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From: James Antill <james@and.org>
To: "David Schwartz" <davids@webmaster.com>
Cc: "Davide Libenzi" <davidel@xmailserver.org>,
	"Eric Varsanyi" <e0206@foo21.com>,
	"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>
Subject: Re: [Patch][RFC] epoll and half closed TCP connections
Date: 15 Jul 2003 16:27:56 -0400	[thread overview]
Message-ID: <m3y8yz3583.fsf@code.and.org> (raw)
In-Reply-To: <MDEHLPKNGKAHNMBLJOLKGEFKEFAA.davids@webmaster.com>

"David Schwartz" <davids@webmaster.com> writes:

> 	This is really just due to bad coding in 'poll', or more precisely very bad
> for this case. For example, why is it allocating a wait queue buffer if the
> odds that it will need to wait are basically zero? Why is it adding file
> descriptors to the wait queue before it has determined that it needs to
> wait?

 Because this is much easier to do in userspace, it's just not very
well documented that you should almost always call poll() with a zero
timeout first. However it's been there for years, and things have used
it[1].
 There are still optimizations that could have been done to poll() to
speed it up but Linus has generally refused to add them.

[1] http://www.and.org/socket_poll/

-- 
# James Antill -- james@and.org
:0:
* ^From: .*james@and\.org
/dev/null

  parent reply	other threads:[~2003-07-15 20:15 UTC|newest]

Thread overview: 58+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-07-12 18:16 [Patch][RFC] epoll and half closed TCP connections Eric Varsanyi
2003-07-12 19:44 ` Jamie Lokier
2003-07-12 20:51   ` Eric Varsanyi
2003-07-12 20:48     ` Davide Libenzi
2003-07-12 21:19       ` Eric Varsanyi
2003-07-12 21:20         ` Davide Libenzi
2003-07-12 21:41         ` Davide Libenzi
2003-07-12 23:11           ` Eric Varsanyi
2003-07-12 23:55             ` Davide Libenzi
2003-07-13  1:05               ` Eric Varsanyi
2003-07-13 20:32       ` David Schwartz
2003-07-13 21:10         ` Jamie Lokier
2003-07-13 23:05           ` David Schwartz
2003-07-13 23:09             ` Davide Libenzi
2003-07-14  8:14               ` Alan Cox
2003-07-14 15:03                 ` Davide Libenzi
2003-07-14  1:27             ` Jamie Lokier
2003-07-13 21:14         ` Davide Libenzi
2003-07-13 23:05           ` David Schwartz
2003-07-13 23:11             ` Davide Libenzi
2003-07-13 23:52             ` Entrope
2003-07-14  6:14               ` David Schwartz
2003-07-14  7:20                 ` Jamie Lokier
2003-07-14  1:51             ` Jamie Lokier
2003-07-14  6:14               ` David Schwartz
2003-07-15 20:27             ` James Antill [this message]
2003-07-16  1:46               ` David Schwartz
2003-07-16  2:09                 ` James Antill
2003-07-13 13:12     ` Jamie Lokier
2003-07-13 16:55       ` Davide Libenzi
2003-07-12 20:01 ` Davide Libenzi
2003-07-13  5:24   ` David S. Miller
2003-07-13 14:07     ` Jamie Lokier
2003-07-13 17:00       ` Davide Libenzi
2003-07-13 19:15         ` Jamie Lokier
2003-07-13 23:03           ` Davide Libenzi
2003-07-14  1:41             ` Jamie Lokier
2003-07-14  2:24               ` POLLRDONCE optimisation for epoll users (was: epoll and half closed TCP connections) Jamie Lokier
2003-07-14  2:37                 ` Davide Libenzi
2003-07-14  2:43                   ` Davide Libenzi
2003-07-14  2:56                   ` Jamie Lokier
2003-07-14  3:02                     ` Davide Libenzi
2003-07-14  3:16                       ` Jamie Lokier
2003-07-14  3:21                         ` Davide Libenzi
2003-07-14  3:42                           ` Jamie Lokier
2003-07-14  4:00                             ` Davide Libenzi
2003-07-14  5:51                               ` Jamie Lokier
2003-07-14  6:24                                 ` Davide Libenzi
2003-07-14  6:57                                   ` Jamie Lokier
2003-07-14  3:12                     ` Jamie Lokier
2003-07-14  3:17                       ` Davide Libenzi
2003-07-14  3:35                         ` Jamie Lokier
2003-07-14  3:04                   ` Jamie Lokier
2003-07-14  3:12                     ` Davide Libenzi
2003-07-14  3:27                       ` Jamie Lokier
2003-07-14 17:09     ` [Patch][RFC] epoll and half closed TCP connections kuznet
2003-07-14 17:09       ` Davide Libenzi
2003-07-14 21:45       ` Jamie Lokier

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