Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 8 Oct 2002 15:35:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 8 Oct 2002 15:34:46 -0400 Received: from packet.digeo.com ([12.110.80.53]:27880 "EHLO packet.digeo.com") by vger.kernel.org with ESMTP id ; Tue, 8 Oct 2002 15:33:29 -0400 Message-ID: <3DA33455.4065101E@digeo.com> Date: Tue, 08 Oct 2002 12:39:01 -0700 From: Andrew Morton X-Mailer: Mozilla 4.79 [en] (X11; U; Linux 2.4.19-pre4 i686) X-Accept-Language: en MIME-Version: 1.0 To: "Theodore Ts'o" CC: Linus Torvalds , Daniel Phillips , Chris Friesen , "Martin J. Bligh" , Oliver Neukum , Rob Landley , linux-kernel@vger.kernel.org Subject: Re: The reason to call it 3.0 is the desktop (was Re: [OT] 2.6 not 3.0 - (NUMA)) References:

<20021008003903.GA473@think.thunk.org> <3DA24A0E.D2AC3E1B@digeo.com> <20021008161555.GA2913@think.thunk.org> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 08 Oct 2002 19:39:01.0451 (UTC) FILETIME=[5A3F49B0:01C26F02] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1977 Lines: 47 Theodore Ts'o wrote: > > On Mon, Oct 07, 2002 at 07:59:26PM -0700, Andrew Morton wrote: > > In the testing which I did, based on Keith Smith's traces, the > > current code really isn't very effective. > > > > What I did was to run his aging workload an increasing number of > > times. Then measured the fragmentation of the files which it > > left behind. I measured the fragmentation simply by timing > > how long it took to read all the files, and compared that to > > how long it took to read the same files when they had been laid > > down on a fresh fs. > > What access pattern did you use when you read the files? Did you > sweep through filesystem directory by directory, or did you use some > other pattern (perhaps random)? Well this is all rather dim in my memory, so the confidence level is drooping. I am sure that the timing was a single find | xargs cat thing. I also know that I investigated whether the increased time was due to the metadata access or the data access. I _think_ it was mainly metadata. But it all needs to be redone, really. > ... > > Maybe a mount option? But I think the current algorithm should > > default to "off". > > How about a mount option with the possible values: "fast", "slow", > "hinted", and "auto", with the default being "auto" or "hinted"? > (Where hinted utilizes user-space hints, and "auto" utilizes > user-space hints if present, plus some of the so-called ugly > hueristics which you had discussed?) > Well the current Orlov patch will spread top-level directories, so as long as /home is a mountpoint, we're fine. For more generalality, yes, I think a new chattr flag on the parent directory which says "spread my subdirectories out" would be a good solution. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/