Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754581AbZA1LIb (ORCPT ); Wed, 28 Jan 2009 06:08:31 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750995AbZA1LIX (ORCPT ); Wed, 28 Jan 2009 06:08:23 -0500 Received: from mu-out-0910.google.com ([209.85.134.191]:46046 "EHLO mu-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750753AbZA1LIW (ORCPT ); Wed, 28 Jan 2009 06:08:22 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=Mz4QhEW17uWzL0FmRCmKvxh55jPiH8pqtYIIfAAvOKE+6q5bmMwRYVWvs83A6Gx7my AU4c0Sjfdz6IdMgp7GntpbLlTUYEej+Zfmp4B64mYa7C9JQmcgCsZ/EO6brBEhzXlK09 8PIrB3D2EhrB+IwvVI3kgZvKbHJaGIZDS7I+8= MIME-Version: 1.0 In-Reply-To: <20090128053204.GB8720@brong.net> References: <20090128033824.GA1662@brong.net> <59410684d947bc68862a4f5d6c2a5bb1f29519ee.1233114169.git.brong@fastmail.fm> <20090128053204.GB8720@brong.net> Date: Wed, 28 Jan 2009 12:08:20 +0100 Message-ID: <19f34abd0901280308w18407fd5rd4d7d95e3799cf60@mail.gmail.com> Subject: Re: [PATCH 1/3] epoll: increase default max_user_instances to 1024 From: Vegard Nossum To: Bron Gondwana Cc: Davide Libenzi , Linux Kernel Mailing List , Greg KH Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1196 Lines: 29 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? So you would still get the "upwards cascading" behaviour (i.e. A can monitor B and C), but the "downwards cascading" would be prohibited (i.e. B and C can't both monitor A). I think this is a reasonable alternative, which would again allow a number of epoll instances limited only by the number of open file descriptors. Vegard -- "The animistic metaphor of the bug that maliciously sneaked in while the programmer was not looking is intellectually dishonest as it disguises that the error is the programmer's own creation." -- E. W. Dijkstra, EWD1036 -- 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/