From mboxrd@z Thu Jan 1 00:00:00 1970 From: Damien Millescamps Subject: Re: Best example for showing throughput? Date: Sat, 25 May 2013 21:23:47 +0200 Message-ID: <51A10FC3.5050703@6wind.com> References: <519F74F6.3000903@mahan.org> <201305241641.38896.thomas.monjalon@6wind.com> <201305241745.25844.thomas.monjalon@6wind.com> <5BBC85C7-B39F-4200-AB7B-CD5464BDA431@mahan.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit To: dev-VfR2kkLFssw@public.gmane.org Return-path: In-Reply-To: <5BBC85C7-B39F-4200-AB7B-CD5464BDA431-5dHXHCkEAVbYtjvyW6yDsg@public.gmane.org> List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces-VfR2kkLFssw@public.gmane.org Sender: "dev" On 05/24/2013 08:51 PM, Patrick Mahan wrote: >> > >> > Are you sending and receiving on the 2 ports at the same time ? >> > Forwarding in the 2 directions is equivalent to double the bandwidth. >> > Maybe that 14.88*2 = 29.76 Mpps is too much for your hardware. >> > > Yes I am running traffic both ways. Interestingly, the amount of drops seem consistent in both directions. This makes sense since testpmd is spinning off a thread to read from each input queue. > Hi Patrick, If you are using both ports of the same Niantics at the same time then you won't be able to reach the line-rate on both port. It is a limitation of the PLX bridge on the board. The expected performance on port 1 when port 0 is used at line-rate should be around 75% of the line-rate from what I know. Since you are forwarding packets from one port to another, the packet dropped because of this will impact the performance on both ways since what is dropped on port 1 won't be forwarded for obvious reasons, and some of the packets from port 0 will be lost while trying to transmit them on port 1. Eventually, you will end up with the lower performance of the two ports which seems to be consistent with the performance you report. Hope this helps, -- Damien