From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eliezer Tamir Subject: Re: [RFC PATCH 0/5] net: low latency Ethernet device polling Date: Sat, 02 Mar 2013 19:02:31 +0200 Message-ID: <513230A7.6050301@linux.intel.com> References: <20130227175549.10611.82188.stgit@gitlad.jf.intel.com> <20130301.162400.1645765127882618751.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: eliezer.tamir@linux.jf.intel.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, jesse.brandeburg@intel.com, e1000-devel@lists.sourceforge.net, willemb@google.com, andi@firstfloor.org, hpa@zytor.com, eliezer@tamir.org.il To: David Miller Return-path: In-Reply-To: <20130301.162400.1645765127882618751.davem@davemloft.net> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On 01/03/2013 23:24, David Miller wrote: > From: Eliezer Tamir > Date: Wed, 27 Feb 2013 09:55:49 -0800 > >> This patchset adds the ability for the socket layer code to poll directly >> on an Ethernet device's RX queue. This eliminates the cost of the interrupt >> and context switch and with proper tuning allows us to get very close >> to the HW latency. >> >> This is a follow up to Jesse Brandeburg's Kernel Plumbers talk from last year >> http://www.linuxplumbersconf.org/2012/wp-content/uploads/2012/09/2012-lpc-Low-Latency-Sockets-slides-brandeburg.pdf > > I just wanted to say that I like this work a lot. > > It proves a lot of things I try to impress upon people who talk about > how RDMA is such a "must have" because the software stack can't > possibly give anything near HW latency. > > Obviously such arguments are complete bullshit as is shown by these > changes. > > This is exactly the kind of approach that makes sense rather than > trying to put entire TCP stacks in the network card firmware. > > Thanks again for doing this work and I look forward to applying > this stuff once all the kinks are worked out. The folks in the > Intel NIC group continue to impress me. It would really help us to hear opinions on the open issues we listed. Thanks, Eliezer