From: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
To: Nicholas Piggin <npiggin@gmail.com>
Cc: Ravikumar Bangoria <ravi.bangoria@linux.ibm.com>,
linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH] powerpc/watchdog: Use hrtimers for per-CPU heartbeat
Date: Wed, 3 Apr 2019 09:12:54 +0530 [thread overview]
Message-ID: <cb7241fc-f649-b53d-ea0f-530aaeda83f3@linux.ibm.com> (raw)
In-Reply-To: <20190402112521.24888-1-npiggin@gmail.com>
On 4/2/19 4:55 PM, Nicholas Piggin wrote:
> Using a jiffies timer creates a dependency on the tick_do_timer_cpu
> incrementing jiffies. If that CPU has locked up and jiffies is not
> incrementing, the watchdog heartbeat timer for all CPUs stops and
> creates false positives and confusing warnings on local CPUs, and
> also causes the SMP detector to stop, so the root cause is never
> detected.
>
> Fix this by using hrtimer based timers for the watchdog heartbeat,
> like the generic kernel hardlockup detector.
>
> Reported-by: Ravikumar Bangoria <ravi.bangoria@in.ibm.com>
Reported-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Thanks,
Ravi
next prev parent reply other threads:[~2019-04-03 3:44 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-02 11:25 [PATCH] powerpc/watchdog: Use hrtimers for per-CPU heartbeat Nicholas Piggin
2019-04-03 3:42 ` Ravi Bangoria [this message]
2019-04-04 11:19 ` Gautham R Shenoy
2019-04-04 16:03 ` Nicholas Piggin
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