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| author | Peter Zijlstra <peterz@infradead.org> | 2021-06-11 10:28:13 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2021-06-18 11:43:07 +0200 |
| commit | 3ba9f93b12361e005dd65fcc8072b42e3189f4f4 (patch) | |
| tree | ff7b3224fb4f03ea17ac76b0d1ad0c2431d0a7ab | |
| parent | b03fbd4ff24c5f075e58eb19261d5f8b3e40d7c6 (diff) | |
| download | linux-3ba9f93b12361e005dd65fcc8072b42e3189f4f4.tar.bz2 | |
sched,perf,kvm: Fix preemption condition
When ran from the sched-out path (preempt_notifier or perf_event),
p->state is irrelevant to determine preemption. You can get preempted
with !task_is_running() just fine.
The right indicator for preemption is if the task is still on the
runqueue in the sched-out path.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20210611082838.285099381@infradead.org
| -rw-r--r-- | kernel/events/core.c | 7 | ||||
| -rw-r--r-- | virt/kvm/kvm_main.c | 2 |
2 files changed, 4 insertions, 5 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index fe88d6eea3c2..fd89000c9bf5 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -8682,13 +8682,12 @@ static void perf_event_switch(struct task_struct *task, }, }; - if (!sched_in && task->state == TASK_RUNNING) + if (!sched_in && task->on_rq) { switch_event.event_id.header.misc |= PERF_RECORD_MISC_SWITCH_OUT_PREEMPT; + } - perf_iterate_sb(perf_event_switch_output, - &switch_event, - NULL); + perf_iterate_sb(perf_event_switch_output, &switch_event, NULL); } /* diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 6a6bc7af0e28..5f166eb8ee2e 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -5025,7 +5025,7 @@ static void kvm_sched_out(struct preempt_notifier *pn, { struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn); - if (current->state == TASK_RUNNING) { + if (current->on_rq) { WRITE_ONCE(vcpu->preempted, true); WRITE_ONCE(vcpu->ready, true); } |