[Intel-gfx] [PATCH 07/11] drm/i915/gem: Try allocating va from free space

[Chris Wilson]

Quoting Matthew Auld (2020-04-01 19:20:56)
> On Tue, 31 Mar 2020 at 22:31, Chris Wilson <chris at chris-wilson.co.uk> wrote:
> >
> > If the current node/entry location is occupied, and the object is not
> > pinned, try assigning it some free space. We cannot wait here, so if in
> > doubt, we unreserve and try to grab all at once.
> >
> > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> > ---
> >  drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c | 13 +++++++++++--
> >  1 file changed, 11 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> > index bc8aa9604787..d8c746108d85 100644
> > --- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> > +++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> > @@ -446,8 +446,17 @@ eb_pin_vma(struct i915_execbuffer *eb,
> >         if (unlikely(ev->flags & EXEC_OBJECT_NEEDS_GTT))
> >                 pin_flags |= PIN_GLOBAL;
> >
> > -       if (unlikely(i915_vma_pin(vma, 0, 0, pin_flags)))
> > -               return false;
> > +       if (unlikely(i915_vma_pin(vma, 0, 0, pin_flags))) {
> > +               if (entry->flags & EXEC_OBJECT_PINNED)
> > +                       return false;
> > +
> > +               pin_flags &= ~PIN_OFFSET_FIXED;
> > +               if (unlikely(i915_vma_pin(vma,
> > +                                         entry->pad_to_size,
> > +                                         entry->alignment,
> > +                                         pin_flags)))
> 
> Just curious, why not just apply the rest of the flags here(MAP, 48B,
> BIAS etc) which saves us from having to bind/unbind/bind if it's
> trivially misplaced?

That required actually doing some work to refactor the flag selection!
-Chris