From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751659AbaL1Vsw (ORCPT ); Sun, 28 Dec 2014 16:48:52 -0500 Received: from mail-wg0-f45.google.com ([74.125.82.45]:33377 "EHLO mail-wg0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751148AbaL1Vst (ORCPT ); Sun, 28 Dec 2014 16:48:49 -0500 Date: Sun, 28 Dec 2014 22:48:35 +0100 From: Beniamino Galvani To: Dave Taht Cc: Giuseppe Cavallaro , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH net-next] net: stmmac: add BQL support Message-ID: <20141228214059.GA25570@gmail.com> References: <1419778631-23067-1-git-send-email-b.galvani@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Dec 28, 2014 at 08:25:40AM -0800, Dave Taht wrote: > On Sun, Dec 28, 2014 at 6:57 AM, Beniamino Galvani wrote: > > Add support for Byte Queue Limits to the STMicro MAC driver. > > Thank you! > > > Tested on a Amlogic S805 Cortex-A5 board, where the use of BQL > > slightly decreases the ping latency from ~10ms to ~3ms when the > > 100Mbps link is saturated by TCP streams. No difference is > > observed at 1Gbps. > > I see the plural. With TSQ in place it is hard (without something like > the rrul test driving multiple streams) to drive a driver to > saturation with small numbers of flows. This was with pfifo_fast, not > sch_fq, at 100mbit? Hi Dave, yes, this was with pfifo_fast and I used 4 iperf TCP streams. The total throughput didn't seem to increase adding more streams. > > Can this board actually drive a full gigabit in the first place? Until > now most of the low end arm boards I have seen only came with > a 100mbit mac, and the gig ones lacking offloads seemed to peak > out at about 600mbit. I measured a throughput of 650mbit in rx and 600mbit in tx. > > Under my christmas tree landed a quad core A5 (odroid-c1), also an > xgene and zedboard - both of the latter are a-needing BQL, > and I haven't booted the udroid yet. Hopefully it is the > same driver you just improved. I'm using the odroid-c1 too, with this tree based on the recent Amlogic mainline work: https://github.com/bengal/linux/tree/meson8b Unfortunately at the moment the support for the board is very basic (for example, SMP is not working yet) but it's enough to do some NIC tests. Beniamino