Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753615AbZFVHqV (ORCPT ); Mon, 22 Jun 2009 03:46:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752420AbZFVHqN (ORCPT ); Mon, 22 Jun 2009 03:46:13 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:64458 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1752371AbZFVHqN (ORCPT ); Mon, 22 Jun 2009 03:46:13 -0400 Message-ID: <4A3F3648.7080007@cn.fujitsu.com> Date: Mon, 22 Jun 2009 15:44:08 +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] io-controller: Preempt a non-rt queue if a rt ioq is present in ancestor or sibling groups References: <1245443858-8487-1-git-send-email-vgoyal@redhat.com> <1245443858-8487-21-git-send-email-vgoyal@redhat.com> In-Reply-To: <1245443858-8487-21-git-send-email-vgoyal@redhat.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: 3386 Lines: 119 Preempt the ongoing non-rt ioq if there are rt ioqs waiting for dispatching in ancestor or sibling groups. It will give other group's rt ioq an chance to dispatch ASAP. Signed-off-by: Gui Jianfeng --- block/elevator-fq.c | 44 +++++++++++++++++++++++++++++++++++++++----- block/elevator-fq.h | 1 + 2 files changed, 40 insertions(+), 5 deletions(-) diff --git a/block/elevator-fq.c b/block/elevator-fq.c index 2ad40eb..80526fd 100644 --- a/block/elevator-fq.c +++ b/block/elevator-fq.c @@ -3245,8 +3245,16 @@ void elv_add_ioq_busy(struct elv_fq_data *efqd, struct io_queue *ioq) elv_mark_ioq_busy(ioq); efqd->busy_queues++; if (elv_ioq_class_rt(ioq)) { + struct io_entity *entity; struct io_group *iog = ioq_to_io_group(ioq); + iog->busy_rt_queues++; + entity = iog->entity.parent; + + for_each_entity(entity) { + iog = io_entity_to_iog(entity); + iog->sub_busy_rt_queues++; + } } #ifdef CONFIG_DEBUG_GROUP_IOSCHED @@ -3290,9 +3298,18 @@ void elv_del_ioq_busy(struct elevator_queue *e, struct io_queue *ioq, elv_clear_ioq_busy(ioq); BUG_ON(efqd->busy_queues == 0); efqd->busy_queues--; + if (elv_ioq_class_rt(ioq)) { + struct io_entity *entity; struct io_group *iog = ioq_to_io_group(ioq); + iog->busy_rt_queues--; + entity = iog->entity.parent; + + for_each_entity(entity) { + iog = io_entity_to_iog(entity); + iog->sub_busy_rt_queues--; + } } elv_deactivate_ioq(efqd, ioq, requeue); @@ -3735,12 +3752,32 @@ int elv_iosched_expire_ioq(struct request_queue *q, int slice_expired, return ret; } +static int check_rt_queue(struct io_queue *ioq) +{ + struct io_group *iog; + struct io_entity *entity; + + iog = ioq_to_io_group(ioq); + + if (iog->busy_rt_queues) + return 1; + + entity = iog->entity.parent; + + for_each_entity(entity) { + iog = io_entity_to_iog(entity); + if (iog->sub_busy_rt_queues) + return 1; + } + + return 0; +} + /* Common layer function to select the next queue to dispatch from */ void *elv_fq_select_ioq(struct request_queue *q, int force) { struct elv_fq_data *efqd = &q->elevator->efqd; struct io_queue *new_ioq = NULL, *ioq = elv_active_ioq(q->elevator); - struct io_group *iog; int slice_expired = 1; if (!elv_nr_busy_ioq(q->elevator)) @@ -3811,12 +3848,9 @@ void *elv_fq_select_ioq(struct request_queue *q, int force) /* * If we have a RT cfqq waiting, then we pre-empt the current non-rt * cfqq. - * - * TODO: This does not seem right across the io groups. Fix it. */ - iog = ioq_to_io_group(ioq); - if (!elv_ioq_class_rt(ioq) && iog->busy_rt_queues) { + if (!elv_ioq_class_rt(ioq) && check_rt_queue(ioq)) { /* * We simulate this as cfqq timed out so that it gets to bank * the remaining of its time slice. diff --git a/block/elevator-fq.h b/block/elevator-fq.h index b3193f8..be6c1af 100644 --- a/block/elevator-fq.h +++ b/block/elevator-fq.h @@ -248,6 +248,7 @@ struct io_group { * non-RT cfqq in service when this value is non-zero. */ unsigned int busy_rt_queues; + unsigned int sub_busy_rt_queues; int deleting; unsigned short iocg_id; -- 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/