lkml.org 
[lkml]   [2009]   [Nov]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: PATCH: softlockup: Fix hung_task_check_count sysctl
From
On Fri, Nov 27, 2009 at 10:28 AM, Anton Blanchard <anton@samba.org> wrote:
>
> I'm seeing spikes of up to 0.5ms in khungtaskd on a large machine. To reduce
> this source of jitter I tried setting hung_task_check_count to 0:
>
> # echo 0 > /proc/sys/kernel/hung_task_check_count
>
> which didn't have the intended response. Change to a post increment of
> max_count, so a value of 0 means check 0 tasks.
>
> Signed-off-by: Anton Blanchard <anton@samba.org>


Ack.

I would also suggest to make 'max_count' as unsigned long,
since sysctl_hung_task_check_count is.

Thanks.

> ---
>
> Index: linux.trees.git/kernel/hung_task.c
> ===================================================================
> --- linux.trees.git.orig/kernel/hung_task.c     2009-11-27 13:11:46.000000000 +1100
> +++ linux.trees.git/kernel/hung_task.c  2009-11-27 13:11:57.000000000 +1100
> @@ -144,7 +144,7 @@ static void check_hung_uninterruptible_t
>
>        rcu_read_lock();
>        do_each_thread(g, t) {
> -               if (!--max_count)
> +               if (!max_count--)
>                        goto unlock;
>                if (!--batch_count) {
>                        batch_count = HUNG_TASK_BATCHING;
--
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/

\
 
 \ /
  Last update: 2009-11-27 03:49    [W:0.070 / U:0.032 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site