From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753952AbbJSP5N (ORCPT ); Mon, 19 Oct 2015 11:57:13 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51773 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752969AbbJSP5M (ORCPT ); Mon, 19 Oct 2015 11:57:12 -0400 From: Jeff Moyer To: Ming Lei Cc: Jens Axboe , linux-kernel@vger.kernel.org, Ming Lin , Kent Overstreet , Christoph Hellwig Subject: Re: [PATCH v1 6/6] blk-mq: mark ctx as pending at batch in flush plug path References: <1445097154-18229-1-git-send-email-ming.lei@canonical.com> <1445097154-18229-7-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: Mon, 19 Oct 2015 11:57:10 -0400 In-Reply-To: <1445097154-18229-7-git-send-email-ming.lei@canonical.com> (Ming Lei's message of "Sat, 17 Oct 2015 23:52:34 +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. > > Signed-off-by: Ming Lei I agree this looks like a better approach. Whether it makes a difference or not, I can't say. Reviewed-by: Jeff Moyer > --- > 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 a5e33bc..b169e2d 100644 > --- a/block/blk-mq.c > +++ b/block/blk-mq.c > @@ -990,18 +990,25 @@ 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); > } > > @@ -1057,8 +1064,9 @@ 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);