[igt-dev] [PATCH i-g-t 7/7] benchmarks/gem_exec_fault: Add softpin mode to support gens with ppgtt

[Dixit, Ashutosh]

On Wed, 13 Oct 2021 22:01:22 -0700, Dixit, Ashutosh wrote:
>
> On Thu, 07 Oct 2021 23:54:32 -0700, Zbigniew Kempczyński wrote:
> >
> > +	/*
> > +	 * For older gens .alignment = 1ull << 63 lead do bind/unbind,
> > +	 * what doesn't work for newer gens with ppgtt.
> > +	 * For ppgtt case we use reloc allocator which would just assigns
> > +	 * new offset for each batch. This way we enforce bind/unbind vma
> > +	 * for each execbuf.
>
> So assigning a new offset will cause a new fault-in (bind) but not sure if
> it will cause an actual fault-out (unbind). Though I am not sure if there
> is actually a way to force it to happen if this doesn't work? Is there a
> way to verify that the unbind is actually happening?

Maybe if assign the same offset to a different object/page that will cause
a fault-out (unbind) followed by a fault-in (bind).