Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757449AbXFDWVP (ORCPT ); Mon, 4 Jun 2007 18:21:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753941AbXFDWVA (ORCPT ); Mon, 4 Jun 2007 18:21:00 -0400 Received: from tomts25-srv.bellnexxia.net ([209.226.175.188]:44116 "EHLO tomts25-srv.bellnexxia.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752719AbXFDWU7 (ORCPT ); Mon, 4 Jun 2007 18:20:59 -0400 Date: Mon, 4 Jun 2007 18:20:58 -0400 From: Mathieu Desnoyers To: William Lee Irwin III Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: [patch 9/9] Scheduler profiling - Use conditional calls Message-ID: <20070604222058.GB1169@Krystal> References: <20070530140025.917261793@polymtl.ca> <20070530140229.811672406@polymtl.ca> <20070530205927.GE6909@holomorphy.com> <20070531211258.GB904@Krystal> <20070531234154.GL6909@holomorphy.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline In-Reply-To: <20070531234154.GL6909@holomorphy.com> X-Editor: vi X-Info: http://krystal.dyndns.org:8080 X-Operating-System: Linux/2.6.21.3-grsec (i686) X-Uptime: 18:20:22 up 7 days, 6:59, 3 users, load average: 0.49, 0.40, 0.36 User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1284 Lines: 31 * William Lee Irwin III (wli@holomorphy.com) wrote: > On Wed, May 30, 2007 at 10:00:34AM -0400, Mathieu Desnoyers wrote: > >>> + if (prof_on) > >>> + BUG_ON(cond_call_arm("profile_on")); > > * William Lee Irwin III (wli@holomorphy.com) wrote: > >> What's the point of this BUG_ON()? The condition is a priori impossible. > > On Thu, May 31, 2007 at 05:12:58PM -0400, Mathieu Desnoyers wrote: > > Not impossible: hash_add_cond_call() can return -ENOMEM if kmalloc lacks > > memory. > > Shouldn't it just propagate the errors like anything else instead of > going BUG(), then? One can easily live without profiling if the profile > buffers should fail to be allocated e.g. due to memory fragmentation. > > These things all have to handle errors for hotplugging anyway AIUI. > Cond call arming will not reserve memory anymore in the next release. (hash table is gone). -- Mathieu Desnoyers Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68 - 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/