Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754225AbZFWMNR (ORCPT ); Tue, 23 Jun 2009 08:13:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755491AbZFWMNA (ORCPT ); Tue, 23 Jun 2009 08:13:00 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:58539 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1753275AbZFWMNA (ORCPT ); Tue, 23 Jun 2009 08:13:00 -0400 Message-ID: <4A40C64E.8040305@cn.fujitsu.com> Date: Tue, 23 Jun 2009 20:10:54 +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: Re: [PATCH 07/20] io-controller: Export disk time used and nr sectors dipatched through cgroups References: <1245443858-8487-1-git-send-email-vgoyal@redhat.com> <1245443858-8487-8-git-send-email-vgoyal@redhat.com> In-Reply-To: <1245443858-8487-8-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: 3008 Lines: 112 Vivek Goyal wrote: ... > + > +static int io_cgroup_disk_sectors_read(struct cgroup *cgroup, > + struct cftype *cftype, struct seq_file *m) > +{ > + struct io_cgroup *iocg; > + struct io_group *iog; > + struct hlist_node *n; > + > + if (!cgroup_lock_live_group(cgroup)) > + return -ENODEV; > + > + iocg = cgroup_to_io_cgroup(cgroup); > + > + spin_lock_irq(&iocg->lock); It's better to make use of rcu_read_lock instead since it's a read action. Signed-off-by: Gui Jianfeng --- block/elevator-fq.c | 12 ++++++------ 1 files changed, 6 insertions(+), 6 deletions(-) diff --git a/block/elevator-fq.c b/block/elevator-fq.c index 2ad40eb..d779282 100644 --- a/block/elevator-fq.c +++ b/block/elevator-fq.c @@ -1418,7 +1418,7 @@ static int io_cgroup_disk_time_read(struct cgroup *cgroup, iocg = cgroup_to_io_cgroup(cgroup); - spin_lock_irq(&iocg->lock); + rcu_read_lock(); hlist_for_each_entry_rcu(iog, n, &iocg->group_data, group_node) { /* * There might be groups which are not functional and @@ -1430,7 +1430,7 @@ static int io_cgroup_disk_time_read(struct cgroup *cgroup, iog->entity.total_service); } } - spin_unlock_irq(&iocg->lock); + rcu_read_unlock(); cgroup_unlock(); return 0; @@ -1448,7 +1448,7 @@ static int io_cgroup_disk_sectors_read(struct cgroup *cgroup, iocg = cgroup_to_io_cgroup(cgroup); - spin_lock_irq(&iocg->lock); + rcu_read_lock(); hlist_for_each_entry_rcu(iog, n, &iocg->group_data, group_node) { /* * There might be groups which are not functional and @@ -1460,7 +1460,7 @@ static int io_cgroup_disk_sectors_read(struct cgroup *cgroup, iog->entity.total_sector_service); } } - spin_unlock_irq(&iocg->lock); + rcu_read_unlock(); cgroup_unlock(); return 0; @@ -1478,7 +1478,7 @@ static int io_cgroup_disk_queue_read(struct cgroup *cgroup, return -ENODEV; iocg = cgroup_to_io_cgroup(cgroup); - spin_lock_irq(&iocg->lock); + rcu_read_lock(); /* Loop through all the io groups and print statistics */ hlist_for_each_entry_rcu(iog, n, &iocg->group_data, group_node) { /* @@ -1491,7 +1491,7 @@ static int io_cgroup_disk_queue_read(struct cgroup *cgroup, iog->queue_duration); } } - spin_unlock_irq(&iocg->lock); + rcu_read_unlock(); cgroup_unlock(); return 0; -- 1.5.4.rc3 > + hlist_for_each_entry_rcu(iog, n, &iocg->group_data, group_node) { > + /* > + * There might be groups which are not functional and > + * waiting to be reclaimed upon cgoup deletion. > + */ > + if (iog->key) { > + seq_printf(m, "%u %u %lu\n", MAJOR(iog->dev), > + MINOR(iog->dev), > + iog->entity.total_sector_service); > + } > + } > + spin_unlock_irq(&iocg->lock); > + cgroup_unlock(); > + > + return 0; > +} > + > -- 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/