[Intel-gfx] [PATCH] drm/i915/selftests: Use igt_random_offset()

[Chris Wilson]

Quoting Matthew Auld (2020-03-12 17:00:58)
> On Thu, 12 Mar 2020 at 15:47, Chris Wilson <chris at chris-wilson.co.uk> wrote:
> >
> > Switch igt_vm_isolation() to using igt_random_offset().
> >
> > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> > Cc: Matthew Auld <matthew.auld at intel.com>
> > Cc: Akeem G Abodunrin <akeem.g.abodunrin at intel.com>
> > ---
> >  drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c | 8 +++-----
> >  1 file changed, 3 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c b/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c
> > index 77c7e65de7c3..62157e7567da 100644
> > --- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c
> > +++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c
> > @@ -1809,7 +1809,6 @@ static int igt_vm_isolation(void *arg)
> >
> >         vm_total = ctx_vm(ctx_a)->total;
> >         GEM_BUG_ON(ctx_vm(ctx_b)->total != vm_total);
> > -       vm_total -= I915_GTT_PAGE_SIZE;
> >
> >         count = 0;
> >         num_engines = 0;
> > @@ -1828,10 +1827,9 @@ static int igt_vm_isolation(void *arg)
> >                         u32 value = 0xc5c5c5c5;
> >                         u64 offset;
> >
> > -                       div64_u64_rem(i915_prandom_u64_state(&prng),
> > -                                     vm_total, &offset);
> > -                       offset = round_down(offset, alignof_dword);
> > -                       offset += I915_GTT_PAGE_SIZE;
> > +                       offset = igt_random_offset(&prng, 0, vm_total,
> > +                                                  I915_GTT_PAGE_SIZE,
> > +                                                  I915_GTT_PAGE_SIZE);
> 
> Further down is: GEM_BUG_ON(offset < I915_GTT_PAGE_SIZE);

Makes sense, we need to keep a page for the batch. Thanks will fixup the
start.
-Chris