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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B6AAEECAAD5 for ; Mon, 29 Aug 2022 13:59:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229664AbiH2N7A (ORCPT ); Mon, 29 Aug 2022 09:59:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39532 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229477AbiH2N67 (ORCPT ); Mon, 29 Aug 2022 09:58:59 -0400 Received: from mx1.molgen.mpg.de (mx3.molgen.mpg.de [141.14.17.11]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 23CE97E004; Mon, 29 Aug 2022 06:58:57 -0700 (PDT) Received: from [192.168.0.6] (ip5f5aec76.dynamic.kabel-deutschland.de [95.90.236.118]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: pmenzel) by mx.molgen.mpg.de (Postfix) with ESMTPSA id 75D2861EA192D; Mon, 29 Aug 2022 15:58:54 +0200 (CEST) Message-ID: <70172016-8ae5-92b8-2a43-8f0d4a2f6668@molgen.mpg.de> Date: Mon, 29 Aug 2022 15:58:53 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.2.0 Subject: Re: [PATCH -next 0/3] md/raid10: reduce lock contention for io To: Yu Kuai Cc: song@kernel.org, linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org, yukuai3@huawei.com, yi.zhang@huawei.com References: <20220829131502.165356-1-yukuai1@huaweicloud.com> Content-Language: en-US From: Paul Menzel In-Reply-To: <20220829131502.165356-1-yukuai1@huaweicloud.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-raid@vger.kernel.org Dear Yu, Thank you for your patches. Am 29.08.22 um 15:14 schrieb Yu Kuai: > From: Yu Kuai > > patch 1 is a small problem found by code review. > patch 2 avoid holding resync_lock in fast path. > patch 3 avoid holding lock in wake_up() in fast path. > > Test environment: > > Architecture: aarch64 > Cpu: Huawei KUNPENG 920, there are four numa nodes > > Raid10 initialize: > mdadm --create /dev/md0 --level 10 --bitmap none --raid-devices 4 /dev/nvme0n1 /dev/nvme1n1 /dev/nvme2n1 /dev/nvme3n1 > > Test cmd: > fio -name=0 -ioengine=libaio -direct=1 -group_reporting=1 -randseed=2022 -rwmixread=70 -refill_buffers -filename=/dev/md0 -numjobs=16 -runtime=60s -bs=4k -iodepth=256 -rw=randread > > Test result: > before this patchset: 2.9 GiB/s > after this patchset: 6.6 Gib/s Could you please give more details about the test setup, like the drives used? Did you use some tools like ftrace to figure out the bottleneck? > Please noted that in kunpeng-920, memory access latency is very bad > accross nodes compare to local node, and in other architecture > performance improvement might not be significant. > > Yu Kuai (3): > md/raid10: fix improper BUG_ON() in raise_barrier() > md/raid10: convert resync_lock to use seqlock > md/raid10: prevent unnecessary calls to wake_up() in fast path > > drivers/md/raid10.c | 88 +++++++++++++++++++++++++++++---------------- > drivers/md/raid10.h | 2 +- > 2 files changed, 59 insertions(+), 31 deletions(-) Kind regards, Paul