From: Benjamin LaHaise <bcrl@redhat.com>
To: Andrea Arcangeli <andrea@suse.de>
Cc: Linus Torvalds <torvalds@transmeta.com>,
linux-kernel@vger.kernel.org, linux-aio@kvack.org
Subject: Re: [rfc] aio-core for 2.5.29 (Re: async-io API registration for 2.5.29)
Date: Wed, 31 Jul 2002 10:46:13 -0400 [thread overview]
Message-ID: <20020731104613.B10270@redhat.com> (raw)
In-Reply-To: <20020731004451.GI1181@dualathlon.random>; from andrea@suse.de on Wed, Jul 31, 2002 at 02:44:51AM +0200
On Wed, Jul 31, 2002 at 02:44:51AM +0200, Andrea Arcangeli wrote:
> So I'm not very excited about this change, I would prefer the previous
> version. Also consider with the vsyscall doing the gettimeofday
> calculation in userspace based on "when" rather than in-kernel isn't
> going to be more expensive than your new API even of applications that
> really want the "when" behaviour instead of the "timeout". While the
> applications that wants the "timeout" this way we'll be forced to a
> vgettimeofday in userspace and one in kernel which is a pure overhead
> for them.
That's still racy. There are several hundred instructions from the
time the timeout is calculated until the kernel actually uses the
timeout to calculate an offset relative to jiffies, during which a
task switch may occur. I suppose that this could be handled via a
separate timer interface (we should probably implement posix timers
anyways). I can see the arguments, and I guess it's easier to just
revert it.
-ben
--
"You will be reincarnated as a toad; and you will be much happier."
next prev parent reply other threads:[~2002-07-31 14:42 UTC|newest]
Thread overview: 83+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-07-30 5:41 async-io API registration for 2.5.29 Andrea Arcangeli
2002-07-30 8:11 ` Christoph Hellwig
2002-07-30 13:40 ` Linus Torvalds
2002-07-30 13:52 ` Benjamin LaHaise
2002-07-30 16:43 ` Andrea Arcangeli
2002-07-30 16:59 ` Benjamin LaHaise
2002-07-30 19:10 ` Jeff Dike
2002-07-30 18:09 ` Benjamin LaHaise
2002-07-30 18:15 ` Linus Torvalds
2002-07-30 18:31 ` Benjamin LaHaise
2002-07-30 20:57 ` Jeff Dike
2002-07-30 20:47 ` Jeff Dike
2002-07-30 21:26 ` Andrea Arcangeli
2002-07-30 10:50 ` Rik van Riel
2002-07-30 12:49 ` Benjamin LaHaise
2002-07-30 13:29 ` Suparna Bhattacharya
2002-07-30 21:41 ` Andrea Arcangeli
2002-07-30 21:54 ` [rfc] aio-core for 2.5.29 (Re: async-io API registration for 2.5.29) Benjamin LaHaise
2002-07-31 0:44 ` Andrea Arcangeli
2002-07-31 14:46 ` Benjamin LaHaise [this message]
2002-07-31 16:31 ` Charles 'Buck' Krasic
2002-08-01 10:30 ` Pavel Machek
2002-08-01 14:47 ` Benjamin LaHaise
2002-08-01 15:00 ` Chris Friesen
2002-08-01 16:09 ` Linus Torvalds
2002-08-01 17:30 ` Alan Cox
2002-08-01 16:30 ` Linus Torvalds
2002-08-01 16:41 ` [rfc] aio-core for 2.5.29 (Re: async-io API registration for2.5.29) Chris Friesen
2002-08-01 18:01 ` [rfc] aio-core for 2.5.29 (Re: async-io API registration for 2.5.29) Benjamin LaHaise
2002-08-15 23:54 ` aio-core why not using SuS? [Re: [rfc] aio-core for 2.5.29 (Re: async-io API registration for 2.5.29)] Andrea Arcangeli
2002-08-16 1:42 ` Benjamin LaHaise
2002-08-16 1:57 ` Andrea Arcangeli
2002-08-16 2:00 ` Benjamin LaHaise
2002-08-16 2:08 ` Linus Torvalds
2002-08-16 2:16 ` Benjamin LaHaise
2002-08-16 2:40 ` Andrea Arcangeli
2002-08-16 3:43 ` Linus Torvalds
2002-08-16 3:50 ` Linus Torvalds
2002-08-16 4:47 ` William Lee Irwin III
2002-08-17 3:46 ` Martin J. Bligh
2002-08-17 4:00 ` Linus Torvalds
2002-08-17 4:15 ` Martin J. Bligh
2002-08-17 4:46 ` Linus Torvalds
2001-11-02 5:12 ` Pavel Machek
2002-08-17 5:04 ` Linus Torvalds
2002-08-17 5:24 ` lots of mem on 32 bit machines (was: aio-core why not using SuS?) Martin J. Bligh
2002-08-17 5:12 ` aio-core why not using SuS? [Re: [rfc] aio-core for 2.5.29 (Re: async-io API registration for 2.5.29)] Martin J. Bligh
2002-08-17 17:02 ` Linus Torvalds
2002-08-17 21:27 ` 32 bit arch with lots of RAM Martin J. Bligh
2002-08-22 16:30 ` Andrea Arcangeli
2002-08-22 16:36 ` Martin J. Bligh
2002-08-22 16:15 ` aio-core why not using SuS? [Re: [rfc] aio-core for 2.5.29 (Re: async-io API registration for 2.5.29)] Andrea Arcangeli
2002-08-22 16:12 ` Andrea Arcangeli
2002-08-20 0:35 ` Ingo Molnar
2002-08-17 4:36 ` William Lee Irwin III
2002-08-16 2:32 ` Rik van Riel
2002-08-16 2:32 ` Andrea Arcangeli
2002-08-16 9:39 ` Suparna Bhattacharya
2002-08-16 10:03 ` Andrea Arcangeli
2002-08-16 11:23 ` Suparna Bhattacharya
2002-08-16 11:28 ` Suparna Bhattacharya
2002-08-16 13:49 ` Dan Kegel
2002-09-02 18:40 ` Andrea Arcangeli
2002-09-03 12:04 ` aio-core in 2.5 - io_queue_wait and io_getevents Suparna Bhattacharya
2002-09-05 5:21 ` aio-core why not using SuS? [Re: [rfc] aio-core for 2.5.29 (Re: async-io API registration for 2.5.29)] Benjamin LaHaise
2002-08-16 13:43 ` Dan Kegel
2002-08-16 14:21 ` Jamie Lokier
2002-08-16 14:42 ` Benjamin LaHaise
2002-08-16 15:40 ` John Gardiner Myers
2002-08-23 16:11 ` aio-core why not using SuS? [Re: [rfc] aio-core for 2.5.29 (Re:async-io " Dan Kegel
2002-08-16 1:53 ` aio-core why not using SuS? [Re: [rfc] aio-core for 2.5.29 (Re: async-io " Dan Kegel
2002-08-01 19:18 ` [rfc] aio-core for 2.5.29 (Re: async-io API registration for 2.5.29) Chris Wedgwood
2002-08-01 19:25 ` Linus Torvalds
2002-08-01 19:31 ` Chris Wedgwood
2002-08-02 8:24 ` Pavel Machek
2002-08-02 11:59 ` Alan Cox
2002-08-02 15:56 ` Linus Torvalds
2002-07-31 1:20 ` async-io API registration for 2.5.29 Rik van Riel
2002-07-31 1:32 ` Andrea Arcangeli
2002-07-31 8:25 ` Christoph Hellwig
2002-07-31 13:19 ` Andrea Arcangeli
2002-07-30 13:34 ` Linus Torvalds
2002-07-30 16:49 ` Andrea Arcangeli
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