Re: [PATCH 1/2] watchdog: Fix output

From	Jiri Kosina <jikos@kernel.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH 1/2] watchdog: Fix output
Date	2016-03-19 01:40 +0100
Message-ID	<red5U-59o-3@gated-at.bofh.it> (permalink)
References	<re4Fj-pn-7@gated-at.bofh.it> <re4Fj-pn-11@gated-at.bofh.it> <re5Bo-1Rm-7@gated-at.bofh.it> <re6QP-3H6-19@gated-at.bofh.it> <recMy-4Kg-1@gated-at.bofh.it>
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On Sat, 19 Mar 2016, Jiri Kosina wrote:

> > It was Jiri who made this mess by replacing WARN(), which has a very
> > distinct format, with this custom stuff.
> 
> Right, this was in 55537871e ("kernel/watchdog.c: perform all-CPU 
> backtrace in case of hard lockup").
> 
> To be really honest, I don't really have 100% reliable explanation why I 
> did it this way; I *think* it was because otherwise, in case WARN is 
> preserved, we'll either
> 
> - have different output format for current (warning) CPU and all the 
>   others (trigger_allbutself_cpu_backtrace())
> 
> or
> 
> - have duplicated backtrace for current CPU, one coming from WARN and one 
>   coming from the all-cpu backtrace
> 
> > I think we should go back to the WARN() thing.
> 
> I don't really have strong opinion on this, but someone should pick the 
> poison from the two options above; I tried in the mentioned commit, but 
> apparently not to general satisfaction :)

Hmm, or we can actually make the whole thing behave the way that was 
introduced by 55537871e only in case of 
sysctl_hardlockup_all_cpu_backtrace being set, and use WARN() otherwise.

I'll send out a patch for this during / after the weekend if noone else 
beats me to do it.

-- 
Jiri Kosina
SUSE Labs

Thread

[PATCH 0/2] random debug patches Peter Zijlstra <peterz@infradead.org> - 2016-03-18 16:40 +0100
  [PATCH 1/2] watchdog: Fix output Peter Zijlstra <peterz@infradead.org> - 2016-03-18 16:40 +0100
    Re: [PATCH 1/2] watchdog: Fix output Don Zickus <dzickus@redhat.com> - 2016-03-18 17:40 +0100
      Re: [PATCH 1/2] watchdog: Fix output Peter Zijlstra <peterz@infradead.org> - 2016-03-18 17:50 +0100
        Re: [PATCH 1/2] watchdog: Fix output Peter Zijlstra <peterz@infradead.org> - 2016-03-18 17:50 +0100
          Re: [PATCH 1/2] watchdog: Fix output Joe Perches <joe@perches.com> - 2016-03-18 18:50 +0100
          Re: [PATCH 1/2] watchdog: Fix output Don Zickus <dzickus@redhat.com> - 2016-03-18 19:20 +0100
      Re: [PATCH 1/2] watchdog: Fix output Peter Zijlstra <peterz@infradead.org> - 2016-03-18 19:00 +0100
        Re: [PATCH 1/2] watchdog: Fix output Jiri Kosina <jikos@kernel.org> - 2016-03-19 01:20 +0100
          Re: [PATCH 1/2] watchdog: Fix output Jiri Kosina <jikos@kernel.org> - 2016-03-19 01:40 +0100
  [PATCH 2/2] trace: Record and show NMI state Peter Zijlstra <peterz@infradead.org> - 2016-03-18 16:40 +0100

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