From patchwork Mon Jul 17 04:00:54 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chengming Zhou X-Patchwork-Id: 13315170 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 EA968C0015E for ; Mon, 17 Jul 2023 04:01:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230448AbjGQEBw (ORCPT ); Mon, 17 Jul 2023 00:01:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50914 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229564AbjGQEBo (ORCPT ); Mon, 17 Jul 2023 00:01:44 -0400 Received: from out-37.mta0.migadu.com (out-37.mta0.migadu.com [91.218.175.37]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ECFA11B8 for ; Sun, 16 Jul 2023 21:01:40 -0700 (PDT) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1689566498; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=26hmSG3cG2qMCZKRMNmjIWTmveuGKUdShNQ0HXNAgXQ=; b=KT4Rcz6CdcyuiL90HQra1ibRCSc7FHSuWb9BOasmWz3ts1PocJEODxPlSJyVe+qCmWHfDj QPzUrxCYjH1fO34VkW1lk6xW4cEmZBwoDRji8kvBLKE6RQhe0xNQ9eD1aKITbnAEAiR8bL B4XWxTNnO9MShteo3pKdWZnSotdyXSU= From: chengming.zhou@linux.dev To: axboe@kernel.dk, ming.lei@redhat.com, hch@lst.de, bvanassche@acm.org Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, zhouchengming@bytedance.com Subject: [PATCH v4 0/4] blk-mq: optimize flush and request size Date: Mon, 17 Jul 2023 12:00:54 +0800 Message-ID: <20230717040058.3993930-1-chengming.zhou@linux.dev> MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org From: Chengming Zhou v4: - Rebase on the updated block/master branch, which include a flush bugfix from Christoph. Please help to check patch 04. Thanks! - Add a bugfix patch 02 for post-flush requests, put before other flush optimizations. - Collect Reviewed-by tags from Ming and Christoph. Thanks! - [v3] https://lore.kernel.org/lkml/20230707093722.1338589-1-chengming.zhou@linux.dev/ v3: - Collect Reviewed-by tags from Ming and Christoph. Thanks! - Remove the list and csd variables which are only used once. - Fix a bug report of blktests nvme/012 by re-initialization of rq->queuelist, which maybe corrupted by rq->rq_next reuse. - [v2] https://lore.kernel.org/all/20230629110359.1111832-1-chengming.zhou@linux.dev/ v2: - Change to use call_single_data_t, which use __aligned() to avoid to use 2 cache lines for 1 csd. Thanks Ming Lei. - [v1] https://lore.kernel.org/all/20230627120854.971475-1-chengming.zhou@linux.dev/ Hello, After the commit be4c427809b0 ("blk-mq: use the I/O scheduler for writes from the flush state machine"), rq->flush can't reuse rq->elv anymore, since flush_data requests can go into io scheduler now. That increased the size of struct request by 24 bytes, but this patchset can decrease the size by 40 bytes, which is good I think. patch 1 use percpu csd to do remote complete instead of per-rq csd, decrease the size by 24 bytes. patch 2 fixes a bug in blk-flush for post-flush requests. patch 3-4 reuse rq->queuelist in flush state machine pending list, and maintain unsigned long counter of inflight flush_data requests, decrease the size by 16 bytes. Thanks for comments! Chengming Zhou (4): blk-mq: use percpu csd to remote complete instead of per-rq csd blk-flush: fix rq->flush.seq for post-flush requests blk-flush: count inflight flush_data requests blk-flush: reuse rq queuelist in flush state machine block/blk-flush.c | 26 +++++++++++++++----------- block/blk-mq.c | 12 ++++++------ block/blk.h | 5 ++--- include/linux/blk-mq.h | 6 +----- 4 files changed, 24 insertions(+), 25 deletions(-)