From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-f179.google.com ([209.85.213.179]:51289 "EHLO mail-ig0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751601AbbBWMUq (ORCPT ); Mon, 23 Feb 2015 07:20:46 -0500 Message-ID: <54EB1B19.8050808@gmail.com> Date: Mon, 23 Feb 2015 07:20:41 -0500 From: Austin S Hemmelgarn MIME-Version: 1.0 To: "Theodore Ts'o" , Eric Sandeen CC: Michael Kerrisk , Ext4 Developers List , Linux btrfs Developers List , XFS Developers , linux-man@vger.kernel.org, Linux-Fsdevel , Linux API Subject: Re: Documenting MS_LAZYTIME References: <54E7578E.4090809@redhat.com> <20150221025636.GB7922@thunk.org> In-Reply-To: <20150221025636.GB7922@thunk.org> Content-Type: text/plain; charset=windows-1252; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 2015-02-20 21:56, Theodore Ts'o wrote: > On Fri, Feb 20, 2015 at 09:49:34AM -0600, Eric Sandeen wrote: >> >>> This mount option significantly reduces writes to the >>> inode table for workloads that perform frequent random >>> writes to preallocated files. >> >> This seems like an overly specific description of a single workload out >> of many which may benefit, but what do others think? "inode table" is also >> fairly extN-specific. > > How about somethign like "This mount significantly reduces writes > needed to update the inode's timestamps, especially mtime and actime. > Examples of workloads where this could be a large win include frequent > random writes to preallocated files, as well as cases where the > MS_STRICTATIME mount option is enabled."? > > (The advantage of MS_STRICTATIME | MS_LAZYTIME is that stat system > calls will return the correctly updated atime, but those atime updates > won't get flushed to disk unless the inode needs to be updated for > file system / data consistency reasons, or when the inode is pushed > out of memory, or when the file system is unmounted.) > If you want to list some specific software, it should help with anything that uses sqlite (which notably includes firefox and chrome), as well as most RDMS software and systemd-journald.