From: Jens Axboe <axboe@fb.com>
Date: Wed, 7 Jan 2015 17:44:04 +0000 (-0700)
Subject: blk-mq: get rid of ->cmd_size in the hardware queue
X-Git-Tag: firefly_0821_release~176^2~2521^2~12
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=17ded320706c6316376059cfbe9dccab32c62b42;p=firefly-linux-kernel-4.4.55.git

blk-mq: get rid of ->cmd_size in the hardware queue

We store it in the tag set, we don't need it in the hardware queue.
While removing cmd_size, place ->queue_num further down to avoid
a hole on 64-bit archs. It's not used in any fast paths, so we
can safely move it.

Signed-off-by: Jens Axboe <axboe@fb.com>
---

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 1a41d7aefbd5..cbd2a55d69b8 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1615,7 +1615,6 @@ static int blk_mq_init_hctx(struct request_queue *q,
 	hctx->queue = q;
 	hctx->queue_num = hctx_idx;
 	hctx->flags = set->flags;
-	hctx->cmd_size = set->cmd_size;
 
 	blk_mq_init_cpu_notifier(&hctx->cpu_notifier,
 					blk_mq_hctx_notify, hctx);
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 3b43f509432c..d0de259e92b2 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -34,7 +34,6 @@ struct blk_mq_hw_ctx {
 	unsigned long		flags;		/* BLK_MQ_F_* flags */
 
 	struct request_queue	*queue;
-	unsigned int		queue_num;
 	struct blk_flush_queue	*fq;
 
 	void			*driver_data;
@@ -54,7 +53,7 @@ struct blk_mq_hw_ctx {
 	unsigned long		dispatched[BLK_MQ_MAX_DISPATCH_ORDER];
 
 	unsigned int		numa_node;
-	unsigned int		cmd_size;	/* per-request extra data */
+	unsigned int		queue_num;
 
 	atomic_t		nr_active;