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From: "Albert D. Cahalan" <acahalan@cs.uml.edu>
To: mfedyk@matchmail.com (Mike Fedyk)
Cc: akpm@zip.com.au (Andrew Morton),
	linux-kernel@vger.kernel.org (lkml),
	ext2-devel@lists.sourceforge.net
Subject: Re: [Ext2-devel] disk throughput
Date: Mon, 5 Nov 2001 00:54:58 -0500 (EST)	[thread overview]
Message-ID: <200111050554.fA55swt273156@saturn.cs.uml.edu> (raw)
In-Reply-To: <20011104193232.A16679@mikef-linux.matchmail.com> from "Mike Fedyk" at Nov 04, 2001 07:32:32 PM

Mike Fedyk writes:
> On Sun, Nov 04, 2001 at 06:13:19PM -0800, Andrew Morton wrote:

>> All well and good, and still a WIP.  But by far the most dramatic
>> speedups come from disabling ext2's policy of placing new directories
>> in a different blockgroup from the parent:
> [snip]
>> A significant thing here is the improvement in read performance as well
>> as writes.  All of the other speedup changes only affect writes.
>>
>> We are paying an extremely heavy price for placing directories in
>> different block groups from their parent.  Why do we do this, and
>> is it worth the cost?
>
> My God!  I'm no kernel hacker, but I would think the first thing
> you would want to do is keep similar data (in this case similar
> because of proximity in the dir tree) as close as possible to
> reduce seeking...

By putting directories far apart, you leave room for regular
files (added at some future time) to be packed close together.

I'm sure your benchmark doesn't fill directories with files
by adding a few files every day over a period of many months.
Think about projects under your home directory though.

  parent reply	other threads:[~2001-11-05  5:55 UTC|newest]

Thread overview: 79+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2001-11-05  2:13 disk throughput Andrew Morton
2001-11-05  3:20 ` Mohammad A. Haque
2001-11-05  3:31   ` Andrew Morton
2001-11-05  3:32 ` [Ext2-devel] " Mike Fedyk
2001-11-05  3:45   ` Andrew Morton
2001-11-05  4:39     ` Mike Fedyk
2001-11-05  7:06     ` Jens Axboe
2001-11-05  7:14       ` Andrew Morton
2001-11-05  7:26         ` Jens Axboe
2001-11-05  7:14       ` Mike Fedyk
2001-11-05  7:18         ` Jens Axboe
2001-11-05  7:18       ` Jens Axboe
2001-11-05  9:14         ` Mike Fedyk
2001-11-05  9:20           ` Jens Axboe
2001-11-05  5:54   ` Albert D. Cahalan [this message]
2001-11-05  8:04     ` Andrew Morton
2001-11-05 12:28       ` Matthias Andree
2001-11-05 14:23       ` Alexander Viro
2001-11-05 22:22         ` Andrew Morton
2001-11-05 22:41           ` Andreas Dilger
2001-11-05 22:53             ` Andrew Morton
2001-11-08 15:28               ` Constantin Loizides
2001-11-05 23:14             ` Dan Hollis
2001-11-06 10:52           ` Daniel Phillips
2001-11-06 16:17           ` Jeremy Fitzhardinge
2001-11-08 15:24             ` Constantin Loizides
2001-11-08 16:46             ` Jeremy Fitzhardinge
2001-11-09  6:08               ` Andrew Morton
2001-11-09  8:49               ` Jeremy Fitzhardinge
2001-11-06 21:45           ` Stephen Tweedie
2001-11-05 20:16       ` Andreas Dilger
2001-11-05 20:28         ` m
2001-11-05 21:39           ` Andrew Morton
2001-11-05 22:59             ` Linus Torvalds
2001-11-05 23:36               ` Alexander Viro
2001-11-05 23:50                 ` Linus Torvalds
2001-11-06  0:03                   ` Linus Torvalds
2001-11-06  1:33                     ` Alexander Viro
2001-11-06  2:10                       ` Linus Torvalds
2001-11-06  3:02                         ` Alexander Viro
2001-11-06  8:39                           ` Alan Cox
2001-11-06  8:37                             ` Alexander Viro
2001-11-06  8:48                               ` Andrew Morton
2001-11-06  3:49                         ` Alexander Viro
2001-11-06  4:01                           ` Linus Torvalds
2001-11-06  4:21                             ` Alexander Viro
2001-11-06  5:01                               ` Linus Torvalds
2001-11-06  5:31                                 ` Andrew Morton
2001-11-06  5:48                                   ` Linus Torvalds
2001-11-06  7:34                                     ` Mike Castle
2001-11-06  7:10                                   ` Kai Henningsen
2001-11-09 22:35                       ` Riley Williams
2001-11-06  1:28                   ` Alexander Viro
2001-11-06  9:16                     ` Wojtek Pilorz
2001-11-06  9:58                       ` Alexander Viro
2001-11-08 12:51                   ` Pavel Machek
2001-11-06 21:48           ` Stephen Tweedie
2001-11-06 23:17             ` ext2/ialloc.c cleanup Alexander Viro
2001-11-07 19:34               ` [Ext2-devel] " Andreas Dilger
2001-11-07 20:02                 ` Alexander Viro
2001-11-08  2:06                   ` Andrew Morton
2001-11-08 20:45                     ` Andrew Morton
2001-11-08 22:16                       ` Alexander Viro
2001-11-08 22:43                         ` Andreas Dilger
2001-11-08 23:08                           ` Alexander Viro
2001-11-09  6:15                             ` Andrew Morton
2001-11-09  6:56                               ` Andreas Dilger
2001-11-09  7:09                                 ` Andrew Morton
2001-11-09  7:12                                 ` Alexander Viro
2001-11-09  7:18                                   ` Andrew Morton
2001-11-05  9:45     ` [Ext2-devel] disk throughput Alex Bligh - linux-kernel
2001-11-05  9:58       ` Alex Bligh - linux-kernel
2001-11-05  8:47 ` Jan Kara
2001-11-05  8:50   ` [Ext2-devel] " Mike Fedyk
2001-11-05  9:01     ` Jan Kara
2001-11-05 12:23 ` Matthias Andree
2001-11-05 22:39   ` Andrew Morton
2001-11-05 23:41     ` Matthias Andree
2001-11-12  6:04 [Ext2-devel] " Yan, Noah

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