Re: Umem Questions

On Wed, May 19, 2021 at 11:09 PM Dan Siemon <[email protected]> wrote:
>
>
> > > 2) It looks like there is a limit of 2GB on the maximum Umem size?
> > > I've
> > > tried with and without huge pages. Is this fundamental? How hard
> > > would
> > > it be to increase this?
> >
> > This was news to me. Do you know where in the xdp_umem_reg code it
> > complains about this? I guess it is xsk_umem__create() that fails,
> > or?
> > The only limit I see from a basic inspection of the code is that the
> > number of packet buffers cannot be larger than a u32 (4G). But you
> > are
> > not close to that limit.
>
> Yes, the failure is in xsk_umem__create(). I don't know where
> specifically but there are a couple spots in kernel side of that which
> return ENOMEM which is the return value.

Can you issue a "ulimit -a" on your system and share the result? Just
to verify that there is no per process limit that kicks in.