From: Phillip Lougher <phillip@lougher.org.uk>
To: Al Viro <viro@ftp.linux.org.uk>
Cc: Pavel Machek <pavel@ucw.cz>,
"unlisted-recipients: no To-header on input <;,
Jeff Garzik" <jeff@garzik.org>,
J?rn Engel <joern@wohnheim.fh-wedel.de>,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [ANN] Squashfs 3.0 released
Date: Tue, 21 Mar 2006 19:08:21 +0000 [thread overview]
Message-ID: <44204F25.4090403@lougher.org.uk> (raw)
In-Reply-To: <20060321161452.GG27946@ftp.linux.org.uk>
Al Viro wrote:
>On Tue, Mar 21, 2006 at 04:01:51PM +0000, Phillip Lougher wrote:
>
>
>>Perhaps, but almost all the byteswap is performed on the metadata side,
>>reading directories and inodes, where nearly every byte will need to be
>>swapped. As inodes are compacted and compressed in 8 KB blocks, and are
>>on average 15 bytes in size, for each 8 KB decompress you're potentially
>>doing 8192/15 inode byteswaps. This is probably sufficent to affect
>>directory search and lookup on a slow processor.
>>
>>
>
>Oh, please... Conversion from known endianness to host-endian is considerably
>faster than checking flag + branch + two variants, not to mention being
>smaller.
>
>
It's one flag check, and one set of swap code actually. The point that
was being made is it is better to avoid byte swapping if possible.
next prev parent reply other threads:[~2006-03-21 19:08 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-03-17 0:45 [ANN] Squashfs 3.0 released Phillip Lougher
[not found] ` <20060317010529.GB30801@schatzie.adilger.int>
2006-03-17 1:30 ` Phillip Lougher
2006-03-17 1:51 ` Samuel Masham
2006-03-17 10:40 ` Jörn Engel
2006-03-17 11:16 ` Phillip Lougher
2006-03-17 12:43 ` Jörn Engel
2006-03-17 16:00 ` Jeff Garzik
2006-03-17 17:04 ` Phillip Lougher
2006-03-17 17:25 ` Jeff Garzik
2006-03-17 20:39 ` Willy Tarreau
2006-03-19 1:38 ` Phillip Lougher
2006-03-21 15:33 ` Francesco Biscani
2006-03-19 1:42 ` Phillip Lougher
2006-03-19 16:32 ` Pavel Machek
2006-03-21 16:01 ` Phillip Lougher
[not found] ` <20060321161452.GG27946@ftp.linux.org.uk>
2006-03-21 19:08 ` Phillip Lougher [this message]
2006-03-21 19:11 ` Pavel Machek
2006-03-21 20:03 ` Phillip Lougher
2006-03-21 20:07 ` Al Viro
2006-03-21 22:01 ` Jan Engelhardt
2006-03-21 22:11 ` Jeff Garzik
2006-03-21 22:59 ` Al Viro
2006-03-21 20:15 ` Pavel Machek
2006-03-21 20:33 ` Al Viro
2006-03-21 21:28 ` Andreas Dilger
2006-03-21 23:24 ` Jörn Engel
2006-03-17 21:32 ` Jan Engelhardt
2006-03-17 15:54 ` Xavier Bestel
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