From patchwork Fri Jun 26 08:13:51 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gui Jianfeng X-Patchwork-Id: 32530 Received: from hormel.redhat.com (hormel1.redhat.com [209.132.177.33]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n5Q8FYqj006454 for ; Fri, 26 Jun 2009 08:15:34 GMT Received: from listman.util.phx.redhat.com (listman.util.phx.redhat.com [10.8.4.110]) by hormel.redhat.com (Postfix) with ESMTP id BDE696198B7; Fri, 26 Jun 2009 04:15:33 -0400 (EDT) Received: from int-mx1.corp.redhat.com (int-mx1.corp.redhat.com [172.16.52.254]) by listman.util.phx.redhat.com (8.13.1/8.13.1) with ESMTP id n5Q8FU5K008925 for ; Fri, 26 Jun 2009 04:15:30 -0400 Received: from mx1.redhat.com (mx1.redhat.com [172.16.48.31]) by int-mx1.corp.redhat.com (8.13.1/8.13.1) with ESMTP id n5Q8FTd8028071; Fri, 26 Jun 2009 04:15:29 -0400 Received: from song.cn.fujitsu.com (cn.fujitsu.com [222.73.24.84] (may be forged)) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id n5Q8E2xe030446; Fri, 26 Jun 2009 04:14:03 -0400 Received: from tang.cn.fujitsu.com (tang.cn.fujitsu.com [10.167.250.3]) by song.cn.fujitsu.com (Postfix) with ESMTP id 277E3170116; Fri, 26 Jun 2009 16:16:20 +0800 (CST) Received: from fnst.cn.fujitsu.com (localhost.localdomain [127.0.0.1]) by tang.cn.fujitsu.com (8.13.1/8.13.1) with ESMTP id n5Q8bdgs016083; Fri, 26 Jun 2009 16:37:40 +0800 Received: from [127.0.0.1] (unknown [10.167.141.226]) by fnst.cn.fujitsu.com (Postfix) with ESMTPA id 969DFD403A; Fri, 26 Jun 2009 16:15:58 +0800 (CST) Message-ID: <4A44833F.8040308@cn.fujitsu.com> Date: Fri, 26 Jun 2009 16:13:51 +0800 From: Gui Jianfeng User-Agent: Thunderbird 2.0.0.5 (Windows/20070716) MIME-Version: 1.0 To: Vivek Goyal References: <1245443858-8487-1-git-send-email-vgoyal@redhat.com> <1245443858-8487-21-git-send-email-vgoyal@redhat.com> <4A3F3648.7080007@cn.fujitsu.com> <20090622172123.GE15600@redhat.com> <4A4079B8.4020402@cn.fujitsu.com> <20090623140250.GA4262@redhat.com> <4A41EFE1.5050101@cn.fujitsu.com> In-Reply-To: <4A41EFE1.5050101@cn.fujitsu.com> X-RedHat-Spam-Score: -0.88 X-Scanned-By: MIMEDefang 2.58 on 172.16.52.254 X-Scanned-By: MIMEDefang 2.63 on 172.16.48.31 X-loop: dm-devel@redhat.com Cc: dhaval@linux.vnet.ibm.com, snitzer@redhat.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, fernando@oss.ntt.co.jp, mikew@google.com, jmoyer@redhat.com, nauman@google.com, m-ikeda@ds.jp.nec.com, lizf@cn.fujitsu.com, fchecconi@gmail.com, akpm@linux-foundation.org, jbaron@redhat.com, linux-kernel@vger.kernel.org, s-uchida@ap.jp.nec.com, righi.andrea@gmail.com, containers@lists.linux-foundation.org Subject: [dm-devel] [PATCH 2/2] io-controller: make rt preemption happen in the whole hierarchy X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.5 Precedence: junk Reply-To: device-mapper development List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com let rt queue preempt non-rt queue if needed. Make sure comparision happens at the same level. Signed-off-by: Gui Jianfeng --- block/elevator-fq.c | 28 +++++++++++++++++++++++++++- 1 files changed, 27 insertions(+), 1 deletions(-) diff --git a/block/elevator-fq.c b/block/elevator-fq.c index 1d4ec1f..21d38f5 100644 --- a/block/elevator-fq.c +++ b/block/elevator-fq.c @@ -3742,6 +3742,31 @@ int elv_iosched_expire_ioq(struct request_queue *q, int slice_expired, return ret; } +static int check_rt_preemption(struct io_queue *ioq) +{ + struct hlist_node *node; + struct hlist_head *hhead = &ioq->efqd->rt_ioq_list; + struct io_queue *rt_ioq; + struct io_entity *entity = &ioq->entity; + struct io_entity *new_entity; + + rcu_read_lock(); + hlist_for_each_entry_rcu(rt_ioq, node, hhead, rt_node) { + new_entity = &rt_ioq->entity; + + bfq_find_matching_entity(&entity, &new_entity); + + if (new_entity->ioprio_class == IOPRIO_CLASS_RT && + entity->ioprio_class != IOPRIO_CLASS_RT) { + rcu_read_unlock(); + return 1; + } + } + rcu_read_unlock(); + + return 0; +} + /* Common layer function to select the next queue to dispatch from */ void *elv_fq_select_ioq(struct request_queue *q, int force) { @@ -3823,7 +3848,8 @@ void *elv_fq_select_ioq(struct request_queue *q, int force) */ iog = ioq_to_io_group(ioq); - if (!elv_ioq_class_rt(ioq) && iog->busy_rt_queues) { + if (!elv_ioq_class_rt(ioq) && + (iog->busy_rt_queues || check_rt_preemption(ioq))) { /* * We simulate this as cfqq timed out so that it gets to bank * the remaining of its time slice.