From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966580Ab3E2PAP (ORCPT ); Wed, 29 May 2013 11:00:15 -0400 Received: from mga03.intel.com ([143.182.124.21]:45380 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966260Ab3E2PAN (ORCPT ); Wed, 29 May 2013 11:00:13 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.87,764,1363158000"; d="scan'208";a="341998675" Message-ID: <51A617D7.6000406@linux.intel.com> Date: Wed, 29 May 2013 17:59:35 +0300 From: Eliezer Tamir User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/20130509 Thunderbird/17.0.6 MIME-Version: 1.0 To: Or Gerlitz CC: Eric Dumazet , David Miller , linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Jesse Brandeburg , Don Skidmore , e1000-devel@lists.sourceforge.net, Willem de Bruijn , Andi Kleen , HPA , Eilon Greenstien , Alex Rosenbaum , Eliezer Tamir Subject: Re: [PATCH v6 net-next 2/5] net: implement support for low latency socket polling References: <20130529063916.27486.3841.stgit@ladj378.jer.intel.com> <20130529063935.27486.18610.stgit@ladj378.jer.intel.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 29/05/2013 17:14, Or Gerlitz wrote: > On Wed, May 29, 2013 at 9:39 AM, Eliezer Tamir > wrote: >> Adds a new ndo_ll_poll method and the code that supports and uses it. >> This method can be used by low latency applications to busy poll Ethernet >> device queues directly from the socket code. The value of sysctl_net_ll_poll >> controls how many microseconds to poll. Set to zero to disable. > > Unlike with TCP sockets, UDP sockets may receive packets from multiple > sources and hence the receiving context may be steered to be executed > on different cores through RSS or other Flow-Steering HW mechanisms > which could mean different napi contexts for the same socket, is that > a problem here? what's the severity? Nothing will break if you poll on the wrong queue. Your data will come through normal NAPI processing of the right queue. One of the things we plan on adding in the next version is a more fine grained control over which sockets get to busy poll. -Eliezer From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eliezer Tamir Subject: Re: [PATCH v6 net-next 2/5] net: implement support for low latency socket polling Date: Wed, 29 May 2013 17:59:35 +0300 Message-ID: <51A617D7.6000406@linux.intel.com> References: <20130529063916.27486.3841.stgit@ladj378.jer.intel.com> <20130529063935.27486.18610.stgit@ladj378.jer.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Willem de Bruijn , e1000-devel@lists.sourceforge.net, netdev@vger.kernel.org, HPA , Jesse Brandeburg , Alex Rosenbaum , linux-kernel@vger.kernel.org, Eliezer Tamir , Andi Kleen , Eric Dumazet , Eilon Greenstien , David Miller To: Or Gerlitz Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: e1000-devel-bounces@lists.sourceforge.net List-Id: netdev.vger.kernel.org On 29/05/2013 17:14, Or Gerlitz wrote: > On Wed, May 29, 2013 at 9:39 AM, Eliezer Tamir > wrote: >> Adds a new ndo_ll_poll method and the code that supports and uses it. >> This method can be used by low latency applications to busy poll Ethernet >> device queues directly from the socket code. The value of sysctl_net_ll_poll >> controls how many microseconds to poll. Set to zero to disable. > > Unlike with TCP sockets, UDP sockets may receive packets from multiple > sources and hence the receiving context may be steered to be executed > on different cores through RSS or other Flow-Steering HW mechanisms > which could mean different napi contexts for the same socket, is that > a problem here? what's the severity? Nothing will break if you poll on the wrong queue. Your data will come through normal NAPI processing of the right queue. One of the things we plan on adding in the next version is a more fine grained control over which sockets get to busy poll. -Eliezer ------------------------------------------------------------------------------ Introducing AppDynamics Lite, a free troubleshooting tool for Java/.NET Get 100% visibility into your production application - at no cost. Code-level diagnostics for performance bottlenecks with <2% overhead Download for free and get started troubleshooting in minutes. http://p.sf.net/sfu/appdyn_d2d_ap1 _______________________________________________ E1000-devel mailing list E1000-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/e1000-devel To learn more about Intel® Ethernet, visit http://communities.intel.com/community/wired