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=-3.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 A08CFC433E1 for ; Tue, 25 Aug 2020 17:18:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 62EB52076C for ; Tue, 25 Aug 2020 17:18:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b="SVrqDkjA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726374AbgHYRSx (ORCPT ); Tue, 25 Aug 2020 13:18:53 -0400 Received: from fanzine.igalia.com ([178.60.130.6]:38392 "EHLO fanzine.igalia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726813AbgHYRS2 (ORCPT ); Tue, 25 Aug 2020 13:18:28 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Content-Type:MIME-Version:Message-ID:Date:References:In-Reply-To:Subject:Cc:To:From; bh=NRuZ0LyzRm4DjommZhDcvSlF725dOGlT2jpGRP/6sTE=; b=SVrqDkjA5NLym8V/ERjmtPwQdbukrc/bGdB4ViJwrptUP0t2vvDZZ3oaM4NjQMsm3fbNoaEkqyBEdFpMtLlFZe1v9cXuBw4HGJcGZXqLoUh42k0g84pTeAKREk4VgYrWuofXtckK8MDT/t1vMkskcWJQIGiH3DL0Gp2nyRhJLVK4OYAscLWKHAoJ66PHkuKjTAGVo3ptoaplOu9jPDzIybnVPE8oPB1jMb3Vdx+xX1dxOrPPFZnTojsPBp7yfsEpA+uf1MAgo091DN5/wNKAH++smJ97U+kVfM2msiLE2MXgAMMoXT+4ZS4kN5+7pWwCCN/18jtQH70WOE8c/fwpaQ==; Received: from maestria.local.igalia.com ([192.168.10.14] helo=mail.igalia.com) by fanzine.igalia.com with esmtps (Cipher TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim) id 1kAcaS-00048N-28; Tue, 25 Aug 2020 19:18:20 +0200 Received: from berto by mail.igalia.com with local (Exim) id 1kAcaR-000403-Ot; Tue, 25 Aug 2020 19:18:19 +0200 From: Alberto Garcia To: Brian Foster Cc: Dave Chinner , Kevin Wolf , Vladimir Sementsov-Ogievskiy , qemu-block@nongnu.org, qemu-devel@nongnu.org, Max Reitz , linux-xfs@vger.kernel.org Subject: Re: [PATCH 0/1] qcow2: Skip copy-on-write when allocating a zero cluster In-Reply-To: <20200825165415.GB321765@bfoster> References: <20200819150711.GE10272@linux.fritz.box> <20200819175300.GA141399@bfoster> <20200820215811.GC7941@dread.disaster.area> <20200821110506.GB212879@bfoster> <20200821170232.GA220086@bfoster> <20200825165415.GB321765@bfoster> User-Agent: Notmuch/0.18.2 (http://notmuchmail.org) Emacs/24.4.1 (i586-pc-linux-gnu) Date: Tue, 25 Aug 2020 19:18:19 +0200 Message-ID: MIME-Version: 1.0 Content-Type: text/plain Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Tue 25 Aug 2020 06:54:15 PM CEST, Brian Foster wrote: > If I compare this 5m fio test between XFS and ext4 on a couple of my > systems (with either no prealloc or full file prealloc), I end up seeing > ext4 run slightly faster on my vm and XFS slightly faster on bare metal. > Either way, I don't see that huge disparity where ext4 is 5-6 times > faster than XFS. Can you describe the test, filesystem and storage in > detail where you observe such a discrepancy? Here's the test: fio --filename=/path/to/file.raw --direct=1 --randrepeat=1 \ --eta=always --ioengine=libaio --iodepth=32 --numjobs=1 \ --name=test --size=25G --io_limit=25G --ramp_time=0 \ --rw=randwrite --bs=4k --runtime=300 --time_based=1 The size of the XFS filesystem is 126 GB and it's almost empty, here's the xfs_info output: meta-data=/dev/vg/test isize=512 agcount=4, agsize=8248576 blks = sectsz=512 attr=2, projid32bit=1 = crc=1 finobt=1, sparse=1, rmapbt=0 = reflink=0 data = bsize=4096 blocks=32994304, imaxpct=25 = sunit=0 swidth=0 blks naming =version 2 bsize=4096 ascii-ci=0, ftype=1 log =internal log bsize=4096 blocks=16110, version=2 = sectsz=512 sunit=0 blks, lazy-count=1 realtime =none extsz=4096 blocks=0, rtextents=0 The size of the ext4 filesystem is 99GB, of which 49GB are free (that is, without the file used in this test). The filesystem uses 4KB blocks, a 128M journal and these features: Filesystem revision #: 1 (dynamic) Filesystem features: has_journal ext_attr resize_inode dir_index filetype needs_recovery extent flex_bg sparse_super large_file huge_file uninit_bg dir_nlink extra_isize Filesystem flags: signed_directory_hash Default mount options: user_xattr acl In both cases I'm using LVM on top of LUKS and the hard drive is a Samsung SSD 850 PRO 1TB. The Linux version is 4.19.132-1 from Debian. Berto