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Fri, 1 May 2020 21:41:50 +0000 (UTC) Received: from optiplex-lnx (unknown [10.3.128.26]) by smtp.corp.redhat.com (Postfix) with ESMTPS id A01BD5EE11; Fri, 1 May 2020 21:41:47 +0000 (UTC) Date: Fri, 1 May 2020 17:41:44 -0400 From: Rafael Aquini To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, iamjoonsoo.kim@lge.com, rientjes@google.com, penberg@kernel.org, cl@linux.com Subject: Re: [PATCH] mm: slub: add panic_on_error to the debug facilities Message-ID: <20200501214144.GD27720@optiplex-lnx> References: <20200501211540.71216-1-aquini@redhat.com> <20200501143751.97a25bb7f89f8d93ec443868@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200501143751.97a25bb7f89f8d93ec443868@linux-foundation.org> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri, May 01, 2020 at 02:37:51PM -0700, Andrew Morton wrote: > On Fri, 1 May 2020 17:15:40 -0400 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. > > > > This patch introduces a new debug flag SLAB_PANIC_ON_ERROR, > > along with its related SLUB-machinery, in order to extend > > current slub_debug facilites and provide the aforementioned > > behavior override. > > > > Sees reasonable. > > > --- a/Documentation/vm/slub.rst > > +++ b/Documentation/vm/slub.rst > > @@ -54,6 +54,8 @@ Possible debug options are:: > > caused higher minimum slab orders > > - Switch all debugging off (useful if the kernel is > > configured with CONFIG_SLUB_DEBUG_ON) > > + C Toggle panic on error (crash) to allow for post-mortem > > + analysis of a coredump taken at the error-spotting time > > nit: "toggle" means to switch to the other state. But what we're doing > here is to set to the "on" state. This: > Thanks Andrew, that's indeed much better. > --- a/Documentation/vm/slub.rst~mm-slub-add-panic_on_error-to-the-debug-facilities-fix > +++ a/Documentation/vm/slub.rst > @@ -49,12 +49,12 @@ Possible debug options are:: > P Poisoning (object and padding) > U User tracking (free and alloc) > T Trace (please only use on single slabs) > - A Toggle failslab filter mark for the cache > + A Enable failslab filter mark for the cache > O Switch debugging off for caches that would have > caused higher minimum slab orders > - Switch all debugging off (useful if the kernel is > configured with CONFIG_SLUB_DEBUG_ON) > - C Toggle panic on error (crash) to allow for post-mortem > + C Enable panic on error (crash) to allow for post-mortem > analysis of a coredump taken at the error-spotting time > > F.e. in order to boot just with sanity checks and red zoning one would specify:: > _ > >