From mboxrd@z Thu Jan 1 00:00:00 1970 From: rosenp@gmail.com Subject: Re: [PATCH] bgmac: Remove all offloading features, including GRO. Date: Wed, 20 Sep 2017 14:27:44 -0700 Message-ID: <1505942864.3451.3.camel@gmail.com> References: <20170916002305.2794-1-rosenp@gmail.com> <1505522096.29839.13.camel@edumazet-glaptop3.roam.corp.google.com> <1505522322.3726.0.camel@gmail.com> <0CEBE536-2C18-4ED2-90CB-3836CEF9A70E@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: Florian Fainelli , Eric Dumazet Return-path: Received: from mail-pf0-f195.google.com ([209.85.192.195]:34867 "EHLO mail-pf0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751636AbdITV1r (ORCPT ); Wed, 20 Sep 2017 17:27:47 -0400 Received: by mail-pf0-f195.google.com with SMTP id i23so1657939pfi.2 for ; Wed, 20 Sep 2017 14:27:47 -0700 (PDT) In-Reply-To: <0CEBE536-2C18-4ED2-90CB-3836CEF9A70E@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: Sorry for the noise. After more testing I've found out that the cause was that I had BBR enabled on my laptop. Switching back to CUBIC fixed the issue. In other words, this patch is detrimental. ~67mbps - gro off ~87mbps - gro on On Fri, 2017-09-15 at 23:04 -0700, Florian Fainelli wrote: > On September 15, 2017 5:38:42 PM PDT, rosenp@gmail.com wrote: > > I have not. Unfortunately I own no gigabit hardware to test this > > on. > > The MIPS CPU runs at 300MHz on my unit. > > > > bgmac is used on Gigabit capable hardware, like Northstar and > Northstar Plus, and others too, so unless you can get access to such > HW or get confirmation from someone that your patches changes > something, I would just drop this change and not bother. This is > already not 100mbits/sec linerate... > > > On Fri, 2017-09-15 at 17:34 -0700, Eric Dumazet wrote: > > > On Fri, 2017-09-15 at 17:23 -0700, Rosen Penev wrote: > > > > On a linksys E1200v1 (actually a crossflashed E1000v2), the > > > > offloading features give no measurable benefit to speed or > > > > latency. > > > > Furthermore, disabling GRO actually improves iperf performance > > > > by a > > > > whoppimg 3mbps. Results: > > > > > > > > Currently: > > > > > > > > v2: Changed napi_gro_receive to netif_receive_skb. Seems to > > > > have an > > > > identical result. > > > > > > > > Signed-off-by: Rosen Penev > > > > --- > > > > drivers/net/ethernet/broadcom/bgmac.c | 2 +- > > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > > > diff --git a/drivers/net/ethernet/broadcom/bgmac.c > > > > b/drivers/net/ethernet/broadcom/bgmac.c > > > > index 48d672b204a4..1fb0053aeee7 100644 > > > > --- a/drivers/net/ethernet/broadcom/bgmac.c > > > > +++ b/drivers/net/ethernet/broadcom/bgmac.c > > > > @@ -483,7 +483,7 @@ static int bgmac_dma_rx_read(struct bgmac > > > > *bgmac, struct bgmac_dma_ring *ring, > > > > skb->protocol = eth_type_trans(skb, > > > > bgmac- > > > > > net_dev); > > > > > > > > bgmac->net_dev->stats.rx_bytes += len; > > > > bgmac->net_dev->stats.rx_packets++; > > > > - napi_gro_receive(&bgmac->napi, skb); > > > > + netif_receive_skb(skb); > > > > handled++; > > > > } while (0); > > > > > > > > > > And have you tested 1Gbit link speed ? > > > ( Or 2.5 Gbit link speed ) > > > > > > If you want to disable GRO on your host, fine : you can use > > > ethtool > > > -K > > > > > > > > > > > (please don't top-post)