From: Trond Myklebust <trond.myklebust@fys.uio.no>
To: Linus Torvalds <torvalds@osdl.org>
Cc: Xavier Bestel <xavier.bestel@free.fr>,
Nick Piggin <nickpiggin@yahoo.com.au>,
Aubrey <aubreylee@gmail.com>, Hua Zhong <hzhong@gmail.com>,
Hugh Dickins <hugh@veritas.com>,
linux-kernel@vger.kernel.org, hch@infradead.org,
kenneth.w.chen@intel.com, akpm@osdl.org, mjt@tls.msk.ru
Subject: Re: O_DIRECT question
Date: Thu, 11 Jan 2007 13:41:15 -0500 [thread overview]
Message-ID: <1168540875.6170.46.camel@lade.trondhjem.org> (raw)
In-Reply-To: <Pine.LNX.4.64.0701110900090.3594@woody.osdl.org>
On Thu, 2007-01-11 at 09:04 -0800, Linus Torvalds wrote:
> That is what I think some users could do. If the main issue with O_DIRECT
> is the page cache allocations, if we instead had better (read: "any")
> support for POSIX_FADV_NOREUSE, one class of reasons O_DIRECT usage would
> just go away.
For NFS, the main feature of interest when it comes to O_DIRECT is
strictly uncached I/O. Replacing it with POSIX_FADV_NOREUSE won't help
because it can't guarantee that the page will be thrown out of the page
cache before some second process tries to read it. That is particularly
true if some dopey third party process has mmapped the file.
Trond
next prev parent reply other threads:[~2007-01-11 18:41 UTC|newest]
Thread overview: 130+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-01-11 2:57 Aubrey
2007-01-11 3:05 ` Linus Torvalds
2007-01-11 3:15 ` Linus Torvalds
2007-01-11 6:09 ` Nick Piggin
2007-01-11 15:50 ` Linus Torvalds
2007-01-11 16:19 ` Aubrey
2007-01-16 3:41 ` Jörn Engel
2007-01-11 16:23 ` bert hubert
2007-01-11 16:52 ` Xavier Bestel
2007-01-11 17:04 ` Linus Torvalds
2007-01-11 18:41 ` Trond Myklebust [this message]
2007-01-11 19:00 ` Linus Torvalds
2007-01-11 19:49 ` Trond Myklebust
2007-01-12 17:03 ` Viktor
2007-01-20 16:19 ` Denis Vlasenko
2007-01-22 15:52 ` Phillip Susi
2007-01-11 5:50 ` Aubrey
2007-01-11 6:06 ` Andrew Morton
2007-01-11 6:45 ` Aubrey
2007-01-11 6:57 ` Andrew Morton
2007-01-11 7:05 ` Nick Piggin
2007-01-11 7:54 ` Aubrey
2007-01-11 8:05 ` Roy Huang
2007-01-11 16:45 ` Linus Torvalds
2007-01-17 4:29 ` Aubrey Li
2007-01-12 2:12 ` Aubrey
2007-01-12 2:47 ` Nick Piggin
2007-01-12 3:59 ` Roy Huang
2007-01-11 8:12 ` Nick Piggin
2007-01-11 8:49 ` Roy Huang
2007-01-11 9:09 ` Nick Piggin
2007-01-12 2:48 ` Bill Davidsen
2007-01-12 4:30 ` Nick Piggin
2007-01-12 4:46 ` Linus Torvalds
2007-01-12 4:56 ` Nick Piggin
2007-01-12 4:58 ` Nick Piggin
2007-01-12 5:18 ` Linus Torvalds
2007-01-12 5:22 ` Aubrey
2007-01-12 14:59 ` Bill Davidsen
2007-01-13 4:51 ` Nick Piggin
2007-01-11 6:16 ` Alexander Shishkin
2007-01-11 6:57 ` Aubrey
2007-01-11 12:13 ` Viktor
2007-01-11 15:53 ` Phillip Susi
2007-01-11 16:20 ` Linus Torvalds
2007-01-11 17:13 ` Michael Tokarev
2007-01-11 23:01 ` Phillip Susi
2007-01-11 23:06 ` Hua Zhong
2007-01-12 15:21 ` Phillip Susi
2007-01-20 16:36 ` Denis Vlasenko
2007-01-20 20:55 ` Michael Tokarev
2007-01-20 23:05 ` Denis Vlasenko
2007-01-21 12:09 ` Michael Tokarev
2007-01-21 20:02 ` Denis Vlasenko
2007-01-22 16:17 ` Phillip Susi
2007-01-24 21:15 ` Denis Vlasenko
2007-01-25 15:44 ` Phillip Susi
2007-01-25 17:38 ` Denis Vlasenko
2007-01-25 19:28 ` Phillip Susi
2007-01-25 19:52 ` Denis Vlasenko
2007-01-25 20:03 ` Phillip Susi
2007-01-25 20:45 ` Michael Tokarev
2007-01-25 21:11 ` Denis Vlasenko
2007-01-26 16:02 ` Mark Lord
2007-01-26 16:52 ` Viktor
2007-01-26 16:58 ` Phillip Susi
2007-01-26 17:05 ` Phillip Susi
2007-01-26 23:16 ` Denis Vlasenko
2007-02-06 20:39 ` Pavel Machek
2007-01-26 18:23 ` Bill Davidsen
2007-01-26 23:35 ` Denis Vlasenko
2007-01-28 15:18 ` Bill Davidsen
2007-01-28 17:03 ` Denis Vlasenko
2007-01-29 15:43 ` Phillip Susi
2007-01-29 17:00 ` Andrea Arcangeli
2007-01-30 0:05 ` Denis Vlasenko
[not found] ` <45BE7D99.70200@cfl.rr.com>
[not found] ` <20070130023056.GN8030@opteron.random>
[not found] ` <45BF65E3.6070102@cfl.rr.com>
[not found] ` <20070130164806.GQ8030@opteron.random>
2007-01-30 18:50 ` Phillip Susi
2007-01-30 19:57 ` Andrea Arcangeli
2007-01-30 20:06 ` Andrea Arcangeli
2007-01-30 23:07 ` Phillip Susi
2007-01-31 2:28 ` Andrea Arcangeli
2007-01-31 9:37 ` Michael Tokarev
2007-01-26 15:53 ` Bill Davidsen
2007-01-11 17:42 ` Alan
2007-01-11 18:00 ` Linus Torvalds
2007-01-12 7:57 ` dean gaudet
2007-01-12 15:27 ` Phillip Susi
2007-01-12 18:06 ` Linus Torvalds
2007-01-12 20:23 ` Chris Mason
2007-01-12 20:46 ` Michael Tokarev
2007-01-12 20:52 ` Michael Tokarev
2007-01-12 21:03 ` Michael Tokarev
2007-01-12 21:17 ` Linus Torvalds
2007-01-12 21:54 ` Michael Tokarev
2007-01-12 22:09 ` Linus Torvalds
2007-01-12 22:26 ` Michael Tokarev
2007-01-12 22:35 ` Erik Andersen
2007-01-12 22:47 ` Andrew Morton
2007-01-14 9:11 ` Nate Diller
2007-01-20 16:45 ` Denis Vlasenko
2007-01-22 1:47 ` Andrea Arcangeli
2007-01-13 20:07 ` Bill Davidsen
2007-01-13 20:27 ` Michael Tokarev
2007-01-14 15:39 ` Bill Davidsen
2007-01-12 21:39 ` Disk Cache, Was: " Zan Lynx
2007-01-12 22:10 ` Michael Tokarev
2007-01-15 12:11 ` Helge Hafting
2007-01-12 16:59 ` Viktor
2007-01-11 12:45 ` Erik Mouw
2007-01-11 4:51 ` Andrew Morton
2007-01-11 5:06 ` Gerrit Huizenga
2007-01-11 16:09 ` Badari Pulavarty
2007-01-11 12:34 ` linux-os (Dick Johnson)
2007-01-11 13:06 ` Martin Mares
2007-01-11 14:15 ` Jens Axboe
2007-01-12 2:13 ` Bill Davidsen
2007-01-17 14:27 Alex Tomas
2007-01-22 15:59 Al Boldi
[not found] <7BYkO-5OV-17@gated-at.bofh.it>
[not found] ` <7BYul-6gz-5@gated-at.bofh.it>
[not found] ` <7C18X-1zo-5@gated-at.bofh.it>
[not found] ` <7C1iw-22q-7@gated-at.bofh.it>
[not found] ` <7C1Vb-2Ny-3@gated-at.bofh.it>
[not found] ` <7C256-2ZR-27@gated-at.bofh.it>
[not found] ` <7C2eE-3rT-15@gated-at.bofh.it>
[not found] ` <7C31d-4qb-11@gated-at.bofh.it>
[not found] ` <7C3kj-55E-9@gated-at.bofh.it>
2007-01-11 13:20 ` Bodo Eggert
[not found] ` <7C74B-2A4-23@gated-at.bofh.it>
[not found] ` <7CaYA-mT-19@gated-at.bofh.it>
[not found] ` <7Cpuz-64X-1@gated-at.bofh.it>
[not found] ` <7Cz0T-4PH-17@gated-at.bofh.it>
[not found] ` <7CBcl-86B-9@gated-at.bofh.it>
[not found] ` <7CBvH-52-9@gated-at.bofh.it>
[not found] ` <7CBFn-hw-1@gated-at.bofh.it>
[not found] ` <7CBP1-KI-3@gated-at.bofh.it>
[not found] ` <7CBYG-WK-3@gated-at.bofh.it>
2007-01-13 16:53 ` Bodo Eggert
2007-01-13 19:30 ` Bill Davidsen
2007-01-14 18:51 ` Bodo Eggert
[not found] ` <7CXmz-88G-29@gated-at.bofh.it>
[not found] ` <7CXFR-8vZ-15@gated-at.bofh.it>
[not found] ` <7DfMP-2ak-19@gated-at.bofh.it>
2007-01-14 19:39 ` Bodo Eggert
[not found] ` <7DyYK-6lE-3@gated-at.bofh.it>
2007-01-16 20:26 ` Bodo Eggert
2007-01-17 5:55 ` Arjan van de Ven
2007-01-17 22:36 ` Bodo Eggert
[not found] ` <7HkaQ-2Nb-9@gated-at.bofh.it>
[not found] ` <7HDZP-Pv-1@gated-at.bofh.it>
[not found] ` <7HIPV-8kp-35@gated-at.bofh.it>
2007-01-27 14:01 ` Bodo Eggert
2007-01-27 14:14 ` Denis Vlasenko
2007-01-28 15:30 ` Bill Davidsen
2007-01-28 17:18 ` Denis Vlasenko
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