From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758071AbYFLIgO (ORCPT ); Thu, 12 Jun 2008 04:36:14 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754444AbYFLIf7 (ORCPT ); Thu, 12 Jun 2008 04:35:59 -0400 Received: from smtp-out04.alice-dsl.net ([88.44.63.6]:58893 "EHLO smtp-out04.alice-dsl.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754300AbYFLIf6 (ORCPT ); Thu, 12 Jun 2008 04:35:58 -0400 To: Andrew Morton Cc: Nadia Derbey , Manfred Spraul , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Pekka Enberg Subject: Re: repeatable slab corruption with LTP msgctl08 From: Andi Kleen References: <20080611221324.42270ef2.akpm@linux-foundation.org> <20080611233449.08e6eaa0.akpm@linux-foundation.org> <20080612010200.106df621.akpm@linux-foundation.org> <20080612011537.6146c41d.akpm@linux-foundation.org> Date: Thu, 12 Jun 2008 10:35:55 +0200 In-Reply-To: <20080612011537.6146c41d.akpm@linux-foundation.org> (Andrew Morton's message of "Thu, 12 Jun 2008 01:15:37 -0700") Message-ID: <87mylrnj84.fsf@basil.nowhere.org> User-Agent: Gnus/5.1008 (Gnus v5.10.8) Emacs/21.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-OriginalArrivalTime: 12 Jun 2008 08:28:43.0225 (UTC) FILETIME=[530E8490:01C8CC66] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Andrew Morton writes: > > Doing the same thing on 2.6.26-rc5-mm3, msgctl08 also runs to > completion, in 20.9 seconds. So > > - it got slower That is because it scales itself to the number of available msg queues. So with Nadia's patch there are more and it runs slower. In fact it seems to start one process per message queue, so perhaps it's just running out of processes or something. Ok it should not segfault. BTW a great way to debug slab corruptions with LTP faster is to run with a slab thrasher stress module like http://firstfloor.org/~andi/crasher-26.diff -Andi