Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754308AbZA1QxQ (ORCPT ); Wed, 28 Jan 2009 11:53:16 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751740AbZA1QxA (ORCPT ); Wed, 28 Jan 2009 11:53:00 -0500 Received: from x35.xmailserver.org ([64.71.152.41]:46031 "EHLO x35.xmailserver.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750951AbZA1Qw7 (ORCPT ); Wed, 28 Jan 2009 11:52:59 -0500 X-AuthUser: davidel@xmailserver.org Date: Wed, 28 Jan 2009 08:52:51 -0800 (PST) From: Davide Libenzi X-X-Sender: davide@alien.or.mcafeemobile.com To: Vegard Nossum cc: Bron Gondwana , Linux Kernel Mailing List , Greg KH Subject: Re: [PATCH 1/3] epoll: increase default max_user_instances to 1024 In-Reply-To: <19f34abd0901280308w18407fd5rd4d7d95e3799cf60@mail.gmail.com> Message-ID: References: <20090128033824.GA1662@brong.net> <59410684d947bc68862a4f5d6c2a5bb1f29519ee.1233114169.git.brong@fastmail.fm> <20090128053204.GB8720@brong.net> <19f34abd0901280308w18407fd5rd4d7d95e3799cf60@mail.gmail.com> User-Agent: Alpine 1.10 (DEB 962 2008-03-14) X-GPG-FINGRPRINT: CFAE 5BEE FD36 F65E E640 56FE 0974 BF23 270F 474E X-GPG-PUBLIC_KEY: http://www.xmailserver.org/davidel.asc MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 948 Lines: 24 On Wed, 28 Jan 2009, Vegard Nossum wrote: > On Wed, Jan 28, 2009 at 6:32 AM, Bron Gondwana wrote: > > That's clearly not happening here - so it seems that maybe our "happy > > medium" is actually in closer inspection of what's going on rather than > > a blanket low N to keep N^2 down. > > Mh, could another solution to this all be to limit the number times > you can add a single epoll descriptor to another descriptor's set? In the example that was posted, a single fd was added a single time inside the other 1000+ fds. Epoll already has detection for too long chains and closed loops, but you can't put those in the fast path. And epoll_ctl() is one of those. - Davide -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/