Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762358AbXH0W10 (ORCPT ); Mon, 27 Aug 2007 18:27:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751418AbXH0W1S (ORCPT ); Mon, 27 Aug 2007 18:27:18 -0400 Received: from tomts13-srv.bellnexxia.net ([209.226.175.34]:44011 "EHLO tomts13-srv.bellnexxia.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752051AbXH0W1R (ORCPT ); Mon, 27 Aug 2007 18:27:17 -0400 Date: Mon, 27 Aug 2007 18:27:15 -0400 From: Mathieu Desnoyers To: Christoph Lameter Cc: Peter Zijlstra , akpm@linux-foundation.org, linux-kernel@vger.kernel.org, mingo@redhat.com Subject: Re: [PATCH] SLUB use cmpxchg_local Message-ID: <20070827222715.GA16982@Krystal> References: <1188197539.6114.426.camel@twins> <20070827202203.GB5653@Krystal> <20070827203913.GA7416@Krystal> <20070827211003.GA10627@Krystal> <20070827213845.GB9748@Krystal> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline In-Reply-To: X-Editor: vi X-Info: http://krystal.dyndns.org:8080 X-Operating-System: Linux/2.6.21.3-grsec (i686) X-Uptime: 18:25:14 up 28 days, 22:44, 3 users, load average: 0.21, 0.38, 0.86 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: 1250 Lines: 32 * Christoph Lameter (clameter@sgi.com) wrote: > On Mon, 27 Aug 2007, Mathieu Desnoyers wrote: > > > > The slow path would require disable preemption and two interrupt disables. > > If the slow path have to call new_slab, then yes. But it seems that not > > every slow path must call it, so for the other slow paths, only one > > interrupt disable would be required. > > If we include new_slab then we get to 3 times: > > 1. In the cmpxchg_local emulation that fails > > 2. For the slow path > > 3. When calling the page allocator. > Hrm, I just want to certify one thing: A lot of code paths seems to go to the slow path without requiring cmpxchg_local to execute at all. So is the slow path more likely to be triggered by the (!object), (!node_match) tests or by these same tests done in the redo after the initial cmpxchg_local ? -- 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/