Quoting Chris Wilson (2018-06-05 09:19:07)
> Quoting Joonas Lahtinen (2018-06-05 08:51:39)
> > Quoting Chris Wilson (2018-06-05 10:19:40)
> > > In preparation, for having non-vma objects stored inside the ggtt, to
> > > handle restoration of the GGTT following resume, we need to walk over
> > > the ggtt address space rebinding vma, as opposed to walking over bound
> > > objects looking for ggtt entries.
> > >
> > > Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
> > > Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx>
> > > Cc: Mika Kuoppala <mika.kuoppala@xxxxxxxxxxxxxxx>
> > > Cc: Matthew Auld <matthew.william.auld@xxxxxxxxx>
> >
> > Comment below.
> >
> > Reviewed-by: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx>
> >
> > > @@ -3578,21 +3578,15 @@ void i915_gem_restore_gtt_mappings(struct drm_i915_private *dev_priv)
> > > ggtt->vm.closed = true; /* skip rewriting PTE on VMA unbind */
> > >
> > > /* clflush objects bound into the GGTT and rebind them. */
> > > - list_for_each_entry_safe(obj, on, &dev_priv->mm.bound_list, mm.link) {
> > > - bool ggtt_bound = false;
> > > - struct i915_vma *vma;
> > > -
> > > - for_each_ggtt_vma(vma, obj) {
> > > - if (!i915_vma_unbind(vma))
> > > - continue;
> > > + GEM_BUG_ON(!list_empty(&ggtt->vm.active_list));
> > > + list_for_each_entry_safe(vma, vn, &ggtt->vm.inactive_list, vm_link) {
> > > + struct drm_i915_gem_object *obj = vma->obj;
> > >
> > > - WARN_ON(i915_vma_bind(vma, obj->cache_level,
> > > - PIN_UPDATE));
> > > - ggtt_bound = true;
> > > - }
> > > + if (!i915_vma_unbind(vma))
> > > + continue;
> > >
> > > - if (ggtt_bound)
> > > - WARN_ON(i915_gem_object_set_to_gtt_domain(obj, false));
> > > + WARN_ON(i915_vma_bind(vma, obj->cache_level, PIN_UPDATE));
> > > + WARN_ON(i915_gem_object_set_to_gtt_domain(obj, false));
> >
> > This gets called multiple times per an object for partial and rotated
> > views, but that should not be our performance bottleneck.
>
> It is however worth mentioning that rewriting the GTT is one of the pain
> points for resume. A few GiB of WC writes is not free, so we have tried
> hard not to rewrite it multiple times and to defer setup until use.
> (With ppGTT, the GGTT is emptier so full-ppgtt should be a net win.)
Hmm, we can filter on vma->flags & PIN_GLOBAL so that we don't touch
aliasing_ppgtt only vma...
-Chris
_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
