RE: [Patch][RFC] epoll and half closed TCP connections

From: Davide Libenzi <davidel@xmailserver.org>
To: David Schwartz <davids@webmaster.com>
Cc: Jamie Lokier <jamie@shareable.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: Sun, 13 Jul 2003 16:09:23 -0700 (PDT)	[thread overview]
Message-ID: <Pine.LNX.4.55.0307131605480.15022@bigblue.dev.mcafeelabs.com> (raw)
In-Reply-To: <MDEHLPKNGKAHNMBLJOLKEEFKEFAA.davids@webmaster.com>

On Sun, 13 Jul 2003, David Schwartz wrote:

> 	It's not O(N) with 'poll' and 'select'. Twice as many file descriptors
> means twice as many active file descriptors which means twice as many
> discovered per call to 'poll'. If the calls to 'poll' are further apart

It is O(N), if N if the number of fds queried. The poll code does "at least"
2 * N loops among the set (plus other stuff), and hence it is O(N). Even
if you do N "nop" in your implementation, this becomes O(N) from a
mathematical point of view.

- Davide