From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E9BE6C2BA19 for ; Wed, 15 Apr 2020 09:40:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C217E2074F for ; Wed, 15 Apr 2020 09:40:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Y9S0dV0t" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2895738AbgDOJkY (ORCPT ); Wed, 15 Apr 2020 05:40:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50394 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S2895721AbgDOJkP (ORCPT ); Wed, 15 Apr 2020 05:40:15 -0400 Received: from merlin.infradead.org (unknown [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0347EC061A0C for ; Wed, 15 Apr 2020 02:40:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=XM1Z8cdaxW1gEH8XQB3f7fNbxixDQWXVOYGx3dfIihk=; b=Y9S0dV0t/YeSgy4L/RLwRlkYiv Z7Fkjr/gFed11uPUOn+zTOtYFinIXW3jjeriZ4DmvbNf5dPzO1zvMREfDakzTlBAe2kAO+wbrXSU8 LSPa+qM7Q/HlIaPOV8ikP27M49+ldf8TwaySmcpqKsslmMH3H0pIbQthSp7jugwllyZCJ4OD7uvHq ySVc6Mkaz9eQxhJ9lUy1LIItSvlJDP+VO6zekMTJpYU5zCfY1SWpmheQnuSZWcPblt2ht5H646P3T WsaMS5bfYk/ZdAtBVdJY4WyhnNyR5yTBAymiRRFh1wT1IIiYFr/rdhtPDiZI5JKH14YuOQha6Rqri z4/fiwOA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jOeW9-0006G1-1l; Wed, 15 Apr 2020 09:39:37 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 50D3C30066E; Wed, 15 Apr 2020 11:39:35 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 336532BC6F2D8; Wed, 15 Apr 2020 11:39:35 +0200 (CEST) Date: Wed, 15 Apr 2020 11:39:35 +0200 From: Peter Zijlstra To: Steven Rostedt Cc: Valentin Schneider , Qais Yousef , Ingo Molnar , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Ben Segall , Mel Gorman , Andrew Morton , Thomas Gleixner , Yury Norov , Paul Turner , Alexey Dobriyan , Josh Don , Pavan Kondeti , linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/4] sched/rt: Distribute tasks in find_lowest_rq() Message-ID: <20200415093935.GA20730@hirez.programming.kicks-ass.net> References: <20200414150556.10920-1-qais.yousef@arm.com> <20200414162742.0ef4d9ee@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200414162742.0ef4d9ee@gandalf.local.home> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 14, 2020 at 04:27:42PM -0400, Steven Rostedt wrote: > On Tue, 14 Apr 2020 19:58:49 +0100 > Valentin Schneider wrote: > > > To move this forward, I would suggest renaming the current cpumask_any_*() > > into cpumask_first_*(), and THEN introduce the new pseudo-random > > ones. People are then free to hand-fix specific locations if it makes sense > > there, like you're doing for RT. > > Or leave "cpumask_any()" as is, and create a new "cpumask_random()" for > this purpose. Well, that's just twisting words, not sure I like that. 'Any' really means 'any'. So in order to preserve long term sanity, I'd vote for Valentin's approach of converting existing users over to first.