diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2024-07-01 21:38:11 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2024-08-17 11:06:44 +0200 |
| commit | e1459a50ba31831efdfc35278023d959e4ba775b (patch) | |
| tree | fab2d16fe841769e869950db14649853bc4f93ef | |
| parent | a1c446611e31ca5363d4db51e398271da1dce0af (diff) | |
sched: Teach dequeue_task() about special task states
Since special task states must not suffer spurious wakeups, and the
proposed delayed dequeue can cause exactly these (under some boundary
conditions), propagate this knowledge into dequeue_task() such that it
can do the right thing.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Tested-by: Valentin Schneider <vschneid@redhat.com>
Link: https://lkml.kernel.org/r/20240727105030.110439521@infradead.org
| -rw-r--r-- | kernel/sched/core.c | 7 | ||||
| -rw-r--r-- | kernel/sched/sched.h | 3 |
2 files changed, 8 insertions, 2 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 80e639e23140..868b71b9f2e4 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -6530,11 +6530,16 @@ static void __sched notrace __schedule(unsigned int sched_mode) if (signal_pending_state(prev_state, prev)) { WRITE_ONCE(prev->__state, TASK_RUNNING); } else { + int flags = DEQUEUE_NOCLOCK; + prev->sched_contributes_to_load = (prev_state & TASK_UNINTERRUPTIBLE) && !(prev_state & TASK_NOLOAD) && !(prev_state & TASK_FROZEN); + if (unlikely(is_special_task_state(prev_state))) + flags |= DEQUEUE_SPECIAL; + /* * __schedule() ttwu() * prev_state = prev->state; if (p->on_rq && ...) @@ -6546,7 +6551,7 @@ static void __sched notrace __schedule(unsigned int sched_mode) * * After this, schedule() must not care about p->state any more. */ - block_task(rq, prev, DEQUEUE_NOCLOCK); + block_task(rq, prev, flags); } switch_count = &prev->nvcsw; } diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index ffca9779519c..263b4ded2b47 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -2248,10 +2248,11 @@ extern const u32 sched_prio_to_wmult[40]; * */ -#define DEQUEUE_SLEEP 0x01 +#define DEQUEUE_SLEEP 0x01 /* Matches ENQUEUE_WAKEUP */ #define DEQUEUE_SAVE 0x02 /* Matches ENQUEUE_RESTORE */ #define DEQUEUE_MOVE 0x04 /* Matches ENQUEUE_MOVE */ #define DEQUEUE_NOCLOCK 0x08 /* Matches ENQUEUE_NOCLOCK */ +#define DEQUEUE_SPECIAL 0x10 #define DEQUEUE_MIGRATING 0x100 /* Matches ENQUEUE_MIGRATING */ #define DEQUEUE_DELAYED 0x200 /* Matches ENQUEUE_DELAYED */ |