From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753037Ab1E3BkS (ORCPT ); Sun, 29 May 2011 21:40:18 -0400 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:47099 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751920Ab1E3BkQ (ORCPT ); Sun, 29 May 2011 21:40:16 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 Message-ID: <4DE2F577.3000105@jp.fujitsu.com> Date: Mon, 30 May 2011 10:40:07 +0900 From: KOSAKI Motohiro User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; ja; rv:1.9.2.17) Gecko/20110414 Lightning/1.0b2 Thunderbird/3.1.10 MIME-Version: 1.0 To: a.p.zijlstra@chello.nl CC: linux-kernel@vger.kernel.org, akpm@linux-foundation.org, efault@gmx.de, mingo@elte.hu Subject: Re: [PATCH] cpumask: convert cpumask_of_cpu() with cpumask_of() References: <1303814572.20212.249.camel@twins> <20110426203520.F3AE.A69D9226@jp.fujitsu.com> <20110427193419.D17F.A69D9226@jp.fujitsu.com> <1306442327.2497.108.camel@laptop> In-Reply-To: <1306442327.2497.108.camel@laptop> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >> The trick is, >> - Typical linux userland applications don't use mempolicy and/or cpusets >> API at all. >> - Then, 99.99% thread's tsk->cpus_alloed have cpu_all_mask. >> - cpu_all_mask case, every thread can share the same bitmap. It may help to >> reduce L1 cache miss in scheduler. >> >> What do you think? > > Nice! > > If you finish the first patch (sort the TODOs) I'll take it. Yeah, now I'm submitting a lot of cpumask cleanup patches to various arch and subsystems. So, I expect I can finish this work in June. > I'm unsure about the PF_THREAD_UNBOUND thing though, then again, the > alternative is adding another struct cpumask * and have that point to > the shared mask or the private mask. Ahhh, I'm sorry. My explanation was bad. PF_THREAD_UNBOUND is not my point. It's only concept proof patch, not for submitting. yes, I did cheat for getting number easily. I think the good way is probably to add another cpumask* and implement COW shared mask. but I'm ok other way too. > But yeah, looks quite feasible. Thank you to pay attention my patch!