Subject: Re: Soft-Lockup/Race in networking in 2.6.31-rc1+195 ( possibly?caused by netem)

From: Jarek Poplawski <[email-masked]>
Date: Thu, 9 Jul 2009 00:07:49 +0200

On Wed, Jul 08, 2009 at 10:44:47PM +0100, Joao Correia wrote:
> Hello again
Hello!

...
> So again, the only thing that stops that freeze is  `echo 0 >>
> /proc/sys/kernel/timer_migration`. Apologies for pointing you in the
> wrong direction.

No problem: the direction is almost right, we only need one U-turn ;-)
In case you're not bored or too bored, one little patch to check the
other side (after reverting the previous patch).

Thanks,
Jarek P.
---

 kernel/hrtimer.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 9002958..23387e4 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -203,7 +203,7 @@ switch_hrtimer_base(struct hrtimer *timer, struct hrtimer_clock_base *base,
 	int cpu, preferred_cpu = -1;
 
 	cpu = smp_processor_id();
-#if defined(CONFIG_NO_HZ) && defined(CONFIG_SMP)
+#if 0
 	if (!pinned && get_sysctl_timer_migration() && idle_cpu(cpu)) {
 		preferred_cpu = get_nohz_load_balancer();
 		if (preferred_cpu >= 0)