| Message ID | 20200902122643.634143-3-ming.lei@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | percpu_ref & block: reduce memory footprint of percpu_ref in fast path | expand |
On Wed, Sep 02, 2020 at 08:26:43PM +0800, Ming Lei wrote: > 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. Looks good, Reviewed-by: Christoph Hellwig <hch@lst.de>
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index d0d61bc81615..7575fa0aae6e 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -397,6 +397,8 @@ 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; @@ -567,7 +569,6 @@ 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;
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(-)