From: Thomas Gleixner Problem description at: http://bugzilla.kernel.org/show_bug.cgi?id=8048 Commit b18ec80396834497933d77b81ec0918519f4e2a7 [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 Acked-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- kernel/sched.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- linux-2.6.20.1.orig/kernel/sched.c +++ linux-2.6.20.1/kernel/sched.c @@ -3547,7 +3547,7 @@ 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; -- - 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/