Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936318Ab3DKOrv (ORCPT ); Thu, 11 Apr 2013 10:47:51 -0400 Received: from mail-ob0-f171.google.com ([209.85.214.171]:36920 "EHLO mail-ob0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934526Ab3DKOru (ORCPT ); Thu, 11 Apr 2013 10:47:50 -0400 MIME-Version: 1.0 In-Reply-To: <20130411131333.GD1910@1wt.eu> References: <1365684023-9967-1-git-send-email-sebastian.hesselbarth@gmail.com> <20130411131333.GD1910@1wt.eu> Date: Thu, 11 Apr 2013 16:47:49 +0200 Message-ID: Subject: Re: [PATCH] net: mv643xx_eth: Add GRO support From: Sebastian Hesselbarth To: Willy Tarreau Cc: Andrew Lunn , Jason Cooper , Benjamin Herrenschmidt , linux-kernel@vger.kernel.org, "David S. Miller" , Soeren Moch , Paul Mackerras , linux-arm-kernel@lists.infradead.org, Dale Farnsworth , netdev@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Florian Fainelli , Lennert Buytenhek Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4668 Lines: 107 On Thu, Apr 11, 2013 at 3:13 PM, Willy Tarreau wrote: > On Thu, Apr 11, 2013 at 02:40:23PM +0200, Sebastian Hesselbarth wrote: >> This patch adds GRO support to mv643xx_eth by making it invoke >> napi_gro_receive instead of netif_receive_skb. >> >> Signed-off-by: Soeren Moch >> Signed-off-by: Sebastian Hesselbarth >> --- >> Cc: "David S. Miller" >> Cc: Lennert Buytenhek >> Cc: Andrew Lunn >> Cc: Jason Cooper >> Cc: Florian Fainelli >> Cc: Benjamin Herrenschmidt >> Cc: Paul Mackerras >> Cc: Dale Farnsworth >> Cc: netdev@vger.kernel.org >> Cc: linux-arm-kernel@lists.infradead.org >> Cc: linuxppc-dev@lists.ozlabs.org >> Cc: linux-kernel@vger.kernel.org >> --- >> drivers/net/ethernet/marvell/mv643xx_eth.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/net/ethernet/marvell/mv643xx_eth.c b/drivers/net/ethernet/marvell/mv643xx_eth.c >> index 305038f..c850d04 100644 >> --- a/drivers/net/ethernet/marvell/mv643xx_eth.c >> +++ b/drivers/net/ethernet/marvell/mv643xx_eth.c >> @@ -604,7 +604,7 @@ static int rxq_process(struct rx_queue *rxq, int budget) >> lro_receive_skb(&rxq->lro_mgr, skb, (void *)cmd_sts); >> lro_flush_needed = 1; >> } else >> - netif_receive_skb(skb); >> + napi_gro_receive(&mp->napi, skb); >> >> continue; > > I remember having experimented with this on 3.6 a few months ago with this > driver and finally switching back to something like this instead which > showed better performance on my tests : > > if (skb->ip_summed == CHECKSUM_UNNECESSARY) > napi_gro_receive(napi, skb); > else > netif_receive_skb(skb); > > Unfortunately I don't have more details as my commit message was rather > short due to this resulting from experimentation. Did you verify that > you did not lose any performance in various workloads ? I was playing > with bridges at this time, it's possible that I got better performance > on bridging with netif_receive_skb() than with napi_gro_receive(). Hi Willy, I did some simple tests on Dove/Cubox with 'netperf -cCD' and gso/gro/lro options on mv643xx_eth. The tests may not be sufficient, as I am not that into net performance testing. I tried todays net-next on top of 3.9-rc6 without any gro patch, with the initial patch (Soeren) and your proposed patch (Willy). The results show that both patches allow a significant increase in throughput compared to netif_receive_skb (!gro, !lro) alone. Having gro with lro disabled gives some 2% more throughput compared to lro only. Sebastian Recv Send Send Utilization Service Demand Socket Socket Message Elapsed Send Recv Send Recv Size Size Size Time Throughput local remote local remote bytes bytes bytes secs. 10^6bits/s % S % S us/KB us/KB 87380 16384 16384 10.02 615.65 19.15 99.90 5.097 13.293 (3.9-rc6: gso) 87380 16384 16384 10.02 615.82 19.05 99.90 5.067 13.289 (3.9-rc6: gso, gro) 87380 16384 16384 10.03 747.44 23.17 99.80 5.079 10.938 (3.9-rc6: gso, lro) 87380 16384 16384 10.02 745.28 22.57 99.80 4.963 10.970 (3.9.rc6: gso, gro, lro) 87380 16384 16384 10.02 600.34 19.10 99.90 5.211 13.632 (3.9-rc6+soeren: gso) 87380 16384 16384 10.02 764.23 23.42 99.80 5.021 10.698 (3.9-rc6+soeren: gso, gro) 87380 16384 16384 10.02 749.81 23.13 99.80 5.055 10.904 (3.9-rc6+soeren: gso, lro) 87380 16384 16384 10.02 745.84 22.34 99.80 4.907 10.962 (3.9.rc6+soeren: gso, gro, lro) 87380 16384 16384 10.02 605.79 18.79 100.00 5.082 13.523 (3.9-rc6+willy: gso) 87380 16384 16384 10.02 765.64 24.68 99.80 5.281 10.678 (3.9-rc6+willy: gso, gro) 87380 16384 16384 10.02 750.30 26.02 99.80 5.682 10.897 (3.9-rc6+willy: gso, lro) 87380 16384 16384 10.03 749.40 21.86 99.80 4.778 10.910 (3.9.rc6+willy: gso, gro, lro) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/