From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752440AbbJOP0q (ORCPT ); Thu, 15 Oct 2015 11:26:46 -0400 Received: from mx1.redhat.com ([209.132.183.28]:46759 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751145AbbJOP0p (ORCPT ); Thu, 15 Oct 2015 11:26:45 -0400 From: Jeff Moyer To: Ming Lei Cc: Jens Axboe , linux-kernel@vger.kernel.org, Ming Lin , Kent Overstreet , Christoph Hellwig Subject: Re: [PATCH 4/4] blk-mq: mark ctx as pending at batch in flush plug path References: <1444793448-9994-1-git-send-email-ming.lei@canonical.com> <1444793448-9994-5-git-send-email-ming.lei@canonical.com> X-PGP-KeyID: 1F78E1B4 X-PGP-CertKey: F6FE 280D 8293 F72C 65FD 5A58 1FF8 A7CA 1F78 E1B4 X-PCLoadLetter: What the f**k does that mean? Date: Thu, 15 Oct 2015 11:26:43 -0400 In-Reply-To: <1444793448-9994-5-git-send-email-ming.lei@canonical.com> (Ming Lei's message of "Wed, 14 Oct 2015 11:30:48 +0800") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ming Lei writes: > Most of times, flush plug should be the hottest I/O path, > so mark ctx as pending after all requests in the list are > inserted. Hi, Ming, Did you see some performance gain from this? -Jeff > > Signed-off-by: Ming Lei > --- > block/blk-mq.c | 18 +++++++++++++----- > 1 file changed, 13 insertions(+), 5 deletions(-) > > diff --git a/block/blk-mq.c b/block/blk-mq.c > index deb5f4c..1c943b9 100644 > --- a/block/blk-mq.c > +++ b/block/blk-mq.c > @@ -993,18 +993,25 @@ void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs) > } > EXPORT_SYMBOL(blk_mq_delay_queue); > > -static void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, > - struct request *rq, bool at_head) > +static inline void __blk_mq_insert_req_list(struct blk_mq_hw_ctx *hctx, > + struct blk_mq_ctx *ctx, > + struct request *rq, > + bool at_head) > { > - struct blk_mq_ctx *ctx = rq->mq_ctx; > - > trace_block_rq_insert(hctx->queue, rq); > > if (at_head) > list_add(&rq->queuelist, &ctx->rq_list); > else > list_add_tail(&rq->queuelist, &ctx->rq_list); > +} > + > +static void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, > + struct request *rq, bool at_head) > +{ > + struct blk_mq_ctx *ctx = rq->mq_ctx; > > + __blk_mq_insert_req_list(hctx, ctx, rq, at_head); > blk_mq_hctx_mark_pending(hctx, ctx); > } > > @@ -1060,8 +1067,9 @@ static void blk_mq_insert_requests(struct request_queue *q, > rq = list_first_entry(list, struct request, queuelist); > list_del_init(&rq->queuelist); > rq->mq_ctx = ctx; > - __blk_mq_insert_request(hctx, rq, false); > + __blk_mq_insert_req_list(hctx, ctx, rq, false); > } > + blk_mq_hctx_mark_pending(hctx, ctx); > spin_unlock(&ctx->lock); > > blk_mq_run_hw_queue(hctx, from_schedule);