From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jonathan Rosser Subject: Re: asynchronous operation with poll() Date: Wed, 10 Nov 2010 16:05:02 +0000 Message-ID: References: <20101109204452.GG909@obsidianresearch.com> <4538690.1289385043068.SLOX.WebMail.wwwrun@imap.lnl.infn.it> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4538690.1289385043068.SLOX.WebMail.wwwrun-XDIR3SKYeFbgKi2NxijLtw@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-rdma@vger.kernel.org On 11/10/10 10:30, Andrea Gozzelino wrote: > Hi Jonathan, > > I wrote down a test (latency and transfer speed) with RDMA. > Server and client work with the same code and they change defined size > buffers for n times (loop). In the makefile.txt, you can find an help to > use the code. > > I tested Intel NetEffect NE020 E10G81GP cards with this code and I found > minimum latency about 11 us,maximum transfer speed about 9,6 GBytes, CPU > usage up to 90% on client side. > The last value is not good for us. Hi Andrea, Thanks for the code. With the advice from Jason I have changed my test program to get reliable communication using 1Mbyte buffers. The CPU usage is less than 2% on both client and server for 10Gb throughput. I have Chelsio S310CR. I find using the poll() approach more natural as I have experience with conventional sockets based programming before. The rdma_client/rdma_server example programs from librdmacm were the easiest to start from and I have incrementally changed them from synchronous to asynchronous operation, and moved the internals of the high level functions in into my own code piece by piece. The learning curve is very steep :) I found this paper quite interesting www.systems.ethz.ch/research/awards/minimizingthehidden.pdf Cheers, Jonathan. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html