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From: Ingo Molnar <mingo@kernel.org>
To: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ingo Molnar <mingo@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] kernel/sysrq: reset watchdog on all CPUs while processing sysrq-w
Date: Wed, 8 Jun 2016 15:13:24 +0200	[thread overview]
Message-ID: <20160608131324.GA15193@gmail.com> (raw)
In-Reply-To: <1464353394-30528-1-git-send-email-aryabinin@virtuozzo.com>


* Andrey Ryabinin <aryabinin@virtuozzo.com> wrote:

> Lengthy output of sysrq-w may take a lot of time on slow serial console.
> Currently we reset NMI-watchdog on the current CPU to avoid softlockup.
> Sometimes this doesn't work since watchdog might trigger on the other
> CPU which is waiting for an IPI to proceed.
> 
> Reset watchdog on all CPUs to prevent spurious softlockup messages.
> 
> Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
> ---
>  kernel/sched/core.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> index 7f2cae4..c135eee 100644
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -5134,7 +5134,7 @@ void show_state_filter(unsigned long state_filter)
>  		 * reset the NMI-timeout, listing all files on a slow
>  		 * console might take a lot of time:
>  		 */
> -		touch_nmi_watchdog();
> +		touch_all_softlockup_watchdogs();

So don't we want both?

Thanks,

	Ingo

  reply	other threads:[~2016-06-08 13:13 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-05-27 12:49 [PATCH] kernel/sysrq: reset watchdog on all CPUs while processing sysrq-w Andrey Ryabinin
2016-06-08 13:13 ` Ingo Molnar [this message]
2016-06-08 14:39   ` Andrey Ryabinin
2016-06-09 12:20 ` [PATCH v2] " Andrey Ryabinin
2016-06-14 11:35   ` [tip:sched/urgent] kernel/sysrq, watchdog, sched/core: Reset " tip-bot for Andrey Ryabinin

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