From: Dennis Zhou <dennisszhou@gmail.com>
To: Jens Axboe <axboe@kernel.dk>, Tejun Heo <tj@kernel.org>,
Johannes Weiner <hannes@cmpxchg.org>,
Josef Bacik <josef@toxicpanda.com>
Cc: kernel-team@fb.com, linux-block@vger.kernel.org,
cgroups@vger.kernel.org, linux-kernel@vger.kernel.org,
"Dennis Zhou (Facebook)" <dennisszhou@gmail.com>
Subject: [PATCH 12/12] blkcg: rename blkg_try_get to blkg_tryget
Date: Thu, 6 Sep 2018 17:10:45 -0400 [thread overview]
Message-ID: <20180906211045.29055-13-dennisszhou@gmail.com> (raw)
In-Reply-To: <20180906211045.29055-1-dennisszhou@gmail.com>
From: "Dennis Zhou (Facebook)" <dennisszhou@gmail.com>
blkg reference counting now uses percpu_ref rather than atomic_t. Let's
make this consistent with css_tryget. This renames blkg_try_get to
blkg_tryget and now returns a bool rather than the blkg or NULL.
Signed-off-by: Dennis Zhou <dennisszhou@gmail.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Acked-by: Tejun Heo <tj@kernel.org>
---
block/bio.c | 2 +-
block/blk-cgroup.c | 3 +--
block/blk-iolatency.c | 2 +-
include/linux/blk-cgroup.h | 14 ++++++--------
4 files changed, 9 insertions(+), 12 deletions(-)
diff --git a/block/bio.c b/block/bio.c
index 3cc8fcd8b827..bed3328c92ff 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1971,7 +1971,7 @@ int bio_associate_blkg(struct bio *bio, struct blkcg_gq *blkg)
{
if (unlikely(bio->bi_blkg))
return -EBUSY;
- bio->bi_blkg = blkg_try_get_closest(blkg);
+ bio->bi_blkg = blkg_tryget_closest(blkg);
return 0;
}
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 1efd697c9019..0c9aeb30ba8e 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -1793,8 +1793,7 @@ void blkcg_maybe_throttle_current(void)
blkg = blkg_lookup(blkcg, q);
if (!blkg)
goto out;
- blkg = blkg_try_get(blkg);
- if (!blkg)
+ if (!blkg_tryget(blkg))
goto out;
rcu_read_unlock();
diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c
index 9d7052bad6f7..5a4cec54c998 100644
--- a/block/blk-iolatency.c
+++ b/block/blk-iolatency.c
@@ -628,7 +628,7 @@ static void blkiolatency_timer_fn(struct timer_list *t)
* We could be exiting, don't access the pd unless we have a
* ref on the blkg.
*/
- if (!blkg_try_get(blkg))
+ if (!blkg_tryget(blkg))
continue;
iolat = blkg_to_lat(blkg);
diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
index f8edff271a17..b5bbd9bdf37e 100644
--- a/include/linux/blk-cgroup.h
+++ b/include/linux/blk-cgroup.h
@@ -494,27 +494,25 @@ static inline void blkg_get(struct blkcg_gq *blkg)
}
/**
- * blkg_try_get - try and get a blkg reference
+ * blkg_tryget - try and get a blkg reference
* @blkg: blkg to get
*
* This is for use when doing an RCU lookup of the blkg. We may be in the midst
* of freeing this blkg, so we can only use it if the refcnt is not zero.
*/
-static inline struct blkcg_gq *blkg_try_get(struct blkcg_gq *blkg)
+static inline bool blkg_tryget(struct blkcg_gq *blkg)
{
- if (percpu_ref_tryget(&blkg->refcnt))
- return blkg;
- return NULL;
+ return percpu_ref_tryget(&blkg->refcnt);
}
/**
- * blkg_try_get_closest - try and get a blkg ref on the closet blkg
+ * blkg_tryget_closest - try and get a blkg ref on the closet blkg
* @blkg: blkg to get
*
* This walks up the blkg tree to find the closest non-dying blkg and returns
* the blkg that it did association with as it may not be the passed in blkg.
*/
-static inline struct blkcg_gq *blkg_try_get_closest(struct blkcg_gq *blkg)
+static inline struct blkcg_gq *blkg_tryget_closest(struct blkcg_gq *blkg)
{
while (!percpu_ref_tryget(&blkg->refcnt))
blkg = blkg->parent;
@@ -599,7 +597,7 @@ static inline struct request_list *blk_get_rl(struct request_queue *q,
if (unlikely(!blkg))
blkg = __blkg_lookup_create(blkcg, q);
- if (!blkg_try_get(blkg))
+ if (!blkg_tryget(blkg))
goto rl_use_root;
rcu_read_unlock();
--
2.17.1
next prev parent reply other threads:[~2018-09-06 21:11 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-06 21:10 [PATCH 00/12] block: always associate blkg and refcount cleanup Dennis Zhou
2018-09-06 21:10 ` [PATCH 01/12] blkcg: fix ref count issue with bio_blkcg using task_css Dennis Zhou
2018-09-07 16:52 ` Tejun Heo
2018-09-06 21:10 ` [PATCH 02/12] blkcg: update blkg_lookup_create to do locking Dennis Zhou
2018-09-07 6:17 ` Liu Bo
2018-09-06 21:10 ` [PATCH 03/12] blkcg: convert blkg_lookup_create to find closest blkg Dennis Zhou
2018-09-07 17:27 ` Tejun Heo
2018-09-07 20:33 ` Dennis Zhou
2018-09-06 21:10 ` [PATCH 04/12] blkcg: always associate a bio with a blkg Dennis Zhou
2018-09-06 21:10 ` [PATCH 05/12] blkcg: consolidate bio_issue_init to be a part of core Dennis Zhou
2018-09-07 19:18 ` Liu Bo
2018-09-06 21:10 ` [PATCH 06/12] blkcg: associate a blkg for pages being evicted by swap Dennis Zhou
2018-09-06 21:10 ` [PATCH 07/12] blkcg: associate writeback bios with a blkg Dennis Zhou
2018-09-06 21:10 ` [PATCH 08/12] blkcg: remove bio->bi_css and instead use bio->bi_blkg Dennis Zhou
2018-09-06 21:10 ` [PATCH 09/12] blkcg: remove additional reference to the css Dennis Zhou
2018-09-07 17:54 ` Tejun Heo
2018-09-07 20:24 ` Dennis Zhou
2018-09-06 21:10 ` [PATCH 10/12] blkcg: cleanup and make blk_get_rl use blkg_lookup_create Dennis Zhou
2018-09-11 5:11 ` [LKP] [blkcg] 1d0e59f90b: BUG:unable_to_handle_kernel kernel test robot
2018-09-06 21:10 ` [PATCH 11/12] blkcg: change blkg reference counting to use percpu_ref Dennis Zhou
2018-09-07 17:59 ` Tejun Heo
2018-09-06 21:10 ` Dennis Zhou [this message]
2018-09-11 18:41 [PATCH v3 00/12] block: always associate blkg and refcount cleanup Dennis Zhou
2018-09-11 18:41 ` [PATCH 12/12] blkcg: rename blkg_try_get to blkg_tryget Dennis Zhou
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