From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753453AbcEPLSy (ORCPT ); Mon, 16 May 2016 07:18:54 -0400 Received: from merlin.infradead.org ([205.233.59.134]:35656 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752059AbcEPLSw (ORCPT ); Mon, 16 May 2016 07:18:52 -0400 Date: Mon, 16 May 2016 13:18:49 +0200 From: Peter Zijlstra To: Konstantin Khlebnikov Cc: Ingo Molnar , linux-kernel@vger.kernel.org, Tejun Heo , cgroups@vger.kernel.org, containers@lists.linux-foundation.org Subject: Re: [PATCH RFC 0/3] sched/fair: cpu time reserves for cgroups Message-ID: <20160516111849.GN3193@twins.programming.kicks-ass.net> References: <146339085068.25295.7687045977863852568.stgit@buzz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <146339085068.25295.7687045977863852568.stgit@buzz> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 16, 2016 at 12:36:19PM +0300, Konstantin Khlebnikov wrote: > This feature allows to change cpu cgroup weight for a limited time. > > Cgroup interface: > cpu.cfs_reserve_us - reserved time for each cpu.cfs_period_us > cpu.cfs_reserve_shares - group weight during reserved time > > While cfs group consumes reserved cpu time it has different weight, > thus it gets different vruntime penalty for that execution. > > ^ weight > | > | > reserve | > shares -------* > | | > | | > | | > shares - *-----------------* > | | > | | > 0------|-----------------|-----------> time > reserve quota > > Reserve can work as a "low limit": boost weight for "guaranteed" time, > and as a "high limit": give normal weight for a limited time and allow > utilize cpu when nobody else needs it. > You forgot to explain why I should care about this.