From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755924AbYB2JB5 (ORCPT ); Fri, 29 Feb 2008 04:01:57 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753460AbYB2JBs (ORCPT ); Fri, 29 Feb 2008 04:01:48 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:44659 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753536AbYB2JBr (ORCPT ); Fri, 29 Feb 2008 04:01:47 -0500 Date: Fri, 29 Feb 2008 10:00:50 +0100 From: Ingo Molnar To: Max Krasnyanskiy Cc: Jason Baron , Mathieu Desnoyers , akpm@linux-foundation.org, linux-kernel@vger.kernel.org, Rusty Russell , Peter Zijlstra Subject: Re: [patch 1/2] add ALL_CPUS option to stop_machine_run() Message-ID: <20080229090050.GA19519@elte.hu> References: <20080202210828.840735763@polymtl.ca> <20080202211204.268876860@polymtl.ca> <20080226225242.GA15926@redhat.com> <20080227190519.GA14335@Krystal> <20080228163303.GA6195@redhat.com> <47C73121.2000109@qualcomm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <47C73121.2000109@qualcomm.com> User-Agent: Mutt/1.5.17 (2007-11-01) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Max Krasnyanskiy wrote: >> -allow stop_mahcine_run() to call a function on all cpus. Calling >> stop_machine_run() with a 'ALL_CPUS' invokes this new behavior. >> stop_machine_run() proceeds as normal until the calling cpu has >> invoked 'fn'. Then, we tell all the other cpus to call 'fn'. > > Jason, we're actually trying to reduce the usage of the stop_machine > in general. [...] please talk in your own name. Stop-machine is a very elegant tool that simplifies a lot of hard things in the kernel and is reasonably fast as well. We've just recently added two new usages of it and more are planned. _you_ might be the one who wants to 'reduce the usage of stop_machine' - but that means it is _you_ who first has to convert a number of very difficult pieces of code to "something else". Ingo