blk-mq: initialize req->q in allocation

The patch basically reverts the patch of(blk-mq:
initialize request on allocation) in Jens's tree(already
in -next), and only initialize req->q in allocation
for two reasons:

	- presumed cache hotness on completion
	- blk_rq_tagged(rq) depends on reset of req->mq_ctx

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Ming Lei 2014-04-19 18:00:19 +08:00 committed by Jens Axboe
parent 4ca085009f
commit 6a3c8a3ac0

View file

@ -82,7 +82,6 @@ static struct request *__blk_mq_alloc_request(struct blk_mq_hw_ctx *hctx,
tag = blk_mq_get_tag(hctx->tags, gfp, reserved);
if (tag != BLK_MQ_TAG_FAIL) {
rq = hctx->tags->rqs[tag];
blk_rq_init(hctx->queue, rq);
rq->tag = tag;
return rq;
@ -187,6 +186,7 @@ static void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx,
if (blk_queue_io_stat(q))
rw_flags |= REQ_IO_STAT;
rq->q = q;
rq->mq_ctx = ctx;
rq->cmd_flags = rw_flags;
rq->start_time = jiffies;
@ -258,6 +258,7 @@ static void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx,
const int tag = rq->tag;
struct request_queue *q = rq->q;
blk_rq_init(hctx->queue, rq);
blk_mq_put_tag(hctx->tags, tag);
blk_mq_queue_exit(q);
}
@ -1194,6 +1195,7 @@ static struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set,
left -= to_do * rq_size;
for (j = 0; j < to_do; j++) {
tags->rqs[i] = p;
blk_rq_init(NULL, tags->rqs[i]);
if (set->ops->init_request) {
if (set->ops->init_request(set->driver_data,
tags->rqs[i], hctx_idx, i,