From: Alexander Viro <viro@math.psu.edu>
To: Andreas Dilger <adilger@turbolabs.com>
Cc: Stephen Tweedie <sct@redhat.com>,
ext2-devel@lists.sourceforge.net, m@mo.optusnet.com.au,
Andrew Morton <akpm@zip.com.au>,
"Albert D. Cahalan" <acahalan@cs.uml.edu>,
Mike Fedyk <mfedyk@matchmail.com>,
lkml <linux-kernel@vger.kernel.org>
Subject: Re: [Ext2-devel] ext2/ialloc.c cleanup
Date: Wed, 7 Nov 2001 15:02:29 -0500 (EST) [thread overview]
Message-ID: <Pine.GSO.4.21.0111071446020.4283-100000@weyl.math.psu.edu> (raw)
In-Reply-To: <20011107123430.D5922@lynx.no>
On Wed, 7 Nov 2001, Andreas Dilger wrote:
> Minor nits, from my changes to this same function:
> 1) please replace use of "i" for best block group in find_cg_*, to
> something better like "group", just for clarity.
Consider that done.
> 2) in find_cg_*, when you fail the quadratic search, the linear search
> should skip groups that were previously checked in the quadratic search,
> with slight changes to both loops:
I'm not actually sure that it's a good thing. The different between the
sequences we do is that I do
n n+1 n+3 n+7 ... n+2 (linear)
and you do
n n+1 n+2 n+4 n+8 ... n+3 (linear)
which has slightly worse properties. You avoid duplicated check on n+3,
but lose a very nice property - shifting the old sequence is guaranteed
not to have many intersections with original in the beginning (distances
between elements do not repeat). With your sequence it's no longer true.
> 3) I know that "cylinder groups" were used in old FFS/whatever implementation,
> but all of the ext2 code/documentation refers to these as block groups.
> Can you stick with that for ext2 (e.g. gdp, not cg; bg_foo, not cg_foo)?
Ehh... Try to read that aloud. Maybe it's just me, but "gdp" sounds (and
looks) bad...
> 4) sbi can be gotten by "EXT2_SB(sb)".
True, consider that done.
Right now I'm doing alternative strategy for directory allocation, as soon
as I finish that I'll put the result on usual place.
next prev parent reply other threads:[~2001-11-07 20:03 UTC|newest]
Thread overview: 78+ 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
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 [this message]
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
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