From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:33681 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S933900AbcKVXLh (ORCPT ); Tue, 22 Nov 2016 18:11:37 -0500 Date: Tue, 22 Nov 2016 15:11:21 -0800 From: Shaohua Li To: Tejun Heo CC: , , , , Subject: Re: [PATCH V4 03/15] blk-throttle: configure bps/iops limit for cgroup in high limit Message-ID: <20161122231120.GB14628@shli-mbp.local> References: <7a4f1b1b0f67bb02d0caadae808c1a89413c202d.1479161136.git.shli@fb.com> <20161122201643.GB17534@htj.duckdns.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" In-Reply-To: <20161122201643.GB17534@htj.duckdns.org> Sender: linux-block-owner@vger.kernel.org List-Id: linux-block@vger.kernel.org On Tue, Nov 22, 2016 at 03:16:43PM -0500, Tejun Heo wrote: > On Mon, Nov 14, 2016 at 02:22:10PM -0800, Shaohua Li wrote: > > each queue will have a state machine. Initially queue is in LIMIT_HIGH > > state, which means all cgroups will be throttled according to their high > > limit. After all cgroups with high limit cross the limit, the queue state > > gets upgraded to LIMIT_MAX state. > > cgroups without high limit will use max limit for their high limit. > > Haven't looked at the actual mechanism yet so please correct me if I'm > getting it wrong but at least the above explanation reads incorrect. > Shouldn't max limits applied regardless of whether other cgroups are > above high or not? That's true. Since the max limit is higher than high limit (the interface patch 2 has the check), if cgroup is throttled according to high limit, max limit is respected too. Thanks, Shaohua