Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 040ec23d authored by Ingo Molnar's avatar Ingo Molnar
Browse files

sched: sched_clock() lockdep fix 



Sitsofe Wheeler bisected the following commit to cause a lockdep to
warn about itself and turn itself off:

> commit c6531cce
> Author: Ingo Molnar <mingo@elte.hu>
> Date:   Mon May 12 21:21:14 2008 +0200
>
>     sched: do not trace sched_clock

do not use raw irq flags in cpu_clock() as it causes lockdep to lose
track of the true state of the IRQ flag.

Reported-and-bisected-by: default avatarSitsofe Wheeler <sitsofe@yahoo.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 34078a5e

kernel/sched.c

+2 −2
Original line number Diff line number Diff line
@@ -889,7 +889,7 @@ unsigned long long notrace cpu_clock(int cpu) 
	unsigned long long prev_cpu_time, time, delta_time;

	unsigned long flags;



	raw_local_irq_save(flags);

	local_irq_save(flags);

	prev_cpu_time = per_cpu(prev_cpu_time, cpu);

	time = __cpu_clock(cpu) + per_cpu(time_offset, cpu);

	delta_time = time-prev_cpu_time;
@@ -898,7 +898,7 @@ unsigned long long notrace cpu_clock(int cpu) 
		time = __sync_cpu_clock(time, cpu);

		per_cpu(prev_cpu_time, cpu) = time;

	}

	raw_local_irq_restore(flags);

	local_irq_restore(flags);



	return time;

}