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| author |   Peter Zijlstra <peterz@infradead.org> | 2022-09-06 12:39:55 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2022-09-07 21:53:49 +0200 |
| commit | f9fc8cad9728124cefe8844fb53d1814c92c6bfc (patch) | |
| tree | 1d8a1b332af2b0f921951310852284b8e556f162 /kernel/sched/core.c | |
| parent | sched: Change wait_task_inactive()s match_state (diff) | |
| download | linux-dev-f9fc8cad9728124cefe8844fb53d1814c92c6bfc.tar.xz linux-dev-f9fc8cad9728124cefe8844fb53d1814c92c6bfc.zip | |
sched: Add TASK_ANY for wait_task_inactive()
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
Diffstat (limited to '')
| -rw-r--r-- | kernel/sched/core.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 43d71c696125..ea26526b45bb 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3253,12 +3253,12 @@ out: /* * wait_task_inactive - wait for a thread to unschedule. * - * If @match_state is nonzero, it's the @p->state value just checked and - * not expected to change. If it changes, i.e. @p might have woken up, - * then return zero. When we succeed in waiting for @p to be off its CPU, - * we return a positive number (its total switch count). If a second call - * a short while later returns the same number, the caller can be sure that - * @p has remained unscheduled the whole time. + * Wait for the thread to block in any of the states set in @match_state. + * If it changes, i.e. @p might have woken up, then return zero. When we + * succeed in waiting for @p to be off its CPU, we return a positive number + * (its total switch count). If a second call a short while later returns the + * same number, the caller can be sure that @p has remained unscheduled the + * whole time. * * The caller must ensure that the task *will* unschedule sometime soon, * else this function might spin for a *long* time. This function can't @@ -3294,7 +3294,7 @@ unsigned long wait_task_inactive(struct task_struct *p, unsigned int match_state * is actually now running somewhere else! */ while (task_on_cpu(rq, p)) { - if (match_state && !(READ_ONCE(p->__state) & match_state)) + if (!(READ_ONCE(p->__state) & match_state)) return 0; cpu_relax(); } @@ -3309,7 +3309,7 @@ unsigned long wait_task_inactive(struct task_struct *p, unsigned int match_state running = task_on_cpu(rq, p); queued = task_on_rq_queued(p); ncsw = 0; - if (!match_state || (READ_ONCE(p->__state) & match_state)) + if (READ_ONCE(p->__state) & match_state) ncsw = p->nvcsw | LONG_MIN; /* sets MSB */ task_rq_unlock(rq, p, &rf); |