linux-kernel - Re: [PATCH] mm: slub: add panic_on

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Date:   Fri, 8 May 2020 03:06:56 +0000 (UTC)
From:   Christopher Lameter <cl@...ux.com>
To:     Rafael Aquini <aquini@...hat.com>
cc:     linux-mm@...ck.org, linux-kernel@...r.kernel.org,
        akpm@...ux-foundation.org, iamjoonsoo.kim@....com,
        rientjes@...gle.com, penberg@...nel.org
Subject: Re: [PATCH] mm: slub: add panic_on_error to the debug facilities

On Sun, 3 May 2020, Rafael Aquini wrote:

> On Sat, May 02, 2020 at 11:16:30PM +0000, Christopher Lameter wrote:
> > On Fri, 1 May 2020, Rafael Aquini wrote:
> >
> > > Sometimes it is desirable to override SLUB's debug facilities
> > > default behavior upon stumbling on a cache or object error
> > > and just stop the execution in order to grab a coredump, at
> > > the error-spotting time, instead of trying to fix the issue
> > > and report in an attempt to keep the system rolling.
> >
> > The stopping of execution on an error is the default behavior. Usually
> > you get some OOPS somewhere when data is corrupted and that causes a core
> > dump.
> >
> > SLUB can fix the issue and continue if enabled by specifying special
> > options on boot. That is *not* the default.
> >
> It is the default behavior when slub_debug is turned on, which is what
> this patch is trying to override, when needed. We've been seeing the
> need for such feature as, most often than not, by letting the system
> running to crash somewhere else after hitting occurrences reported by
> slub_debug ends up clobbering clues to the original issue.

Ok. The backtrace is not sufficient in that case?