From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757003AbcBCN2c (ORCPT ); Wed, 3 Feb 2016 08:28:32 -0500 Received: from mail-wm0-f52.google.com ([74.125.82.52]:33792 "EHLO mail-wm0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755308AbcBCN23 (ORCPT ); Wed, 3 Feb 2016 08:28:29 -0500 Date: Wed, 3 Feb 2016 14:28:18 +0100 From: luca abeni To: Juri Lelli Cc: Peter Zijlstra , linux-kernel@vger.kernel.org, Ingo Molnar Subject: Re: [RFC 8/8] Do not reclaim the whole CPU bandwidth Message-ID: <20160203142818.62d7b8c9@utopia> In-Reply-To: <20160203113019.GT3947@e106622-lin> References: <1452785094-3086-1-git-send-email-luca.abeni@unitn.it> <1452785094-3086-9-git-send-email-luca.abeni@unitn.it> <20160114195904.GH6357@twins.programming.kicks-ass.net> <5698ABFD.1040704@unitn.it> <20160115085004.GE3421@worktop> <20160126135219.338e8ccb@utopia> <20160127144422.GS6357@twins.programming.kicks-ass.net> <20160202215310.43fef86b@luca-1225C> <20160203113019.GT3947@e106622-lin> Organization: university of trento X-Mailer: Claws Mail 3.12.0 (GTK+ 2.24.28; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Juri, On Wed, 3 Feb 2016 11:30:19 +0000 Juri Lelli wrote: [...] > > > > Which kind of interface is better for this? Would adding > > > > something like /proc/sys/kernel/sched_other_period_us > > > > /proc/sys/kernel/sched_other_runtime_us > > > > be ok? > > > > > > > > If this is ok, I'll add these two procfs files, and store > > > > (sched_other_runtime / sched_other_period) << 20 in the runqueue > > > > field which represents the unreclaimable utilization > > > > (implementing hierarchical SCHED_DEADLINE/CFS scheduling right > > > > now is too complex for this patchset... But if the exported > > > > interface is ok, it can be implemented later). > > > > > > > > Is this approach acceptable? Or am I misunderstanding your > > > > comment? > > > > > > No, I think that's fine. > > So, I implemented this idea (/proc/sys/kernel/sched_other_period_us > > and /proc/sys/kernel/sched_other_runtime_us to set the unreclaimable > > utilization), and some initial testing seems to show that it works > > fine. > > > > Sorry for not saying this before, but why can't we use the existing > sched_rt_runtime_us/sched_rt_runtime_period cap for this? I mean, > other will have (1 - rt_runtime_ratio) available to run. I was thinking about providing a more flexible interface (allowing to use rt_runtime/rt_period for admission control and other_runtime/other_period for reclaiming), but using using sched_rt_runtime_us/sched_rt_runtime_period makes sense too. If this solution is preferred, I'll adapt my patch. Thanks, Luca