On Wed, Sep 15, 2010 at 02:27:39PM +0200, Or Gerlitz wrote:
> Jason Gunthorpe wrote:
> >The code to check that the send packet size is less than the MTU is only 
> >invoked in the non-GSO case. This lets packets which are too large pass 
> >through. 
> Jason,
> 
> Did you get here following code inspection or during debugging? if the 
> latter, what does it take to reproduce that?

I noticed it when I was working on the code for the patch after, IPoIB
was still causing MTU discards in my network and that was why. I
didn't try it with CM mode, but I can't see that it would be any
different.

In my testing what I noticed was that the first few packets of a TCP
session triggered the PMTU stuff, but immediately after were a few
GSO packets that tried to go through with the larger MTU. They were
resent fairly quickly with the correct MTU due to the PMTU fixup that
happened.

Jason
--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to