Re: [bisect] kernel 2.6.38 regression with root nfs mounting

From: Mark Brown
Date: Tue Mar 29 2011 - 17:22:09 EST


On Tue, Mar 29, 2011 at 04:24:08PM -0400, Will Simoneau wrote:

> Interestingly, we are both using DM9000 network chips. I wonder if there
> is a UDP-related problem on the DM9000. I will play with my
> configuration a little more (in particular testing proto=tcp and revert
> of 53d4737580535e073963b91ce87d4216e434fab5) but my guess is the DM9000
> driver/chip is to blame. The DM9000A on my board has 16K of on-chip SRAM
> used for its RX/TX buffers which may be playing a part in the problem.

It's more likely that the DM9000 is just slow and fragile. One thing to
note with a lot of the lower end network chips is that you end up
needing to specify rsize and wsize so that you don't get fragmentation -
about 1k tends to work well IME. Otherwise performance often degrades
to the point of unusability.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/