sched: Be more strict about p->is_blocked

Upon entry to try_to_block_task(), p->is_blocked should be false. After all, the prior wakeup would have made it so per ttwu_do_wakeup(). Ensure this is the case, rather than clearing it in the path that doesn't set it.

Peter Zijlstra committed 5 months ago

Commit 708024b1 parent abc40cc1 file · +2 −1Browse files

Showing the changes to kernel (1 of 1 file). Show all

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kernel/sched/core.c+2−1

@@ -6676,8 +6676,9 @@ static bool try_to_block_task(struct rq rq, struct task_struct p, · 6675 unmodified lines
6676	6676	{
6677	6677	unsigned long task_state = *task_state_p;
6678	6678
	6679	+ WARN_ON_ONCE(p->is_blocked);
	6680	+
6679	6681	if (signal_pending_state(task_state, p)) {
6680		− p->is_blocked = 0;
6681	6682	WRITE_ONCE(p->__state, TASK_RUNNING);
6682	6683	*task_state_p = TASK_RUNNING;
6683	6684	clear_task_blocked_on(p, NULL);