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From: Tejun Heo <tj@kernel.org>
To: axboe@kernel.dk
Cc: shli@kernel.org, linux-kernel@vger.kernel.org,
	kernel-team@fb.com, lizefan@huawei.com, hannes@cmpxchg.org,
	cgroups@vger.kernel.org, guro@fb.com, Tejun Heo <tj@kernel.org>
Subject: [PATCH 1/7] blkcg: relocate __blkg_release_rcu()
Date: Sun, 12 Nov 2017 14:26:07 -0800	[thread overview]
Message-ID: <20171112222613.3613362-2-tj@kernel.org> (raw)
In-Reply-To: <20171112222613.3613362-1-tj@kernel.org>

Move __blkg_release_rcu() above blkg_alloc().  This is a pure code
reorganization to prepare for the switch to percpu_ref.

Signed-off-by: Tejun Heo <tj@kernel.org>
---
 block/blk-cgroup.c | 46 +++++++++++++++++++++++-----------------------
 1 file changed, 23 insertions(+), 23 deletions(-)

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index d3f56ba..6482be5 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -81,6 +81,29 @@ static void blkg_free(struct blkcg_gq *blkg)
 	kfree(blkg);
 }
 
+/*
+ * A group is RCU protected, but having an rcu lock does not mean that one
+ * can access all the fields of blkg and assume these are valid.  For
+ * example, don't try to follow throtl_data and request queue links.
+ *
+ * Having a reference to blkg under an rcu allows accesses to only values
+ * local to groups like group stats and group rate limits.
+ */
+void __blkg_release_rcu(struct rcu_head *rcu_head)
+{
+	struct blkcg_gq *blkg = container_of(rcu_head, struct blkcg_gq, rcu_head);
+
+	/* release the blkcg and parent blkg refs this blkg has been holding */
+	css_put(&blkg->blkcg->css);
+	if (blkg->parent)
+		blkg_put(blkg->parent);
+
+	wb_congested_put(blkg->wb_congested);
+
+	blkg_free(blkg);
+}
+EXPORT_SYMBOL_GPL(__blkg_release_rcu);
+
 /**
  * blkg_alloc - allocate a blkg
  * @blkcg: block cgroup the new blkg is associated with
@@ -378,29 +401,6 @@ static void blkg_destroy_all(struct request_queue *q)
 }
 
 /*
- * A group is RCU protected, but having an rcu lock does not mean that one
- * can access all the fields of blkg and assume these are valid.  For
- * example, don't try to follow throtl_data and request queue links.
- *
- * Having a reference to blkg under an rcu allows accesses to only values
- * local to groups like group stats and group rate limits.
- */
-void __blkg_release_rcu(struct rcu_head *rcu_head)
-{
-	struct blkcg_gq *blkg = container_of(rcu_head, struct blkcg_gq, rcu_head);
-
-	/* release the blkcg and parent blkg refs this blkg has been holding */
-	css_put(&blkg->blkcg->css);
-	if (blkg->parent)
-		blkg_put(blkg->parent);
-
-	wb_congested_put(blkg->wb_congested);
-
-	blkg_free(blkg);
-}
-EXPORT_SYMBOL_GPL(__blkg_release_rcu);
-
-/*
  * The next function used by blk_queue_for_each_rl().  It's a bit tricky
  * because the root blkg uses @q->root_rl instead of its own rl.
  */
-- 
2.9.5

  reply	other threads:[~2017-11-12 22:26 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-11-12 22:26 [PATCHSET] blkcg: basic accounting and throttling fixes Tejun Heo
2017-11-12 22:26 ` Tejun Heo [this message]
2017-11-14 23:12   ` [PATCH 1/7] blkcg: relocate __blkg_release_rcu() Shaohua Li
2017-11-12 22:26 ` [PATCH 2/7] blkcg: use percpu_ref for blkcg_gq->refcnt Tejun Heo
2017-11-14 23:12   ` Shaohua Li
2017-11-12 22:26 ` [PATCH 3/7] blkcg: associate a request with its blkcg_gq instead of request_list Tejun Heo
2017-11-13 20:15   ` [PATCH v2 " Tejun Heo
2017-11-14 23:17     ` Shaohua Li
2017-11-15 17:11       ` Tejun Heo
2017-11-12 22:26 ` [PATCH 4/7] blkcg: refactor blkcg_gq lookup and creation in blkcg_bio_issue_check() Tejun Heo
2017-11-14 23:18   ` Shaohua Li
2017-11-12 22:26 ` [PATCH 5/7] blkcg: associate blk-mq requests with the matching blkcg_gqs Tejun Heo
2017-11-12 22:26 ` [PATCH 6/7] blkcg: account requests instead of bios for request based request_queues Tejun Heo
2017-11-14 23:23   ` Shaohua Li
2017-11-15 17:18     ` [PATCH v2 " Tejun Heo
2017-11-15 17:19     ` [PATCH " Jens Axboe
2017-11-15 17:22       ` [PATCH v3 " Tejun Heo
2017-11-12 22:26 ` [PATCH 7/7] blk-throtl: don't throttle the same IO multiple times Tejun Heo
2017-11-13  4:07   ` Shaohua Li
2017-11-13 11:13     ` Tejun Heo
2017-11-13 15:57       ` Tejun Heo
2017-11-13 19:54         ` Shaohua Li
2017-11-13 19:58           ` Tejun Heo
2017-11-13 19:58         ` Shaohua Li

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