Re: [Xen-devel] "tcp: refine TSO autosizing" causes performance regression on Xen

From: Eric Dumazet
Date: Mon Apr 13 2015 - 09:49:38 EST

On Mon, 2015-04-13 at 11:56 +0100, George Dunlap wrote:

> Is the problem perhaps that netback/netfront delays TX completion?
> Would it be better to see if that can be addressed properly, so that
> the original purpose of the patch (fighting bufferbloat) can be
> achieved while not degrading performance for Xen? Or at least, so
> that people get decent perfomance out of the box without having to
> tweak TCP parameters?

Sure, please provide a patch, that does not break back pressure.

But just in case, if Xen performance relied on bufferbloat, it might be
very difficult to reach a stable equilibrium : Any small change in stack
or scheduling might introduce a significant difference in 'raw

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at