Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756459AbYHKS3u (ORCPT ); Mon, 11 Aug 2008 14:29:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753847AbYHKS3l (ORCPT ); Mon, 11 Aug 2008 14:29:41 -0400 Received: from tomts22-srv.bellnexxia.net ([209.226.175.184]:60552 "EHLO tomts22-srv.bellnexxia.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752978AbYHKS3k (ORCPT ); Mon, 11 Aug 2008 14:29:40 -0400 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AmoFAAMcoEhMRKxB/2dsb2JhbACBX6oR Date: Mon, 11 Aug 2008 14:29:38 -0400 From: Mathieu Desnoyers To: Christoph Lameter Cc: Steven Rostedt , Pekka Enberg , Eduard - Gabriel Munteanu , linux-mm@kvack.org, linux-kernel@vger.kernel.org, rdunlap@xenotime.net, mpm@selenic.com, tglx@linutronix.de Subject: Re: [PATCH 4/5] kmemtrace: SLUB hooks. Message-ID: <20080811182938.GD32207@Krystal> References: <1218388447-5578-1-git-send-email-eduard.munteanu@linux360.ro> <1218388447-5578-2-git-send-email-eduard.munteanu@linux360.ro> <1218388447-5578-3-git-send-email-eduard.munteanu@linux360.ro> <1218388447-5578-4-git-send-email-eduard.munteanu@linux360.ro> <1218388447-5578-5-git-send-email-eduard.munteanu@linux360.ro> <48A046F5.2000505@linux-foundation.org> <1218463774.7813.291.camel@penberg-laptop> <48A048FD.30909@linux-foundation.org> <48A04EC2.1080302@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline In-Reply-To: <48A04EC2.1080302@linux-foundation.org> X-Editor: vi X-Info: http://krystal.dyndns.org:8080 X-Operating-System: Linux/2.6.21.3-grsec (i686) X-Uptime: 14:28:52 up 67 days, 23:09, 7 users, load average: 0.22, 0.28, 0.41 User-Agent: Mutt/1.5.16 (2007-06-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1176 Lines: 29 * Christoph Lameter (cl@linux-foundation.org) wrote: > Steven Rostedt wrote: > > > The kmemtrace_mark_alloc_node itself is an inline function, which calls > > another inline function "trace_mark" which is designed to test a > > read_mostly variable, and will do an "unlikely" jmp if the variable is > > set (which it is when tracing is enabled), to the actual function call. > > > > There should be no extra function calls when this is configured on but > > tracing disabled. We try very hard to keep the speed of the tracer as > > close to a non tracing kernel as possible when tracing is disabled. > > Makes sense. But then we have even more code bloat because of the tests that > are inserted in all call sites of kmalloc. > The long-term goal is to turn the tests into NOPs, but only once we get gcc support. Mathieu -- Mathieu Desnoyers 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/