kern/174851: [bxe] [patch] UDP checksum offload is wrong in bxe driver

[Garrett Cooper]

On Mon, Dec 31, 2012 at 7:53 AM, Barney Cordoba
<barney_cordoba at yahoo.com> wrote:

...

> Has anyone done an analysis on modern hardware as to whether udp csum
> offloading is actually beneficial? Even on 2007 hardware I came to the
> conclusion that using offloading was a negative.
>
> Reminds me of the days when people were using "intelligent" ethernet cards
> that were slower than the host cpu. The handshaking cost you more than
> just using shared memory.

I would ask David about whether or not there was a performance
difference because they might have some numbers for if_bxe.

Not sure about the concept in general, but it seems like a reasonable
application protocol specific request. But by and large, I agree that
UDP checksumming doesn't make logical sense because it adds
unnecessary overhead on a L3 protocol that's assumed to be unreliable.

Thanks,
-Garrett