From patchwork Fri Jul 7 09:37:18 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chengming Zhou X-Patchwork-Id: 13304633 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 5BDF8EB64D9 for ; Fri, 7 Jul 2023 09:39:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232052AbjGGJjD (ORCPT ); Fri, 7 Jul 2023 05:39:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53196 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231421AbjGGJjC (ORCPT ); Fri, 7 Jul 2023 05:39:02 -0400 Received: from out-44.mta0.migadu.com (out-44.mta0.migadu.com [IPv6:2001:41d0:1004:224b::2c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DD8842106 for ; Fri, 7 Jul 2023 02:39:01 -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=1688722740; 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=H8lodFl56b2KExC0gt827b28JNOFi4rlCN2zLgYnfQM=; b=LChLQBDKrnKjm1wTuC5RsNjieLetgMS+bReOjGftTGZVrxI3/fBDORG0ipWCNknYLe8Vqp IXwX7MzO51p62ijVzcl4oMlw2g2QPZAUz/MtYU+xnlaIdA8JFNl75LYjjMBVfo1zRnaev8 yulxGymtWYRWQ973u3VprI6V3cr3psg= From: chengming.zhou@linux.dev To: axboe@kernel.dk, ming.lei@redhat.com, hch@lst.de, tj@kernel.org Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, zhouchengming@bytedance.com Subject: [PATCH v3 0/4] blk-mq: optimize the size of struct request Date: Fri, 7 Jul 2023 17:37:18 +0800 Message-ID: <20230707093722.1338589-1-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 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 is just cleanup by the way. patch 2 use percpu csd to do remote complete instead of per-rq csd, decrease the size by 24 bytes. 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: delete unused completion_data in struct request blk-mq: use percpu csd to remote complete instead of per-rq csd blk-flush: count inflight flush_data requests blk-flush: reuse rq queuelist in flush state machine block/blk-flush.c | 24 ++++++++++++++---------- block/blk-mq.c | 12 ++++++------ block/blk.h | 5 ++--- include/linux/blk-mq.h | 10 ++-------- 4 files changed, 24 insertions(+), 27 deletions(-)