OpenE2K
/
linux
6
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

[PATCH] Fix posix-cpu-timer breakage caused by stale p->last_ran value 

Problem description at:
http://bugzilla.kernel.org/show_bug.cgi?id=8048

Commit b18ec80396
    [PATCH] sched: improve migration accuracy
optimized the scheduler time calculations, but broke posix-cpu-timers.

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>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Thomas Gleixner 2007-02-28 20:12:19 -08:00 committed by Linus Torvalds
parent ae73fc093a
commit c1e16aa279
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
kernel/sched.c
View File

@ -3566,7 +3566,7 @@ switch_tasks:
sched_info_switch(prev, next);
if (likely(prev != next)) {
next->timestamp = now;
next->timestamp = next->last_ran = now;
rq->nr_switches++;
rq->curr = next;
++*switch_count;