lkml.org 
[lkml]   [2007]   [Jul]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [patch] softlockup watchdog: fix Xen bogosity
Ingo Molnar wrote:
> Subject: softlockup: fix Xen bogosity
> From: Ingo Molnar <mingo@elte.hu>
>
> this Xen related commit:
>

Well, not just Xen. It relates to any virtual environment: kvm, lguest,
vmi, xen... (Not that they all implement a measure of unstolen time.)

How about a more descriptive patch title, along the lines of "softlockup
watchdog: fix rate limiting"?

> commit 966812dc98e6a7fcdf759cbfa0efab77500a8868
> Author: Jeremy Fitzhardinge <jeremy@goop.org>
> Date: Tue May 8 00:28:02 2007 -0700
>
> Ignore stolen time in the softlockup watchdog
>
> broke the softlockup watchdog to never report any lockups. (!)
>
> print_timestamp defaults to 0, this makes the following condition
> always true:
>
> if (print_timestamp < (touch_timestamp + 1) ||
>
> and we'll never report soft lockups.
>
> apparently the functionality of the soft lockup watchdog was never
> actually tested with that patch applied ...
>
> [ this is -stable material too. ]
>
> Signed-off-by: Ingo Molnar <mingo@elte.hu>
> ---
> kernel/softlockup.c | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> Index: linux/kernel/softlockup.c
> ===================================================================
> --- linux.orig/kernel/softlockup.c
> +++ linux/kernel/softlockup.c
> @@ -79,10 +79,11 @@ void softlockup_tick(void)
> print_timestamp = per_cpu(print_timestamp, this_cpu);
>
> /* report at most once a second */
> - if (print_timestamp < (touch_timestamp + 1) ||
> - did_panic ||
> - !per_cpu(watchdog_task, this_cpu))
> + if ((print_timestamp >= touch_timestamp &&
> + print_timestamp < (touch_timestamp + 1)) ||
> + did_panic || !per_cpu(watchdog_task, this_cpu)) {
> return;
> + }
>

OK, thanks.

Acked-by: Jeremy Fitzhardinge <jeremy@xensource.com>

J
-
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: 2007-07-17 16:27    [W:0.102 / U:3.052 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site