From patchwork Wed Mar 9 06:42:09 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Song Liu X-Patchwork-Id: 12774791 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1DF86C433FE for ; Wed, 9 Mar 2022 06:42:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230084AbiCIGnu convert rfc822-to-8bit (ORCPT ); Wed, 9 Mar 2022 01:43:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46384 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229645AbiCIGnq (ORCPT ); Wed, 9 Mar 2022 01:43:46 -0500 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 875A7A9E13 for ; Tue, 8 Mar 2022 22:42:45 -0800 (PST) Received: from pps.filterd (m0044012.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.1.2/8.16.1.2) with ESMTP id 228Iormd017320 for ; Tue, 8 Mar 2022 22:42:45 -0800 Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3ep52tq76w-4 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Tue, 08 Mar 2022 22:42:45 -0800 Received: from twshared33837.14.frc2.facebook.com (2620:10d:c085:108::4) by mail.thefacebook.com (2620:10d:c085:11d::4) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Tue, 8 Mar 2022 22:42:43 -0800 Received: by devbig932.frc1.facebook.com (Postfix, from userid 4523) id 1FC6D1EBC0D9; Tue, 8 Mar 2022 22:42:40 -0800 (PST) From: Song Liu To: , CC: , Song Liu , , Larkin Lowrey , Wilson Jonathan , Roger Heflin Subject: [PATCH] block: check more requests for multiple_queues in blk_attempt_plug_merge Date: Tue, 8 Mar 2022 22:42:09 -0800 Message-ID: <20220309064209.4169303-1-song@kernel.org> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-ORIG-GUID: cIhkDlCtbyQfP_IZQTlYF0vagpPa1ucp X-Proofpoint-GUID: cIhkDlCtbyQfP_IZQTlYF0vagpPa1ucp X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.816,Hydra:6.0.425,FMLib:17.11.64.514 definitions=2022-03-09_02,2022-03-04_01,2022-02-23_01 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org RAID arrays check/repair operations benefit a lot from merging requests. If we only check the previous entry for merge attempt, many merge will be missed. As a result, significant regression is observed for RAID check and repair. Fix this by checking more than just the previous entry when plug->multiple_queues == true. This improves the check/repair speed of a 20-HDD raid6 from 19 MB/s to 103 MB/s. Fixes: d38a9c04c0d5 ("block: only check previous entry for plug merge attempt") Cc: stable@vger.kernel.org # v5.16 Reported-by: Larkin Lowrey Reported-by: Wilson Jonathan Reported-by: Roger Heflin Signed-off-by: Song Liu --- block/blk-merge.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/block/blk-merge.c b/block/blk-merge.c index 4de34a332c9f..57e2075fb2f4 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -1089,12 +1089,14 @@ bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio, if (!plug || rq_list_empty(plug->mq_list)) return false; - /* check the previously added entry for a quick merge attempt */ - rq = rq_list_peek(&plug->mq_list); - if (rq->q == q) { - if (blk_attempt_bio_merge(q, rq, bio, nr_segs, false) == - BIO_MERGE_OK) - return true; + rq_list_for_each(&plug->mq_list, rq) { + if (rq->q == q) { + if (blk_attempt_bio_merge(q, rq, bio, nr_segs, false) == + BIO_MERGE_OK) + return true; + } + if (!plug->multiple_queues) + break; } return false; }