From: Nick Piggin <nickpiggin@yahoo.com.au>
Hmm, patch 3/4 added the following comment:
/* FIXME: updates to ->parent are racy */
After getting some sleep, it appears to be easily fixed instead of leaving the
FIXME for someone else ;)
This is probably faster too because you're not doing the additional
local_irq_save/restore pair.
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/kernel/sched.c | 13 +++++--------
1 files changed, 5 insertions(+), 8 deletions(-)
diff -puN kernel/sched.c~sched-exit-race kernel/sched.c
--- 25/kernel/sched.c~sched-exit-race 2004-06-25 02:50:09.643107192 -0700
+++ 25-akpm/kernel/sched.c 2004-06-25 02:50:09.649106280 -0700
@@ -1051,19 +1051,16 @@ void fastcall sched_exit(task_t * p)
unsigned long flags;
runqueue_t *rq;
- local_irq_save(flags);
- if (p->first_time_slice) {
- /* FIXME: updates to ->parent are racy */
- p->parent->time_slice += p->time_slice;
- if (unlikely(p->parent->time_slice > MAX_TIMESLICE))
- p->parent->time_slice = MAX_TIMESLICE;
- }
- local_irq_restore(flags);
/*
* If the child was a (relative-) CPU hog then decrease
* the sleep_avg of the parent as well.
*/
rq = task_rq_lock(p->parent, &flags);
+ if (p->first_time_slice) {
+ p->parent->time_slice += p->time_slice;
+ if (unlikely(p->parent->time_slice > MAX_TIMESLICE))
+ p->parent->time_slice = MAX_TIMESLICE;
+ }
if (p->sleep_avg < p->parent->sleep_avg)
p->parent->sleep_avg = p->parent->sleep_avg /
(EXIT_WEIGHT + 1) * EXIT_WEIGHT + p->sleep_avg /
_