[Intel-gfx] [PATCH 08/16] drm/i915/error: Do a better job of disambiguating VMAs

[Chris Wilson]

On Tue, Jul 01, 2014 at 11:17:43AM -0700, Ben Widawsky wrote:
> Some of the original PPGTT patches in this area where unmerged, and this
> left a lot of confusion in our error capture with regard to which vm/obj
> we want to capture. There have been at least a couple of patches from
> Chris, and myself to try to fix this up; so here is another shot. Nobody
> running without full PPGTT is effected by this, and that is probably why
> nobody has bothered to fix it yet.
> 
> Instead of using any of the global lists to find the VMAs we want to
> capture, we use the union of the active, and the inactive list in the
> VM. This allows us to replace our capture_bo with capture_vma, and know
> all the VMAs we want to capture are valid.
> 
> I could have probably figured out a way to reuse mm_list. As we've had
> bugs here before in the shrinker, I think the best way forward is to get
> it working, and then optimize it later.
> 
> Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
> ---
>  drivers/gpu/drm/i915/i915_gem_gtt.c   |  1 +
>  drivers/gpu/drm/i915/i915_gem_gtt.h   |  2 ++
>  drivers/gpu/drm/i915/i915_gpu_error.c | 39 ++++++++++++++++++++++-------------
>  3 files changed, 28 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
> index a4153ee..88451dc 100644
> --- a/drivers/gpu/drm/i915/i915_gem_gtt.c
> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
> @@ -2114,6 +2114,7 @@ static struct i915_vma *__i915_gem_vma_create(struct drm_i915_gem_object *obj,
>  		return ERR_PTR(-ENOMEM);
>  
>  	INIT_LIST_HEAD(&vma->vma_link);
> +	INIT_LIST_HEAD(&vma->pin_capture_link);
>  	INIT_LIST_HEAD(&vma->mm_list);
>  	INIT_LIST_HEAD(&vma->exec_list);
>  	vma->vm = vm;
> diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.h b/drivers/gpu/drm/i915/i915_gem_gtt.h
> index 8d6f7c1..1d75801 100644
> --- a/drivers/gpu/drm/i915/i915_gem_gtt.h
> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.h
> @@ -126,6 +126,8 @@ struct i915_vma {
>  
>  	struct list_head vma_link; /* Link in the object's VMA list */
>  
> +	struct list_head pin_capture_link; /* Link in the error capture */
> +
>  	/** This vma's place in the batchbuffer or on the eviction list */
>  	struct list_head exec_list;

We already have a slot for temporary lists...
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre