Re: [patch] softlockup: fix false positives on nohz if CPU is 100%idle for more than 60 seconds

From: Ingo Molnar
Date: Wed Apr 23 2008 - 09:37:26 EST



* David Miller <davem@xxxxxxxxxxxxx> wrote:

> > It may take some time, as each test run the verify the existence of
> > the problem takes several minutes.
>
> Ok, Ingo, none of your patches fix even the initial buggy changeset,
> for reference:

as a temporary workaround please try the patch below, until we can
reproduce and fix the bug.

Ingo

------------------------------->
Subject: softlockup: nohz workaround
From: Ingo Molnar <mingo@xxxxxxx>
Date: Wed Apr 23 15:19:32 CEST 2008

Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
kernel/softlockup.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

Index: linux/kernel/softlockup.c
===================================================================
--- linux.orig/kernel/softlockup.c
+++ linux/kernel/softlockup.c
@@ -245,7 +245,7 @@ static int watchdog(void *__bind_cpu)
*/
while (!kthread_should_stop()) {
touch_softlockup_watchdog();
- schedule();
+ schedule_timeout(softlockup_thresh/2);

if (kthread_should_stop())
break;
--
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