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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_PASS autolearn=ham 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 0440EC43381 for ; Tue, 5 Mar 2019 11:36:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C80FA20842 for ; Tue, 5 Mar 2019 11:36:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=broadcom.com header.i=@broadcom.com header.b="fWFVIvgE" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727100AbfCELgh (ORCPT ); Tue, 5 Mar 2019 06:36:37 -0500 Received: from mail-oi1-f173.google.com ([209.85.167.173]:46251 "EHLO mail-oi1-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727611AbfCELgg (ORCPT ); Tue, 5 Mar 2019 06:36:36 -0500 Received: by mail-oi1-f173.google.com with SMTP id j10so6546106oij.13 for ; Tue, 05 Mar 2019 03:36:36 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=broadcom.com; s=google; h=from:mime-version:thread-index:date:message-id:subject:to :content-transfer-encoding; bh=8QK8NVufTNeGGGTLfV2UoyYgP9Mhsrk10ad1VxIZOJA=; b=fWFVIvgEcsGAPCDSdeIOU9vG3JuJbyf9PZGO944wdr5OFbUT98D0rZGTcjrF8JsODG XbexFe40FovUrb1/rgpLrA6O1tTjwqP3i0mcPgjtHDACZ1xsEWsTcfgepMbhageEpg4n DDmg2ttScNy6+FHB6rcZgpzpBa2CJNEkj8asw= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:mime-version:thread-index:date:message-id :subject:to:content-transfer-encoding; bh=8QK8NVufTNeGGGTLfV2UoyYgP9Mhsrk10ad1VxIZOJA=; b=nskR0Dow+9rjogy77Ey2x9Uqt6+1JrMzwmF10uH5yAUJujResi4u2hCK2CpnkLBZTj bgvxOX6n3QkVIbmVtR89eUyrsE6W81QZpZNZWAw3gGxcuWPDt3zM4l67yJC1+oWiuDM/ VKXuosPyukcQS+77Ms4uwF7C6Kr3TvzyrecNF09sZpcR0p6wyd2EyodjE2JrOld2Pwb1 gwtObN372BWf7aoeVQCdBvyyldFazF+aaFJBv2f6IEKVaMKdK0ip6m7taGkU3o9FoyEy P4j3Y62BLkgMYVWjiLHv7tGGKdsbJ6h4a0zl8iXTX1O2J9ycMEufhCqcNj+xM/NdGMVt r31Q== X-Gm-Message-State: APjAAAXgtwTLN8ZV4AnD0JGCppW2ZEW5yyYyFRv/57wXdiI8vc1pcKXu Byskp6D9FxMV/XayzBJxkH1as0qYpLK7No2sLNec4Tsf X-Google-Smtp-Source: APXvYqyONviaaLtObp63GsmHs+xF8wZfUNaC3MtOssseul32G947rucWWhDMAnSg03S6nJW1cAt8ocZDQDjZy3q2R4Y= X-Received: by 2002:aca:3786:: with SMTP id e128mr1731645oia.120.1551785795266; Tue, 05 Mar 2019 03:36:35 -0800 (PST) From: Muneendra Kumar M MIME-Version: 1.0 X-Mailer: Microsoft Outlook 15.0 Thread-Index: AdTTRts7AwDmUBW9T5qtbC0vW+jJqA== Date: Tue, 5 Mar 2019 17:06:32 +0530 Message-ID: <27226a7453efa3b147da2ea9f361437b@mail.gmail.com> Subject: number of write I/Os processed keeps changing for a same test case To: linux-block@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Hi , Iam running the below fio test case and collecting the cat /sys/class/block/sda/stat before after the test. And below are the max_sectors_kb and max_hw_sectors_kb settings for the device. cat /sys/class/block/sdb/queue/max_hw_sectors_kb 32767 [root@localhost ~]# cat /sys/class/block/sdb/queue/max_sectors_kb 1280 Test Case: [root@localhost ~]# io --filename=3D/dev/sdb --direct=3D1 --rw=3Dwrite --norandommap --randrepeat=3D0 --ioengine=3Dsync --bs=3D1m --iodepth=3D1 --numjobs=3D1 --group_reporting --name=3D4ktest -= -size=3D50m And below is the o/p of the test . [root@localhost ~]#cat /sys/class/block/sdb/stat 6439 0 1513128 1618 4645 0 3332736 2697 0 3356 633 0 0 0 0 [root@localhost ~]# io --filename=3D/dev/sdb --direct=3D1 --rw=3Dwrite --norandommap --randrepeat=3D0 --ioengine=3Dsync --bs=3D1m --iodepth=3D1 --numjobs=3D1 --group_reporting --name=3D4ktest -= -size=3D50m 4ktest: (g=3D0): rw=3Dwrite, bs=3D(R) 1024KiB-1024KiB, (W) 1024KiB-1024KiB,= (T) 1024KiB-1024KiB, ioengine=3Dsync, iodepth=3D1 fio-3.1 =E2=80=A6.. Run status group 0 (all jobs): WRITE: bw=3D943MiB/s (989MB/s), 943MiB/s-943MiB/s (989MB/s-989MB/s), io=3D50.0MiB (52.4MB), run=3D53-53msec Disk stats (read/write): sdb: ios=3D0/0, merge=3D0/0, ticks=3D0/0, in_queue=3D0, util=3D0.00% [root@localhost ~]# cat /sys/class/block/sdb/stat 6519 0 1517272 1628 4795 0 3435136 2785 0 3420 633 0 0 0 0 And when I compare the difference between the number of write I/Os processe= d between the two stats(4795-4645) it gave me 50 as it has submitted the 50 requests of 1MB each(since max_sectors_kb is set to 1280). But when I ran the same test multiple the number of write I/Os processed (collected as above) keeps changing which is more than 50. Not sure on what basis the requests are getting splitted when I run same test case on the same setup. Any input here will help me to understand more. Iam running kernel of 5.0.0-rc+ version. Regards, Muneendra