From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761036Ab2BNVX7 (ORCPT ); Tue, 14 Feb 2012 16:23:59 -0500 Received: from shards.monkeyblade.net ([198.137.202.13]:49444 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755364Ab2BNVX4 (ORCPT ); Tue, 14 Feb 2012 16:23:56 -0500 Date: Tue, 14 Feb 2012 16:23:49 -0500 (EST) Message-Id: <20120214.162349.569596872424068284.davem@davemloft.net> To: hagen@jauu.net Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, davidel@xmailserver.org, eric.dumazet@gmail.com Subject: Re: [PATCH net-next] epoll: add EPOLLEXCLUSIVE support From: David Miller In-Reply-To: <1329252484-6309-1-git-send-email-hagen@jauu.net> References: <1329252484-6309-1-git-send-email-hagen@jauu.net> X-Mailer: Mew version 6.4 on Emacs 23.3 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.2.6 (shards.monkeyblade.net [198.137.202.13]); Tue, 14 Feb 2012 13:23:52 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Hagen Paul Pfeifer Date: Tue, 14 Feb 2012 21:48:04 +0100 > High performance server sometimes create one listening socket (e.g. port > 80), create a epoll file descriptor and add the socket. Afterwards > create SC_NPROCESSORS_ONLN threads and wait for events. This often > result in a thundering herd problem because all CPUs are scheduled. > > This patch add an additional flag to epoll_ctl(2) called EPOLLEXCLUSIVE. > If a descriptor is added with this flag only one CPU is scheduled in. > > Signed-off-by: Hagen Paul Pfeifer > Reported-by: Li Yu This is not a networking specific change and therefore should not be submitted via my tree(s).