Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964926AbXAJSVb (ORCPT ); Wed, 10 Jan 2007 13:21:31 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964944AbXAJSVb (ORCPT ); Wed, 10 Jan 2007 13:21:31 -0500 Received: from omx2-ext.sgi.com ([192.48.171.19]:58049 "EHLO omx2.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S964926AbXAJSVa (ORCPT ); Wed, 10 Jan 2007 13:21:30 -0500 Date: Wed, 10 Jan 2007 10:20:28 -0800 (PST) From: Christoph Lameter To: Heiko Carstens cc: Srivatsa Vaddagiri , Benjamin Gilbert , linux-kernel@vger.kernel.org, Ingo Molnar , Gautham shenoy , Andrew Morton , Pekka Enberg Subject: Re: [patch -mm] slab: use CPU_LOCK_[ACQUIRE|RELEASE] In-Reply-To: <20070109150615.GF9563@osiris.boeblingen.de.ibm.com> Message-ID: References: <20070108120719.16d4674e.bgilbert@cs.cmu.edu> <20070109121738.GC9563@osiris.boeblingen.de.ibm.com> <20070109122740.GC22080@in.ibm.com> <20070109150351.GD9563@osiris.boeblingen.de.ibm.com> <20070109150615.GF9563@osiris.boeblingen.de.ibm.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 853 Lines: 20 On Tue, 9 Jan 2007, Heiko Carstens wrote: > - case CPU_UP_PREPARE: > + case CPU_LOCK_ACQUIRE: > mutex_lock(&cache_chain_mutex); > + break; I have got a bad feeling about upcoming deadlock problems when looking at the mutex_lock / unlock code in cpuup_callback in slab.c. Branches that just obtain a lock or release a lock? I hope there is some control of what happens between lock acquisition and release? You are aware that this lock is taken for cache shrinking/destroy, tuning of cpu cache sizes, proc output and cache creation? Any of those run on the same processor should cause a deadlock. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/