From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gui Jianfeng Subject: Re: [PATCH] IO-Controller: clear ioq wait flag if a request goes into that ioq Date: Fri, 21 Aug 2009 08:57:27 +0800 Message-ID: <4A8DF0F7.6070100@cn.fujitsu.com> References: <1250451046-9966-1-git-send-email-vgoyal@redhat.com> <1250451046-9966-12-git-send-email-vgoyal@redhat.com> <4A8CAAE2.1030804@cn.fujitsu.com> <20090820134221.GC10615@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20090820134221.GC10615@redhat.com> Sender: linux-kernel-owner@vger.kernel.org To: Vivek Goyal Cc: linux-kernel@vger.kernel.org, containers@lists.linux-foundation.org, dm-devel@redhat.com, jens.axboe@oracle.com, ryov@valinux.co.jp, balbir@linux.vnet.ibm.com, righi.andrea@gmail.com, nauman@google.com, dpshah@google.com, lizf@cn.fujitsu.com, mikew@google.com, fchecconi@gmail.com, paolo.valente@unimore.it, fernando@oss.ntt.co.jp, s-uchida@ap.jp.nec.com, taka@valinux.co.jp, jmoyer@redhat.com, dhaval@linux.vnet.ibm.com, m-ikeda@ds.jp.nec.com, agk@redhat.com, akpm@linux-foundation.org, peterz@infradead.org, jmarchan@redhat.com List-Id: dm-devel.ids Vivek Goyal wrote: > On Thu, Aug 20, 2009 at 09:46:10AM +0800, Gui Jianfeng wrote: >> Vivek Goyal wrote: >> ... >>> /* >>> * Remember that we saw a request from this process, but >>> @@ -1940,7 +2013,7 @@ void elv_ioq_request_add(struct request_queue *q, struct request *rq) >>> * has other work pending, don't risk delaying until the >>> * idle timer unplug to continue working. >>> */ >>> - if (elv_ioq_wait_request(ioq)) { >>> + if (group_wait || elv_ioq_wait_request(ioq)) { >> Hi Vivek, >> >> I guess we need to clear ioq_wait_request flags if there are requests to >> go in this ioq. Otherwise, once waitting request on ioq, it will go into >> this path every time when a request is enqueued. >> >> Signed-off-by: Gui Jianfeng > > Hi Gui, > > It does sound like that we need to clear ioq wait_request flag here. In > fact upstream CFQ code is also not clearing this flag. Looking at the > code, can't think why it should not be cleared here. > > Can you please also generate a patch for CFQ and post to lkml. > Sure, will do. -- Regards Gui Jianfeng