From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Hutchings Subject: Re: [PATCH v6 net-next 2/5] net: implement support for low latency socket polling Date: Wed, 29 May 2013 21:20:35 +0100 Message-ID: <1369858835.1971.26.camel@bwh-desktop.uk.level5networks.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 , Eliezer Tamir , 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 Wed, 2013-05-29 at 17:14 +0300, 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? Maybe ARFS could be extended so the driver can tell whether a UDP socket it's steering for is connected or not. Then for disconnected sockets the driver can use a filter that only matches destination address. (Though that's probably undesirable if the socket has SO_REUSEPORT set.) Ben. -- Ben Hutchings, Staff Engineer, Solarflare Not speaking for my employer; that's the marketing department's job. They asked us to note that Solarflare product names are trademarked. ------------------------------------------------------------------------------ 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