lkml.org 
[lkml]   [2007]   [Feb]   [22]   [last100]   RSS Feed
Views: [more markup]  [less markup]  [headers]  [forward] 
 
Messages in this thread
/
DateThu, 22 Feb 2007 08:46:24 +0100
FromIngo Molnar <>
SubjectRe: [PATCH] Fix posix-cpu-timer breakage caused by stale p->last_ran value
* Thomas Gleixner <tglx@linutronix.de> wrote:

> The problem is that the p->last_ran value is not updated after a 
> context switch. So a subsequent call to current_sched_time() 
> calculates with a stale p->last_ran value, i.e. accounts the full 
> time, which the task was scheduled away.
> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

>  	sched_info_switch(prev, next);
>  	if (likely(prev != next)) {
> -		next->timestamp = now;
> +		next->timestamp = next->last_ran = now;

ouch! nice catch. Also for v2.6.20.2 i think. 2.6.19 should be 
unaffected.

Acked-by: Ingo Molnar <mingo@elte.hu>

	Ingo
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-02-22 08:53    [from the cache]
©2003-2008