From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:46503 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751870AbbBTPto (ORCPT ); Fri, 20 Feb 2015 10:49:44 -0500 Message-ID: <54E7578E.4090809@redhat.com> Date: Fri, 20 Feb 2015 09:49:34 -0600 From: Eric Sandeen MIME-Version: 1.0 To: Michael Kerrisk , "Theodore Ts'o" CC: Ext4 Developers List , Linux btrfs Developers List , XFS Developers , linux-man@vger.kernel.org, Linux-Fsdevel , Linux API Subject: Re: Documenting MS_LAZYTIME References: In-Reply-To: Content-Type: text/plain; charset=utf-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 2/20/15 2:50 AM, Michael Kerrisk wrote: > Hello Ted, > > Based on your commit message 0ae45f63d4e, I I wrote the documentation > below for MS_LAZYTIME, to go into the mount(2) man page. Could you > please check it over and let me know if it's accurate. In particular, > I added pieces marked with "*" below that were not part of the commit > message and I'd like confirmation that they're accurate. > > Thanks, > > Michael > > [[ > MS_LAZYTIME (since Linux 3.20) > Only update filetimes (atime, mtime, ctime) on the in- > memory version of the file inode. The on-disk time‐ > stamps are updated only when: "filetimes" and "file inode" seems a bit awkward. How about: > MS_LAZYTIME (since Linux 3.20) > Reduce on-disk updates of inode timestamps (atime, mtime, ctime) > by maintaining these changes only in memory, unless: (maybe I'm bike-shedding too much, if so, sorry). > (a) the inode needs to be updated for some change unre‐ > lated to file timestamps; > > (b) the application employs fsync(2), syncfs(2), or > sync(2); > > (c) an undeleted inode is evicted from memory; or > > * (d) more than 24 hours have passed since the i-node was > * written to disk. Please don't use "i-node" - simply "inode" is much more common in the manpages AFAICT. > 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. -Eric > * As at Linux 3.20, this option is supported only on ext4. > ]] >