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 5F8DBC433EF for ; Mon, 25 Apr 2022 13:42:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242131AbiDYNpY (ORCPT ); Mon, 25 Apr 2022 09:45:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35104 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242117AbiDYNpJ (ORCPT ); Mon, 25 Apr 2022 09:45:09 -0400 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 67F6A49276; Mon, 25 Apr 2022 06:42:05 -0700 (PDT) Received: from kwepemi100013.china.huawei.com (unknown [172.30.72.56]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4Kn5kv6Hqzz1JBhH; Mon, 25 Apr 2022 21:41:11 +0800 (CST) Received: from kwepemm600009.china.huawei.com (7.193.23.164) by kwepemi100013.china.huawei.com (7.221.188.136) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Mon, 25 Apr 2022 21:42:03 +0800 Received: from [10.174.176.73] (10.174.176.73) by kwepemm600009.china.huawei.com (7.193.23.164) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Mon, 25 Apr 2022 21:42:02 +0800 Subject: Re: [PATCH -next RFC v3 0/8] improve tag allocation under heavy load To: Damien Le Moal , , , , , , CC: , , References: <20220415101053.554495-1-yukuai3@huawei.com> <3fbadd9f-11dd-9043-11cf-f0839dcf30e1@opensource.wdc.com> <63e84f2a-2487-a0c3-cab2-7d2011bc2db4@huawei.com> <55e8b04f-0d2f-2ce1-6514-5abd0b67fd48@opensource.wdc.com> <6957af40-8720-d74b-5be7-6bcdd9aa1089@huawei.com> <237a43f0-3b09-46d0-e73c-57ef51e39590@opensource.wdc.com> <2e7969ea-68d0-964a-808e-ee8943de70e3@opensource.wdc.com> <35f18afa-0db1-b423-5824-4d5631b0422f@huawei.com> <88d9e8f4-cc5a-4897-f511-8f5b7d9a0acd@opensource.wdc.com> From: "yukuai (C)" Message-ID: <937972f1-5718-0409-c849-37d757950e14@huawei.com> Date: Mon, 25 Apr 2022 21:42:01 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <88d9e8f4-cc5a-4897-f511-8f5b7d9a0acd@opensource.wdc.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.176.73] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To kwepemm600009.china.huawei.com (7.193.23.164) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 在 2022/04/25 19:20, Damien Le Moal 写道: > On 4/25/22 16:28, yukuai (C) wrote: >> 在 2022/04/25 15:06, Damien Le Moal 写道: >> >>>>> By the way, did you check that doing something like: >>>>> >>>>> echo 2048 > /sys/block/sdX/queue/nr_requests >>>>> >>>>> improves performance for your high number of jobs test case ? >>>> >>>> Yes, performance will not degrade when numjobs is not greater than 256 >>>> in this case. >>> >>> That is my thinking as well. I am asking if did check that (did you run it ?). >> >> Hi, >> >> I'm sure I ran it with 256 jobs before. >> >> However, I didn't run it with 512 jobs. And following is the result I >> just tested: > > What was nr_requests ? The default 64 ? > If you increase that number, do you see better throughput/more requests > being sequential ? Sorry if I didn't explain this clearly. If nr_requests is 64, numjobs is 512, the ratio of sequential is about 20%. If nr_requests is 2048, numjobs is 512, the ratio is 49.1%. Then yes, increase nr_requests can improve performance in the test case. > > >> >> ratio of sequential io: 49.1% >> >> Read|Write seek >> >> cnt 99338, zero cnt 48753 >> >> >=(KB) .. <(KB) : count ratio |distribution >> | >> 0 .. 1 : 48753 49.1% >> |########################################| >> 1 .. 2 : 0 0.0% | >> | >> 2 .. 4 : 0 0.0% | >> | >> 4 .. 8 : 0 0.0% | >> | >> 8 .. 16 : 0 0.0% | >> | >> 16 .. 32 : 0 0.0% | >> | >> 32 .. 64 : 0 0.0% | >> | >> 64 .. 128 : 4975 5.0% |##### >> | >> 128 .. 256 : 4439 4.5% |#### >> | >> 256 .. 512 : 2615 2.6% |### >> | >> 512 .. 1024 : 967 1.0% |# >> | >> 1024 .. 2048 : 213 0.2% |# >> | >> 2048 .. 4096 : 375 0.4% |# >> | >> 4096 .. 8192 : 723 0.7% |# >> | >> 8192 .. 16384 : 1436 1.4% |## >> | >> 16384 .. 32768 : 2626 2.6% |### >> | >> 32768 .. 65536 : 4197 4.2% |#### >> | >> 65536 .. 131072 : 6431 6.5% |###### >> | >> 131072 .. 262144 : 7590 7.6% |####### >> | >> 262144 .. 524288 : 6433 6.5% |###### >> | >> 524288 .. 1048576 : 4583 4.6% |#### >> | >> 1048576 .. 2097152 : 2237 2.3% |## >> | >> 2097152 .. 4194304 : 489 0.5% |# >> | >> 4194304 .. 8388608 : 83 0.1% |# >> | >> 8388608 .. 16777216 : 36 0.0% |# >> | >> 16777216 .. 33554432 : 0 0.0% | >> | >> 33554432 .. 67108864 : 0 0.0% | >> | >> 67108864 .. 134217728 : 137 0.1% |# >> | > >