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From: Don Zickus <dzickus@redhat.com>
To: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: "Jörn Engel" <joern@purestorage.com>,
	"Spencer Baugh" <sbaugh@catern.com>,
	"Andrew Morton" <akpm@linux-foundation.org>,
	"Ulrich Obergfell" <uobergfe@redhat.com>,
	"Ingo Molnar" <mingo@kernel.org>,
	"Andrew Jones" <drjones@redhat.com>,
	"chai wen" <chaiw.fnst@cn.fujitsu.com>,
	"Chris Metcalf" <cmetcalf@ezchip.com>,
	"Stephane Eranian" <eranian@google.com>,
	"open list" <linux-kernel@vger.kernel.org>,
	"Spencer Baugh" <Spencer.baugh@purestorage.com>,
	"Joern Engel" <joern@logfs.org>
Subject: Re: [PATCH] soft lockup: kill realtime threads before panic
Date: Wed, 22 Jul 2015 09:52:04 -0400	[thread overview]
Message-ID: <20150722135204.GE178524@redhat.com> (raw)
In-Reply-To: <1437550528.3106.107.camel@gmail.com>

On Wed, Jul 22, 2015 at 09:35:28AM +0200, Mike Galbraith wrote:
> On Tue, 2015-07-21 at 23:33 -0700, Jörn Engel wrote:
> 
> > One could argue that killing the realtime thread is even better than
> > panic, as things can restart with a blank slate even faster.  But the
> > real benefit is that we get better debug data for the failing component.
> > If we had a kernel bug, the backtrace would usually be sufficient to
> > point fingers.  With a bonkers realtime thread, not so much.
> 
> If userspace wants a watchdog, it should train a userspace dog, not turn
> the kernel watchdog into a userspace attack dog.

I agree.  The spirit of the watchdog was detection and panic (if configured
that way).  I don't think adding policy like this works well in the long
run.

Cheers,
Don

  reply	other threads:[~2015-07-22 13:52 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-07-21 22:07 [PATCH] soft lockup: kill realtime threads before panic Spencer Baugh
2015-07-22  4:36 ` Mike Galbraith
2015-07-22  5:18   ` Jörn Engel
2015-07-22  5:41     ` Mike Galbraith
2015-07-22  6:33       ` Jörn Engel
2015-07-22  7:35         ` Mike Galbraith
2015-07-22 13:52           ` Don Zickus [this message]
2015-07-22 16:35           ` Jörn Engel
2015-07-22  6:59 ` yalin wang
2015-07-22 22:54 ` Andrew Morton
2015-07-22 23:29   ` Jörn Engel

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