Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756231AbZFZIOX (ORCPT ); Fri, 26 Jun 2009 04:14:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755402AbZFZIOA (ORCPT ); Fri, 26 Jun 2009 04:14:00 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:55434 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1755699AbZFZIN7 (ORCPT ); Fri, 26 Jun 2009 04:13:59 -0400 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 CC: linux-kernel@vger.kernel.org, containers@lists.linux-foundation.org, dm-devel@redhat.com, jens.axboe@oracle.com, nauman@google.com, dpshah@google.com, lizf@cn.fujitsu.com, mikew@google.com, fchecconi@gmail.com, paolo.valente@unimore.it, ryov@valinux.co.jp, fernando@oss.ntt.co.jp, s-uchida@ap.jp.nec.com, taka@valinux.co.jp, jmoyer@redhat.com, dhaval@linux.vnet.ibm.com, balbir@linux.vnet.ibm.com, righi.andrea@gmail.com, m-ikeda@ds.jp.nec.com, jbaron@redhat.com, agk@redhat.com, snitzer@redhat.com, akpm@linux-foundation.org, peterz@infradead.org Subject: [PATCH 2/2] io-controller: make rt preemption happen in the whole hierarchy 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> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1885 Lines: 63 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. -- 1.5.4.rc3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/