From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754239Ab2AaNCL (ORCPT ); Tue, 31 Jan 2012 08:02:11 -0500 Received: from merlin.infradead.org ([205.233.59.134]:50646 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752081Ab2AaNCK convert rfc822-to-8bit (ORCPT ); Tue, 31 Jan 2012 08:02:10 -0500 Message-ID: <1328014916.2446.217.camel@twins> Subject: Re: x86: clean up smpboot.c's use of udelay+schedule From: Peter Zijlstra To: Ingo Molnar Cc: Arjan van de Ven , linux-kernel@vger.kernel.org, x86@kernel.org, arjanvandeven@gmail.com, Thomas Gleixner Date: Tue, 31 Jan 2012 14:01:56 +0100 In-Reply-To: <20120131125331.GE4408@elte.hu> References: <20120130205304.0e10b05e@infradead.org> <20120131124341.GC4408@elte.hu> <1328014076.2446.210.camel@twins> <20120131125331.GE4408@elte.hu> Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT X-Mailer: Evolution 3.2.1- Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2012-01-31 at 13:53 +0100, Ingo Molnar wrote: > Wanna give a short TODO list to anyone wanting to work on that? I paged out most details again, but it goes something like: - read and understand the current generic code - and all architecture code, at which point you'll probably boggle at all the similarities that are all subtly different (there's about 3 actually different ways in the arch code). - pick one, preferably one that keeps additional state and doesn't fully rely on the online bits and pull it into generic code and provide a small vector of arch specific functions. - convert all archs over. Also related: - figure out why cpu_down needs kstopmachine, I'm not sure it does.. we should be able to tear down a cpu using synchronize_sched() and a single stop_one_cpu(). (someday when there's time I might actually try to implement this).