Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752278Ab3HUPJN (ORCPT ); Wed, 21 Aug 2013 11:09:13 -0400 Received: from mga09.intel.com ([134.134.136.24]:1080 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751829Ab3HUPJM (ORCPT ); Wed, 21 Aug 2013 11:09:12 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.89,928,1367996400"; d="scan'208";a="366250145" Message-ID: <5214D812.3090906@linux.intel.com> Date: Wed, 21 Aug 2013 18:09:06 +0300 From: Eliezer Tamir User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/20130801 Thunderbird/17.0.8 MIME-Version: 1.0 To: Eric Dumazet CC: David Miller , linux-kernel@vger.kernel.org, netdev@vger.kernel.org, e1000-devel@lists.sourceforge.net, Eilon Greenstein , Amir Vadai , Willem de Bruijn , Eliezer Tamir Subject: Re: [PATCH RFC net-next] net: epoll support for busy poll References: <20130821103954.30607.6819.stgit@ladj378.jer.intel.com> <1377093188.4226.108.camel@edumazet-glaptop> In-Reply-To: <1377093188.4226.108.camel@edumazet-glaptop> 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: 1243 Lines: 30 On 21/08/2013 16:53, Eric Dumazet wrote: > On Wed, 2013-08-21 at 13:39 +0300, Eliezer Tamir wrote: > >> >> Instead of remembering the napi_id for all the sockets in an epoll, >> we only track the first socket we see with any unique napi_id. >> The rational for this is that while there may be many thousands of >> sockets tracked by a single epoll, we expect to only see a handful >> of unique napi_ids in most cases. > > This looks buggy assumption to me. > > We use epoll() with in the order of millions of fds per epoller, and > typically one napi_id per cpu. > > With your model, we would have to use nr_cpu epollers and make sure that > sockets are properly placed on those epollers by their napi_ids. There is no assumption here on how the user configures epoll. All we are doing is reducing the list of sockets monitored by an epoll instance to a smaller subset where each NAPI_ID appears only once. The user is free to have an epoll monitor sockets from queues associated to any CPU. -- 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/