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

[Matthew Auld]

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?

Reviewed-by: Matthew Auld <matthew.auld at intel.com>