From: "Ragnar Kjørstad" <kernel@ragnark.vestdata.no>
To: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Christoph Hellwig <hch@infradead.org>,
Rob Ross <rross@mcs.anl.gov>,
Andreas Dilger <adilger@clusterfs.com>,
Sage Weil <sage@newdream.net>, Brad Boyer <flar@allandria.com>,
Anton Altaparmakov <aia21@cam.ac.uk>,
Gary Grider <ggrider@lanl.gov>,
linux-fsdevel@vger.kernel.org
Subject: Re: NFSv4/pNFS possible POSIX I/O API standards
Date: Wed, 6 Dec 2006 13:22:51 +0100 [thread overview]
Message-ID: <20061206122251.GG17226@vestdata.no> (raw)
In-Reply-To: <1165330516.5742.24.camel@lade.trondhjem.org>
On Tue, Dec 05, 2006 at 09:55:16AM -0500, Trond Myklebust wrote:
> > The again statlite and
> > readdirplus really are the most sane bits of these proposals as they
> > fit nicely into the existing set of APIs. The filehandle idiocy on
> > the other hand is way of into crackpipe land.
>
> ...
>
> a) networked filesystem specific. The mask stuff etc adds no
> value whatsoever to actual "posix" filesystems. In fact it is
> telling the kernel that it can violate posix semantics.
I don't see what's network filesystem specific about it. Correct me if
I'm wrong, but today ls -l on a local filesystem will first do readdir
and then n stat calls. In the worst case scenario this will generate n+1
disk seeks.
Local filesystems go through a lot of trouble to try to make the disk
layout of the directory entries and the inodes optimal so that readahead
and caching reduces the number of seeks.
With readdirplus on the other hand, the filesystem would be able to send
all the requests to the block layer and it would be free to optimize
through disk elevators and what not.
And this is not simply an "ls -l" optimization. Allthough I can no loger
remember why, I think this is exactly what imap servers are doing when
opening up big imap folders stored in maildir.
--
Ragnar Kjørstad
Software Engineer
Scali - http://www.scali.com
Scaling the Linux Datacenter
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next prev parent reply other threads:[~2006-12-06 12:23 UTC|newest]
Thread overview: 124+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-11-28 4:34 NFSv4/pNFS possible POSIX I/O API standards Gary Grider
2006-11-28 5:54 ` Christoph Hellwig
2006-11-28 10:54 ` Andreas Dilger
2006-11-28 11:28 ` Anton Altaparmakov
2006-11-28 20:17 ` Russell Cattelan
2006-11-28 23:28 ` Wendy Cheng
2006-11-29 9:12 ` Christoph Hellwig
2006-11-29 9:04 ` Christoph Hellwig
2006-11-29 9:14 ` Christoph Hellwig
2006-11-29 9:48 ` Andreas Dilger
2006-11-29 10:18 ` Anton Altaparmakov
2006-11-29 8:26 ` Brad Boyer
2006-11-30 9:25 ` Christoph Hellwig
2006-11-30 17:49 ` Sage Weil
2006-12-01 5:26 ` Trond Myklebust
2006-12-01 7:08 ` Sage Weil
2006-12-01 14:41 ` Trond Myklebust
2006-12-01 16:47 ` Sage Weil
2006-12-01 18:07 ` Trond Myklebust
2006-12-01 18:42 ` Sage Weil
2006-12-01 19:13 ` Trond Myklebust
2006-12-01 20:32 ` Sage Weil
2006-12-04 18:02 ` Peter Staubach
2006-12-05 23:20 ` readdirplus() as possible POSIX I/O API Sage Weil
2006-12-06 15:48 ` Peter Staubach
2006-12-03 1:57 ` NFSv4/pNFS possible POSIX I/O API standards Andreas Dilger
2006-12-03 7:34 ` Kari Hurtta
2006-12-03 1:52 ` Andreas Dilger
2006-12-03 16:10 ` Sage Weil
2006-12-04 7:32 ` Andreas Dilger
2006-12-04 15:15 ` Trond Myklebust
2006-12-05 0:59 ` Rob Ross
2006-12-05 4:44 ` Gary Grider
2006-12-05 10:05 ` Christoph Hellwig
2006-12-05 5:56 ` Trond Myklebust
2006-12-05 10:07 ` Christoph Hellwig
2006-12-05 14:20 ` Matthew Wilcox
2006-12-06 15:04 ` Rob Ross
2006-12-06 15:44 ` Matthew Wilcox
2006-12-06 16:15 ` Rob Ross
2006-12-05 14:55 ` Trond Myklebust
2006-12-05 22:11 ` Rob Ross
2006-12-05 23:24 ` Trond Myklebust
2006-12-06 16:42 ` Rob Ross
2006-12-06 12:22 ` Ragnar Kjørstad [this message]
2006-12-06 15:14 ` Trond Myklebust
2006-12-05 16:55 ` Latchesar Ionkov
2006-12-05 22:12 ` Christoph Hellwig
2006-12-06 23:12 ` Latchesar Ionkov
2006-12-06 23:33 ` Trond Myklebust
2006-12-05 21:50 ` Rob Ross
2006-12-05 22:05 ` Christoph Hellwig
2006-12-05 23:18 ` Sage Weil
2006-12-05 23:55 ` Ulrich Drepper
2006-12-06 10:06 ` Andreas Dilger
2006-12-06 17:19 ` Ulrich Drepper
2006-12-06 17:27 ` Rob Ross
2006-12-06 17:42 ` Ulrich Drepper
2006-12-06 18:01 ` Ragnar Kjørstad
2006-12-06 18:13 ` Ulrich Drepper
2006-12-17 14:41 ` Ragnar Kjørstad
2006-12-17 19:07 ` Ulrich Drepper
2006-12-17 19:38 ` Matthew Wilcox
2006-12-17 21:51 ` Ulrich Drepper
2006-12-18 2:57 ` Ragnar Kjørstad
2006-12-18 3:54 ` Gary Grider
2006-12-07 5:57 ` Andreas Dilger
2006-12-15 22:37 ` Ulrich Drepper
2006-12-16 18:13 ` Andreas Dilger
2006-12-16 19:08 ` Ulrich Drepper
2006-12-14 23:58 ` statlite() Rob Ross
2006-12-07 23:39 ` NFSv4/pNFS possible POSIX I/O API standards Nikita Danilov
2006-12-05 14:37 ` Peter Staubach
2006-12-05 10:26 ` readdirplus() as possible POSIX I/O API Andreas Dilger
2006-12-05 15:23 ` Trond Myklebust
2006-12-06 10:28 ` Andreas Dilger
2006-12-06 15:10 ` Trond Myklebust
2006-12-05 17:06 ` Latchesar Ionkov
2006-12-05 22:48 ` Rob Ross
2006-11-29 10:25 ` NFSv4/pNFS possible POSIX I/O API standards Steven Whitehouse
2006-11-30 12:29 ` Christoph Hellwig
2006-12-01 15:52 ` Ric Wheeler
2006-11-29 12:23 ` Matthew Wilcox
2006-11-29 12:35 ` Matthew Wilcox
2006-11-29 16:26 ` Gary Grider
2006-11-29 17:18 ` Christoph Hellwig
2006-11-29 12:39 ` Christoph Hellwig
2006-12-01 22:29 ` Rob Ross
2006-12-02 2:35 ` Latchesar Ionkov
2006-12-05 0:37 ` Rob Ross
2006-12-05 10:02 ` Christoph Hellwig
2006-12-05 16:47 ` Latchesar Ionkov
2006-12-05 17:01 ` Matthew Wilcox
[not found] ` <f158dc670612050909m366594c5ubaa87d9a9ecc8c2a@mail.gmail.com>
2006-12-05 17:10 ` Latchesar Ionkov
2006-12-05 17:39 ` Matthew Wilcox
2006-12-05 21:55 ` Rob Ross
2006-12-05 21:50 ` Peter Staubach
2006-12-05 21:44 ` Rob Ross
2006-12-06 11:01 ` openg Christoph Hellwig
2006-12-06 15:41 ` openg Trond Myklebust
2006-12-06 15:42 ` openg Rob Ross
2006-12-06 23:32 ` openg Christoph Hellwig
2006-12-14 23:36 ` openg Rob Ross
2006-12-06 23:25 ` Re: NFSv4/pNFS possible POSIX I/O API standards Latchesar Ionkov
2006-12-06 9:48 ` David Chinner
2006-12-06 15:53 ` openg and path_to_handle Rob Ross
2006-12-06 16:04 ` Matthew Wilcox
2006-12-06 16:20 ` Rob Ross
2006-12-06 20:57 ` David Chinner
2006-12-06 20:40 ` David Chinner
2006-12-06 20:50 ` Matthew Wilcox
2006-12-06 21:09 ` David Chinner
2006-12-06 22:09 ` Andreas Dilger
2006-12-06 22:17 ` Matthew Wilcox
2006-12-06 22:41 ` Andreas Dilger
2006-12-06 23:39 ` Christoph Hellwig
2006-12-14 22:52 ` Rob Ross
2006-12-06 20:50 ` Rob Ross
2006-12-06 21:01 ` David Chinner
2006-12-06 23:19 ` Latchesar Ionkov
2006-12-14 21:00 ` Rob Ross
2006-12-14 21:20 ` Matthew Wilcox
2006-12-14 23:02 ` Rob Ross
2006-11-28 15:08 ` NFSv4/pNFS possible POSIX I/O API standards Matthew Wilcox
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