From 8f9fbf092cd0ae31722b42c9abb427a87d55c18a Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Tue, 7 Oct 2014 21:51:08 +0200 Subject: sched: Fix the PREEMPT_ACTIVE check in __trace_sched_switch_state() task_preempt_count() has nothing to do with the actual preempt counter, thread_info->saved_preempt_count is only valid right after switch_to(). __trace_sched_switch_state() can use preempt_count(), prev is still the current task when trace_sched_switch() is called. Signed-off-by: Oleg Nesterov [ Added BUG_ON(). ] Signed-off-by: Peter Zijlstra (Intel) Cc: Andrew Morton Cc: Andy Lutomirski Cc: Linus Torvalds Cc: Mel Gorman Cc: Oleg Nesterov Cc: Steven Rostedt Link: http://lkml.kernel.org/r/20141007195108.GB28002@redhat.com Signed-off-by: Ingo Molnar --- include/trace/events/sched.h | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'include/trace') diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h index 0a68d5ae584e..30fedaf3e56a 100644 --- a/include/trace/events/sched.h +++ b/include/trace/events/sched.h @@ -97,16 +97,19 @@ static inline long __trace_sched_switch_state(struct task_struct *p) long state = p->state; #ifdef CONFIG_PREEMPT +#ifdef CONFIG_SCHED_DEBUG + BUG_ON(p != current); +#endif /* CONFIG_SCHED_DEBUG */ /* * For all intents and purposes a preempted task is a running task. */ - if (task_preempt_count(p) & PREEMPT_ACTIVE) + if (preempt_count() & PREEMPT_ACTIVE) state = TASK_RUNNING | TASK_STATE_MAX; -#endif +#endif /* CONFIG_PREEMPT */ return state; } -#endif +#endif /* CREATE_TRACE_POINTS */ /* * Tracepoint for task switches, performed by the scheduler: -- cgit v1.2.3-59-g8ed1b