From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: Re: [PATCH RFC 0/3] sched/fair: cpu time reserves for cgroups Date: Mon, 16 May 2016 13:18:49 +0200 Message-ID: <20160516111849.GN3193@twins.programming.kicks-ass.net> References: <146339085068.25295.7687045977863852568.stgit@buzz> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: <146339085068.25295.7687045977863852568.stgit@buzz> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Konstantin Khlebnikov Cc: Ingo Molnar , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Tejun Heo , cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.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.