From: Ming Lei <ming.lei@redhat.com>
To: linux-kernel@vger.kernel.org, linux-block@vger.kernel.org
Cc: Ming Lei <ming.lei@redhat.com>, Sagi Grimberg <sagi@grimberg.me>,
Tejun Heo <tj@kernel.org>, Christoph Hellwig <hch@lst.de>,
Jens Axboe <axboe@kernel.dk>,
Bart Van Assche <bvanassche@acm.org>
Subject: [PATCH 2/2] block: move 'q_usage_counter' into front of 'request_queue'
Date: Tue, 25 Aug 2020 18:12:48 +0800 [thread overview]
Message-ID: <20200825101248.8027-3-ming.lei@redhat.com> (raw)
In-Reply-To: <20200825101248.8027-1-ming.lei@redhat.com>
The field of 'q_usage_counter' is always fetched in fast path of every
block driver, and move it into front of 'request_queue', so it can be
fetched into 1st cacheline of 'request_queue' instance.
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
include/linux/blkdev.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index bb5636cc17b9..d8dba550ecac 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -396,6 +396,8 @@ struct request_queue {
struct request *last_merge;
struct elevator_queue *elevator;
+ struct percpu_ref q_usage_counter;
+
struct blk_queue_stats *stats;
struct rq_qos *rq_qos;
@@ -566,7 +568,6 @@ struct request_queue {
* percpu_ref_kill() and percpu_ref_reinit().
*/
struct mutex mq_freeze_lock;
- struct percpu_ref q_usage_counter;
struct blk_mq_tag_set *tag_set;
struct list_head tag_set_list;
--
2.25.2
prev parent reply other threads:[~2020-08-25 10:13 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-25 10:12 [PATCH 0/2] percpu_ref & block: reduce memory footprint of percpu_ref in fast path Ming Lei
2020-08-25 10:12 ` [PATCH 1/2] percpu_ref: " Ming Lei
2020-08-31 9:48 ` [percpu_ref] 13f0f97539: blktests.block.027.fail kernel test robot
2020-08-25 10:12 ` Ming Lei [this message]
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