_on_remote_rq() assumes that the task is on a CPU that's different from the targeted CPU but the callers doesn't uphold the assumption and may call the function when the task is already on the target CPU. When such task has migration disabled, task_can_run_on_remote_rq() ends up returning %false incorrectly unnecessarily bouncing the task to a global DSQ. Fix it by updating the callers to only call task_can_run_on_remote_rq() when the task is on a different CPU than the target CPU. As this is a bit subtle, for clarity and documentation: - Make task_can_run_on_remote_rq() trigger SCHED_WARN_ON() if the task is on the same CPU as the target CPU. - is_migration_disabled() test in task_can_run_on_remote_rq() cannot trigger if the task is on a different CPU than the target CPU as the preceding task_allowed_on_cpu() test should fail beforehand. Convert the test into SCHED_WARN_ON(). Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: 4c30f5ce4f ("sched_ext: Implement scx_bpf_dispatch[_vtime]_from_dsq()") Fixes: 0366017e09 ("sched_ext: Use task_can_run_on_remote_rq() test in dispatch_to_local_dsq()") Cc: stable@vger.kernel.org # v6.12+	2025-02-08 20:33:25 -10:00
Tejun Heo	2fa0fbeb69	sched_ext: Implement auto local dispatching of migration disabled tasks ... Migration disabled tasks are special and pinned to their previous CPUs. They tripped up some unsuspecting BPF schedulers as their ->nr_cpus_allowed may not agree with the bits set in ->cpus_ptr. Make it easier for BPF schedulers by automatically dispatching them to the pinned local DSQs by default. If a BPF scheduler wants to handle migration disabled tasks explicitly, it can set SCX_OPS_ENQ_MIGRATION_DISABLED. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Andrea Righi <arighi@nvidia.com>	2025-02-08 20:32:54 -10:00
Linus Torvalds	c7b92e8969	Fix a cfs_rq->h_nr_runnable accounting bug that trips up a ... defensive SCHED_WARN_ON() on certain workloads. The bug is believed to be (accidentally) self-correcting, hence no behavioral side effects are expected. Also print se.slice in debug output, since this value can now be set via the syscall ABI and can be useful to track. Signed-off-by: Ingo Molnar <mingo@kernel.org> -----BEGIN PGP SIGNATURE----- iQJFBAABCgAvFiEEBpT5eoXrXCwVQwEKEnMQ0APhK1gFAmenIcsRHG1pbmdvQGtl cm5lbC5vcmcACgkQEnMQ0APhK1iyZA//ZpzGiiZ8coXBk4PQ77c0+BOgSGdkbWeR zicKvqWd+j9skOTVrIk8MPs7D3C5uNuDuVAeNWYalBHRO7ndLfCg36pHqR8tQ3xN 2GwziJzKpi1r4WXBSCtFe/abKrMhIsMYiqKDQz3Ry2Zfn+TuY4t4bzEYgfm481mO FkLcXs97RI5sFsCBI0uhRu76A9jrNRZKW2zczHTb2MS4zjwGq1yL3vkx2M11d0Su BqrcPjz6mZFuzCrA6pW0QeSP4Mn5xL8c2seoMYnvFrPYzq47Thxm4nOWPURCN9uX 6MmqNXisJjTe00noswhbcUia1n2cr37uu5d21tXhn7Rf2XTO4+WRE7zjzvxLKQCr DtcH1XqvnChPGPFTsSlso4vbygfEZIk14DWZ71mXQJto6t06A/yjFiAR82ZIKzLA ZlK6hnX2rQ8WST3XSixiRPU/5xDu3ptJ0aDRV/dScCMzb7c0Y2YSeqA4xBMcZDPq A1TrNUsnsvH0TJXXqeslDSxxEFUKHNiOI2itzMCxAteEZXPysa8Rvcl4zFOZ5A6F nb8hDN94dydNnPpf4g+ZIVEHs5ES3Yeexh1dGwCjQSp72qAJK3wkHQ6KfPN/T3Gb PbDVw93cYJI/fhB2BX9DcnN+uNLTrqr1kfY7uFBE1feMdnQNBHILdjbByILfQAQ+ 0r7+aYwn0F0= =5mot -----END PGP SIGNATURE----- Merge tag 'sched-urgent-2025-02-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar: "Fix a cfs_rq->h_nr_runnable accounting bug that trips up a defensive SCHED_WARN_ON() on certain workloads. The bug is believed to be (accidentally) self-correcting, hence no behavioral side effects are expected. Also print se.slice in debug output, since this value can now be set via the syscall ABI and can be useful to track" * tag 'sched-urgent-2025-02-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/debug: Provide slice length for fair tasks sched/fair: Fix inaccurate h_nr_runnable accounting with delayed dequeue	2025-02-08 11:16:22 -08:00
Jann Horn	bcc6244e13	sched: Clarify wake_up_q()'s write to task->wake_q.next ... Clarify that wake_up_q() does an atomic write to task->wake_q.next, after which a concurrent __wake_q_add() can immediately overwrite task->wake_q.next again. Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20250129-sched-wakeup-prettier-v1-1-2f51f5f663fa@google.com	2025-02-08 15:43:12 +01:00
Christian Loehle	9065ce6975	sched/debug: Provide slice length for fair tasks ... Since commit: 857b158dc5 ("sched/eevdf: Use sched_attr::sched_runtime to set request/slice suggestion") ... we have the userspace per-task tunable slice length, which is a key parameter that is otherwise difficult to obtain, so provide it in /proc/$PID/sched. [ mingo: Clarified the changelog. ] Signed-off-by: Christian Loehle <christian.loehle@arm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/453349b1-1637-42f5-a7b2-2385392b5956@arm.com	2025-01-31 10:45:33 +01:00
Linus Torvalds	f55b0671e3	More power management updates for 6.14-rc1 ... - Add missing error handling for syscore_suspend() to the hibernation core code (Wentao Liang). - Revert a commit that added unused macros (Andy Shevchenko). - Synchronize the runtime PM status of devices that were runtime- suspended before a system-wide suspend and need to be resumed during the subsequent system-wide resume transition (Rafael Wysocki). - Clean up the teo cpuidle governor and make the handling of short idle intervals in it consistent regardless of the properties of idle states supplied by the cpuidle driver (Rafael Wysocki). - Fix some boost-related issues in cpufreq (Lifeng Zheng). - Fix build issues in the s3c64xx and airoha cpufreq drivers (Viresh Kumar). - Remove unconditional binding of schedutil governor kthreads to the affected CPUs if the cpufreq driver indicates that updates can happen from any CPU (Christian Loehle). -----BEGIN PGP SIGNATURE----- iQJGBAABCAAwFiEE4fcc61cGeeHD/fCwgsRv/nhiVHEFAmeb5xYSHHJqd0Byand5 c29ja2kubmV0AAoJEILEb/54YlRxcFsP/2FIoEI2G6J7pk8zChWT225qkkaieh5P tHIkcFINlgzyjLnqmyWELUdt+sB7re6/dMmoLor+abudHimvBvUfAj6Oiz1F3p2F utE9TpfhOkXi1ci5zBl9h6+iDj2Z5op3Qe/qw/W3DTlcManAD+6r60A2tOEy0jhi GTbp2SEEU28+LU/2J59IfxEuRTTH4pbQGXi+iKv/k9bmtLvQofa1saXyQCBSZrvO z3MBdqnAxLeZCg/qILmEGsBvbv1wpugvp3yoMLVwGNyul12Augcs8PreQz7e5tFq spEuCfpBJwyJLAGlOnjOYgsPbJBXWRkIBeLH7JealfZr9TX0y4LZSAHi/xe0Asd3 BBZLLDojxhYMLzmqSkuafHlQd5J7jKl++RS1A9Qm6aqglKjeSOC9Ca9fmrc9Ub9P Jpf1SVJ3kJsv1Z7wuUcaj6oLxD8wlAgCo5pigNgWTP2HllhP2bmc22M8JWxpAz+m nMeW8nr8bAu4XViZeb74YKGgUDngO/uKRwBpthSkE2fqM7q0Wr5E7G0u9M91mzG6 nd/XDwta5TeznMQpSy339NgT61i4HHfyc/SDIdpkBxI0C5l6jknNawq79i9gy7/E In4MyooOlls/iX/JR0uxx2hXEByltF0IHqwsRYeJ6dmIajYgASXR1Hhh5Iy9fPJ/ JTJ7vR5oZPB/ =EgsM -----END PGP SIGNATURE----- Merge tag 'pm-6.14-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull more power management updates from Rafael Wysocki: "These are mostly fixes on top of the previously merged power management material with the addition of some teo cpuidle governor updates, some of which may also be regarded as fixes: - Add missing error handling for syscore_suspend() to the hibernation core code (Wentao Liang) - Revert a commit that added unused macros (Andy Shevchenko) - Synchronize the runtime PM status of devices that were runtime- suspended before a system-wide suspend and need to be resumed during the subsequent system-wide resume transition (Rafael Wysocki) - Clean up the teo cpuidle governor and make the handling of short idle intervals in it consistent regardless of the properties of idle states supplied by the cpuidle driver (Rafael Wysocki) - Fix some boost-related issues in cpufreq (Lifeng Zheng) - Fix build issues in the s3c64xx and airoha cpufreq drivers (Viresh Kumar) - Remove unconditional binding of schedutil governor kthreads to the affected CPUs if the cpufreq driver indicates that updates can happen from any CPU (Christian Loehle)" * tag 'pm-6.14-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: PM: sleep: core: Synchronize runtime PM status of parents and children cpufreq: airoha: Depends on OF PM: Revert "Add EXPORT macros for exporting PM functions" PM: hibernate: Add error handling for syscore_suspend() cpufreq/schedutil: Only bind threads if needed cpufreq: ACPI: Remove set_boost in acpi_cpufreq_cpu_init() cpufreq: CPPC: Fix wrong max_freq in policy initialization cpufreq: Introduce a more generic way to set default per-policy boost flag cpufreq: Fix re-boost issue after hotplugging a CPU cpufreq: s3c64xx: Fix compilation warning cpuidle: teo: Skip sleep length computation for low latency constraints cpuidle: teo: Replace time_span_ns with a flag cpuidle: teo: Simplify handling of total events count cpuidle: teo: Skip getting the sleep length if wakeups are very frequent cpuidle: teo: Simplify counting events used for tick management cpuidle: teo: Clarify two code comments cpuidle: teo: Drop local variable prev_intercept_idx cpuidle: teo: Combine candidate state index checks against 0 cpuidle: teo: Reorder candidate state index checks cpuidle: teo: Rearrange idle state lookup code	2025-01-30 15:10:34 -08:00
Joel Granados	1751f872cc	treewide: const qualify ctl_tables where applicable ... Add the const qualifier to all the ctl_tables in the tree except for watchdog_hardlockup_sysctl, memory_allocation_profiling_sysctls, loadpin_sysctl_table and the ones calling register_net_sysctl (./net, drivers/inifiniband dirs). These are special cases as they use a registration function with a non-const qualified ctl_table argument or modify the arrays before passing them on to the registration function. Constifying ctl_table structs will prevent the modification of proc_handler function pointers as the arrays would reside in .rodata. This is made possible after commit 78eb4ea25c ("sysctl: treewide: constify the ctl_table argument of proc_handlers") constified all the proc_handlers. Created this by running an spatch followed by a sed command: Spatch: virtual patch @ depends on !(file in "net") disable optional_qualifier @ identifier table_name != { watchdog_hardlockup_sysctl, iwcm_ctl_table, ucma_ctl_table, memory_allocation_profiling_sysctls, loadpin_sysctl_table }; @@ + const struct ctl_table table_name [] = { ... }; sed: sed --in-place \ -e "s/struct ctl_table .table = &uts_kern/const struct ctl_table *table = \&uts_kern/" \ kernel/utsname_sysctl.c Reviewed-by: Song Liu <song@kernel.org> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> # for kernel/trace/ Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> # SCSI Reviewed-by: Darrick J. Wong <djwong@kernel.org> # xfs Acked-by: Jani Nikula <jani.nikula@intel.com> Acked-by: Corey Minyard <cminyard@mvista.com> Acked-by: Wei Liu <wei.liu@kernel.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Bill O'Donnell <bodonnel@redhat.com> Acked-by: Baoquan He <bhe@redhat.com> Acked-by: Ashutosh Dixit <ashutosh.dixit@intel.com> Acked-by: Anna Schumaker <anna.schumaker@oracle.com> Signed-off-by: Joel Granados <joel.granados@kernel.org>	2025-01-28 13:48:37 +01:00
Andrea Righi	1626e5ef0b	sched_ext: Fix lock imbalance in dispatch_to_local_dsq() ... While performing the rq locking dance in dispatch_to_local_dsq(), we may trigger the following lock imbalance condition, in particular when multiple tasks are rapidly changing CPU affinity (i.e., running a `stress-ng --race-sched 0`): [ 13.413579] ===================================== [ 13.413660] WARNING: bad unlock balance detected! [ 13.413729] 6.13.0-virtme #15 Not tainted [ 13.413792] ------------------------------------- [ 13.413859] kworker/1:1/80 is trying to release lock (&rq->__lock) at: [ 13.413954] [<ffffffff873c6c48>] dispatch_to_local_dsq+0x108/0x1a0 [ 13.414111] but there are no more locks to release! [ 13.414176] [ 13.414176] other info that might help us debug this: [ 13.414258] 1 lock held by kworker/1:1/80: [ 13.414318] #0: ffff8b66feb41698 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x20/0x90 [ 13.414612] [ 13.414612] stack backtrace: [ 13.415255] CPU: 1 UID: 0 PID: 80 Comm: kworker/1:1 Not tainted 6.13.0-virtme #15 [ 13.415505] Workqueue: 0x0 (events) [ 13.415567] Sched_ext: dsp_local_on (enabled+all), task: runnable_at=-2ms [ 13.415570] Call Trace: [ 13.415700] <TASK> [ 13.415744] dump_stack_lvl+0x78/0xe0 [ 13.415806] ? dispatch_to_local_dsq+0x108/0x1a0 [ 13.415884] print_unlock_imbalance_bug+0x11b/0x130 [ 13.415965] ? dispatch_to_local_dsq+0x108/0x1a0 [ 13.416226] lock_release+0x231/0x2c0 [ 13.416326] _raw_spin_unlock+0x1b/0x40 [ 13.416422] dispatch_to_local_dsq+0x108/0x1a0 [ 13.416554] flush_dispatch_buf+0x199/0x1d0 [ 13.416652] balance_one+0x194/0x370 [ 13.416751] balance_scx+0x61/0x1e0 [ 13.416848] prev_balance+0x43/0xb0 [ 13.416947] __pick_next_task+0x6b/0x1b0 [ 13.417052] __schedule+0x20d/0x1740 This happens because dispatch_to_local_dsq() is racing with dispatch_dequeue() and, when the latter wins, we incorrectly assume that the task has been moved to dst_rq. Fix by properly tracking the currently locked rq. Fixes: 4d3ca89bdd ("sched_ext: Refactor consume_remote_task()") Signed-off-by: Andrea Righi <arighi@nvidia.com> Signed-off-by: Tejun Heo <tj@kernel.org>	2025-01-27 12:41:12 -10:00
Tejun Heo	d6f3e7d564	sched_ext: Fix incorrect autogroup migration detection ... scx_move_task() is called from sched_move_task() and tells the BPF scheduler that cgroup migration is being committed. sched_move_task() is used by both cgroup and autogroup migrations and scx_move_task() tried to filter out autogroup migrations by testing the destination cgroup and PF_EXITING but this is not enough. In fact, without explicitly tagging the thread which is doing the cgroup migration, there is no good way to tell apart scx_move_task() invocations for racing migration to the root cgroup and an autogroup migration. This led to scx_move_task() incorrectly ignoring a migration from non-root cgroup to an autogroup of the root cgroup triggering the following warning: WARNING: CPU: 7 PID: 1 at kernel/sched/ext.c:3725 scx_cgroup_can_attach+0x196/0x340 ... Call Trace: <TASK> cgroup_migrate_execute+0x5b1/0x700 cgroup_attach_task+0x296/0x400 __cgroup_procs_write+0x128/0x140 cgroup_procs_write+0x17/0x30 kernfs_fop_write_iter+0x141/0x1f0 vfs_write+0x31d/0x4a0 __x64_sys_write+0x72/0xf0 do_syscall_64+0x82/0x160 entry_SYSCALL_64_after_hwframe+0x76/0x7e Fix it by adding an argument to sched_move_task() that indicates whether the moving is for a cgroup or autogroup migration. After the change, scx_move_task() is called only for cgroup migrations and renamed to scx_cgroup_move_task(). Link: https://github.com/sched-ext/scx/issues/370 Fixes: 8195136669 ("sched_ext: Add cgroup support") Cc: stable@vger.kernel.org # v6.12+ Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Tejun Heo <tj@kernel.org>	2025-01-27 08:31:50 -10:00
Linus Torvalds	9c5968db9e	The various patchsets are summarized below. Plus of course many ... indivudual patches which are described in their changelogs. - "Allocate and free frozen pages" from Matthew Wilcox reorganizes the page allocator so we end up with the ability to allocate and free zero-refcount pages. So that callers (ie, slab) can avoid a refcount inc & dec. - "Support large folios for tmpfs" from Baolin Wang teaches tmpfs to use large folios other than PMD-sized ones. - "Fix mm/rodata_test" from Petr Tesarik performs some maintenance and fixes for this small built-in kernel selftest. - "mas_anode_descend() related cleanup" from Wei Yang tidies up part of the mapletree code. - "mm: fix format issues and param types" from Keren Sun implements a few minor code cleanups. - "simplify split calculation" from Wei Yang provides a few fixes and a test for the mapletree code. - "mm/vma: make more mmap logic userland testable" from Lorenzo Stoakes continues the work of moving vma-related code into the (relatively) new mm/vma.c. - "mm/page_alloc: gfp flags cleanups for alloc_contig_*()" from David Hildenbrand cleans up and rationalizes handling of gfp flags in the page allocator. - "readahead: Reintroduce fix for improper RA window sizing" from Jan Kara is a second attempt at fixing a readahead window sizing issue. It should reduce the amount of unnecessary reading. - "synchronously scan and reclaim empty user PTE pages" from Qi Zheng addresses an issue where "huge" amounts of pte pagetables are accumulated (https://lore.kernel.org/lkml/cover.1718267194.git.zhengqi.arch@bytedance.com/). Qi's series addresses this windup by synchronously freeing PTE memory within the context of madvise(MADV_DONTNEED). - "selftest/mm: Remove warnings found by adding compiler flags" from Muhammad Usama Anjum fixes some build warnings in the selftests code when optional compiler warnings are enabled. - "mm: don't use __GFP_HARDWALL when migrating remote pages" from David Hildenbrand tightens the allocator's observance of __GFP_HARDWALL. - "pkeys kselftests improvements" from Kevin Brodsky implements various fixes and cleanups in the MM selftests code, mainly pertaining to the pkeys tests. - "mm/damon: add sample modules" from SeongJae Park enhances DAMON to estimate application working set size. - "memcg/hugetlb: Rework memcg hugetlb charging" from Joshua Hahn provides some cleanups to memcg's hugetlb charging logic. - "mm/swap_cgroup: remove global swap cgroup lock" from Kairui Song removes the global swap cgroup lock. A speedup of 10% for a tmpfs-based kernel build was demonstrated. - "zram: split page type read/write handling" from Sergey Senozhatsky has several fixes and cleaups for zram in the area of zram_write_page(). A watchdog softlockup warning was eliminated. - "move pagetable_*_dtor() to __tlb_remove_table()" from Kevin Brodsky cleans up the pagetable destructor implementations. A rare use-after-free race is fixed. - "mm/debug: introduce and use VM_WARN_ON_VMG()" from Lorenzo Stoakes simplifies and cleans up the debugging code in the VMA merging logic. - "Account page tables at all levels" from Kevin Brodsky cleans up and regularizes the pagetable ctor/dtor handling. This results in improvements in accounting accuracy. - "mm/damon: replace most damon_callback usages in sysfs with new core functions" from SeongJae Park cleans up and generalizes DAMON's sysfs file interface logic. - "mm/damon: enable page level properties based monitoring" from SeongJae Park increases the amount of information which is presented in response to DAMOS actions. - "mm/damon: remove DAMON debugfs interface" from SeongJae Park removes DAMON's long-deprecated debugfs interfaces. Thus the migration to sysfs is completed. - "mm/hugetlb: Refactor hugetlb allocation resv accounting" from Peter Xu cleans up and generalizes the hugetlb reservation accounting. - "mm: alloc_pages_bulk: small API refactor" from Luiz Capitulino removes a never-used feature of the alloc_pages_bulk() interface. - "mm/damon: extend DAMOS filters for inclusion" from SeongJae Park extends DAMOS filters to support not only exclusion (rejecting), but also inclusion (allowing) behavior. - "Add zpdesc memory descriptor for zswap.zpool" from Alex Shi "introduces a new memory descriptor for zswap.zpool that currently overlaps with struct page for now. This is part of the effort to reduce the size of struct page and to enable dynamic allocation of memory descriptors." - "mm, swap: rework of swap allocator locks" from Kairui Song redoes and simplifies the swap allocator locking. A speedup of 400% was demonstrated for one workload. As was a 35% reduction for kernel build time with swap-on-zram. - "mm: update mips to use do_mmap(), make mmap_region() internal" from Lorenzo Stoakes reworks MIPS's use of mmap_region() so that mmap_region() can be made MM-internal. - "mm/mglru: performance optimizations" from Yu Zhao fixes a few MGLRU regressions and otherwise improves MGLRU performance. - "Docs/mm/damon: add tuning guide and misc updates" from SeongJae Park updates DAMON documentation. - "Cleanup for memfd_create()" from Isaac Manjarres does that thing. - "mm: hugetlb+THP folio and migration cleanups" from David Hildenbrand provides various cleanups in the areas of hugetlb folios, THP folios and migration. - "Uncached buffered IO" from Jens Axboe implements the new RWF_DONTCACHE flag which provides synchronous dropbehind for pagecache reading and writing. To permite userspace to address issues with massive buildup of useless pagecache when reading/writing fast devices. - "selftests/mm: virtual_address_range: Reduce memory" from Thomas Weißschuh fixes and optimizes some of the MM selftests. -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCZ5a+cwAKCRDdBJ7gKXxA jtoyAP9R58oaOKPJuTizEKKXvh/RpMyD6sYcz/uPpnf+cKTZxQEAqfVznfWlw/Lz uC3KRZYhmd5YrxU4o+qjbzp9XWX/xAE= =Ib2s -----END PGP SIGNATURE----- Merge tag 'mm-stable-2025-01-26-14-59' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: "The various patchsets are summarized below. Plus of course many indivudual patches which are described in their changelogs. - "Allocate and free frozen pages" from Matthew Wilcox reorganizes the page allocator so we end up with the ability to allocate and free zero-refcount pages. So that callers (ie, slab) can avoid a refcount inc & dec - "Support large folios for tmpfs" from Baolin Wang teaches tmpfs to use large folios other than PMD-sized ones - "Fix mm/rodata_test" from Petr Tesarik performs some maintenance and fixes for this small built-in kernel selftest - "mas_anode_descend() related cleanup" from Wei Yang tidies up part of the mapletree code - "mm: fix format issues and param types" from Keren Sun implements a few minor code cleanups - "simplify split calculation" from Wei Yang provides a few fixes and a test for the mapletree code - "mm/vma: make more mmap logic userland testable" from Lorenzo Stoakes continues the work of moving vma-related code into the (relatively) new mm/vma.c - "mm/page_alloc: gfp flags cleanups for alloc_contig_*()" from David Hildenbrand cleans up and rationalizes handling of gfp flags in the page allocator - "readahead: Reintroduce fix for improper RA window sizing" from Jan Kara is a second attempt at fixing a readahead window sizing issue. It should reduce the amount of unnecessary reading - "synchronously scan and reclaim empty user PTE pages" from Qi Zheng addresses an issue where "huge" amounts of pte pagetables are accumulated: https://lore.kernel.org/lkml/cover.1718267194.git.zhengqi.arch@bytedance.com/ Qi's series addresses this windup by synchronously freeing PTE memory within the context of madvise(MADV_DONTNEED) - "selftest/mm: Remove warnings found by adding compiler flags" from Muhammad Usama Anjum fixes some build warnings in the selftests code when optional compiler warnings are enabled - "mm: don't use __GFP_HARDWALL when migrating remote pages" from David Hildenbrand tightens the allocator's observance of __GFP_HARDWALL - "pkeys kselftests improvements" from Kevin Brodsky implements various fixes and cleanups in the MM selftests code, mainly pertaining to the pkeys tests - "mm/damon: add sample modules" from SeongJae Park enhances DAMON to estimate application working set size - "memcg/hugetlb: Rework memcg hugetlb charging" from Joshua Hahn provides some cleanups to memcg's hugetlb charging logic - "mm/swap_cgroup: remove global swap cgroup lock" from Kairui Song removes the global swap cgroup lock. A speedup of 10% for a tmpfs-based kernel build was demonstrated - "zram: split page type read/write handling" from Sergey Senozhatsky has several fixes and cleaups for zram in the area of zram_write_page(). A watchdog softlockup warning was eliminated - "move pagetable_*_dtor() to __tlb_remove_table()" from Kevin Brodsky cleans up the pagetable destructor implementations. A rare use-after-free race is fixed - "mm/debug: introduce and use VM_WARN_ON_VMG()" from Lorenzo Stoakes simplifies and cleans up the debugging code in the VMA merging logic - "Account page tables at all levels" from Kevin Brodsky cleans up and regularizes the pagetable ctor/dtor handling. This results in improvements in accounting accuracy - "mm/damon: replace most damon_callback usages in sysfs with new core functions" from SeongJae Park cleans up and generalizes DAMON's sysfs file interface logic - "mm/damon: enable page level properties based monitoring" from SeongJae Park increases the amount of information which is presented in response to DAMOS actions - "mm/damon: remove DAMON debugfs interface" from SeongJae Park removes DAMON's long-deprecated debugfs interfaces. Thus the migration to sysfs is completed - "mm/hugetlb: Refactor hugetlb allocation resv accounting" from Peter Xu cleans up and generalizes the hugetlb reservation accounting - "mm: alloc_pages_bulk: small API refactor" from Luiz Capitulino removes a never-used feature of the alloc_pages_bulk() interface - "mm/damon: extend DAMOS filters for inclusion" from SeongJae Park extends DAMOS filters to support not only exclusion (rejecting), but also inclusion (allowing) behavior - "Add zpdesc memory descriptor for zswap.zpool" from Alex Shi introduces a new memory descriptor for zswap.zpool that currently overlaps with struct page for now. This is part of the effort to reduce the size of struct page and to enable dynamic allocation of memory descriptors - "mm, swap: rework of swap allocator locks" from Kairui Song redoes and simplifies the swap allocator locking. A speedup of 400% was demonstrated for one workload. As was a 35% reduction for kernel build time with swap-on-zram - "mm: update mips to use do_mmap(), make mmap_region() internal" from Lorenzo Stoakes reworks MIPS's use of mmap_region() so that mmap_region() can be made MM-internal - "mm/mglru: performance optimizations" from Yu Zhao fixes a few MGLRU regressions and otherwise improves MGLRU performance - "Docs/mm/damon: add tuning guide and misc updates" from SeongJae Park updates DAMON documentation - "Cleanup for memfd_create()" from Isaac Manjarres does that thing - "mm: hugetlb+THP folio and migration cleanups" from David Hildenbrand provides various cleanups in the areas of hugetlb folios, THP folios and migration - "Uncached buffered IO" from Jens Axboe implements the new RWF_DONTCACHE flag which provides synchronous dropbehind for pagecache reading and writing. To permite userspace to address issues with massive buildup of useless pagecache when reading/writing fast devices - "selftests/mm: virtual_address_range: Reduce memory" from Thomas Weißschuh fixes and optimizes some of the MM selftests" * tag 'mm-stable-2025-01-26-14-59' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (321 commits) mm/compaction: fix UBSAN shift-out-of-bounds warning s390/mm: add missing ctor/dtor on page table upgrade kasan: sw_tags: use str_on_off() helper in kasan_init_sw_tags() tools: add VM_WARN_ON_VMG definition mm/damon/core: use str_high_low() helper in damos_wmark_wait_us() seqlock: add missing parameter documentation for raw_seqcount_try_begin() mm/page-writeback: consolidate wb_thresh bumping logic into __wb_calc_thresh mm/page_alloc: remove the incorrect and misleading comment zram: remove zcomp_stream_put() from write_incompressible_page() mm: separate move/undo parts from migrate_pages_batch() mm/kfence: use str_write_read() helper in get_access_type() selftests/mm/mkdirty: fix memory leak in test_uffdio_copy() kasan: hw_tags: Use str_on_off() helper in kasan_init_hw_tags() selftests/mm: virtual_address_range: avoid reading from VM_IO mappings selftests/mm: vm_util: split up /proc/self/smaps parsing selftests/mm: virtual_address_range: unmap chunks after validation selftests/mm: virtual_address_range: mmap() without PROT_WRITE selftests/memfd/memfd_test: fix possible NULL pointer dereference mm: add FGP_DONTCACHE folio creation flag mm: call filemap_fdatawrite_range_kick() after IOCB_DONTCACHE issue ...	2025-01-26 18:36:23 -08:00
Linus Torvalds	c159dfbdd4	Mainly individually changelogged singleton patches. The patch series in ... this pull are: - "lib min_heap: Improve min_heap safety, testing, and documentation" from Kuan-Wei Chiu provides various tightenings to the min_heap library code. - "xarray: extract __xa_cmpxchg_raw" from Tamir Duberstein preforms some cleanup and Rust preparation in the xarray library code. - "Update reference to include/asm-<arch>" from Geert Uytterhoeven fixes pathnames in some code comments. - "Converge on using secs_to_jiffies()" from Easwar Hariharan uses the new secs_to_jiffies() in various places where that is appropriate. - "ocfs2, dlmfs: convert to the new mount API" from Eric Sandeen switches two filesystems to the new mount API. - "Convert ocfs2 to use folios" from Matthew Wilcox does that. - "Remove get_task_comm() and print task comm directly" from Yafang Shao removes now-unneeded calls to get_task_comm() in various places. - "squashfs: reduce memory usage and update docs" from Phillip Lougher implements some memory savings in squashfs and performs some maintainability work. - "lib: clarify comparison function requirements" from Kuan-Wei Chiu tightens the sort code's behaviour and adds some maintenance work. - "nilfs2: protect busy buffer heads from being force-cleared" from Ryusuke Konishi fixes an issues in nlifs when the fs is presented with a corrupted image. - "nilfs2: fix kernel-doc comments for function return values" from Ryusuke Konishi fixes some nilfs kerneldoc. - "nilfs2: fix issues with rename operations" from Ryusuke Konishi addresses some nilfs BUG_ONs which syzbot was able to trigger. - "minmax.h: Cleanups and minor optimisations" from David Laight does some maintenance work on the min/max library code. - "Fixes and cleanups to xarray" from Kemeng Shi does maintenance work on the xarray library code. -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCZ5SP5QAKCRDdBJ7gKXxA jqN7AQChvwXGG43n4d5SDiA/rH7ddvowQcDqhC9cAMJ1ReR7qwEA8/LIWDE4PdMX mJnaZ1/ibpEpearrChCViApQtcyEGQI= =ti4E -----END PGP SIGNATURE----- Merge tag 'mm-nonmm-stable-2025-01-24-23-16' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull non-MM updates from Andrew Morton: "Mainly individually changelogged singleton patches. The patch series in this pull are: - "lib min_heap: Improve min_heap safety, testing, and documentation" from Kuan-Wei Chiu provides various tightenings to the min_heap library code - "xarray: extract __xa_cmpxchg_raw" from Tamir Duberstein preforms some cleanup and Rust preparation in the xarray library code - "Update reference to include/asm-<arch>" from Geert Uytterhoeven fixes pathnames in some code comments - "Converge on using secs_to_jiffies()" from Easwar Hariharan uses the new secs_to_jiffies() in various places where that is appropriate - "ocfs2, dlmfs: convert to the new mount API" from Eric Sandeen switches two filesystems to the new mount API - "Convert ocfs2 to use folios" from Matthew Wilcox does that - "Remove get_task_comm() and print task comm directly" from Yafang Shao removes now-unneeded calls to get_task_comm() in various places - "squashfs: reduce memory usage and update docs" from Phillip Lougher implements some memory savings in squashfs and performs some maintainability work - "lib: clarify comparison function requirements" from Kuan-Wei Chiu tightens the sort code's behaviour and adds some maintenance work - "nilfs2: protect busy buffer heads from being force-cleared" from Ryusuke Konishi fixes an issues in nlifs when the fs is presented with a corrupted image - "nilfs2: fix kernel-doc comments for function return values" from Ryusuke Konishi fixes some nilfs kerneldoc - "nilfs2: fix issues with rename operations" from Ryusuke Konishi addresses some nilfs BUG_ONs which syzbot was able to trigger - "minmax.h: Cleanups and minor optimisations" from David Laight does some maintenance work on the min/max library code - "Fixes and cleanups to xarray" from Kemeng Shi does maintenance work on the xarray library code" * tag 'mm-nonmm-stable-2025-01-24-23-16' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (131 commits) ocfs2: use str_yes_no() and str_no_yes() helper functions include/linux/lz4.h: add some missing macros Xarray: use xa_mark_t in xas_squash_marks() to keep code consistent Xarray: remove repeat check in xas_squash_marks() Xarray: distinguish large entries correctly in xas_split_alloc() Xarray: move forward index correctly in xas_pause() Xarray: do not return sibling entries from xas_find_marked() ipc/util.c: complete the kernel-doc function descriptions gcov: clang: use correct function param names latencytop: use correct kernel-doc format for func params minmax.h: remove some #defines that are only expanded once minmax.h: simplify the variants of clamp() minmax.h: move all the clamp() definitions after the min/max() ones minmax.h: use BUILD_BUG_ON_MSG() for the lo < hi test in clamp() minmax.h: reduce the #define expansion of min(), max() and clamp() minmax.h: update some comments minmax.h: add whitespace around operators and after commas nilfs2: do not update mtime of renamed directory that is not moved nilfs2: handle errors that nilfs_prepare_chunk() may return CREDITS: fix spelling mistake ...	2025-01-26 17:50:53 -08:00
Oxana Kharitonova	65ef17aa07	hung_task: add task->flags, blocked by coredump to log ... Resending this patch as I haven't received feedback on my initial submission https://lore.kernel.org/all/20241204182953.10854-1-oxana@cloudflare.com/ For the processes which are terminated abnormally the kernel can provide a coredump if enabled. When the coredump is performed, the process and all its threads are put into the D state (TASK_UNINTERRUPTIBLE | TASK_FREEZABLE). On the other hand, we have kernel thread khungtaskd which monitors the processes in the D state. If the task stuck in the D state more than kernel.hung_task_timeout_secs, the hung_task alert appears in the kernel log. The higher memory usage of a process, the longer it takes to create coredump, the longer tasks are in the D state. We have hung_task alerts for the processes with memory usage above 10Gb. Although, our kernel.hung_task_timeout_secs is 10 sec when the default is 120 sec. Adding additional information to the log that the task is blocked by coredump will help with monitoring. Another approach might be to completely filter out alerts for such tasks, but in that case we would lose transparency about what is putting pressure on some system resources, e.g. we saw an increase in I/O when coredump occurs due its writing to disk. Additionally, it would be helpful to have task_struct->flags in the log from the function sched_show_task(). Currently it prints task_struct->thread_info->flags, this seems misleading as the line starts with "task:xxxx". [akpm@linux-foundation.org: fix printk control string] Link: https://lkml.kernel.org/r/20250110160328.64947-1-oxana@cloudflare.com Signed-off-by: Oxana Kharitonova <oxana@cloudflare.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Ben Segall <bsegall@google.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>	2025-01-24 22:47:24 -08:00
Andrea Righi	2279563e3a	sched_ext: Include task weight in the error state dump ... Report the task weight when dumping the task state during an error exit. Moreover, adjust the output format to display dsq_vtime, slice, and weight on the same line. This can help identify whether certain tasks were excessively prioritized or de-prioritized due to large niceness gaps. Signed-off-by: Andrea Righi <arighi@nvidia.com> Signed-off-by: Tejun Heo <tj@kernel.org>	2025-01-24 08:07:42 -10:00
Atul Kumar Pant	be8ee18152	sched_ext: Fixes typos in comments ... Fixes some spelling errors in the comments. Signed-off-by: Atul Kumar Pant <atulpant.linux@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>	2025-01-24 08:06:05 -10:00
Linus Torvalds	bc8198dc7e	sched_ext: Changes for v6.14 ... - scx_bpf_now() added so that BPF scheduler can access the cached timestamp in struct rq to avoid reading TSC multiple times within a locked scheduling operation. - Minor updates to the built-in idle CPU selection logic. - tool/sched_ext updates and other misc changes. Pulling sched_ext/for-6.14 into master causes a merge conflict between the following two commits (first commit in master, second in for-6.14): a2a3374c47 sched_ext: idle: Refresh idle masks during idle-to-idle transitions 9cf9aceed2 sched_ext: idle: use assign_cpu() to update the idle cpumask static void update_builtin_idle(int cpu, bool idle) { <<<<<<< HEAD if (idle) cpumask_set_cpu(cpu, idle_masks.cpu); else cpumask_clear_cpu(cpu, idle_masks.cpu); ======= int cpu = cpu_of(rq); if (SCX_HAS_OP(update_idle) && !scx_rq_bypassing(rq)) { SCX_CALL_OP(SCX_KF_REST, update_idle, cpu_of(rq), idle); if (!static_branch_unlikely(&scx_builtin_idle_enabled)) return; } assign_cpu(cpu, idle_masks.cpu, idle); >>>>>>> 987ce79b52 The first commit factored out update_builtin_idle() and the second replaced cpumask_set/clear_cpu() calls with assign_cpu(). The conflict can be resolved by taking the code from the first and then replacing the cpumask_set/clear_cpu() calls with assign_cpu(): static void update_builtin_idle(int cpu, bool idle) { assign_cpu(cpu, idle_masks.cpu, idle); -----BEGIN PGP SIGNATURE----- iIQEABYKACwWIQTfIjM1kS57o3GsC/uxYfJx3gVYGQUCZ4/yjw4cdGpAa2VybmVs Lm9yZwAKCRCxYfJx3gVYGc/3AQChJ2zxBLMtQOfNVWgqhAyatCnFquMncl/IeGAs Sf4eawD/QHNWYBPx0nOFQS8RZNmUcXuEDeHMy+1MvTUaIDL5MQM= =6t0t -----END PGP SIGNATURE----- Merge tag 'sched_ext-for-6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext Pull sched_ext updates from Tejun Heo: - scx_bpf_now() added so that BPF scheduler can access the cached timestamp in struct rq to avoid reading TSC multiple times within a locked scheduling operation. - Minor updates to the built-in idle CPU selection logic. - tool/sched_ext updates and other misc changes. * tag 'sched_ext-for-6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext: sched_ext: fix kernel-doc warnings sched_ext: Use time helpers in BPF schedulers sched_ext: Replace bpf_ktime_get_ns() to scx_bpf_now() sched_ext: Add time helpers for BPF schedulers sched_ext: Add scx_bpf_now() for BPF scheduler sched_ext: Implement scx_bpf_now() sched_ext: Relocate scx_enabled() related code sched_ext: Add option -l in selftest runner to list all available tests sched_ext: Include remaining task time slice in error state dump sched_ext: update scx_bpf_dsq_insert() doc for SCX_DSQ_LOCAL_ON sched_ext: idle: small CPU iteration refactoring sched_ext: idle: introduce check_builtin_idle_enabled() helper sched_ext: idle: clarify comments sched_ext: idle: use assign_cpu() to update the idle cpumask sched_ext: Use str_enabled_disabled() helper in update_selcpu_topology() sched_ext: Use sizeof_field for key_len in dsq_hash_params tools/sched_ext: Receive updates from SCX repo sched_ext: Use the NUMA scheduling domain for NUMA optimizations	2025-01-23 18:49:43 -08:00
Christian Loehle	93940fbdc4	cpufreq/schedutil: Only bind threads if needed ... Remove the unconditional binding of sugov kthreads to the affected CPUs if the cpufreq driver indicates that updates can happen from any CPU. This allows userspace to set affinities to either save power (waking up bigger CPUs on HMP can be expensive) or increasing performance (by letting the utilized CPUs run without preemption of the sugov kthread). Signed-off-by: Christian Loehle <christian.loehle@arm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Vincent Guittot <vincent.guittot@linaro.org> Acked-by: Rafael J. Wysocki <rafael@kernel.org> Acked-by: Juri Lelli <juri.lelli@redhat.com> Link: https://patch.msgid.link/5a8deed4-7764-4729-a9d4-9520c25fa7e8@arm.com Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>	2025-01-23 21:09:25 +01:00
Linus Torvalds	f4b9d3bf44	Power management updates for 6.14-rc1 ... - Use str_enable_disable()-like helpers in cpufreq (Krzysztof Kozlowski). - Extend the Apple cpufreq driver to support more SoCs (Hector Martin, Nick Chan). - Add new cpufreq driver for Airoha SoCs (Christian Marangi). - Fix using cpufreq-dt as module (Andreas Kemnade). - Minor fixes for Sparc, SCMI, and Qcom cpufreq drivers (Ethan Carter Edwards, Sibi Sankar, Manivannan Sadhasivam). - Fix the maximum supported frequency computation in the ACPI cpufreq driver to avoid relying on unfounded assumptions (Gautham Shenoy). - Fix an amd-pstate driver regression with preferred core rankings not being used (Mario Limonciello). - Fix a precision issue with frequency calculation in the amd-pstate driver (Naresh Solanki). - Add ftrace event to the amd-pstate driver for active mode (Mario Limonciello). - Set default EPP policy on Ryzen processors in amd-pstate (Mario Limonciello). - Clean up the amd-pstate cpufreq driver and optimize it to increase code reuse (Mario Limonciello, Dhananjay Ugwekar). - Use CPPC to get scaling factors between HWP performance levels and frequency in the intel_pstate driver and make it stop using a built -in scaling factor for Arrow Lake processors (Rafael Wysocki). - Make intel_pstate initialize epp_policy to CPUFREQ_POLICY_UNKNOWN for consistency with CPU offline (Christian Loehle). - Fix superfluous updates caused by need_freq_update in the schedutil cpufreq governor (Sultan Alsawaf). - Allow configuring the system suspend-resume (DPM) watchdog to warn earlier than panic (Douglas Anderson). - Implement devm_device_init_wakeup() helper and introduce a device- managed variant of dev_pm_set_wake_irq() (Joe Hattori, Peng Fan). - Remove direct inclusions of 'pm_wakeup.h' which should be only included via 'device.h' (Wolfram Sang). - Clean up two comments in the core system-wide PM code (Rafael Wysocki, Randy Dunlap). - Add Clearwater Forest processor support to the intel_idle cpuidle driver (Artem Bityutskiy). - Clean up the Exynos devfreq driver and devfreq core (Markus Elfring, Jeongjun Park). - Minor cleanups and fixes for OPP (Dan Carpenter, Neil Armstrong, Joe Hattori). - Implement dev_pm_opp_get_bw() (Neil Armstrong). - Expose OPP reference counting helpers for Rust (Viresh Kumar). - Fix TSC MHz calculation in cpupower (He Rongguang). - Add install and uninstall options to bindings Makefile and add header changes for cpufreq.h to SWIG bindings in cpupower (John B. Wyatt IV). - Add missing residency header changes in cpuidle.h to SWIG bindings in cpupower (John B. Wyatt IV). - Add output files to .gitignore and clean them up in "make clean" in selftests/cpufreq (Li Zhijian). - Fix cross-compilation in cpupower Makefile (Peng Fan). - Revise the is_valid flag handling for idle_monitor in the cpupower utility (wangfushuai). - Extend and clean up AMD processors support in cpupower (Mario Limonciello). -----BEGIN PGP SIGNATURE----- iQJGBAABCAAwFiEE4fcc61cGeeHD/fCwgsRv/nhiVHEFAmeOthsSHHJqd0Byand5 c29ja2kubmV0AAoJEILEb/54YlRxqQsP/ivDt8nqDnxdKB7cKFQIsEK+tl0RnFVD o5regvYeRcGWpUXuMaqBtTmCMjsB8bUkcj2yLquM54ubjHAGF6zJuw9ZytMPHVcC b2xk3RCFlXSBFXVK8eOh3XRviA9nGhuY97ZnPsQOlvoECrxT2xyeL+mWo7s+t+q9 2NUH+yfRoi5FM+nqqDhsm0xXxJuPaNg6eAjIASuMjXap48rNk3L5kW6W/6nw7i0I xQWd/pKLHaI5e7DRF/QdMKu8+Fm4BbN0jMqLblKPOmTe9KggvBkck5q1Um20sYkJ vdKMAT02ClGavIC7DtY092Xik84NZfID4ZUchS6e2hJIQ3Uaw/eDvAo/jlT8gIzq fnXPdApRIzQGDvMxFaAsKaGlwxiVlAGHPDSTH6MVWzsp+1DSkbloSwVPAfeYIn44 Jhov+6Ydux3597sSjo+YmD58acimXl7urVuk8P6m3U5+gb8/jlgbxpIn+vbxH3Ka o44Vt7axD63gezOQY134sj5gic5JL0GuZovOlvzrF6+FsjvVqcax6FZ4n3uIXu7P C1nwai+Wdzo7wvuz7RfO0g15Y15wYLQLYsRq/osRlf+sOmGVv7nA9tSzZ0LUdD5D Pp6PxppF6anM0Kjen8Ppuu+Bcr11JfVvhnVTJqhs6u71XdAy4TnG1JjL4lPWYJ4D Gfz2hyPNjiQX =AoMC -----END PGP SIGNATURE----- Merge tag 'pm-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management updates from Rafael Wysocki: "The majority of changes here are cpufreq updates which are dominated by amd-pstate driver changes, like in the previous cycle. Moreover, changes related to amd-pstate are also the majority of cpupower utility updates. Included are some pieces of new hardware support, like the addition of Clearwater Forest processors support to intel_idle, new cpufreq driver for Airoha SoCs, and Apple cpufreq driver extensions to support more SoCs. The intel_pstate driver is also extended to be able to support new platforms by using ACPI CPPC to compute scaling factors between HWP performance states and frequency. The rest is mostly fixes and cleanups in assorted pieces of power management code. Specifics: - Use str_enable_disable()-like helpers in cpufreq (Krzysztof Kozlowski) - Extend the Apple cpufreq driver to support more SoCs (Hector Martin, Nick Chan) - Add new cpufreq driver for Airoha SoCs (Christian Marangi) - Fix using cpufreq-dt as module (Andreas Kemnade) - Minor fixes for Sparc, SCMI, and Qcom cpufreq drivers (Ethan Carter Edwards, Sibi Sankar, Manivannan Sadhasivam) - Fix the maximum supported frequency computation in the ACPI cpufreq driver to avoid relying on unfounded assumptions (Gautham Shenoy) - Fix an amd-pstate driver regression with preferred core rankings not being used (Mario Limonciello) - Fix a precision issue with frequency calculation in the amd-pstate driver (Naresh Solanki) - Add ftrace event to the amd-pstate driver for active mode (Mario Limonciello) - Set default EPP policy on Ryzen processors in amd-pstate (Mario Limonciello) - Clean up the amd-pstate cpufreq driver and optimize it to increase code reuse (Mario Limonciello, Dhananjay Ugwekar) - Use CPPC to get scaling factors between HWP performance levels and frequency in the intel_pstate driver and make it stop using a built-in scaling factor for Arrow Lake processors (Rafael Wysocki) - Make intel_pstate initialize epp_policy to CPUFREQ_POLICY_UNKNOWN for consistency with CPU offline (Christian Loehle) - Fix superfluous updates caused by need_freq_update in the schedutil cpufreq governor (Sultan Alsawaf) - Allow configuring the system suspend-resume (DPM) watchdog to warn earlier than panic (Douglas Anderson) - Implement devm_device_init_wakeup() helper and introduce a device- managed variant of dev_pm_set_wake_irq() (Joe Hattori, Peng Fan) - Remove direct inclusions of 'pm_wakeup.h' which should be only included via 'device.h' (Wolfram Sang) - Clean up two comments in the core system-wide PM code (Rafael Wysocki, Randy Dunlap) - Add Clearwater Forest processor support to the intel_idle cpuidle driver (Artem Bityutskiy) - Clean up the Exynos devfreq driver and devfreq core (Markus Elfring, Jeongjun Park) - Minor cleanups and fixes for OPP (Dan Carpenter, Neil Armstrong, Joe Hattori) - Implement dev_pm_opp_get_bw() (Neil Armstrong) - Expose OPP reference counting helpers for Rust (Viresh Kumar) - Fix TSC MHz calculation in cpupower (He Rongguang) - Add install and uninstall options to bindings Makefile and add header changes for cpufreq.h to SWIG bindings in cpupower (John B. Wyatt IV) - Add missing residency header changes in cpuidle.h to SWIG bindings in cpupower (John B. Wyatt IV) - Add output files to .gitignore and clean them up in "make clean" in selftests/cpufreq (Li Zhijian) - Fix cross-compilation in cpupower Makefile (Peng Fan) - Revise the is_valid flag handling for idle_monitor in the cpupower utility (wangfushuai) - Extend and clean up AMD processors support in cpupower (Mario Limonciello)" * tag 'pm-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (67 commits) PM / OPP: Add reference counting helpers for Rust implementation PM: sleep: wakeirq: Introduce device-managed variant of dev_pm_set_wake_irq() cpufreq: Use str_enable_disable()-like helpers cpufreq: airoha: Add EN7581 CPUFreq SMCCC driver PM: sleep: Allow configuring the DPM watchdog to warn earlier than panic PM: sleep: convert comment from kernel-doc to plain comment cpufreq: ACPI: Fix max-frequency computation pm: cpupower: Add missing residency header changes in cpuidle.h to SWIG PM / devfreq: exynos: remove unused function parameter OPP: OF: Fix an OF node leak in _opp_add_static_v2() cpufreq/amd-pstate: Refactor max frequency calculation cpufreq/amd-pstate: Fix prefcore rankings pm: cpupower: Add header changes for cpufreq.h to SWIG bindings cpufreq: sparc: change kzalloc to kcalloc cpufreq: qcom: Implement clk_ops::determine_rate() for qcom_cpufreq* clocks cpufreq: qcom: Fix qcom_cpufreq_hw_recalc_rate() to query LUT if LMh IRQ is not available cpufreq: apple-soc: Add Apple A7-A8X SoC cpufreq support cpufreq: apple-soc: Set fallback transition latency to APPLE_DVFS_TRANSITION_TIMEOUT cpufreq: apple-soc: Increase cluster switch timeout to 400us cpufreq: apple-soc: Use 32-bit read for status register ...	2025-01-22 11:16:14 -08:00
Linus Torvalds	1d6d399223	Kthreads affinity follow either of 4 existing different patterns: ... 1) Per-CPU kthreads must stay affine to a single CPU and never execute relevant code on any other CPU. This is currently handled by smpboot code which takes care of CPU-hotplug operations. Affinity here is a correctness constraint. 2) Some kthreads _have_ to be affine to a specific set of CPUs and can't run anywhere else. The affinity is set through kthread_bind_mask() and the subsystem takes care by itself to handle CPU-hotplug operations. Affinity here is assumed to be a correctness constraint. 3) Per-node kthreads _prefer_ to be affine to a specific NUMA node. This is not a correctness constraint but merely a preference in terms of memory locality. kswapd and kcompactd both fall into this category. The affinity is set manually like for any other task and CPU-hotplug is supposed to be handled by the relevant subsystem so that the task is properly reaffined whenever a given CPU from the node comes up. Also care should be taken so that the node affinity doesn't cross isolated (nohz_full) cpumask boundaries. 4) Similar to the previous point except kthreads have a _preferred_ affinity different than a node. Both RCU boost kthreads and RCU exp kworkers fall into this category as they refer to "RCU nodes" from a distinctly distributed tree. Currently the preferred affinity patterns (3 and 4) have at least 4 identified users, with more or less success when it comes to handle CPU-hotplug operations and CPU isolation. Each of which do it in its own ad-hoc way. This is an infrastructure proposal to handle this with the following API changes: _ kthread_create_on_node() automatically affines the created kthread to its target node unless it has been set as per-cpu or bound with kthread_bind[_mask]() before the first wake-up. - kthread_affine_preferred() is a new function that can be called right after kthread_create_on_node() to specify a preferred affinity different than the specified node. When the preferred affinity can't be applied because the possible targets are offline or isolated (nohz_full), the kthread is affine to the housekeeping CPUs (which means to all online CPUs most of the time or only the non-nohz_full CPUs when nohz_full= is set). kswapd, kcompactd, RCU boost kthreads and RCU exp kworkers have been converted, along with a few old drivers. Summary of the changes: * Consolidate a bunch of ad-hoc implementations of kthread_run_on_cpu() * Introduce task_cpu_fallback_mask() that defines the default last resort affinity of a task to become nohz_full aware * Add some correctness check to ensure kthread_bind() is always called before the first kthread wake up. * Default affine kthread to its preferred node. * Convert kswapd / kcompactd and remove their halfway working ad-hoc affinity implementation * Implement kthreads preferred affinity * Unify kthread worker and kthread API's style * Convert RCU kthreads to the new API and remove the ad-hoc affinity implementation. -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEd76+gtGM8MbftQlOhSRUR1COjHcFAmeNf8gACgkQhSRUR1CO jHedQQ/+IxTjjqQiItzrq41TES2S0desHDq8lNJFb7rsR/DtKFyLx3s67cOYV+cM Yx54QHg2m/Fz4nXMQ7Po5ygOtJGCKBc5C5QQy7y0lVKeTQK+daDfEtBSa3oG7j3C u+E3tTY6qxkbCzymUyaKkHN4/ay2vLvjFS50luV7KMyI3x47Aji+t7VdCX4LCPP2 eAwOALWD0+7qLJ/VF6gsmQLKA4Qx7PQAzBa3KSBmUN9UcN8Gk1bQHCTIQKDHP9LQ v8BXrNZtYX1o2+snNYpX2z6/ECjxkdwriOgqqZY5306hd9RAQ1u46Dx3byrIqjGn ULG/XQ2istPyhTqb/h+RbrobdOcwEUIeqk8hRRbBXE8bPpqUz9EMuaCMxWDbQjgH NTuKG4ifKJ/IqstkkuDkdOiByE/ysMmwqrTXgSnu2ITNL9yY3BEgFbvA95hgo42s f7QCxEfZb1MHcNEMENSMwM3xw5lLMGMpxVZcMQ3gLwyotMBRrhFZm1qZJG7TITYW IDIeCbH4JOMdQwLs3CcWTXio0N5/85NhRNFV+IDn96OrgxObgnMtV8QwNgjXBAJ5 wGeJWt8s34W1Zo3qS9gEuVzEhW4XaxISQQMkHe8faKkK6iHmIB/VjSQikDwwUNQ/ AspYj82RyWBCDZsqhiYh71kpxjvS6Xp0bj39Ce1sNsOnuksxKkQ= =g8In -----END PGP SIGNATURE----- Merge tag 'kthread-for-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks Pull kthread updates from Frederic Weisbecker: "Kthreads affinity follow either of 4 existing different patterns: 1) Per-CPU kthreads must stay affine to a single CPU and never execute relevant code on any other CPU. This is currently handled by smpboot code which takes care of CPU-hotplug operations. Affinity here is a correctness constraint. 2) Some kthreads _have_ to be affine to a specific set of CPUs and can't run anywhere else. The affinity is set through kthread_bind_mask() and the subsystem takes care by itself to handle CPU-hotplug operations. Affinity here is assumed to be a correctness constraint. 3) Per-node kthreads _prefer_ to be affine to a specific NUMA node. This is not a correctness constraint but merely a preference in terms of memory locality. kswapd and kcompactd both fall into this category. The affinity is set manually like for any other task and CPU-hotplug is supposed to be handled by the relevant subsystem so that the task is properly reaffined whenever a given CPU from the node comes up. Also care should be taken so that the node affinity doesn't cross isolated (nohz_full) cpumask boundaries. 4) Similar to the previous point except kthreads have a _preferred_ affinity different than a node. Both RCU boost kthreads and RCU exp kworkers fall into this category as they refer to "RCU nodes" from a distinctly distributed tree. Currently the preferred affinity patterns (3 and 4) have at least 4 identified users, with more or less success when it comes to handle CPU-hotplug operations and CPU isolation. Each of which do it in its own ad-hoc way. This is an infrastructure proposal to handle this with the following API changes: - kthread_create_on_node() automatically affines the created kthread to its target node unless it has been set as per-cpu or bound with kthread_bind[_mask]() before the first wake-up. - kthread_affine_preferred() is a new function that can be called right after kthread_create_on_node() to specify a preferred affinity different than the specified node. When the preferred affinity can't be applied because the possible targets are offline or isolated (nohz_full), the kthread is affine to the housekeeping CPUs (which means to all online CPUs most of the time or only the non-nohz_full CPUs when nohz_full= is set). kswapd, kcompactd, RCU boost kthreads and RCU exp kworkers have been converted, along with a few old drivers. Summary of the changes: - Consolidate a bunch of ad-hoc implementations of kthread_run_on_cpu() - Introduce task_cpu_fallback_mask() that defines the default last resort affinity of a task to become nohz_full aware - Add some correctness check to ensure kthread_bind() is always called before the first kthread wake up. - Default affine kthread to its preferred node. - Convert kswapd / kcompactd and remove their halfway working ad-hoc affinity implementation - Implement kthreads preferred affinity - Unify kthread worker and kthread API's style - Convert RCU kthreads to the new API and remove the ad-hoc affinity implementation" * tag 'kthread-for-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks: kthread: modify kernel-doc function name to match code rcu: Use kthread preferred affinity for RCU exp kworkers treewide: Introduce kthread_run_worker[_on_cpu]() kthread: Unify kthread_create_on_cpu() and kthread_create_worker_on_cpu() automatic format rcu: Use kthread preferred affinity for RCU boost kthread: Implement preferred affinity mm: Create/affine kswapd to its preferred node mm: Create/affine kcompactd to its preferred node kthread: Default affine kthread to its preferred NUMA node kthread: Make sure kthread hasn't started while binding it sched,arm64: Handle CPU isolation on last resort fallback rq selection arm64: Exclude nohz_full CPUs from 32bits el0 support lib: test_objpool: Use kthread_run_on_cpu() kallsyms: Use kthread_run_on_cpu() soc/qman: test: Use kthread_run_on_cpu() arm/bL_switcher: Use kthread_run_on_cpu()	2025-01-21 17:10:05 -08:00
Linus Torvalds	62de6e1685	Scheduler enhancements for v6.14: ... - Fair scheduler (SCHED_FAIR) enhancements: - Behavioral improvements: - Untangle NEXT_BUDDY and pick_next_task() (Peter Zijlstra) - Delayed-dequeue enhancements & fixes: (Vincent Guittot) - Rename h_nr_running into h_nr_queued - Add new cfs_rq.h_nr_runnable - Use the new cfs_rq.h_nr_runnable - Removed unsued cfs_rq.h_nr_delayed - Rename cfs_rq.idle_h_nr_running into h_nr_idle - Remove unused cfs_rq.idle_nr_running - Rename cfs_rq.nr_running into nr_queued - Do not try to migrate delayed dequeue task - Fix variable declaration position - Encapsulate set custom slice in a __setparam_fair() function - Fixes: - Fix race between yield_to() and try_to_wake_up() (Tianchen Ding) - Fix CPU bandwidth limit bypass during CPU hotplug (Vishal Chourasia) - Cleanups: - Clean up in migrate_degrades_locality() to improve readability (Peter Zijlstra) - Mark m*_vruntime() with __maybe_unused (Andy Shevchenko) - Update comments after sched_tick() rename (Sebastian Andrzej Siewior) - Remove CONFIG_CFS_BANDWIDTH=n definition of cfs_bandwidth_used() (Valentin Schneider) - Deadline scheduler (SCHED_DL) enhancements: - Restore dl_server bandwidth on non-destructive root domain changes (Juri Lelli) - Correctly account for allocated bandwidth during hotplug (Juri Lelli) - Check bandwidth overflow earlier for hotplug (Juri Lelli) - Clean up goto label in pick_earliest_pushable_dl_task() (John Stultz) - Consolidate timer cancellation (Wander Lairson Costa) - Load-balancer enhancements: - Improve performance by prioritizing migrating eligible tasks in sched_balance_rq() (Hao Jia) - Do not compute NUMA Balancing stats unnecessarily during load-balancing (K Prateek Nayak) - Do not compute overloaded status unnecessarily during load-balancing (K Prateek Nayak) - Generic scheduling code enhancements: - Use READ_ONCE() in task_on_rq_queued(), to consistently use the WRITE_ONCE() updated ->on_rq field (Harshit Agarwal) - Isolated CPUs support enhancements: (Waiman Long) - Make "isolcpus=nohz" equivalent to "nohz_full" - Consolidate housekeeping cpumasks that are always identical - Remove HK_TYPE_SCHED - Unify HK_TYPE_{TIMER|TICK|MISC} to HK_TYPE_KERNEL_NOISE - RSEQ enhancements: - Validate read-only fields under DEBUG_RSEQ config (Mathieu Desnoyers) - PSI enhancements: - Fix race when task wakes up before psi_sched_switch() adjusts flags (Chengming Zhou) - IRQ time accounting performance enhancements: (Yafang Shao) - Define sched_clock_irqtime as static key - Don't account irq time if sched_clock_irqtime is disabled - Virtual machine scheduling enhancements: - Don't try to catch up excess steal time (Suleiman Souhlal) - Heterogenous x86 CPU scheduling enhancements: (K Prateek Nayak) - Convert "sysctl_sched_itmt_enabled" to boolean - Use guard() for itmt_update_mutex - Move the "sched_itmt_enabled" sysctl to debugfs - Remove x86_smt_flags and use cpu_smt_flags directly - Use x86_sched_itmt_flags for PKG domain unconditionally - Debugging code & instrumentation enhancements: - Change need_resched warnings to pr_err() (David Rientjes) - Print domain name in /proc/schedstat (K Prateek Nayak) - Fix value reported by hot tasks pulled in /proc/schedstat (Peter Zijlstra) - Report the different kinds of imbalances in /proc/schedstat (Swapnil Sapkal) - Move sched domain name out of CONFIG_SCHED_DEBUG (Swapnil Sapkal) - Update Schedstat version to 17 (Swapnil Sapkal) Signed-off-by: Ingo Molnar <mingo@kernel.org> -----BEGIN PGP SIGNATURE----- iQJFBAABCgAvFiEEBpT5eoXrXCwVQwEKEnMQ0APhK1gFAmePSRcRHG1pbmdvQGtl cm5lbC5vcmcACgkQEnMQ0APhK1hrdBAAjYiLl5Q8SHM0xnl+kbvuUkCTgEB/gSgA mfrZtHRUgRZuA89NZ9NljlCkQSlsLTOjnpNuaeFzs529GMg9iemc99dbnz3BP5F3 V5qpYvWe7yIkJ3hd0TOGLmYEPMNQaAW57YBOrxcPjWNLJ4cr9iMdccVA1OQtcmqD ZUh3nibv81QI8HDmT2G+figxEIqH3yBV1+SmEIxbrdkQpIJ5702Ng6+0KQK5TShN xwjFELWZUl2TfkoCc4nkIpkImV6cI1DvXSw1xK6gbb1xEVOrsmFW3TYFw4trKHBu 2RBG4wtmzNjh+12GmSdIBJHogPNcay+JIJW9EG/unT7jirqzkkeP1X2eJEbh+X1L CMa7GsD9Vy72jCzeJDMuiy7bKfG/MiKUtDXrAZQDo2atbw7H88QOzMuTE5a5WSV+ tRxXGI/dgFVOk+JQUfctfJbYeXjmG8GAflawvXtGDAfDZsja6M+65fH8p0AOgW1E HHmXUzAe2E2xQBiSok/DYHPQeCDBAjoJvU93YhGiXv8UScb2UaD4BAfzfmc8P+Zs Eox6444ah5U0jiXmZ3HU707n1zO+Ql4qKoyyMJzSyP+oYHE/Do7NYTElw2QovVdN FX/9Uae8T4ttA/5lFe7FNoXgKvSxXDKYyKLZcysjVrWJF866Ui/TWtmxA6w8Osn7 sfucuLawLPM= =5ZNW -----END PGP SIGNATURE----- Merge tag 'sched-core-2025-01-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: "Fair scheduler (SCHED_FAIR) enhancements: - Behavioral improvements: - Untangle NEXT_BUDDY and pick_next_task() (Peter Zijlstra) - Delayed-dequeue enhancements & fixes: (Vincent Guittot) - Rename h_nr_running into h_nr_queued - Add new cfs_rq.h_nr_runnable - Use the new cfs_rq.h_nr_runnable - Removed unsued cfs_rq.h_nr_delayed - Rename cfs_rq.idle_h_nr_running into h_nr_idle - Remove unused cfs_rq.idle_nr_running - Rename cfs_rq.nr_running into nr_queued - Do not try to migrate delayed dequeue task - Fix variable declaration position - Encapsulate set custom slice in a __setparam_fair() function - Fixes: - Fix race between yield_to() and try_to_wake_up() (Tianchen Ding) - Fix CPU bandwidth limit bypass during CPU hotplug (Vishal Chourasia) - Cleanups: - Clean up in migrate_degrades_locality() to improve readability (Peter Zijlstra) - Mark m*_vruntime() with __maybe_unused (Andy Shevchenko) - Update comments after sched_tick() rename (Sebastian Andrzej Siewior) - Remove CONFIG_CFS_BANDWIDTH=n definition of cfs_bandwidth_used() (Valentin Schneider) Deadline scheduler (SCHED_DL) enhancements: - Restore dl_server bandwidth on non-destructive root domain changes (Juri Lelli) - Correctly account for allocated bandwidth during hotplug (Juri Lelli) - Check bandwidth overflow earlier for hotplug (Juri Lelli) - Clean up goto label in pick_earliest_pushable_dl_task() (John Stultz) - Consolidate timer cancellation (Wander Lairson Costa) Load-balancer enhancements: - Improve performance by prioritizing migrating eligible tasks in sched_balance_rq() (Hao Jia) - Do not compute NUMA Balancing stats unnecessarily during load-balancing (K Prateek Nayak) - Do not compute overloaded status unnecessarily during load-balancing (K Prateek Nayak) Generic scheduling code enhancements: - Use READ_ONCE() in task_on_rq_queued(), to consistently use the WRITE_ONCE() updated ->on_rq field (Harshit Agarwal) Isolated CPUs support enhancements: (Waiman Long) - Make "isolcpus=nohz" equivalent to "nohz_full" - Consolidate housekeeping cpumasks that are always identical - Remove HK_TYPE_SCHED - Unify HK_TYPE_{TIMER|TICK|MISC} to HK_TYPE_KERNEL_NOISE RSEQ enhancements: - Validate read-only fields under DEBUG_RSEQ config (Mathieu Desnoyers) PSI enhancements: - Fix race when task wakes up before psi_sched_switch() adjusts flags (Chengming Zhou) IRQ time accounting performance enhancements: (Yafang Shao) - Define sched_clock_irqtime as static key - Don't account irq time if sched_clock_irqtime is disabled Virtual machine scheduling enhancements: - Don't try to catch up excess steal time (Suleiman Souhlal) Heterogenous x86 CPU scheduling enhancements: (K Prateek Nayak) - Convert "sysctl_sched_itmt_enabled" to boolean - Use guard() for itmt_update_mutex - Move the "sched_itmt_enabled" sysctl to debugfs - Remove x86_smt_flags and use cpu_smt_flags directly - Use x86_sched_itmt_flags for PKG domain unconditionally Debugging code & instrumentation enhancements: - Change need_resched warnings to pr_err() (David Rientjes) - Print domain name in /proc/schedstat (K Prateek Nayak) - Fix value reported by hot tasks pulled in /proc/schedstat (Peter Zijlstra) - Report the different kinds of imbalances in /proc/schedstat (Swapnil Sapkal) - Move sched domain name out of CONFIG_SCHED_DEBUG (Swapnil Sapkal) - Update Schedstat version to 17 (Swapnil Sapkal)" * tag 'sched-core-2025-01-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (48 commits) rseq: Fix rseq unregistration regression psi: Fix race when task wakes up before psi_sched_switch() adjusts flags sched, psi: Don't account irq time if sched_clock_irqtime is disabled sched: Don't account irq time if sched_clock_irqtime is disabled sched: Define sched_clock_irqtime as static key sched/fair: Do not compute overloaded status unnecessarily during lb sched/fair: Do not compute NUMA Balancing stats unnecessarily during lb x86/topology: Use x86_sched_itmt_flags for PKG domain unconditionally x86/topology: Remove x86_smt_flags and use cpu_smt_flags directly x86/itmt: Move the "sched_itmt_enabled" sysctl to debugfs x86/itmt: Use guard() for itmt_update_mutex x86/itmt: Convert "sysctl_sched_itmt_enabled" to boolean sched/core: Prioritize migrating eligible tasks in sched_balance_rq() sched/debug: Change need_resched warnings to pr_err sched/fair: Encapsulate set custom slice in a __setparam_fair() function sched: Fix race between yield_to() and try_to_wake_up() docs: Update Schedstat version to 17 sched/stats: Print domain name in /proc/schedstat sched: Move sched domain name out of CONFIG_SCHED_DEBUG sched: Report the different kinds of imbalances in /proc/schedstat ...	2025-01-21 11:32:36 -08:00
K Prateek Nayak	3429dd57f0	sched/fair: Fix inaccurate h_nr_runnable accounting with delayed dequeue ... set_delayed() adjusts cfs_rq->h_nr_runnable for the hierarchy when an entity is delayed irrespective of whether the entity corresponds to a task or a cfs_rq. Consider the following scenario: root / \ A B (*) delayed since B is no longer eligible on root | | Task0 Task1 <--- dequeue_task_fair() - task blocks When Task1 blocks (dequeue_entity() for task's se returns true), dequeue_entities() will continue adjusting cfs_rq->h_nr_* for the hierarchy of Task1. However, when the sched_entity corresponding to cfs_rq B is delayed, set_delayed() will adjust the h_nr_runnable for the hierarchy too leading to both dequeue_entity() and set_delayed() decrementing h_nr_runnable for the dequeue of the same task. A SCHED_WARN_ON() to inspect h_nr_runnable post its update in dequeue_entities() like below: cfs_rq->h_nr_runnable -= h_nr_runnable; SCHED_WARN_ON(((int) cfs_rq->h_nr_runnable) < 0); is consistently tripped when running wakeup intensive workloads like hackbench in a cgroup. This error is self correcting since cfs_rq are per-cpu and cannot migrate. The entitiy is either picked for full dequeue or is requeued when a task wakes up below it. Both those paths call clear_delayed() which again increments h_nr_runnable of the hierarchy without considering if the entity corresponds to a task or not. h_nr_runnable will eventually reflect the correct value however in the interim, the incorrect values can still influence PELT calculation which uses se->runnable_weight or cfs_rq->h_nr_runnable. Since only delayed tasks take the early return path in dequeue_entities() and enqueue_task_fair(), adjust the h_nr_runnable in {set,clear}_delayed() only when a task is delayed as this path skips the h_nr_* update loops and returns early. For entities corresponding to cfs_rq, the h_nr_* update loop in the caller will do the right thing. Fixes: 76f2f78329 ("sched/eevdf: More PELT vs DELAYED_DEQUEUE") Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com> Tested-by: Swapnil Sapkal <swapnil.sapkal@amd.com> Link: https://lkml.kernel.org/r/20250117105852.23908-1-kprateek.nayak@amd.com	2025-01-21 13:13:36 +01:00
Rafael J. Wysocki	a5c16f29a8	Merge branch 'pm-cpufreq' ... Merge cpufreq updates for 6.14: - Use str_enable_disable()-like helpers in cpufreq (Krzysztof Kozlowski). - Extend the Apple cpufreq driver to support more SoCs (Hector Martin, Nick Chan). - Add new cpufreq driver for Airoha SoCs (Christian Marangi). - Fix using cpufreq-dt as module (Andreas Kemnade). - Minor fixes for Sparc, SCMI, and Qcom cpufreq drivers (Ethan Carter Edwards, Sibi Sankar, Manivannan Sadhasivam). - Fix the maximum supported frequency computation in the ACPI cpufreq driver to avoid relying on unfounded assumptions (Gautham Shenoy). - Fix an amd-pstate driver regression with preferred core rankings not being used (Mario Limonciello). - Fix a precision issue with frequency calculation in the amd-pstate driver (Naresh Solanki). - Add ftrace event to the amd-pstate driver for active mode (Mario Limonciello). - Set default EPP policy on Ryzen processors in amd-pstate (Mario Limonciello). - Clean up the amd-pstate cpufreq driver and optimize it to increase code reuse (Mario Limonciello, Dhananjay Ugwekar). - Use CPPC to get scaling factors between HWP performance levels and frequency in the intel_pstate driver and make it stop using a built -in scaling factor for the Arrow Lake processor (Rafael Wysocki). - Make intel_pstate initialize epp_policy to CPUFREQ_POLICY_UNKNOWN for consistency with CPU offline (Christian Loehle). - Fix superfluous updates caused by need_freq_update in the schedutil cpufreq governor (Sultan Alsawaf). * pm-cpufreq: (40 commits) cpufreq: Use str_enable_disable()-like helpers cpufreq: airoha: Add EN7581 CPUFreq SMCCC driver cpufreq: ACPI: Fix max-frequency computation cpufreq/amd-pstate: Refactor max frequency calculation cpufreq/amd-pstate: Fix prefcore rankings cpufreq: sparc: change kzalloc to kcalloc cpufreq: qcom: Implement clk_ops::determine_rate() for qcom_cpufreq* clocks cpufreq: qcom: Fix qcom_cpufreq_hw_recalc_rate() to query LUT if LMh IRQ is not available cpufreq: apple-soc: Add Apple A7-A8X SoC cpufreq support cpufreq: apple-soc: Set fallback transition latency to APPLE_DVFS_TRANSITION_TIMEOUT cpufreq: apple-soc: Increase cluster switch timeout to 400us cpufreq: apple-soc: Use 32-bit read for status register cpufreq: apple-soc: Allow per-SoC configuration of APPLE_DVFS_CMD_PS1 cpufreq: apple-soc: Drop setting the PS2 field on M2+ dt-bindings: cpufreq: apple,cluster-cpufreq: Add A7-A11, T2 compatibles dt-bindings: cpufreq: Document support for Airoha EN7581 CPUFreq cpufreq: fix using cpufreq-dt as module cpufreq: scmi: Register for limit change notifications cpufreq: schedutil: Fix superfluous updates caused by need_freq_update cpufreq: intel_pstate: Use CPUFREQ_POLICY_UNKNOWN ...	2025-01-20 20:34:50 +01:00
Rafael J. Wysocki	1225bb42b8	Merge branches 'pm-sleep', 'pm-cpuidle' and 'pm-em' ... Merge updates related to system sleep, a cpuidle update and an Energy Model handling code update for 6.14-rc1: - Allow configuring the system suspend-resume (DPM) watchdog to warn earlier than panic (Douglas Anderson). - Implement devm_device_init_wakeup() helper and introduce a device- managed variant of dev_pm_set_wake_irq() (Joe Hattori, Peng Fan). - Remove direct inclusions of 'pm_wakeup.h' which should be only included via 'device.h' (Wolfram Sang). - Clean up two comments in the core system-wide PM code (Rafael Wysocki, Randy Dunlap). - Add Clearwater Forest processor support to the intel_idle cpuidle driver (Artem Bityutskiy). - Move sched domains rebuild function from the schedutil cpufreq governor to the Energy Model handling code (Rafael Wysocki). * pm-sleep: PM: sleep: wakeirq: Introduce device-managed variant of dev_pm_set_wake_irq() PM: sleep: Allow configuring the DPM watchdog to warn earlier than panic PM: sleep: convert comment from kernel-doc to plain comment PM: wakeup: implement devm_device_init_wakeup() helper PM: sleep: sysfs: don't include 'pm_wakeup.h' directly PM: sleep: autosleep: don't include 'pm_wakeup.h' directly PM: sleep: Update stale comment in device_resume() * pm-cpuidle: intel_idle: add Clearwater Forest SoC support * pm-em: PM: EM: Move sched domains rebuild function from schedutil to EM	2025-01-20 19:14:15 +01:00
Linus Torvalds	8ff6d472ab	- Do not adjust the weight of empty group entities and avoid scheduling ... artifacts - Avoid scheduling lag by computing lag properly and thus address an EEVDF entity placement issue -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmeM2+8ACgkQEsHwGGHe VUrqHA/+PyPsILNfDFnaXD/Shv7kCgk3hH2YVrCnyIQn8fhTCL+K0luXRRmAPhl1 pEbRyEtVRXZM9WyHJ1r7VmnIHVanUKWcuZzAx8HT9b7Tkrqy/xSriH/jAV7FYG9h gIhWA4vXT34HG2MQHTecJ/4gvkeI5tV93nkZ6vwEwwN4pGxSvijPR3yr3yl286Nt BlHP9cXBWWsxTq4CYb2j5q9nmymKuiDmhD8jc1fVjDKxjmrNHEwX5mtvtRLGI1dR O4pjUEqYQ+TWIkX8ZIRBPzLd9b6750ncO/9yb24cY7Z3RMKov4wz8b819Dt77cTp XF+bT+8fsaKNRjkzPEseZU4OL16ZO+33Kcn+JoNPWvbONgFKusZ4qkCCwvWpiQlV 0Eddh1XjKBoXA1tR6VrREcUKQ2zWoXrn8tlHUTMfPuPq1jlbQNtzN7OWcR+WBy7L FiClWzWLv0fCeTXaAEcO9+/MN5z2lDQsJRiLtAlGh0JJU6/1H6IVX2tSZllkpR/R 5pyHCpYsh5cucx6cQPk+rp9O6PDYu2frMuJ8itWlQLHeSzjzOoeE6EwwZcMQG4xb UG/azMbmqWrtmZqCgNCBtq7RAkVRe0IuxWuCtV1VkatU+2RXdtV85tVKn/JG2KLW 05c8GTdQZgnoY65/TZHwudhkzytclynKrrvhfKFllAWnb8D8gyQ= =fZWm -----END PGP SIGNATURE----- Merge tag 'sched_urgent_for_v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Borislav Petkov: - Do not adjust the weight of empty group entities and avoid scheduling artifacts - Avoid scheduling lag by computing lag properly and thus address an EEVDF entity placement issue * tag 'sched_urgent_for_v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/fair: Fix update_cfs_group() vs DELAY_DEQUEUE sched/fair: Fix EEVDF entity placement bug causing scheduling lag	2025-01-19 09:01:17 -08:00
Rafael J. Wysocki	423124ab97	Merge back earlier cpufreq material for 6.14	2025-01-16 20:20:20 +01:00
Nicholas Piggin	21641bd9a7	lazy tlb: fix hotplug exit race with MMU_LAZY_TLB_SHOOTDOWN ... CPU unplug first calls __cpu_disable(), and that's where powerpc calls cleanup_cpu_mmu_context(), which clears this CPU from mm_cpumask() of all mms in the system. However this CPU may still be using a lazy tlb mm, and its mm_cpumask bit will be cleared from it. The CPU does not switch away from the lazy tlb mm until arch_cpu_idle_dead() calls idle_task_exit(). If that user mm exits in this window, it will not be subject to the lazy tlb mm shootdown and may be freed while in use as a lazy mm by the CPU that is being unplugged. cleanup_cpu_mmu_context() could be moved later, but it looks better to move the lazy tlb mm switching earlier. The problem with doing the lazy mm switching in idle_task_exit() is explained in commit bf2c59fce4 ("sched/core: Fix illegal RCU from offline CPUs"), which added a wart to switch away from the mm but leave it set in active_mm to be cleaned up later. So instead, switch away from the lazy tlb mm at sched_cpu_wait_empty(), which is the last hotplug state before teardown (CPUHP_AP_SCHED_WAIT_EMPTY). This CPU will never switch to a user thread from this point, so it has no chance to pick up a new lazy tlb mm. This removes the lazy tlb mm handling wart in CPU unplug. With this, idle_task_exit() is not needed anymore and can be cleaned up. This leaves the prototype alone, to be cleaned after this change. herton: took the suggestions from https://lore.kernel.org/all/87jzvyprsw.ffs@tglx/ and made adjustments on the initial patch proposed by Nicholas. Link: https://lkml.kernel.org/r/20230524060455.147699-1-npiggin@gmail.com Link: https://lore.kernel.org/all/20230525205253.E2FAEC433EF@smtp.kernel.org/ Link: https://lkml.kernel.org/r/20241104142318.3295663-1-herton@redhat.com Fixes: 2655421ae6 ("lazy tlb: shoot lazies, non-refcounting lazy tlb mm reference handling scheme") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Herton R. Krzesinski <herton@redhat.com> Suggested-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>	2025-01-13 22:40:42 -08:00
Peter Zijlstra	d40797d672	kasan: make kasan_record_aux_stack_noalloc() the default behaviour ... kasan_record_aux_stack_noalloc() was introduced to record a stack trace without allocating memory in the process. It has been added to callers which were invoked while a raw_spinlock_t was held. More and more callers were identified and changed over time. Is it a good thing to have this while functions try their best to do a locklessly setup? The only downside of having kasan_record_aux_stack() not allocate any memory is that we end up without a stacktrace if stackdepot runs out of memory and at the same stacktrace was not recorded before To quote Marco Elver from https://lore.kernel.org/all/CANpmjNPmQYJ7pv1N3cuU8cP18u7PP_uoZD8YxwZd4jtbof9nVQ@mail.gmail.com/ | I'd be in favor, it simplifies things. And stack depot should be | able to replenish its pool sufficiently in the "non-aux" cases | i.e. regular allocations. Worst case we fail to record some | aux stacks, but I think that's only really bad if there's a bug | around one of these allocations. In general the probabilities | of this being a regression are extremely small [...] Make the kasan_record_aux_stack_noalloc() behaviour default as kasan_record_aux_stack(). [bigeasy@linutronix.de: dressed the diff as patch] Link: https://lkml.kernel.org/r/20241122155451.Mb2pmeyJ@linutronix.de Fixes: 7cb3007ce2 ("kasan: generic: introduce kasan_record_aux_stack_noalloc()") Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reported-by: syzbot+39f85d612b7c20d8db48@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/67275485.050a0220.3c8d68.0a37.GAE@google.com Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Reviewed-by: Marco Elver <elver@google.com> Reviewed-by: Waiman Long <longman@redhat.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Ben Segall <bsegall@google.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: <kasan-dev@googlegroups.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Liam R. Howlett <Liam.Howlett@Oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Neeraj Upadhyay <neeraj.upadhyay@kernel.org> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: syzkaller-bugs@googlegroups.com Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zqiang <qiang.zhang1211@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>	2025-01-13 22:40:36 -08:00
Randy Dunlap	987ce79b52	sched_ext: fix kernel-doc warnings ... Use the correct function parameter names and function names. Use the correct kernel-doc comment format for struct sched_ext_ops to eliminate a bunch of warnings. ext.c:1418: warning: Excess function parameter 'include_dead' description in 'scx_task_iter_next_locked' ext.c:7261: warning: expecting prototype for scx_bpf_dump(). Prototype was for scx_bpf_dump_bstr() instead ext.c:7352: warning: Excess function parameter 'flags' description in 'scx_bpf_cpuperf_set' ext.c:3150: warning: Function parameter or struct member 'in_fi' not described in 'scx_prio_less' ext.c:4711: warning: Function parameter or struct member 'dur_s' not described in 'scx_softlockup' ext.c:4775: warning: Function parameter or struct member 'bypass' not described in 'scx_ops_bypass' ext.c:7453: warning: Function parameter or struct member 'idle_mask' not described in 'scx_bpf_put_idle_cpumask' ext.c:209: warning: Incorrect use of kernel-doc format: * select_cpu - Pick the target CPU for a task which is being woken up ext.c:236: warning: Incorrect use of kernel-doc format: * enqueue - Enqueue a task on the BPF scheduler ext.c:251: warning: Incorrect use of kernel-doc format: * dequeue - Remove a task from the BPF scheduler ext.c:267: warning: Incorrect use of kernel-doc format: * dispatch - Dispatch tasks from the BPF scheduler and/or user DSQs ext.c:290: warning: Incorrect use of kernel-doc format: * tick - Periodic tick ext.c:300: warning: Incorrect use of kernel-doc format: * runnable - A task is becoming runnable on its associated CPU ext.c:327: warning: Incorrect use of kernel-doc format: * running - A task is starting to run on its associated CPU ext.c:335: warning: Incorrect use of kernel-doc format: * stopping - A task is stopping execution ext.c:346: warning: Incorrect use of kernel-doc format: * quiescent - A task is becoming not runnable on its associated CPU ext.c:366: warning: Incorrect use of kernel-doc format: * yield - Yield CPU ext.c:381: warning: Incorrect use of kernel-doc format: * core_sched_before - Task ordering for core-sched ext.c:399: warning: Incorrect use of kernel-doc format: * set_weight - Set task weight ext.c:408: warning: Incorrect use of kernel-doc format: * set_cpumask - Set CPU affinity ext.c:418: warning: Incorrect use of kernel-doc format: * update_idle - Update the idle state of a CPU ext.c:439: warning: Incorrect use of kernel-doc format: * cpu_acquire - A CPU is becoming available to the BPF scheduler ext.c:449: warning: Incorrect use of kernel-doc format: * cpu_release - A CPU is taken away from the BPF scheduler ext.c:461: warning: Incorrect use of kernel-doc format: * init_task - Initialize a task to run in a BPF scheduler ext.c:476: warning: Incorrect use of kernel-doc format: * exit_task - Exit a previously-running task from the system ext.c:485: warning: Incorrect use of kernel-doc format: * enable - Enable BPF scheduling for a task ext.c:494: warning: Incorrect use of kernel-doc format: * disable - Disable BPF scheduling for a task ext.c:504: warning: Incorrect use of kernel-doc format: * dump - Dump BPF scheduler state on error ext.c:512: warning: Incorrect use of kernel-doc format: * dump_cpu - Dump BPF scheduler state for a CPU on error ext.c:524: warning: Incorrect use of kernel-doc format: * dump_task - Dump BPF scheduler state for a runnable task on error ext.c:535: warning: Incorrect use of kernel-doc format: * cgroup_init - Initialize a cgroup ext.c:550: warning: Incorrect use of kernel-doc format: * cgroup_exit - Exit a cgroup ext.c:559: warning: Incorrect use of kernel-doc format: * cgroup_prep_move - Prepare a task to be moved to a different cgroup ext.c:574: warning: Incorrect use of kernel-doc format: * cgroup_move - Commit cgroup move ext.c:585: warning: Incorrect use of kernel-doc format: * cgroup_cancel_move - Cancel cgroup move ext.c:597: warning: Incorrect use of kernel-doc format: * cgroup_set_weight - A cgroup's weight is being changed ext.c:611: warning: Incorrect use of kernel-doc format: * cpu_online - A CPU became online ext.c:620: warning: Incorrect use of kernel-doc format: * cpu_offline - A CPU is going offline ext.c:633: warning: Incorrect use of kernel-doc format: * init - Initialize the BPF scheduler ext.c:638: warning: Incorrect use of kernel-doc format: * exit - Clean up after the BPF scheduler ext.c:648: warning: Incorrect use of kernel-doc format: * dispatch_max_batch - Max nr of tasks that dispatch() can dispatch ext.c:653: warning: Incorrect use of kernel-doc format: * flags - %SCX_OPS_* flags ext.c:658: warning: Incorrect use of kernel-doc format: * timeout_ms - The maximum amount of time, in milliseconds, that a ext.c:667: warning: Incorrect use of kernel-doc format: * exit_dump_len - scx_exit_info.dump buffer length. If 0, the default ext.c:673: warning: Incorrect use of kernel-doc format: * hotplug_seq - A sequence number that may be set by the scheduler to ext.c:682: warning: Incorrect use of kernel-doc format: * name - BPF scheduler's name ext.c:689: warning: Function parameter or struct member 'select_cpu' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'enqueue' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'dequeue' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'dispatch' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'tick' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'runnable' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'running' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'stopping' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'quiescent' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'yield' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'core_sched_before' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'set_weight' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'set_cpumask' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'update_idle' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'cpu_acquire' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'cpu_release' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'init_task' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'exit_task' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'enable' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'disable' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'dump' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'dump_cpu' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'dump_task' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'cgroup_init' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'cgroup_exit' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'cgroup_prep_move' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'cgroup_move' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'cgroup_cancel_move' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'cgroup_set_weight' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'cpu_online' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'cpu_offline' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'init' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'exit' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'dispatch_max_batch' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'flags' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'timeout_ms' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'exit_dump_len' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'hotplug_seq' not described in 'sched_ext_ops' ext.c:689: warning: Function parameter or struct member 'name' not described in 'sched_ext_ops' Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: David Vernet <void@manifault.com> Cc: Changwoo Min <changwoo@igalia.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: bpf@vger.kernel.org Acked-by: Andrea Righi <arighi@nvidia.com> Signed-off-by: Tejun Heo <tj@kernel.org>	2025-01-13 08:23:29 -10:00
Chengming Zhou	7d9da04057	psi: Fix race when task wakes up before psi_sched_switch() adjusts flags ... When running hackbench in a cgroup with bandwidth throttling enabled, following PSI splat was observed: psi: inconsistent task state! task=1831:hackbench cpu=8 psi_flags=14 clear=0 set=4 When investigating the series of events leading up to the splat, following sequence was observed: [008] d..2.: sched_switch: ... ==> next_comm=hackbench next_pid=1831 next_prio=120 ... [008] dN.2.: dequeue_entity(task delayed): task=hackbench pid=1831 cfs_rq->throttled=0 [008] dN.2.: pick_task_fair: check_cfs_rq_runtime() throttled cfs_rq on CPU8 # CPU8 goes into newidle balance and releases the rq lock ... # CPU15 on same LLC Domain is trying to wakeup hackbench(pid=1831) [015] d..4.: psi_flags_change: psi: task state: task=1831:hackbench cpu=8 psi_flags=14 clear=0 set=4 final=14 # Splat (cfs_rq->throttled=1) [015] d..4.: sched_wakeup: comm=hackbench pid=1831 prio=120 target_cpu=008 # Task has woken on a throttled hierarchy [008] d..2.: sched_switch: prev_comm=hackbench prev_pid=1831 prev_prio=120 prev_state=S ==> ... psi_dequeue() relies on psi_sched_switch() to set the correct PSI flags for the blocked entity, however, with the introduction of DELAY_DEQUEUE, the block task can wakeup when newidle balance drops the runqueue lock during __schedule(). If a task wakes before psi_sched_switch() adjusts the PSI flags, skip any modifications in psi_enqueue() which would still see the flags of a running task and not a blocked one. Instead, rely on psi_sched_switch() to do the right thing. Since the status returned by try_to_block_task() may no longer be true by the time schedule reaches psi_sched_switch(), check if the task is blocked or not using a combination of task_on_rq_queued() and p->se.sched_delayed checks. [ prateek: Commit message, testing, early bailout in psi_enqueue() ] Fixes: 152e11f6df ("sched/fair: Implement delayed dequeue") # 1a6151017e Signed-off-by: Chengming Zhou <chengming.zhou@linux.dev> Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev> Link: https://lore.kernel.org/r/20241227061941.2315-1-kprateek.nayak@amd.com	2025-01-13 14:10:26 +01:00
Yafang Shao	a6fd16148f	sched, psi: Don't account irq time if sched_clock_irqtime is disabled ... sched_clock_irqtime may be disabled due to the clock source. When disabled, irq_time_read() won't change over time, so there is nothing to account. We can save iterating the whole hierarchy on every tick and context switch. Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Michal Koutný <mkoutny@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Link: https://lore.kernel.org/r/20250103022409.2544-4-laoar.shao@gmail.com	2025-01-13 14:10:26 +01:00
Yafang Shao	763a744e24	sched: Don't account irq time if sched_clock_irqtime is disabled ... sched_clock_irqtime may be disabled due to the clock source, in which case IRQ time should not be accounted. Let's add a conditional check to avoid unnecessary logic. Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Michal Koutný <mkoutny@suse.com> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20250103022409.2544-3-laoar.shao@gmail.com	2025-01-13 14:10:25 +01:00
Yafang Shao	8722903cbb	sched: Define sched_clock_irqtime as static key ... Since CPU time accounting is a performance-critical path, let's define sched_clock_irqtime as a static key to minimize potential overhead. Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Michal Koutný <mkoutny@suse.com> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20250103022409.2544-2-laoar.shao@gmail.com	2025-01-13 14:10:25 +01:00
K Prateek Nayak	3229adbe78	sched/fair: Do not compute overloaded status unnecessarily during lb ... Only set sg_overloaded when computing sg_lb_stats() at the highest sched domain since rd->overloaded status is updated only when load balancing at the highest domain. While at it, move setting of sg_overloaded below idle_cpu() check since an idle CPU can never be overloaded. Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com> Link: https://lore.kernel.org/r/20241223043407.1611-8-kprateek.nayak@amd.com	2025-01-13 14:10:25 +01:00
K Prateek Nayak	0ac1ee9ebf	sched/fair: Do not compute NUMA Balancing stats unnecessarily during lb ... Aggregate nr_numa_running and nr_preferred_running when load balancing at NUMA domains only. While at it, also move the aggregation below the idle_cpu() check since an idle CPU cannot have any preferred tasks. Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20241223043407.1611-7-kprateek.nayak@amd.com	2025-01-13 14:10:25 +01:00
Hao Jia	873199d27b	sched/core: Prioritize migrating eligible tasks in sched_balance_rq() ... When the PLACE_LAG scheduling feature is enabled and dst_cfs_rq->nr_queued is greater than 1, if a task is ineligible (lag < 0) on the source cpu runqueue, it will also be ineligible when it is migrated to the destination cpu runqueue. Because we will keep the original equivalent lag of the task in place_entity(). So if the task was ineligible before, it will still be ineligible after migration. So in sched_balance_rq(), we prioritize migrating eligible tasks, and we soft-limit ineligible tasks, allowing them to migrate only when nr_balance_failed is non-zero to avoid load-balancing trying very hard to balance the load. Below are some benchmark test results. From my test results, this patch shows a slight improvement on hackbench. Benchmark ========= All of the benchmarks are done inside a normal cpu cgroup in a clean environment with cpu turbo disabled, and test machine is: Single NUMA machine model is 13th Gen Intel(R) Core(TM) i7-13700, 12 Core/24 HT. Based on master b86545e02e. Results ======= hackbench-process-pipes vanilla patched Amean 1 0.5837 ( 0.00%) 0.5733 ( 1.77%) Amean 4 1.4423 ( 0.00%) 1.4503 ( -0.55%) Amean 7 2.5147 ( 0.00%) 2.4773 ( 1.48%) Amean 12 3.9347 ( 0.00%) 3.8880 ( 1.19%) Amean 21 5.3943 ( 0.00%) 5.3873 ( 0.13%) Amean 30 6.7840 ( 0.00%) 6.6660 ( 1.74%) Amean 48 9.8313 ( 0.00%) 9.6100 ( 2.25%) Amean 79 15.4403 ( 0.00%) 14.9580 ( 3.12%) Amean 96 18.4970 ( 0.00%) 17.9533 ( 2.94%) hackbench-process-sockets vanilla patched Amean 1 0.6297 ( 0.00%) 0.6223 ( 1.16%) Amean 4 2.1517 ( 0.00%) 2.0887 ( 2.93%) Amean 7 3.6377 ( 0.00%) 3.5670 ( 1.94%) Amean 12 6.1277 ( 0.00%) 5.9290 ( 3.24%) Amean 21 10.0380 ( 0.00%) 9.7623 ( 2.75%) Amean 30 14.1517 ( 0.00%) 13.7513 ( 2.83%) Amean 48 24.7253 ( 0.00%) 24.2287 ( 2.01%) Amean 79 43.9523 ( 0.00%) 43.2330 ( 1.64%) Amean 96 54.5310 ( 0.00%) 53.7650 ( 1.40%) tbench4 Throughput vanilla patched Hmean 1 255.97 ( 0.00%) 275.01 ( 7.44%) Hmean 2 511.60 ( 0.00%) 544.27 ( 6.39%) Hmean 4 996.70 ( 0.00%) 1006.57 ( 0.99%) Hmean 8 1646.46 ( 0.00%) 1649.15 ( 0.16%) Hmean 16 2259.42 ( 0.00%) 2274.35 ( 0.66%) Hmean 32 4725.48 ( 0.00%) 4735.57 ( 0.21%) Hmean 64 4411.47 ( 0.00%) 4400.05 ( -0.26%) Hmean 96 4284.31 ( 0.00%) 4267.39 ( -0.39%) Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Hao Jia <jiahao1@lixiang.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20241223091446.90208-1-jiahao.kernel@gmail.com	2025-01-13 14:10:23 +01:00
David Rientjes	8061b9f5e1	sched/debug: Change need_resched warnings to pr_err ... need_resched warnings, if enabled, are treated as WARNINGs. If kernel.panic_on_warn is enabled, then this causes a kernel panic. It's highly unlikely that a panic is desired for these warnings, only a stack trace is normally required to debug and resolve. Thus, switch need_resched warnings to simply be a printk with an associated stack trace so they are no longer in scope for panic_on_warn. Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Madadi Vineeth Reddy <vineethr@linux.ibm.com> Acked-by: Josh Don <joshdon@google.com> Link: https://lkml.kernel.org/r/e8d52023-5291-26bd-5299-8bb9eb604929@google.com	2025-01-13 14:10:23 +01:00
Vincent Guittot	2cf9ac4007	sched/fair: Encapsulate set custom slice in a __setparam_fair() function ... Similarly to dl, create a __setparam_fair() function to set parameters related to fair class and move it in the fair.c file. No functional changes expected Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Phil Auld <pauld@redhat.com> Link: https://lore.kernel.org/r/20250110144656.484601-1-vincent.guittot@linaro.org	2025-01-13 14:10:22 +01:00
Tianchen Ding	5d808c78d9	sched: Fix race between yield_to() and try_to_wake_up() ... We met a SCHED_WARN in set_next_buddy(): __warn_printk set_next_buddy yield_to_task_fair yield_to kvm_vcpu_yield_to [kvm] ... After a short dig, we found the rq_lock held by yield_to() may not be exactly the rq that the target task belongs to. There is a race window against try_to_wake_up(). CPU0 target_task blocking on CPU1 lock rq0 & rq1 double check task_rq == p_rq, ok woken to CPU2 (lock task_pi & rq2) task_rq = rq2 yield_to_task_fair (w/o lock rq2) In this race window, yield_to() is operating the task w/o the correct lock. Fix this by taking task pi_lock first. Fixes: d95f412200 ("sched: Add yield_to(task, preempt) functionality") Signed-off-by: Tianchen Ding <dtcccc@linux.alibaba.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20241231055020.6521-1-dtcccc@linux.alibaba.com	2025-01-13 14:10:22 +01:00