Messages in this thread Patch in this message | | | From | Ming Lei <> | Subject | [PATCH v1 1/5] block: blk-mq: avoid initializing request during its completion | Date | Thu, 26 Dec 2013 21:31:34 +0800 |
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One problem is that request->start_time/start_time_ns could be set as wrong.
Also it is normal to intialize one data structure just after its allocation.
So move the initialization out of its completion path.
Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Ming Lei <tom.leiming@gmail.com> --- block/blk-mq.c | 26 +++++++++----------------- 1 file changed, 9 insertions(+), 17 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c index 53dc9f7..35ae189 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -82,6 +82,7 @@ static struct request *blk_mq_alloc_rq(struct blk_mq_hw_ctx *hctx, gfp_t gfp, tag = blk_mq_get_tag(hctx->tags, gfp, reserved); if (tag != BLK_MQ_TAG_FAIL) { rq = hctx->rqs[tag]; + blk_rq_init(hctx->queue, rq); rq->tag = tag; return rq; @@ -169,9 +170,13 @@ bool blk_mq_can_queue(struct blk_mq_hw_ctx *hctx) } EXPORT_SYMBOL(blk_mq_can_queue); -static void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx, - struct request *rq, unsigned int rw_flags) +static void blk_mq_rq_init(struct request_queue *q, struct blk_mq_ctx *ctx, + struct blk_mq_hw_ctx *hctx, struct request *rq, + unsigned int rw_flags) { + if (hctx->cmd_size) + rq->special = blk_mq_rq_to_pdu(rq); + if (blk_queue_io_stat(q)) rw_flags |= REQ_IO_STAT; @@ -198,7 +203,7 @@ static struct request *blk_mq_alloc_request_pinned(struct request_queue *q, rq = __blk_mq_alloc_request(hctx, gfp & ~__GFP_WAIT, reserved); if (rq) { - blk_mq_rq_ctx_init(q, ctx, rq, rw); + blk_mq_rq_init(q, ctx, hctx, rq, rw); break; } @@ -242,24 +247,12 @@ struct request *blk_mq_alloc_reserved_request(struct request_queue *q, int rw, } EXPORT_SYMBOL(blk_mq_alloc_reserved_request); -/* - * Re-init and set pdu, if we have it - */ -static void blk_mq_rq_init(struct blk_mq_hw_ctx *hctx, struct request *rq) -{ - blk_rq_init(hctx->queue, rq); - - if (hctx->cmd_size) - rq->special = blk_mq_rq_to_pdu(rq); -} - static void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, struct request *rq) { const int tag = rq->tag; struct request_queue *q = rq->q; - blk_mq_rq_init(hctx, rq); blk_mq_put_tag(hctx->tags, tag); blk_mq_queue_exit(q); @@ -889,7 +882,7 @@ static void blk_mq_make_request(struct request_queue *q, struct bio *bio) trace_block_getrq(q, bio, rw); rq = __blk_mq_alloc_request(hctx, GFP_ATOMIC, false); if (likely(rq)) - blk_mq_rq_ctx_init(q, ctx, rq, rw); + blk_mq_rq_init(q, ctx, hctx, rq, rw); else { blk_mq_put_ctx(ctx); trace_block_sleeprq(q, bio, rw); @@ -1123,7 +1116,6 @@ static int blk_mq_init_rq_map(struct blk_mq_hw_ctx *hctx, left -= to_do * rq_size; for (j = 0; j < to_do; j++) { hctx->rqs[i] = p; - blk_mq_rq_init(hctx, hctx->rqs[i]); p += rq_size; i++; } -- 1.7.9.5
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