From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: Difficulties to get 1Gbps on be2net ethernet card Date: Wed, 06 Jun 2012 13:01:24 +0200 Message-ID: <1338980484.2760.4219.camel@edumazet-glaptop> References: <1338360536.2760.85.camel@edumazet-glaptop> <1338361587.2760.94.camel@edumazet-glaptop> <3367B80B08154D42A3B2BC708B5D41F647C678B73F@EXMAIL.ad.emulex.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: Sathya.Perla@emulex.com, netdev@vger.kernel.org To: Jean-Michel Hautbois Return-path: Received: from mail-ey0-f174.google.com ([209.85.215.174]:51047 "EHLO mail-ey0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753006Ab2FFLBb (ORCPT ); Wed, 6 Jun 2012 07:01:31 -0400 Received: by eaak11 with SMTP id k11so1889528eaa.19 for ; Wed, 06 Jun 2012 04:01:30 -0700 (PDT) In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On Wed, 2012-06-06 at 12:04 +0200, Jean-Michel Hautbois wrote: > Well, well, well, after having tested several configurations, several > drivers, I have a big difference between an old 2.6.26 kernel and a > newer one (I tried 3.2 and 3.4). > > Here is my stream : UDP packets (multicast), 4000 bytes length, MTU > set to 4096. I am sending packets only, nothing on RX. > I send from 1Gbps upto 2.4Gbps and I see no drops in tc with 2.6.26 > kernel, but a lot of drops with a newer kernel. > So, I don't know if I missed something in my kernel configuration, but > I have used the 2.6.26 one as a reference, in order to set the same > options (DMA related, etc). > > I easily reproduce this problem and setting a bigger txqueuelen solves > it partially. > 1Gbps requires a txqueulen of 9000, 2.4Gbps requires more than 20000 ! > > If you have any idea, I am interested, as this is a big issue for my use case. > Yep. This driver wants to limit number of tx completions, thats just wrong. Fix and dirty patch: diff --git a/drivers/net/ethernet/emulex/benet/be.h b/drivers/net/ethernet/emulex/benet/be.h index c5c4c0e..1e8f8a6 100644 --- a/drivers/net/ethernet/emulex/benet/be.h +++ b/drivers/net/ethernet/emulex/benet/be.h @@ -105,7 +105,7 @@ static inline char *nic_name(struct pci_dev *pdev) #define MAX_TX_QS 8 #define MAX_ROCE_EQS 5 #define MAX_MSIX_VECTORS (MAX_RSS_QS + MAX_ROCE_EQS) /* RSS qs + RoCE */ -#define BE_TX_BUDGET 256 +#define BE_TX_BUDGET 65535 #define BE_NAPI_WEIGHT 64 #define MAX_RX_POST BE_NAPI_WEIGHT /* Frags posted at a time */ #define RX_FRAGS_REFILL_WM (RX_Q_LEN - MAX_RX_POST)