From patchwork Wed Jul 29 03:28:35 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baolin Wang X-Patchwork-Id: 11690257 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A910613B6 for ; Wed, 29 Jul 2020 03:29:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9AC0E207F5 for ; Wed, 29 Jul 2020 03:29:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726820AbgG2D26 (ORCPT ); Tue, 28 Jul 2020 23:28:58 -0400 Received: from out30-56.freemail.mail.aliyun.com ([115.124.30.56]:52307 "EHLO out30-56.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726319AbgG2D24 (ORCPT ); Tue, 28 Jul 2020 23:28:56 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R351e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e01355;MF=baolin.wang@linux.alibaba.com;NM=1;PH=DS;RN=7;SR=0;TI=SMTPD_---0U46X3YU_1595993331; Received: from localhost(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0U46X3YU_1595993331) by smtp.aliyun-inc.com(127.0.0.1); Wed, 29 Jul 2020 11:28:52 +0800 From: Baolin Wang To: axboe@kernel.dk Cc: ming.lei@redhat.com, hch@lst.de, baolin.wang@linux.alibaba.com, baolin.wang7@gmail.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 3/5] block: Add a new helper to attempt to merge a bio Date: Wed, 29 Jul 2020 11:28:35 +0800 Message-Id: X-Mailer: git-send-email 1.8.3.1 In-Reply-To: References: In-Reply-To: References: Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org There are lots of duplicated code when trying to merge a bio from plug list and sw queue, we can introduce a new helper to attempt to merge a bio, which can simplify the blk_mq_bio_list_merge() and blk_attempt_plug_merge(). Signed-off-by: Baolin Wang --- block/blk-merge.c | 47 +++++++++++++++++++++++++++++------------------ block/blk-mq-sched.c | 22 ++++------------------ block/blk.h | 9 +++++++++ 3 files changed, 42 insertions(+), 36 deletions(-) diff --git a/block/blk-merge.c b/block/blk-merge.c index 1993e6a..feaee53 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -975,6 +975,33 @@ bool bio_attempt_discard_merge(struct request_queue *q, struct request *req, return false; } +enum bio_merge_status blk_attempt_bio_merge(struct request_queue *q, + struct request *rq, + struct bio *bio, + unsigned int nr_segs) +{ + bool merged = false; + + if (!blk_rq_merge_ok(rq, bio)) + return BIO_MERGE_NONE; + + switch (blk_try_merge(rq, bio)) { + case ELEVATOR_BACK_MERGE: + merged = bio_attempt_back_merge(rq, bio, nr_segs); + break; + case ELEVATOR_FRONT_MERGE: + merged = bio_attempt_front_merge(rq, bio, nr_segs); + break; + case ELEVATOR_DISCARD_MERGE: + merged = bio_attempt_discard_merge(q, rq, bio); + break; + default: + return BIO_MERGE_NONE; + } + + return merged ? BIO_MERGE_OK : BIO_MERGE_FAILED; +} + /** * blk_attempt_plug_merge - try to merge with %current's plugged list * @q: request_queue new bio is being queued at @@ -1011,8 +1038,6 @@ bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio, plug_list = &plug->mq_list; list_for_each_entry_reverse(rq, plug_list, queuelist) { - bool merged = false; - if (rq->q == q && same_queue_rq) { /* * Only blk-mq multiple hardware queues case checks the @@ -1022,24 +1047,10 @@ bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio, *same_queue_rq = rq; } - if (rq->q != q || !blk_rq_merge_ok(rq, bio)) + if (rq->q != q) continue; - switch (blk_try_merge(rq, bio)) { - case ELEVATOR_BACK_MERGE: - merged = bio_attempt_back_merge(rq, bio, nr_segs); - break; - case ELEVATOR_FRONT_MERGE: - merged = bio_attempt_front_merge(rq, bio, nr_segs); - break; - case ELEVATOR_DISCARD_MERGE: - merged = bio_attempt_discard_merge(q, rq, bio); - break; - default: - break; - } - - if (merged) + if (blk_attempt_bio_merge(q, rq, bio, nr_segs) == BIO_MERGE_OK) return true; } diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index cc34f69..24d5078 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -391,31 +391,17 @@ bool blk_mq_bio_list_merge(struct request_queue *q, struct list_head *list, { struct request *rq; int checked = 8; + enum bio_merge_status merge; list_for_each_entry_reverse(rq, list, queuelist) { - bool merged = false; - if (!checked--) break; - if (!blk_rq_merge_ok(rq, bio)) + merge = blk_attempt_bio_merge(q, rq, bio, nr_segs); + if (merge == BIO_MERGE_NONE) continue; - switch (blk_try_merge(rq, bio)) { - case ELEVATOR_BACK_MERGE: - merged = bio_attempt_back_merge(rq, bio, nr_segs); - break; - case ELEVATOR_FRONT_MERGE: - merged = bio_attempt_front_merge(rq, bio, nr_segs); - break; - case ELEVATOR_DISCARD_MERGE: - merged = bio_attempt_discard_merge(q, rq, bio); - break; - default: - continue; - } - - return merged; + return merge == BIO_MERGE_OK ? true: false; } return false; diff --git a/block/blk.h b/block/blk.h index 49e2928..a6c54e1 100644 --- a/block/blk.h +++ b/block/blk.h @@ -234,6 +234,15 @@ int blk_attempt_req_merge(struct request_queue *q, struct request *rq, bool blk_rq_merge_ok(struct request *rq, struct bio *bio); enum elv_merge blk_try_merge(struct request *rq, struct bio *bio); +enum bio_merge_status { + BIO_MERGE_OK, + BIO_MERGE_NONE, + BIO_MERGE_FAILED, +}; + +enum bio_merge_status blk_attempt_bio_merge(struct request_queue *q, + struct request *rq, struct bio *bio, unsigned int nr_segs); + int blk_dev_init(void); /*