From: Jens Axboe <axboe@suse.de>
To: Hans Reiser <reiser@namesys.com>
Cc: Edward Shishkin <edward@namesys.com>,
LKML <linux-kernel@vger.kernel.org>,
Reiserfs mail-list <Reiserfs-List@namesys.com>
Subject: Re: random minor benchmark: Re: Copy 20 tarfiles: ext2 vs (reiser4, unixfile) vs (reiser4,cryptcompress)
Date: Fri, 27 Jan 2006 09:09:03 +0100 [thread overview]
Message-ID: <20060127080903.GT4311@suse.de> (raw)
In-Reply-To: <43D9CF3C.9070706@namesys.com>
On Thu, Jan 26 2006, Hans Reiser wrote:
> Edward Shishkin wrote:
>
> >
> > I guess this is because real compression is going in background
> > flush, not in sys_write->write_cryptcompress (which just copies
> > user's data to page cache). So in this case we have something
> > very similar to ext2. Reiser4 plain write (write_unix_file) is
> > more complex, and currently we try to reduce its sys time.
> >
> > Edward.
> >
> >
> >
> >
> Which means that only real time is a meaningful measurement.....
Indeed. I guess the compression stuff cost is hard to quantify, since it
has cache effects on the rest of the system in addition to costing CPU
cycles on its own.
A profile of, say, dbench with and without compression would be
interesting to see. And the actual dbench reults, naturally :-)
--
Jens Axboe
next prev parent reply other threads:[~2006-01-27 8:06 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <43D7C6BE.1010804@namesys.com>
2006-01-25 18:59 ` random minor benchmark: Re: Copy 20 tarfiles: ext2 vs (reiser4, unixfile) vs (reiser4,cryptcompress) Hans Reiser
2006-01-26 15:33 ` Jens Axboe
2006-01-26 18:17 ` Edward Shishkin
2006-01-26 18:56 ` Jens Axboe
2006-01-26 20:41 ` Edward Shishkin
2006-01-27 7:43 ` Hans Reiser
2006-01-27 8:09 ` Jens Axboe [this message]
2006-01-27 8:06 ` Jens Axboe
2006-01-27 8:14 ` Hans Reiser
2006-01-27 8:21 ` Jens Axboe
2006-01-27 8:41 ` Hans Reiser
2006-01-28 16:53 ` Alexander Zarochentsev
2006-01-27 7:30 ` Hans Reiser
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