From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754900Ab2L1Ugw (ORCPT ); Fri, 28 Dec 2012 15:36:52 -0500 Received: from mail-pa0-f52.google.com ([209.85.220.52]:33267 "EHLO mail-pa0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754794Ab2L1Ugo (ORCPT ); Fri, 28 Dec 2012 15:36:44 -0500 From: Tejun Heo To: lizefan@huawei.com, axboe@kernel.dk, vgoyal@redhat.com Cc: containers@lists.linux-foundation.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, ctalbott@google.com, rni@google.com, Tejun Heo Subject: [PATCH 20/24] block: RCU free request_queue Date: Fri, 28 Dec 2012 12:35:42 -0800 Message-Id: <1356726946-26037-21-git-send-email-tj@kernel.org> X-Mailer: git-send-email 1.8.0.2 In-Reply-To: <1356726946-26037-1-git-send-email-tj@kernel.org> References: <1356726946-26037-1-git-send-email-tj@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org RCU free request_queue so that blkcg_gq->q can be dereferenced under RCU lock. This will be used to implement hierarchical stats. Signed-off-by: Tejun Heo --- block/blk-sysfs.c | 9 ++++++++- include/linux/blkdev.h | 2 ++ 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 7881477..6206a93 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -497,6 +497,13 @@ queue_attr_store(struct kobject *kobj, struct attribute *attr, return res; } +static void blk_free_queue_rcu(struct rcu_head *rcu_head) +{ + struct request_queue *q = container_of(rcu_head, struct request_queue, + rcu_head); + kmem_cache_free(blk_requestq_cachep, q); +} + /** * blk_release_queue: - release a &struct request_queue when it is no longer needed * @kobj: the kobj belonging to the request queue to be released @@ -538,7 +545,7 @@ static void blk_release_queue(struct kobject *kobj) bdi_destroy(&q->backing_dev_info); ida_simple_remove(&blk_queue_ida, q->id); - kmem_cache_free(blk_requestq_cachep, q); + call_rcu(&q->rcu_head, blk_free_queue_rcu); } static const struct sysfs_ops queue_sysfs_ops = { diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index f94bc83..406343c 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -19,6 +19,7 @@ #include #include #include +#include #include @@ -437,6 +438,7 @@ struct request_queue { /* Throttle data */ struct throtl_data *td; #endif + struct rcu_head rcu_head; }; #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */ -- 1.8.0.2