From bd091346971c88fccd44afd2547d28366f824572 Mon Sep 17 00:00:00 2001 From: Hui Su Date: Fri, 16 Oct 2026 10:09:44 +0900 Subject: [PATCH] sched/idle: Use hrtimer cleanup class in play_idle_precise() Pair on-stack setup with destruction using the hrtimer_on_stack cleanup class in play_idle_precise(). Keep the cleanup object's scope around timer start and the idle wait. Start the timer in pinned hard mode, so its callback runs as a hardirq on the current CPU. The interrupted task observes it.done only after the callback returns. Since the callback returns HRTIMER_NORESTART, the timer is not requeued before the cleanup object tears down its on-stack debug object. Fixes: c1de45ca831a ("sched/idle: Add support for tasks that inject idle") Signed-off-by: Hui Su Signed-off-by: Thomas Gleixner Link: https://patch.msgid.link/eccd97b2003a16291817974798cbe98b25b582a0.1792083743.git.sh_def@163.com --- kernel/sched/idle.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c index eb73b65ce6c4..2880e01368b8 100644 --- a/kernel/sched/idle.c +++ b/kernel/sched/idle.c @@ -429,13 +429,17 @@ void play_idle_precise(u64 duration_ns, u64 latency_ns) cpuidle_use_deepest_state(latency_ns); it.done = 0; - hrtimer_setup_on_stack(&it.timer, idle_inject_timer_fn, CLOCK_MONOTONIC, - HRTIMER_MODE_REL_HARD); - hrtimer_start(&it.timer, ns_to_ktime(duration_ns), - HRTIMER_MODE_REL_PINNED_HARD); + { + CLASS(hrtimer_on_stack, timer)(&it.timer, idle_inject_timer_fn, + CLOCK_MONOTONIC, + HRTIMER_MODE_REL_HARD); - while (!READ_ONCE(it.done)) - do_idle(); + hrtimer_start(timer, ns_to_ktime(duration_ns), + HRTIMER_MODE_REL_PINNED_HARD); + + while (!READ_ONCE(it.done)) + do_idle(); + } cpuidle_use_deepest_state(0); current->flags &= ~PF_IDLE;