From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753182Ab3LZNb4 (ORCPT ); Thu, 26 Dec 2013 08:31:56 -0500 Received: from mail-pd0-f171.google.com ([209.85.192.171]:42246 "EHLO mail-pd0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751987Ab3LZNby (ORCPT ); Thu, 26 Dec 2013 08:31:54 -0500 From: Ming Lei To: Jens Axboe , linux-kernel@vger.kernel.org Cc: Christoph Hellwig , 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 Message-Id: <1388064698-27344-2-git-send-email-tom.leiming@gmail.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1388064698-27344-1-git-send-email-tom.leiming@gmail.com> References: <1388064698-27344-1-git-send-email-tom.leiming@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 Signed-off-by: Ming Lei --- 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