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| * | sched: Fix TASK_state comparisonsPeter Zijlstra2022-09-281-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Task state is fundamentally a bitmask; direct comparisons are probably not working as intended. Specifically the normal wait-state have a number of possible modifiers: TASK_UNINTERRUPTIBLE: TASK_WAKEKILL, TASK_NOLOAD, TASK_FREEZABLE TASK_INTERRUPTIBLE: TASK_FREEZABLE Specifically, the addition of TASK_FREEZABLE wrecked __wait_is_interruptible(). This however led to an audit of direct comparisons yielding the rest of the changes. Fixes: f5d39b020809 ("freezer,sched: Rewrite core freezer logic") Reported-by: Christian Borntraeger <borntraeger@linux.ibm.com> Debugged-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Christian Borntraeger <borntraeger@linux.ibm.com>
| * | sched/fair: Move call to list_last_entry() in detach_tasksVincent Guittot2022-09-151-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | Move the call to list_last_entry() in detach_tasks() after testing loop_max and loop_break. Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220825122726.20819-4-vincent.guittot@linaro.org
| * | sched/fair: Cleanup loop_max and loop_breakVincent Guittot2022-09-153-12/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | sched_nr_migrate_break is set to a fix value and never changes so we can replace it by a define SCHED_NR_MIGRATE_BREAK. Also, we adjust SCHED_NR_MIGRATE_BREAK to be aligned with the init value of sysctl_sched_nr_migrate which can be init to different values. Then, use SCHED_NR_MIGRATE_BREAK to init sysctl_sched_nr_migrate. The behavior stays unchanged unless you modify sysctl_sched_nr_migrate trough debugfs. Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220825122726.20819-3-vincent.guittot@linaro.org
| * | sched/fair: Make sure to try to detach at least one movable taskVincent Guittot2022-09-151-3/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | During load balance, we try at most env->loop_max time to move a task. But it can happen that the loop_max LRU tasks (ie tail of the cfs_tasks list) can't be moved to dst_cpu because of affinity. In this case, loop in the list until we found at least one. The maximum of detached tasks remained the same as before. Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220825122726.20819-2-vincent.guittot@linaro.org
| * | freezer,sched: Rewrite core freezer logicPeter Zijlstra2022-09-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rewrite the core freezer to behave better wrt thawing and be simpler in general. By replacing PF_FROZEN with TASK_FROZEN, a special block state, it is ensured frozen tasks stay frozen until thawed and don't randomly wake up early, as is currently possible. As such, it does away with PF_FROZEN and PF_FREEZER_SKIP, freeing up two PF_flags (yay!). Specifically; the current scheme works a little like: freezer_do_not_count(); schedule(); freezer_count(); And either the task is blocked, or it lands in try_to_freezer() through freezer_count(). Now, when it is blocked, the freezer considers it frozen and continues. However, on thawing, once pm_freezing is cleared, freezer_count() stops working, and any random/spurious wakeup will let a task run before its time. That is, thawing tries to thaw things in explicit order; kernel threads and workqueues before doing bringing SMP back before userspace etc.. However due to the above mentioned races it is entirely possible for userspace tasks to thaw (by accident) before SMP is back. This can be a fatal problem in asymmetric ISA architectures (eg ARMv9) where the userspace task requires a special CPU to run. As said; replace this with a special task state TASK_FROZEN and add the following state transitions: TASK_FREEZABLE -> TASK_FROZEN __TASK_STOPPED -> TASK_FROZEN __TASK_TRACED -> TASK_FROZEN The new TASK_FREEZABLE can be set on any state part of TASK_NORMAL (IOW. TASK_INTERRUPTIBLE and TASK_UNINTERRUPTIBLE) -- any such state is already required to deal with spurious wakeups and the freezer causes one such when thawing the task (since the original state is lost). The special __TASK_{STOPPED,TRACED} states *can* be restored since their canonical state is in ->jobctl. With this, frozen tasks need an explicit TASK_FROZEN wakeup and are free of undue (early / spurious) wakeups. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Ingo Molnar <mingo@kernel.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://lore.kernel.org/r/20220822114649.055452969@infradead.org
| * | sched/completion: Add wait_for_completion_state()Peter Zijlstra2022-09-071-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | Allows waiting with a custom @state. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20220822114648.922711674@infradead.org
| * | sched: Add TASK_ANY for wait_task_inactive()Peter Zijlstra2022-09-071-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that wait_task_inactive()'s @match_state argument is a mask (like ttwu()) it is possible to replace the special !match_state case with an 'all-states' value such that any blocked state will match. Suggested-by: Ingo Molnar (mingo@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/YxhkzfuFTvRnpUaH@hirez.programming.kicks-ass.net
| * | sched: Change wait_task_inactive()s match_statePeter Zijlstra2022-09-071-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make wait_task_inactive()'s @match_state work like ttwu()'s @state. That is, instead of an equal comparison, use it as a mask. This allows matching multiple block conditions. (removes the unlikely; it doesn't make sense how it's only part of the condition) Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220822114648.856734578@infradead.org
| * | sched: Rename task_running() to task_on_cpu()Peter Zijlstra2022-09-076-14/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is some ambiguity about task_running() in that it is unrelated to TASK_RUNNING but instead tests ->on_cpu. As such, rename the thing task_on_cpu(). Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/Yxhkhn55uHZx+NGl@hirez.programming.kicks-ass.net
| * | sched/fair: Cleanup for SIS_PROPAbel Wu2022-09-071-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The sched-domain of this cpu is only used for some heuristics when SIS_PROP is enabled, and it should be irrelevant whether the local sd_llc is valid or not, since all we care about is target sd_llc if !SIS_PROP. Access the local domain only when there is a need. Signed-off-by: Abel Wu <wuyun.abel@bytedance.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Mel Gorman <mgorman@suse.de> Link: https://lore.kernel.org/r/20220907112000.1854-6-wuyun.abel@bytedance.com
| * | sched/fair: Default to false in test_idle_cores()Abel Wu2022-09-071-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's uncertain whether idle cores exist or not if shared sched- domains are not ready, so returning "no idle cores" usually makes sense. While __update_idle_core() is an exception, it checks status of this core and set hint to shared sched-domain if necessary. So the whole logic of this function depends on the existence of shared sched-domain, and can certainly bail out early if it is not available. It's somehow a little tricky, and as Josh suggested that it should be transient while the domain isn't ready. So remove the self-defined default value to make things more clearer. Signed-off-by: Abel Wu <wuyun.abel@bytedance.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Josh Don <joshdon@google.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Link: https://lore.kernel.org/r/20220907112000.1854-5-wuyun.abel@bytedance.com
| * | sched/fair: Remove useless check in select_idle_core()Abel Wu2022-09-071-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The function select_idle_core() only gets called when has_idle_cores is true which can be possible only when sched_smt_present is enabled. This change also aligns select_idle_core() with select_idle_smt() in the way that the caller do the check if necessary. Signed-off-by: Abel Wu <wuyun.abel@bytedance.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Mel Gorman <mgorman@techsingularity.net> Link: https://lore.kernel.org/r/20220907112000.1854-4-wuyun.abel@bytedance.com
| * | sched/fair: Avoid double search on same cpuAbel Wu2022-09-071-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The prev cpu is checked at the beginning of SIS, and it's unlikely to be idle before the second check in select_idle_smt(). So we'd better focus on its SMT siblings. Signed-off-by: Abel Wu <wuyun.abel@bytedance.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Josh Don <joshdon@google.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Link: https://lore.kernel.org/r/20220907112000.1854-3-wuyun.abel@bytedance.com
| * | sched/fair: Remove redundant check in select_idle_smt()Abel Wu2022-09-071-7/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If two cpus share LLC cache, then the two cores they belong to are also in the same LLC domain. Signed-off-by: Abel Wu <wuyun.abel@bytedance.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Josh Don <joshdon@google.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Link: https://lore.kernel.org/r/20220907112000.1854-2-wuyun.abel@bytedance.com
| * | sched/deadline: Move __dl_clear_params out of dl_bw lockShang XiaoJing2022-09-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As members in sched_dl_entity are independent with dl_bw, move __dl_clear_params out of dl_bw lock. Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Daniel Bristot de Oliveira <bristot@kernel.org> Link: https://lore.kernel.org/r/20220827020911.30641-1-shangxiaojing@huawei.com
| * | sched/deadline: Add replenish_dl_new_period helperShang XiaoJing2022-09-011-10/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Wrap repeated code in helper function replenish_dl_new_period, which set the deadline and runtime of input dl_se based on pi_of(dl_se). Note that setup_new_dl_entity originally set the deadline and runtime base on dl_se, which should equals to pi_of(dl_se) for non-boosted task. Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Daniel Bristot de Oliveira <bristot@kernel.org> Link: https://lore.kernel.org/r/20220826100037.12146-1-shangxiaojing@huawei.com
| * | sched/deadline: Add dl_task_is_earliest_deadline helperShang XiaoJing2022-09-011-12/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Wrap repeated code in helper function dl_task_is_earliest_deadline, which return true if there is no deadline task on the rq at all, or task's deadline earlier than the whole rq. Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Daniel Bristot de Oliveira <bristot@kernel.org> Link: https://lore.kernel.org/r/20220826083453.698-1-shangxiaojing@huawei.com
| * | Merge branch 'sched/warnings' into sched/core, to pick up WARN_ON_ONCE() ↵Ingo Molnar2022-08-309-46/+94
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | conversion commit Merge in the BUG_ON() => WARN_ON_ONCE() conversion commit. Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | sched/all: Change all BUG_ON() instances in the scheduler to WARN_ON_ONCE()Ingo Molnar2022-08-127-25/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's no good reason to crash a user's system with a BUG_ON(), chances are high that they'll never even see the crash message on Xorg, and it won't make it into the syslog either. By using a WARN_ON_ONCE() we at least give the user a chance to report any bugs triggered here - instead of getting silent hangs. None of these WARN_ON_ONCE()s are supposed to trigger, ever - so we ignore cases where a NULL check is done via a BUG_ON() and we let a NULL pointer through after a WARN_ON_ONCE(). There's one exception: WARN_ON_ONCE() arguments with side-effects, such as locking - in this case we use the return value of the WARN_ON_ONCE(), such as in: - BUG_ON(!lock_task_sighand(p, &flags)); + if (WARN_ON_ONCE(!lock_task_sighand(p, &flags))) + return; Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/YvSsKcAXISmshtHo@gmail.com
| * | | sched: Add update_current_exec_runtime helperShang XiaoJing2022-08-274-17/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Wrap repeated code in helper function update_current_exec_runtime for update the exec time of the current. Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220824082856.15674-1-shangxiaojing@huawei.com
| * | | sched/fair: Don't init util/runnable_avg for !fair taskChengming Zhou2022-08-231-14/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | post_init_entity_util_avg() init task util_avg according to the cpu util_avg at the time of fork, which will decay when switched_to_fair() some time later, we'd better to not set them at all in the case of !fair task. Suggested-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20220818124805.601-10-zhouchengming@bytedance.com
| * | | sched/fair: Move task sched_avg attach to enqueue_task_fair()Chengming Zhou2022-08-231-8/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When wake_up_new_task(), we use post_init_entity_util_avg() to init util_avg/runnable_avg based on cpu's util_avg at that time, and attach task sched_avg to cfs_rq. Since enqueue_task_fair() -> enqueue_entity() -> update_load_avg() loop will do attach, we can move this work to update_load_avg(). wake_up_new_task(p) post_init_entity_util_avg(p) attach_entity_cfs_rq() --> (1) activate_task(rq, p) enqueue_task() := enqueue_task_fair() enqueue_entity() loop update_load_avg(cfs_rq, se, UPDATE_TG | DO_ATTACH) if (!se->avg.last_update_time && (flags & DO_ATTACH)) attach_entity_load_avg() --> (2) This patch move attach from (1) to (2), update related comments too. Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20220818124805.601-9-zhouchengming@bytedance.com
| * | | sched/fair: Allow changing cgroup of new forked taskChengming Zhou2022-08-232-20/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 7dc603c9028e ("sched/fair: Fix PELT integrity for new tasks") introduce a TASK_NEW state and an unnessary limitation that would fail when changing cgroup of new forked task. Because at that time, we can't handle task_change_group_fair() for new forked fair task which hasn't been woken up by wake_up_new_task(), which will cause detach on an unattached task sched_avg problem. This patch delete this unnessary limitation by adding check before do detach or attach in task_change_group_fair(). So cpu_cgrp_subsys.can_attach() has nothing to do for fair tasks, only define it in #ifdef CONFIG_RT_GROUP_SCHED. Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20220818124805.601-8-zhouchengming@bytedance.com
| * | | sched/fair: Fix another detach on unattached task corner caseChengming Zhou2022-08-231-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 7dc603c9028e ("sched/fair: Fix PELT integrity for new tasks") fixed two load tracking problems for new task, including detach on unattached new task problem. There still left another detach on unattached task problem for the task which has been woken up by try_to_wake_up() and waiting for actually being woken up by sched_ttwu_pending(). try_to_wake_up(p) cpu = select_task_rq(p) if (task_cpu(p) != cpu) set_task_cpu(p, cpu) migrate_task_rq_fair() remove_entity_load_avg() --> unattached se->avg.last_update_time = 0; __set_task_cpu() ttwu_queue(p, cpu) ttwu_queue_wakelist() __ttwu_queue_wakelist() task_change_group_fair() detach_task_cfs_rq() detach_entity_cfs_rq() detach_entity_load_avg() --> detach on unattached task set_task_rq() attach_task_cfs_rq() attach_entity_cfs_rq() attach_entity_load_avg() The reason of this problem is similar, we should check in detach_entity_cfs_rq() that se->avg.last_update_time != 0, before do detach_entity_load_avg(). Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20220818124805.601-7-zhouchengming@bytedance.com
| * | | sched/fair: Combine detach into dequeue when migrating taskChengming Zhou2022-08-231-12/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we are migrating task out of the CPU, we can combine detach and propagation into dequeue_entity() to save the detach_entity_cfs_rq() in migrate_task_rq_fair(). This optimization is like combining DO_ATTACH in the enqueue_entity() when migrating task to the CPU. So we don't have to traverse the CFS tree extra time to do the detach_entity_cfs_rq() -> propagate_entity_cfs_rq(), which wouldn't be called anymore with this patch's change. detach_task() deactivate_task() dequeue_task_fair() for_each_sched_entity(se) dequeue_entity() update_load_avg() /* (1) */ detach_entity_load_avg() set_task_cpu() migrate_task_rq_fair() detach_entity_cfs_rq() /* (2) */ update_load_avg(); detach_entity_load_avg(); propagate_entity_cfs_rq(); for_each_sched_entity() update_load_avg() This patch save the detach_entity_cfs_rq() called in (2) by doing the detach_entity_load_avg() for a CPU migrating task inside (1) (the task being the first se in the loop) Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20220818124805.601-6-zhouchengming@bytedance.com
| * | | sched/fair: Update comments in enqueue/dequeue_entity()Chengming Zhou2022-08-231-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When reading the sched_avg related code, I found the comments in enqueue/dequeue_entity() are not updated with the current code. We don't add/subtract entity's runnable_avg from cfs_rq->runnable_avg during enqueue/dequeue_entity(), those are done only for attach/detach. This patch updates the comments to reflect the current code working. Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20220818124805.601-5-zhouchengming@bytedance.com
| * | | sched/fair: Reset sched_avg last_update_time before set_task_rq()Chengming Zhou2022-08-231-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | set_task_rq() -> set_task_rq_fair() will try to synchronize the blocked task's sched_avg when migrate, which is not needed for already detached task. task_change_group_fair() will detached the task sched_avg from prev cfs_rq first, so reset sched_avg last_update_time before set_task_rq() to avoid that. Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20220818124805.601-4-zhouchengming@bytedance.com
| * | | sched/fair: Remove redundant cpu_cgrp_subsys->fork()Chengming Zhou2022-08-233-49/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We use cpu_cgrp_subsys->fork() to set task group for the new fair task in cgroup_post_fork(). Since commit b1e8206582f9 ("sched: Fix yet more sched_fork() races") has already set_task_rq() for the new fair task in sched_cgroup_fork(), so cpu_cgrp_subsys->fork() can be removed. cgroup_can_fork() --> pin parent's sched_task_group sched_cgroup_fork() __set_task_cpu() set_task_rq() cgroup_post_fork() ss->fork() := cpu_cgroup_fork() sched_change_group(..., TASK_SET_GROUP) task_set_group_fair() set_task_rq() --> can be removed After this patch's change, task_change_group_fair() only need to care about task cgroup migration, make the code much simplier. Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Link: https://lore.kernel.org/r/20220818124805.601-3-zhouchengming@bytedance.com
| * | | sched/fair: Maintain task se depth in set_task_rq()Chengming Zhou2022-08-232-8/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously we only maintain task se depth in task_move_group_fair(), if a !fair task change task group, its se depth will not be updated, so commit eb7a59b2c888 ("sched/fair: Reset se-depth when task switched to FAIR") fix the problem by updating se depth in switched_to_fair() too. Then commit daa59407b558 ("sched/fair: Unify switched_{from,to}_fair() and task_move_group_fair()") unified these two functions, moved se.depth setting to attach_task_cfs_rq(), which further into attach_entity_cfs_rq() with commit df217913e72e ("sched/fair: Factorize attach/detach entity"). This patch move task se depth maintenance from attach_entity_cfs_rq() to set_task_rq(), which will be called when CPU/cgroup change, so its depth will always be correct. This patch is preparation for the next patch. Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20220818124805.601-2-zhouchengming@bytedance.com
| * | | sched/core: Remove superfluous semicolonXin Gao2022-08-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Xin Gao <gaoxin@cdjrlc.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20220719111044.7095-1-gaoxin@cdjrlc.com
| * | | sched/fair: Make per-cpu cpumasks staticBing Huang2022-08-032-13/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The load_balance_mask and select_rq_mask percpu variables are only used in kernel/sched/fair.c. Make them static and move their allocation into init_sched_fair_class(). Replace kzalloc_node() with zalloc_cpumask_var_node() to get rid of the CONFIG_CPUMASK_OFFSTACK #ifdef and to align with per-cpu cpumask allocation for RT (local_cpu_mask in init_sched_rt_class()) and DL class (local_cpu_mask_dl in init_sched_dl_class()). [ mingo: Tidied up changelog & touched up the code. ] Signed-off-by: Bing Huang <huangbing@kylinos.cn> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20220722213609.3901-1-huangbing775@126.com
| * | | sched/fair: Remove unused parameter idle of _nohz_idle_balance()Hao Jia2022-08-031-4/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After commit 7a82e5f52a35 ("sched/fair: Merge for each idle cpu loop of ILB"), _nohz_idle_balance()'s 'idle' parameter is not used anymore, so we can remove it. Signed-off-by: Hao Jia <jiahao.os@bytedance.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20220803130223.70419-1-jiahao.os@bytedance.com
| * | | sched/debug: Print each field value left-aligned in sched_show_task()Zhen Lei2022-08-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, the values of some fields are printed right-aligned, causing the field value to be next to the next field name rather than next to its own field name. So print each field value left-aligned, to make it more readable. Before: stack: 0 pid: 307 ppid: 2 flags:0x00000008 After: stack:0 pid:308 ppid:2 flags:0x0000000a This also makes them print in the same style as the other two fields: task:demo0 state:R running task Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Valentin Schneider <vschneid@redhat.com> Link: https://lore.kernel.org/r/20220727060819.1085-1-thunder.leizhen@huawei.com
| * | | sched/deadline: Use sched_dl_entity's dl_density in dl_task_fits_capacity()Dietmar Eggemann2022-08-021-15/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Save a multiplication in dl_task_fits_capacity() by using already maintained per-sched_dl_entity (i.e. per-task) `dl_runtime/dl_deadline` (dl_density). cap_scale(dl_deadline, cap) >= dl_runtime dl_deadline * cap >> SCHED_CAPACITY_SHIFT >= dl_runtime cap >= dl_runtime << SCHED_CAPACITY_SHIFT / dl_deadline cap >= (dl_runtime << BW_SHIFT / dl_deadline) >> BW_SHIFT - SCHED_CAPACITY_SHIFT cap >= dl_density >> BW_SHIFT - SCHED_CAPACITY_SHIFT __sched_setscheduler()->__checkparam_dl() ensures that the 2 corner cases (if conditions) `runtime == RUNTIME_INF (-1)` and `period == 0` of to_ratio(deadline, runtime) are not met when setting dl_density in __sched_setscheduler()-> __setscheduler_params()->__setparam_dl(). Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20220729111305.1275158-4-dietmar.eggemann@arm.com
| * | | sched/deadline: Make dl_cpuset_cpumask_can_shrink() capacity-awareDietmar Eggemann2022-08-021-13/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | dl_cpuset_cpumask_can_shrink() is used to validate whether there is still enough CPU capacity for DL tasks in the reduced cpuset. Currently it still operates on `# remaining CPUs in the cpuset` (1). Change this to use the already capacity-aware DL admission control __dl_overflow() for the `cpumask can shrink` test. dl_b->bw = sched_rt_period << BW_SHIFT / sched_rt_period dl_b->bw * (1) >= currently allocated bandwidth in root_domain (rd) Replace (1) w/ `\Sum CPU capacity in rd >> SCHED_CAPACITY_SHIFT` Adapt __dl_bw_capacity() to take a cpumask instead of a CPU number argument so that `rd->span` and `cpumask of the reduced cpuset` can be used here. Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20220729111305.1275158-3-dietmar.eggemann@arm.com
| * | | sched/core: Introduce sched_asym_cpucap_active()Dietmar Eggemann2022-08-025-9/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Create an inline helper for conditional code to be only executed on asymmetric CPU capacity systems. This makes these (currently ~10 and future) conditions a lot more readable. Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20220729111305.1275158-2-dietmar.eggemann@arm.com
* | | | Merge tag 'for-6.1/block-2022-10-03' of git://git.kernel.dk/linuxLinus Torvalds2022-10-071-0/+2
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block updates from Jens Axboe: - NVMe pull requests via Christoph: - handle number of queue changes in the TCP and RDMA drivers (Daniel Wagner) - allow changing the number of queues in nvmet (Daniel Wagner) - also consider host_iface when checking ip options (Daniel Wagner) - don't map pages which can't come from HIGHMEM (Fabio M. De Francesco) - avoid unnecessary flush bios in nvmet (Guixin Liu) - shrink and better pack the nvme_iod structure (Keith Busch) - add comment for unaligned "fake" nqn (Linjun Bao) - print actual source IP address through sysfs "address" attr (Martin Belanger) - various cleanups (Jackie Liu, Wolfram Sang, Genjian Zhang) - handle effects after freeing the request (Keith Busch) - copy firmware_rev on each init (Keith Busch) - restrict management ioctls to admin (Keith Busch) - ensure subsystem reset is single threaded (Keith Busch) - report the actual number of tagset maps in nvme-pci (Keith Busch) - small fabrics authentication fixups (Christoph Hellwig) - add common code for tagset allocation and freeing (Christoph Hellwig) - stop using the request_queue in nvmet (Christoph Hellwig) - set min_align_mask before calculating max_hw_sectors (Rishabh Bhatnagar) - send a rediscover uevent when a persistent discovery controller reconnects (Sagi Grimberg) - misc nvmet-tcp fixes (Varun Prakash, zhenwei pi) - MD pull request via Song: - Various raid5 fix and clean up, by Logan Gunthorpe and David Sloan. - Raid10 performance optimization, by Yu Kuai. - sbitmap wakeup hang fixes (Hugh, Keith, Jan, Yu) - IO scheduler switching quisce fix (Keith) - s390/dasd block driver updates (Stefan) - support for recovery for the ublk driver (ZiyangZhang) - rnbd drivers fixes and updates (Guoqing, Santosh, ye, Christoph) - blk-mq and null_blk map fixes (Bart) - various bcache fixes (Coly, Jilin, Jules) - nbd signal hang fix (Shigeru) - block writeback throttling fix (Yu) - optimize the passthrough mapping handling (me) - prepare block cgroups to being gendisk based (Christoph) - get rid of an old PSI hack in the block layer, moving it to the callers instead where it belongs (Christoph) - blk-throttle fixes and cleanups (Yu) - misc fixes and cleanups (Liu Shixin, Liu Song, Miaohe, Pankaj, Ping-Xiang, Wolfram, Saurabh, Li Jinlin, Li Lei, Lin, Li zeming, Miaohe, Bart, Coly, Gaosheng * tag 'for-6.1/block-2022-10-03' of git://git.kernel.dk/linux: (162 commits) sbitmap: fix lockup while swapping block: add rationale for not using blk_mq_plug() when applicable block: adapt blk_mq_plug() to not plug for writes that require a zone lock s390/dasd: use blk_mq_alloc_disk blk-cgroup: don't update the blkg lookup hint in blkg_conf_prep nvmet: don't look at the request_queue in nvmet_bdev_set_limits nvmet: don't look at the request_queue in nvmet_bdev_zone_mgmt_emulate_all blk-mq: use quiesced elevator switch when reinitializing queues block: replace blk_queue_nowait with bdev_nowait nvme: remove nvme_ctrl_init_connect_q nvme-loop: use the tagset alloc/free helpers nvme-loop: store the generic nvme_ctrl in set->driver_data nvme-loop: initialize sqsize later nvme-fc: use the tagset alloc/free helpers nvme-fc: store the generic nvme_ctrl in set->driver_data nvme-fc: keep ctrl->sqsize in sync with opts->queue_size nvme-rdma: use the tagset alloc/free helpers nvme-rdma: store the generic nvme_ctrl in set->driver_data nvme-tcp: use the tagset alloc/free helpers nvme-tcp: store the generic nvme_ctrl in set->driver_data ...
| * | | | sched/psi: export psi_memstall_{enter,leave}Christoph Hellwig2022-09-201-0/+2
| | |/ / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To properly account for all refaults from file system logic, file systems need to call psi_memstall_enter directly, so export it. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Link: https://lore.kernel.org/r/20220915094200.139713-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
* | | | Merge tag 'pm-6.1-rc1' of ↵Linus Torvalds2022-10-031-15/+15
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management updates from Rafael Wysocki: "These add support for some new hardware, extend the existing hardware support, fix some issues and clean up code Specifics: - Add isupport for Tiger Lake in no-HWP mode to intel_pstate (Doug Smythies) - Update the AMD P-state driver (Perry Yuan): - Fix wrong lowest perf fetch - Map desired perf into pstate scope for powersave governor - Update pstate frequency transition delay time - Fix initial highest_perf value - Clean up - Move max CPU capacity to sugov_policy in the schedutil cpufreq governor (Lukasz Luba) - Add SM6115 to cpufreq-dt blocklist (Adam Skladowski) - Add support for Tegra239 and minor cleanups (Sumit Gupta, ye xingchen, and Yang Yingliang) - Add freq qos for qcom cpufreq driver and minor cleanups (Xuewen Yan, and Viresh Kumar) - Minor cleanups around functions called at module_init() (Xiu Jianfeng) - Use module_init and add module_exit for bmips driver (Zhang Jianhua) - Add AlderLake-N support to intel_idle (Zhang Rui) - Replace strlcpy() with unused retval with strscpy() in intel_idle (Wolfram Sang) - Remove redundant check from cpuidle_switch_governor() (Yu Liao) - Replace strlcpy() with unused retval with strscpy() in the powernv cpuidle driver (Wolfram Sang) - Drop duplicate word from a comment in the coupled cpuidle driver (Jason Wang) - Make rpm_resume() return -EINPROGRESS if RPM_NOWAIT is passed to it in the flags and the device is about to resume (Rafael Wysocki) - Add extra debugging statement for multiple active IRQs to system wakeup handling code (Mario Limonciello) - Replace strlcpy() with unused retval with strscpy() in the core system suspend support code (Wolfram Sang) - Update the intel_rapl power capping driver: - Use standard Energy Unit for SPR Dram RAPL domain (Zhang Rui). - Add support for RAPTORLAKE_S (Zhang Rui). - Fix UBSAN shift-out-of-bounds issue (Chao Qin) - Handle -EPROBE_DEFER when regulator is not probed on mtk-ci-devfreq.c (AngeloGioacchino Del Regno) - Fix message typo and use dev_err_probe() in rockchip-dfi.c (Christophe JAILLET)" * tag 'pm-6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (29 commits) cpufreq: qcom-cpufreq-hw: Add cpufreq qos for LMh cpufreq: Add __init annotation to module init funcs cpufreq: tegra194: change tegra239_cpufreq_soc to static PM / devfreq: rockchip-dfi: Fix an error message PM / devfreq: mtk-cci: Handle sram regulator probe deferral powercap: intel_rapl: Use standard Energy Unit for SPR Dram RAPL domain PM: runtime: Return -EINPROGRESS from rpm_resume() in the RPM_NOWAIT case intel_idle: Add AlderLake-N support powercap: intel_rapl: fix UBSAN shift-out-of-bounds issue cpufreq: tegra194: Add support for Tegra239 cpufreq: qcom-cpufreq-hw: Fix uninitialized throttled_freq warning cpufreq: intel_pstate: Add Tigerlake support in no-HWP mode powercap: intel_rapl: Add support for RAPTORLAKE_S cpufreq: amd-pstate: Fix initial highest_perf value cpuidle: Remove redundant check in cpuidle_switch_governor() PM: wakeup: Add extra debugging statement for multiple active IRQs cpufreq: tegra194: Remove the unneeded result variable PM: suspend: move from strlcpy() with unused retval to strscpy() intel_idle: move from strlcpy() with unused retval to strscpy() cpuidle: powernv: move from strlcpy() with unused retval to strscpy() ...
| * \ \ \ Merge branch 'pm-cpufreq'Rafael J. Wysocki2022-10-031-15/+15
| |\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge cpufreq changes for 6.1-rc1: - Add isupport for Tiger Lake in no-HWP mode to intel_pstate (Doug Smythies). - Update the AMD P-state driver (Perry Yuan): * Fix wrong lowest perf fetch. * Map desired perf into pstate scope for powersave governor. * Update pstate frequency transition delay time. * Fix initial highest_perf value. * Clean up. - Move max CPU capacity to sugov_policy in the schedutil cpufreq governor (Lukasz Luba). - Add SM6115 to cpufreq-dt blocklist (Adam Skladowski). - Add support for Tegra239 and minor cleanups (Sumit Gupta, ye xingchen, and Yang Yingliang). - Add freq qos for qcom cpufreq driver and minor cleanups (Xuewen Yan, and Viresh Kumar). - Minor cleanups around functions called at module_init() (Xiu Jianfeng). - Use module_init and add module_exit for bmips driver (Zhang Jianhua). * pm-cpufreq: cpufreq: qcom-cpufreq-hw: Add cpufreq qos for LMh cpufreq: Add __init annotation to module init funcs cpufreq: tegra194: change tegra239_cpufreq_soc to static cpufreq: tegra194: Add support for Tegra239 cpufreq: qcom-cpufreq-hw: Fix uninitialized throttled_freq warning cpufreq: intel_pstate: Add Tigerlake support in no-HWP mode cpufreq: amd-pstate: Fix initial highest_perf value cpufreq: tegra194: Remove the unneeded result variable cpufreq: amd-pstate: update pstate frequency transition delay time cpufreq: amd_pstate: map desired perf into pstate scope for powersave governor cpufreq: amd_pstate: fix wrong lowest perf fetch cpufreq: amd-pstate: fix white-space cpufreq: amd-pstate: simplify cpudata pointer assignment cpufreq: bmips-cpufreq: Use module_init and add module_exit cpufreq: schedutil: Move max CPU capacity to sugov_policy cpufreq: Add SM6115 to cpufreq-dt-platdev blocklist
| | * | | | cpufreq: schedutil: Move max CPU capacity to sugov_policyLukasz Luba2022-08-231-15/+15
| | |/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is no need to keep the max CPU capacity in the per_cpu instance. Furthermore, there is no need to check and update that variable (sg_cpu->max) every time in the frequency change request, which is part of hot path. Instead use struct sugov_policy to store that information. Initialize the max CPU capacity during the setup and start callback. We can do that since all CPUs in the same frequency domain have the same max capacity (capacity setup and thermal pressure are based on that). Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Lukasz Luba <lukasz.luba@arm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* | | | | Merge tag 'rcu.2022.09.30a' of ↵Linus Torvalds2022-10-031-0/+14
|\ \ \ \ \ | |/ / / / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu Pull RCU updates from Paul McKenney: - Documentation updates. This is the first in a series from an ongoing review of the RCU documentation. "Why are people thinking -that- about RCU? Oh. Because that is an entirely reasonable interpretation of its documentation." - Miscellaneous fixes. - Improved memory allocation and heuristics. - Improve rcu_nocbs diagnostic output. - Add full-sized polled RCU grace period state values. These are the same size as an rcu_head structure, which is double that of the traditional unsigned long state values that may still be obtained from et_state_synchronize_rcu(). The added size avoids missing overlapping grace periods. This benefit is that call_rcu() can be replaced by polling, which can be attractive in situations where RCU-protected data is aged out of memory. Early in the series, the size of this state value is three unsigned longs. Later in the series, the fastpaths in synchronize_rcu() and synchronize_rcu_expedited() are reworked to permit the full state to be represented by only two unsigned longs. This reworking slows these two functions down in SMP kernels running either on single-CPU systems or on systems with all but one CPU offlined, but this should not be a significant problem. And if it somehow becomes a problem in some yet-as-unforeseen situations, three-value state values can be provided for only those situations. Finally, a pair of functions named same_state_synchronize_rcu() and same_state_synchronize_rcu_full() allow grace-period state values to be compared for equality. This permits users to maintain lists of data structures having the same state value, removing the need for per-data-structure grace-period state values, thus decreasing memory footprint. - Polled SRCU grace-period updates, including adding tests to rcutorture and reducing the incidence of Tiny SRCU grace-period-state counter wrap. - Improve Tasks RCU diagnostics and quiescent-state detection. * tag 'rcu.2022.09.30a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (55 commits) rcutorture: Use the barrier operation specified by cur_ops rcu-tasks: Make RCU Tasks Trace check for userspace execution rcu-tasks: Ensure RCU Tasks Trace loops have quiescent states rcu-tasks: Convert RCU_LOCKDEP_WARN() to WARN_ONCE() srcu: Make Tiny SRCU use full-sized grace-period counters srcu: Make Tiny SRCU poll_state_synchronize_srcu() more precise srcu: Add GP and maximum requested GP to Tiny SRCU rcutorture output rcutorture: Make "srcud" option also test polled grace-period API rcutorture: Limit read-side polling-API testing rcu: Add functions to compare grace-period state values rcutorture: Expand rcu_torture_write_types() first "if" statement rcutorture: Use 1-suffixed variable in rcu_torture_write_types() check rcu: Make synchronize_rcu() fastpath update only boot-CPU counters rcutorture: Adjust rcu_poll_need_2gp() for rcu_gp_oldstate field removal rcu: Remove ->rgos_polled field from rcu_gp_oldstate structure rcu: Make synchronize_rcu_expedited() fast path update .expedited_sequence rcu: Remove expedited grace-period fast-path forward-progress helper rcu: Make synchronize_rcu() fast path update ->gp_seq counters rcu-tasks: Remove grace-period fast-path rcu-tasks helper rcu: Set rcu_data structures' initial ->gpwrap value to true ...
| * | | | sched/debug: Show the registers of 'current' in dump_cpu_task()Zhen Lei2022-08-311-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The dump_cpu_task() function does not print registers on architectures that do not support NMIs. However, registers can be useful for debugging. Fortunately, in the case where dump_cpu_task() is invoked from an interrupt handler and is dumping the current CPU's stack, the get_irq_regs() function can be used to get the registers. Therefore, this commit makes dump_cpu_task() check to see if it is being asked to dump the current CPU's stack from within an interrupt handler, and, if so, it uses the get_irq_regs() function to obtain the registers. On systems that do support NMIs, this commit has the further advantage of avoiding a self-NMI in this case. This is an example of rcu self-detected stall on arm64, which does not support NMIs: [ 27.501721] rcu: INFO: rcu_preempt self-detected stall on CPU [ 27.502238] rcu: 0-....: (1250 ticks this GP) idle=4f7/1/0x4000000000000000 softirq=2594/2594 fqs=619 [ 27.502632] (t=1251 jiffies g=2989 q=29 ncpus=4) [ 27.503845] CPU: 0 PID: 306 Comm: test0 Not tainted 5.19.0-rc7-00009-g1c1a6c29ff99-dirty #46 [ 27.504732] Hardware name: linux,dummy-virt (DT) [ 27.504947] pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 27.504998] pc : arch_counter_read+0x18/0x24 [ 27.505301] lr : arch_counter_read+0x18/0x24 [ 27.505328] sp : ffff80000b29bdf0 [ 27.505345] x29: ffff80000b29bdf0 x28: 0000000000000000 x27: 0000000000000000 [ 27.505475] x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000 [ 27.505553] x23: 0000000000001f40 x22: ffff800009849c48 x21: 000000065f871ae0 [ 27.505627] x20: 00000000000025ec x19: ffff80000a6eb300 x18: ffffffffffffffff [ 27.505654] x17: 0000000000000001 x16: 0000000000000000 x15: ffff80000a6d0296 [ 27.505681] x14: ffffffffffffffff x13: ffff80000a29bc18 x12: 0000000000000426 [ 27.505709] x11: 0000000000000162 x10: ffff80000a2f3c18 x9 : ffff80000a29bc18 [ 27.505736] x8 : 00000000ffffefff x7 : ffff80000a2f3c18 x6 : 00000000759bd013 [ 27.505761] x5 : 01ffffffffffffff x4 : 0002dc6c00000000 x3 : 0000000000000017 [ 27.505787] x2 : 00000000000025ec x1 : ffff80000b29bdf0 x0 : 0000000075a30653 [ 27.505937] Call trace: [ 27.506002] arch_counter_read+0x18/0x24 [ 27.506171] ktime_get+0x48/0xa0 [ 27.506207] test_task+0x70/0xf0 [ 27.506227] kthread+0x10c/0x110 [ 27.506243] ret_from_fork+0x10/0x20 This is a marked improvement over the old output: [ 27.944550] rcu: INFO: rcu_preempt self-detected stall on CPU [ 27.944980] rcu: 0-....: (1249 ticks this GP) idle=cbb/1/0x4000000000000000 softirq=2610/2610 fqs=614 [ 27.945407] (t=1251 jiffies g=2681 q=28 ncpus=4) [ 27.945731] Task dump for CPU 0: [ 27.945844] task:test0 state:R running task stack: 0 pid: 306 ppid: 2 flags:0x0000000a [ 27.946073] Call trace: [ 27.946151] dump_backtrace.part.0+0xc8/0xd4 [ 27.946378] show_stack+0x18/0x70 [ 27.946405] sched_show_task+0x150/0x180 [ 27.946427] dump_cpu_task+0x44/0x54 [ 27.947193] rcu_dump_cpu_stacks+0xec/0x130 [ 27.947212] rcu_sched_clock_irq+0xb18/0xef0 [ 27.947231] update_process_times+0x68/0xac [ 27.947248] tick_sched_handle+0x34/0x60 [ 27.947266] tick_sched_timer+0x4c/0xa4 [ 27.947281] __hrtimer_run_queues+0x178/0x360 [ 27.947295] hrtimer_interrupt+0xe8/0x244 [ 27.947309] arch_timer_handler_virt+0x38/0x4c [ 27.947326] handle_percpu_devid_irq+0x88/0x230 [ 27.947342] generic_handle_domain_irq+0x2c/0x44 [ 27.947357] gic_handle_irq+0x44/0xc4 [ 27.947376] call_on_irq_stack+0x2c/0x54 [ 27.947415] do_interrupt_handler+0x80/0x94 [ 27.947431] el1_interrupt+0x34/0x70 [ 27.947447] el1h_64_irq_handler+0x18/0x24 [ 27.947462] el1h_64_irq+0x64/0x68 <--- the above backtrace is worthless [ 27.947474] arch_counter_read+0x18/0x24 [ 27.947487] ktime_get+0x48/0xa0 [ 27.947501] test_task+0x70/0xf0 [ 27.947520] kthread+0x10c/0x110 [ 27.947538] ret_from_fork+0x10/0x20 Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Ben Segall <bsegall@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Valentin Schneider <vschneid@redhat.com>
| * | | | sched/debug: Try trigger_single_cpu_backtrace(cpu) in dump_cpu_task()Zhen Lei2022-08-311-0/+3
| |/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The trigger_all_cpu_backtrace() function attempts to send an NMI to the target CPU, which usually provides much better stack traces than the dump_cpu_task() function's approach of dumping that stack from some other CPU. So much so that most calls to dump_cpu_task() only happen after a call to trigger_all_cpu_backtrace() has failed. And the exception to this rule really should attempt to use trigger_all_cpu_backtrace() first. Therefore, move the trigger_all_cpu_backtrace() invocation into dump_cpu_task(). Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Ben Segall <bsegall@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Valentin Schneider <vschneid@redhat.com>
* | | | Merge tag 'driver-core-6.0-rc5' of ↵Linus Torvalds2022-09-091-1/+1
|\ \ \ \ | |_|_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core fixes from Greg KH: "Here are some small driver core and debugfs fixes for 6.0-rc5. Included in here are: - multiple attempts to get the arch_topology code to work properly on non-cluster SMT systems. First attempt caused build breakages in linux-next and 0-day, second try worked. - debugfs fixes for a long-suffering memory leak. The pattern of debugfs_remove(debugfs_lookup(...)) turns out to leak dentries, so add debugfs_lookup_and_remove() to fix this problem. Also fix up the scheduler debug code that highlighted this problem. Fixes for other subsystems will be trickling in over the next few months for this same issue once the debugfs function is merged. All of these have been in linux-next since Wednesday with no reported problems" * tag 'driver-core-6.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: arch_topology: Make cluster topology span at least SMT CPUs sched/debug: fix dentry leak in update_sched_domain_debugfs debugfs: add debugfs_lookup_and_remove() driver core: fix driver_set_override() issue with empty strings Revert "arch_topology: Make cluster topology span at least SMT CPUs" arch_topology: Make cluster topology span at least SMT CPUs
| * | | sched/debug: fix dentry leak in update_sched_domain_debugfsGreg Kroah-Hartman2022-09-051-1/+1
| |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Kuyo reports that the pattern of using debugfs_remove(debugfs_lookup()) leaks a dentry and with a hotplug stress test, the machine eventually runs out of memory. Fix this up by using the newly created debugfs_lookup_and_remove() call instead which properly handles the dentry reference counting logic. Cc: Major Chen <major.chen@samsung.com> Cc: stable <stable@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ben Segall <bsegall@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Matthias Brugger <matthias.bgg@gmail.com> Reported-by: Kuyo Chang <kuyo.chang@mediatek.com> Tested-by: Kuyo Chang <kuyo.chang@mediatek.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220902123107.109274-2-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | | wait_on_bit: add an acquire memory barrierMikulas Patocka2022-08-261-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are several places in the kernel where wait_on_bit is not followed by a memory barrier (for example, in drivers/md/dm-bufio.c:new_read). On architectures with weak memory ordering, it may happen that memory accesses that follow wait_on_bit are reordered before wait_on_bit and they may return invalid data. Fix this class of bugs by introducing a new function "test_bit_acquire" that works like test_bit, but has acquire memory ordering semantics. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Acked-by: Will Deacon <will@kernel.org> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | sched/psi: Remove unused parameter nbytes of psi_trigger_create()Hao Jia2022-08-151-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | psi_trigger_create()'s 'nbytes' parameter is not used, so we can remove it. Signed-off-by: Hao Jia <jiahao.os@bytedance.com> Reviewed-by: Ingo Molnar <mingo@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Tejun Heo <tj@kernel.org>
* | | sched/psi: Zero the memory of struct psi_groupHao Jia2022-08-151-5/+1
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After commit 5f69a6577bc3 ("psi: dont alloc memory for psi by default"), the memory used by struct psi_group is no longer allocated and zeroed in cgroup_create(). Since the memory of struct psi_group is not zeroed, the data in this memory is random, which will lead to inaccurate psi statistics when creating a new cgroup. So we use kzlloc() to allocate and zero the struct psi_group and remove the redundant zeroing in group_init(). Steps to reproduce: 1. Use cgroup v2 and enable CONFIG_PSI 2. Create a new cgroup, and query psi statistics mkdir /sys/fs/cgroup/test cat /sys/fs/cgroup/test/cpu.pressure some avg10=0.00 avg60=0.00 avg300=47927752200.00 total=12884901 full avg10=561815124.00 avg60=125835394188.00 avg300=1077090462000.00 total=10273561772 cat /sys/fs/cgroup/test/io.pressure some avg10=1040093132823.95 avg60=1203770351379.21 avg300=3862252669559.46 total=4294967296 full avg10=921884564601.39 avg60=0.00 avg300=1984507298.35 total=442381631 cat /sys/fs/cgroup/test/memory.pressure some avg10=232476085778.11 avg60=0.00 avg300=0.00 total=0 full avg10=0.00 avg60=0.00 avg300=2585658472280.57 total=12884901 Fixes: commit 5f69a6577bc3 ("psi: dont alloc memory for psi by default") Signed-off-by: Hao Jia <jiahao.os@bytedance.com> Reviewed-by: Ingo Molnar <mingo@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Tejun Heo <tj@kernel.org>
* | Merge tag 'sched-urgent-2022-08-06' of ↵Linus Torvalds2022-08-062-8/+15
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar: "Various fixes: a deadline scheduler fix, a migration fix, a Sparse fix and a comment fix" * tag 'sched-urgent-2022-08-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/core: Do not requeue task on CPU excluded from cpus_mask sched/rt: Fix Sparse warnings due to undefined rt.c declarations exit: Fix typo in comment: s/sub-theads/sub-threads sched, cpuset: Fix dl_cpu_busy() panic due to empty cs->cpus_allowed
generated by cgit v1.2.3 (git 2.25.1) at 2025-03-22 08:22:48 +0000