From: Rik van Riel Subject: Re: [PATCH 25/23] io-controller: fix queue vs group fairness Date: Wed, 09 Sep 2009 00:44:55 -0400 Message-ID: <4AA732C7.70003@redhat.com> References: <1251495072-7780-1-git-send-email-vgoyal@redhat.com> <20090908222827.GC3558@redhat.com> Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20090908222827.GC3558@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: Vivek Goyal Cc: dhaval@linux.vnet.ibm.com, peterz@infradead.org, dm-devel@redhat.com, dpshah@google.com, jens.axboe@oracle.com, agk@redhat.com, balbir@linux.vnet.ibm.com, paolo.valente@unimore.it, jmarchan@redhat.com, guijianfeng@cn.fujitsu.com, fernando@oss.ntt.co.jp, mikew@google.com, jmoyer@redhat.com, nauman@google.com, mingo@elte.hu, m-ikeda@ds.jp.nec.com, lizf@cn.fujitsu.com, fchecconi@gmail.com, s-uchida@ap.jp.nec.com, containers@lists.linux-foundation.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, righi.andrea@gmail.com, torvalds@linux-foundation.org List-Id: dm-devel.ids Vivek Goyal wrote: > o I found an issue during test and that is if there is a mix of queue and group > at same level, there can be fairness issue. For example, consider following > case. Acked-by: Rik van Riel (assuming the cleanups are done in V10 - the artifact of a wraparound hitting exactly 0 should not be an issue) -- All rights reversed.