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=-2.1 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID, USER_AGENT_MUTT autolearn=ham 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 AB1CBC04ABA for ; Tue, 18 Sep 2018 13:38:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5F6882086E for ; Tue, 18 Sep 2018 13:38:18 +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="fbJoFM63" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5F6882086E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729833AbeIRTKy (ORCPT ); Tue, 18 Sep 2018 15:10:54 -0400 Received: from merlin.infradead.org ([205.233.59.134]:53496 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727207AbeIRTKx (ORCPT ); Tue, 18 Sep 2018 15:10:53 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Transfer-Encoding: Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date: Sender:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=p0rsKkkMM1fWB2KKGf3W9qkuVQvLMIK38763629zTxs=; b=fbJoFM63l2pCC7CrQWNFh4T/CG ZLliht3mJPzU+bg3ntEsNQ3Yy26od+xAelI8+5hM5nqq4XlTpwhM8IRtI95CGFWKVtDEEAZJ8r+V1 zhXlc0ebBC1JbVmIAobGFqvonS5rUcEDKDS0AcPElJzZ4dVuTKBsH1g/1NnHvC6T0AtzLf1Z6upma HlxlG8DhZPEdze7s9GGVP8Ls8LV2XOXuSn+Yd0yFf6fggZ1ywP0bgg/ovzzuAbI5s7bfolVYG59ET FFHGYQ/O0yLsJRaYjSRuBlczvsDRgGUEbW/rJUoq2zw/lbgzuYGkdlD3So5VV9W7m7xjYCpYPQvWm LiTFd0kQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1g2GCd-00030z-2j; Tue, 18 Sep 2018 13:38:07 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 64CE5202C1A38; Tue, 18 Sep 2018 15:38:05 +0200 (CEST) Date: Tue, 18 Sep 2018 15:38:05 +0200 From: Peter Zijlstra To: Jan =?iso-8859-1?Q?H=2E_Sch=F6nherr?= Cc: Ingo Molnar , linux-kernel@vger.kernel.org, Paul Turner , Vincent Guittot , Morten Rasmussen , Tim Chen , Rik van Riel Subject: Re: Task group cleanups and optimizations (was: Re: [RFC 00/60] Coscheduling for Linux) Message-ID: <20180918133805.GN24106@hirez.programming.kicks-ass.net> References: <20180907214047.26914-1-jschoenh@amazon.de> <20180914111251.GC24106@hirez.programming.kicks-ass.net> <1d86f497-9fef-0b19-50d6-d46ef1c0bffa@amazon.de> <282230fe-b8de-01f9-c19b-6070717ba5f8@amazon.de> <20180917094844.GR24124@hirez.programming.kicks-ass.net> <08b930d9-7ffe-7df3-ab35-e7b58073e489@amazon.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <08b930d9-7ffe-7df3-ab35-e7b58073e489@amazon.de> User-Agent: Mutt/1.10.0 (2018-05-17) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 18, 2018 at 03:22:13PM +0200, Jan H. Schönherr wrote: > On 09/17/2018 11:48 AM, Peter Zijlstra wrote: > > On Sat, Sep 15, 2018 at 10:48:20AM +0200, Jan H. Schönherr wrote: > >> On 09/14/2018 06:25 PM, Jan H. Schönherr wrote: > > > >>> b) ability to move CFS RQs between CPUs: someone changed the affinity of > >>> a cpuset? No problem, just attach the runqueue with all the tasks elsewhere. > >>> No need to touch each and every task. > > > > Can't do that, tasks might have individual constraints that are tighter > > than the cpuset. > > AFAIK, changing the affinity of a cpuset overwrites the individual affinities of tasks > within them. Thus, it shouldn't be an issue. No, it only shrinks the set. Also nothing stops you calling sched_setaffinity() once you're inside the cpuset. The only contraint is that your mask is a subset of the cpuset mask.