On Mon, Jul 28, 2025 at 07:03:12PM +0200, Eugenio Perez Martin wrote:
> On Thu, Jul 24, 2025 at 3:21 AM David Gibson
> <david@gibson.dropbear.id.au> wrote:
> >
> > On Wed, Jul 09, 2025 at 07:47:47PM +0200, Eugenio Pérez wrote:
> > > From ~13Gbit/s to ~11.5Gbit/s.
> >
> > Again, I really don't know what you're comparing to what here.
> >
> 
> When the buffer is full I'm using poll() to wait until vhost free some
> buffers, instead of actively checking the used index. This is the cost
> of the syscall.

Ah, right.  So.. I'm not sure if it's so much the cost of the syscall
itself, as the fact that you're actively waiting for free buffers,
rather than returning to the main epoll loop so you can maybe make
progress on something else before returning to the Tx path.

-- 
David Gibson (he or they)	| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you, not the other way
				| around.
http://www.ozlabs.org/~dgibson