diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2024-10-10 11:38:10 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2024-10-14 09:14:35 +0200 |
| commit | cd9626e9ebc77edec33023fe95dab4b04ffc819d (patch) | |
| tree | f634627362f80150130afc99ccda5cf58e584614 /kernel/events | |
| parent | c6508124193d42bbc3224571eb75bfa4c1821fbb (diff) | |
sched/fair: Fix external p->on_rq users
Sean noted that ever since commit 152e11f6df29 ("sched/fair: Implement
delayed dequeue") KVM's preemption notifiers have started
mis-classifying preemption vs blocking.
Notably p->on_rq is no longer sufficient to determine if a task is
runnable or blocked -- the aforementioned commit introduces tasks that
remain on the runqueue even through they will not run again, and
should be considered blocked for many cases.
Add the task_is_runnable() helper to classify things and audit all
external users of the p->on_rq state. Also add a few comments.
Fixes: 152e11f6df29 ("sched/fair: Implement delayed dequeue")
Reported-by: Sean Christopherson <seanjc@google.com>
Tested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20241010091843.GK33184@noisy.programming.kicks-ass.net
Diffstat (limited to 'kernel/events')
| -rw-r--r-- | kernel/events/core.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index e3589c4287cb..cdd09769e6c5 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -9251,7 +9251,7 @@ static void perf_event_switch(struct task_struct *task, }, }; - if (!sched_in && task->on_rq) { + if (!sched_in && task_is_runnable(task)) { switch_event.event_id.header.misc |= PERF_RECORD_MISC_SWITCH_OUT_PREEMPT; } |