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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 876FBC433F5 for ; Fri, 17 Sep 2021 02:34:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6C0446124B for ; Fri, 17 Sep 2021 02:34:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243097AbhIQCgR (ORCPT ); Thu, 16 Sep 2021 22:36:17 -0400 Received: from mail.kernel.org ([198.145.29.99]:33202 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243032AbhIQCft (ORCPT ); Thu, 16 Sep 2021 22:35:49 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id A6824611F2; Fri, 17 Sep 2021 02:34:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631846068; bh=4qL2nCkj/eXevPHCYaUW+W7reTCgw37bnvRwHgmksCw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=at2PYaEqEoNi2GJm07HdNWxsGqQMWx0GIUICxamZGYqh9gHyBUe4uUOmiRVRON41j f/iZiDeihE2YcXaO6LtrRUKqJLt2lIVJomMljyJa3TTHktfa/RpAQv5sWBYkpleKAH HB67EOJCFj+yC0MjOOHT5TdMhrSetGaTo/WzXnkT5138kfnkhG6dHMJMhUYdCOxHlo aVn/ptQUL1Z+10sR62RVvPjpGKuV9GF9Tnaj4J5VyxcPfMHvU6UqbDkDeVIkg1B5kh Sj4ZmkZ1DJDytWwc1byCoqZxewtTFxDiZTKzr4e3F6zwKe8mn/apCnehNjZx9zM+K6 B1MyxQdlUKIfg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Song Liu , Marcin Wanat , Jens Axboe , Sasha Levin Subject: [PATCH AUTOSEL 5.14 17/21] blk-mq: allow 4x BLK_MAX_REQUEST_COUNT at blk_plug for multiple_queues Date: Thu, 16 Sep 2021 22:33:11 -0400 Message-Id: <20210917023315.816225-17-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210917023315.816225-1-sashal@kernel.org> References: <20210917023315.816225-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Song Liu [ Upstream commit 7f2a6a69f7ced6db8220298e0497cf60482a9d4b ] Limiting number of request to BLK_MAX_REQUEST_COUNT at blk_plug hurts performance for large md arrays. [1] shows resync speed of md array drops for md array with more than 16 HDDs. Fix this by allowing more request at plug queue. The multiple_queue flag is used to only apply higher limit to multiple queue cases. [1] https://lore.kernel.org/linux-raid/CAFDAVznS71BXW8Jxv6k9dXc2iR3ysX3iZRBww_rzA8WifBFxGg@mail.gmail.com/ Tested-by: Marcin Wanat Signed-off-by: Song Liu Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- block/blk-mq.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 9d4fdc2be88a..9c64f0025a56 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2135,6 +2135,18 @@ static void blk_add_rq_to_plug(struct blk_plug *plug, struct request *rq) } } +/* + * Allow 4x BLK_MAX_REQUEST_COUNT requests on plug queue for multiple + * queues. This is important for md arrays to benefit from merging + * requests. + */ +static inline unsigned short blk_plug_max_rq_count(struct blk_plug *plug) +{ + if (plug->multiple_queues) + return BLK_MAX_REQUEST_COUNT * 4; + return BLK_MAX_REQUEST_COUNT; +} + /** * blk_mq_submit_bio - Create and send a request to block device. * @bio: Bio pointer. @@ -2231,7 +2243,7 @@ blk_qc_t blk_mq_submit_bio(struct bio *bio) else last = list_entry_rq(plug->mq_list.prev); - if (request_count >= BLK_MAX_REQUEST_COUNT || (last && + if (request_count >= blk_plug_max_rq_count(plug) || (last && blk_rq_bytes(last) >= BLK_PLUG_FLUSH_SIZE)) { blk_flush_plug_list(plug, false); trace_block_plug(q); -- 2.30.2