From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jesper Dangaard Brouer Subject: Re: [RFC PATCH 4/5] mlx4: add support for fast rx drop bpf program Date: Mon, 4 Apr 2016 16:57:01 +0200 Message-ID: <20160404165701.2a25a17a@redhat.com> References: <1459560118-5582-1-git-send-email-bblanco@plumgrid.com> <1459560118-5582-5-git-send-email-bblanco@plumgrid.com> <1459562911.6473.299.camel@edumazet-glaptop3.roam.corp.google.com> <20160402024710.GA59703@ast-mbp.thefacebook.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: Eric Dumazet , Brenden Blanco , davem@davemloft.net, netdev@vger.kernel.org, tom@herbertland.com, Or Gerlitz , daniel@iogearbox.net, john.fastabend@gmail.com, brouer@redhat.com To: Alexei Starovoitov Return-path: Received: from mx1.redhat.com ([209.132.183.28]:55892 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751746AbcDDO5H (ORCPT ); Mon, 4 Apr 2016 10:57:07 -0400 In-Reply-To: <20160402024710.GA59703@ast-mbp.thefacebook.com> Sender: netdev-owner@vger.kernel.org List-ID: On Fri, 1 Apr 2016 19:47:12 -0700 Alexei Starovoitov wrote: > My guess we're hitting 14.5Mpps limit for empty bpf program > and for program that actually looks into the packet because we're > hitting 10G phy limit of 40G nic. Since physically 40G nic > consists of four 10G phys. There will be the same problem > with 100G and 50G nics. Both will be hitting 25G phy limit. > We need to vary packets somehow. Hopefully Or can explain that > bit of hw design. > Jesper's experiments with mlx4 showed the same 14.5Mpps limit > when sender blasting the same packet over and over again. That is an interesting observation Alexei, and could explain the pps limit I hit on 40G, with single flow testing. AFAIK 40G is 4x 10G PHYs, and 100G is 4x 25G PHYs. I have a pktgen script that tried to avoid this pitfall. By creating a new flow per pktgen kthread. I call it "pktgen_sample05_flow_per_thread.sh"[1] [1] https://github.com/netoptimizer/network-testing/blob/master/pktgen/pktgen_sample05_flow_per_thread.sh -- Best regards, Jesper Dangaard Brouer MSc.CS, Principal Kernel Engineer at Red Hat Author of http://www.iptv-analyzer.org LinkedIn: http://www.linkedin.com/in/brouer