From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B8DCAC433E7 for ; Fri, 28 Aug 2020 02:53:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9D54E2080C for ; Fri, 28 Aug 2020 02:53:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728077AbgH1Cx0 (ORCPT ); Thu, 27 Aug 2020 22:53:26 -0400 Received: from out30-132.freemail.mail.aliyun.com ([115.124.30.132]:44590 "EHLO out30-132.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727817AbgH1CxV (ORCPT ); Thu, 27 Aug 2020 22:53:21 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R201e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e01422;MF=baolin.wang@linux.alibaba.com;NM=1;PH=DS;RN=7;SR=0;TI=SMTPD_---0U73Y1vy_1598583196; Received: from localhost(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0U73Y1vy_1598583196) by smtp.aliyun-inc.com(127.0.0.1); Fri, 28 Aug 2020 10:53:17 +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 v3 3/4] block: Add a new helper to attempt to merge a bio Date: Fri, 28 Aug 2020 10:52:56 +0800 Message-Id: <7e4bc05d74f5e71f4680921810a876e5b2d8b85e.1598580324.git.baolin.wang@linux.alibaba.com> 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_bio_list_merge() and blk_attempt_plug_merge(). Signed-off-by: Baolin Wang --- block/blk-merge.c | 104 ++++++++++++++++++++++++++------------------------- block/blk-mq-sched.c | 6 +-- block/blk.h | 21 ++++++++--- 3 files changed, 71 insertions(+), 60 deletions(-) diff --git a/block/blk-merge.c b/block/blk-merge.c index b09e9fc..80c9744 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -907,13 +907,14 @@ static void blk_account_io_merge_bio(struct request *req) part_stat_unlock(); } -bool bio_attempt_back_merge(struct request *req, struct bio *bio, - unsigned int nr_segs) +enum bio_merge_status bio_attempt_back_merge(struct request *req, + struct bio *bio, + unsigned int nr_segs) { const int ff = bio->bi_opf & REQ_FAILFAST_MASK; if (!ll_back_merge_fn(req, bio, nr_segs)) - return false; + return BIO_MERGE_FAILED; trace_block_bio_backmerge(req->q, req, bio); rq_qos_merge(req->q, req, bio); @@ -928,16 +929,17 @@ bool bio_attempt_back_merge(struct request *req, struct bio *bio, bio_crypt_free_ctx(bio); blk_account_io_merge_bio(req); - return true; + return BIO_MERGE_OK; } -bool bio_attempt_front_merge(struct request *req, struct bio *bio, - unsigned int nr_segs) +enum bio_merge_status bio_attempt_front_merge(struct request *req, + struct bio *bio, + unsigned int nr_segs) { const int ff = bio->bi_opf & REQ_FAILFAST_MASK; if (!ll_front_merge_fn(req, bio, nr_segs)) - return false; + return BIO_MERGE_FAILED; trace_block_bio_frontmerge(req->q, req, bio); rq_qos_merge(req->q, req, bio); @@ -954,11 +956,12 @@ bool bio_attempt_front_merge(struct request *req, struct bio *bio, bio_crypt_do_front_merge(req, bio); blk_account_io_merge_bio(req); - return true; + return BIO_MERGE_OK; } -bool bio_attempt_discard_merge(struct request_queue *q, struct request *req, - struct bio *bio) +enum bio_merge_status bio_attempt_discard_merge(struct request_queue *q, + struct request *req, + struct bio *bio) { unsigned short segments = blk_rq_nr_discard_segments(req); @@ -976,10 +979,39 @@ bool bio_attempt_discard_merge(struct request_queue *q, struct request *req, req->nr_phys_segments = segments + 1; blk_account_io_merge_bio(req); - return true; + return BIO_MERGE_OK; no_merge: req_set_nomerge(q, req); - return false; + return BIO_MERGE_FAILED; +} + +static enum bio_merge_status blk_attempt_bio_merge(struct request_queue *q, + struct request *rq, + struct bio *bio, + unsigned int nr_segs, + bool sched_allow_merge) +{ + if (!blk_rq_merge_ok(rq, bio)) + return BIO_MERGE_NONE; + + switch (blk_try_merge(rq, bio)) { + case ELEVATOR_BACK_MERGE: + if (!sched_allow_merge || + (sched_allow_merge && blk_mq_sched_allow_merge(q, rq, bio))) + return bio_attempt_back_merge(rq, bio, nr_segs); + break; + case ELEVATOR_FRONT_MERGE: + if (!sched_allow_merge || + (sched_allow_merge && blk_mq_sched_allow_merge(q, rq, bio))) + return bio_attempt_front_merge(rq, bio, nr_segs); + break; + case ELEVATOR_DISCARD_MERGE: + return bio_attempt_discard_merge(q, rq, bio); + default: + return BIO_MERGE_NONE; + } + + return BIO_MERGE_FAILED; } /** @@ -1018,8 +1050,6 @@ 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 @@ -1029,24 +1059,11 @@ 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, false) == + BIO_MERGE_OK) return true; } @@ -1064,33 +1081,18 @@ bool blk_bio_list_merge(struct request_queue *q, struct list_head *list, int checked = 8; list_for_each_entry_reverse(rq, list, queuelist) { - bool merged = false; - if (!checked--) break; - if (!blk_rq_merge_ok(rq, bio)) - continue; - - switch (blk_try_merge(rq, bio)) { - case ELEVATOR_BACK_MERGE: - if (blk_mq_sched_allow_merge(q, rq, bio)) - merged = bio_attempt_back_merge(rq, bio, - nr_segs); - break; - case ELEVATOR_FRONT_MERGE: - if (blk_mq_sched_allow_merge(q, rq, bio)) - merged = bio_attempt_front_merge(rq, bio, - nr_segs); - break; - case ELEVATOR_DISCARD_MERGE: - merged = bio_attempt_discard_merge(q, rq, bio); - break; - default: + switch (blk_attempt_bio_merge(q, rq, bio, nr_segs, true)) { + case BIO_MERGE_NONE: continue; + case BIO_MERGE_OK: + return true; + case BIO_MERGE_FAILED: + return false; } - return merged; } return false; diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index 82acff9..94db0c9 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -368,7 +368,7 @@ bool blk_mq_sched_try_merge(struct request_queue *q, struct bio *bio, case ELEVATOR_BACK_MERGE: if (!blk_mq_sched_allow_merge(q, rq, bio)) return false; - if (!bio_attempt_back_merge(rq, bio, nr_segs)) + if (bio_attempt_back_merge(rq, bio, nr_segs) != BIO_MERGE_OK) return false; *merged_request = attempt_back_merge(q, rq); if (!*merged_request) @@ -377,14 +377,14 @@ bool blk_mq_sched_try_merge(struct request_queue *q, struct bio *bio, case ELEVATOR_FRONT_MERGE: if (!blk_mq_sched_allow_merge(q, rq, bio)) return false; - if (!bio_attempt_front_merge(rq, bio, nr_segs)) + if (bio_attempt_front_merge(rq, bio, nr_segs) != BIO_MERGE_OK) return false; *merged_request = attempt_front_merge(q, rq); if (!*merged_request) elv_merged_request(q, rq, ELEVATOR_FRONT_MERGE); return true; case ELEVATOR_DISCARD_MERGE: - return bio_attempt_discard_merge(q, rq, bio); + return bio_attempt_discard_merge(q, rq, bio) == BIO_MERGE_OK; default: return false; } diff --git a/block/blk.h b/block/blk.h index d6152d2..a180443 100644 --- a/block/blk.h +++ b/block/blk.h @@ -29,6 +29,12 @@ struct blk_flush_queue { spinlock_t mq_flush_lock; }; +enum bio_merge_status { + BIO_MERGE_OK, + BIO_MERGE_NONE, + BIO_MERGE_FAILED, +}; + extern struct kmem_cache *blk_requestq_cachep; extern struct kobj_type blk_queue_ktype; extern struct ida blk_queue_ida; @@ -169,12 +175,15 @@ static inline void blk_integrity_del(struct gendisk *disk) unsigned long blk_rq_timeout(unsigned long timeout); void blk_add_timer(struct request *req); -bool bio_attempt_front_merge(struct request *req, struct bio *bio, - unsigned int nr_segs); -bool bio_attempt_back_merge(struct request *req, struct bio *bio, - unsigned int nr_segs); -bool bio_attempt_discard_merge(struct request_queue *q, struct request *req, - struct bio *bio); +enum bio_merge_status bio_attempt_front_merge(struct request *req, + struct bio *bio, + unsigned int nr_segs); +enum bio_merge_status bio_attempt_back_merge(struct request *req, + struct bio *bio, + unsigned int nr_segs); +enum bio_merge_status bio_attempt_discard_merge(struct request_queue *q, + struct request *req, + struct bio *bio); bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio, unsigned int nr_segs, struct request **same_queue_rq); bool blk_bio_list_merge(struct request_queue *q, struct list_head *list, -- 1.8.3.1