[Pvfs2-users] PVFS2 & Jumbo Frames

[Robert Olson]

On Nov 3, 2006, at 6:52 AM, Paulo Afonso Lopes wrote:

> Hi, all.
>
> I have measured a 40% to 30% decrease in CPU use (Xeon 2.4G, 512k  
> cache)
> in IBM x335 with the mobo's Broadcom NIC (5703), at 80 MB/s (one port
> only)by going to MTU 9000 instead of the std 1500 (kernel 2.4).

cool.

>
> Some Bcom NICs do support jumbo, others (as the one in the HP DL145/ 
> G2,
> Bcom 5721) do not. I have not played with interrupt coalescing, but  
> it's
> supposed to help a bit, too.
>
> I did not know Bcom NICs had some offload capabilities; can you  
> point out
> where to look (or am I missing the point and you - Rob - are not using
> Bcom?)

On the G5 xserve, lspci sez:

0001:07:04.0 Ethernet controller: Broadcom Corporation NetXtreme  
BCM5704 Gigabit Ethernet (rev 03)
0001:07:04.1 Ethernet controller: Broadcom Corporation NetXtreme  
BCM5704 Gigabit Ethernet (rev 03)

and we have

# ethtool -k eth0
Offload parameters for eth0:
rx-checksumming: on
tx-checksumming: on
scatter-gather: on
tcp segmentation offload: off

--bob