Subject: Re: BCM5704 performance questions.

From: Ben Greear <[email-masked]>
Date: Thu, 09 Jun 2005 19:28:47 -0700

David S. Miller wrote:
> From: Ben Greear <[email-masked]>
> Date: Thu, 09 Jun 2005 18:20:33 -0700
> 
> 
>>I ran a test using pktgen to (try to) send 82kpps, 1514 byte packets between
>>two ports on the tg3 NIC.  It can do about 780Mbps in one direction,
>>and 880Mbps in the other direction.  Lots of harmless hard-start xmit errors reported
>>(tg3 may not stop it's tx queue correctly, or maybe pktgen is screwed up since
>>e1000 reports similar errors).
> 
> 
> There is a known race on SMP with drivers using NETIF_F_LLTX that is
> still not fixed.  It will cause the error message to be reported from
> the driver's ->hard_start_xmit() routine when you hit this race.

Ok, it's not a big deal, since I can just retry the packet when
the tx queue wakes up again.  The message was coming from pktgen, btw.

> You're definitely on an SMP system if you are triggering that message.

Yes, dual xeon with HT as well.

Thanks,
Ben

-- 
Ben Greear <[email-masked]>
Candela Technologies Inc  http://www.candelatech.com