From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay2.corp.sgi.com [137.38.102.29]) by oss.sgi.com (Postfix) with ESMTP id BD0127FC8 for ; Mon, 7 Apr 2014 17:57:15 -0500 (CDT) Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by relay2.corp.sgi.com (Postfix) with ESMTP id 9E116304039 for ; Mon, 7 Apr 2014 15:57:15 -0700 (PDT) Received: from ipmail05.adl6.internode.on.net (ipmail05.adl6.internode.on.net [150.101.137.143]) by cuda.sgi.com with ESMTP id Fmtm3vRS4bBWwPM9 for ; Mon, 07 Apr 2014 15:57:12 -0700 (PDT) Date: Tue, 8 Apr 2014 08:57:10 +1000 From: Dave Chinner Subject: Re: [FAQ v2] XFS speculative preallocation Message-ID: <20140407225710.GC27017@dastard> References: <20140407153906.GC48184@bfoster.bfoster> <53430375.3060203@sgi.com> <20140407214527.GA43531@bfoster.bfoster> <534324D0.3080701@sgi.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <534324D0.3080701@sgi.com> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: Mark Tinguely Cc: Brian Foster , xfs@oss.sgi.com On Mon, Apr 07, 2014 at 05:21:04PM -0500, Mark Tinguely wrote: > On 04/07/14 16:45, Brian Foster wrote: > >On Mon, Apr 07, 2014 at 02:58:45PM -0500, Mark Tinguely wrote: > >>On 04/07/14 10:39, Brian Foster wrote: > >>>XFS speculatively preallocates post-EOF blocks on file extending writes > >>>in anticipation of future extending writes. The size of a preallocation > >>>is dynamic and depends on the runtime state of the file and fs. > >>>Generally speaking, preallocation is disabled for very small files and > >> vague what is very small? ^^^ > >>... > > > >I originally pointed out 64k, but that and other heuristic details that > >are subject to change were purged in v2. I'm personally not against > >including something that indicates the default and the notion that it's > >subject to change. I don't feel too strongly about it either way. > >Thoughts appreciated. > > > I think the details are good since everyone has a different idea on > "very small". The FAQ can be changed with the code. You can expect > the TOT FAQ to represent Linux 3.0-stable. What's that supposed to mean? The FAQ on the xfs.org website does not represent a specific release. It is supposed to contain the most up-to-date information we have about various topics. If there's something specific to a kernel version we need to mention, then that's explicitly stated in the FAQ entry.... Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs