Re: BUG: scheduling while atomic - Linux 2.6.20-rc2-ga3d89517

From: Fabio Comolli
Date: Mon Dec 25 2006 - 14:03:11 EST

OK, I applied your patch to yesterday's Linus' GIT. I will run it for
some days and will let you know if the problem represents. Please note
that it happened only twice and I don't have any clue on how to
reproduce it.

I added Pavel and Rafael to CC-list because for the first time in at
least six months my laptop failed to resume after suspend-to-disk
(userland tools) with this kernel. Guys, do you think that this
failure could be related to this BUG?

Best regards and Happy Holidays,

On 12/24/06, OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx> wrote:
"Fabio Comolli" <fabio.comolli@xxxxxxxxx> writes:

> Just found this in syslog. It was during normal activity, about 6
> minutes after resume-from-ram. I never saw this before.

It seems someone missed to check PREEMPT_ACTIVE in __resched_legal().
Could you please test the following patch?
OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx>

Signed-off-by: OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx>

kernel/sched.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff -puN kernel/sched.c~__resched_legal kernel/sched.c
--- linux-2.6/kernel/sched.c~__resched_legal 2006-12-24 22:40:19.000000000 +0900
+++ linux-2.6-hirofumi/kernel/sched.c 2006-12-24 23:54:01.000000000 +0900
@@ -4619,10 +4619,11 @@ asmlinkage long sys_sched_yield(void)

static inline int __resched_legal(int expected_preempt_count)
+ expected_preempt_count = 0;
if (unlikely(preempt_count() != expected_preempt_count))
return 0;
if (unlikely(system_state != SYSTEM_RUNNING))
return 0;
return 1;

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at