From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 76489C47247 for ; Fri, 8 May 2020 03:06:58 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1FDF6208D6 for ; Fri, 8 May 2020 03:06:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1FDF6208D6 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 8590C900003; Thu, 7 May 2020 23:06:57 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 80914900002; Thu, 7 May 2020 23:06:57 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 74549900003; Thu, 7 May 2020 23:06:57 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0243.hostedemail.com [216.40.44.243]) by kanga.kvack.org (Postfix) with ESMTP id 5A367900002 for ; Thu, 7 May 2020 23:06:57 -0400 (EDT) Received: from smtpin24.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 167608248047 for ; Fri, 8 May 2020 03:06:57 +0000 (UTC) X-FDA: 76792064874.24.sofa72_1f8d886814d1d X-HE-Tag: sofa72_1f8d886814d1d X-Filterd-Recvd-Size: 2390 Received: from gentwo.org (gentwo.org [3.19.106.255]) by imf31.hostedemail.com (Postfix) with ESMTP for ; Fri, 8 May 2020 03:06:56 +0000 (UTC) Received: by gentwo.org (Postfix, from userid 1002) id 3E98C3FEDA; Fri, 8 May 2020 03:06:56 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by gentwo.org (Postfix) with ESMTP id 3CA8A3FED9; Fri, 8 May 2020 03:06:56 +0000 (UTC) Date: Fri, 8 May 2020 03:06:56 +0000 (UTC) From: Christopher Lameter X-X-Sender: cl@www.lameter.com To: Rafael Aquini cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, iamjoonsoo.kim@lge.com, rientjes@google.com, penberg@kernel.org Subject: Re: [PATCH] mm: slub: add panic_on_error to the debug facilities In-Reply-To: <20200504025138.GB18463@t490s> Message-ID: References: <20200501211540.71216-1-aquini@redhat.com> <20200504025138.GB18463@t490s> User-Agent: Alpine 2.22 (DEB 394 2020-01-19) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII 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 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?