[Intel-gfx] [PATCH 06/15] drm/i915: Assert no external observers when unwind a failed request alloc

[Joonas Lahtinen]

On pe, 2016-11-25 at 09:30 +0000, Chris Wilson wrote:
> Before we return the request back to the kmem_cache after a failed
> i915_gem_request_alloc(), we should assert that it has not been added to
> any global state tracking.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>  drivers/gpu/drm/i915/i915_gem_request.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/i915_gem_request.c b/drivers/gpu/drm/i915/i915_gem_request.c
> index bd7b21f70283..ed6cead22a86 100644
> --- a/drivers/gpu/drm/i915/i915_gem_request.c
> +++ b/drivers/gpu/drm/i915/i915_gem_request.c
> @@ -599,6 +599,11 @@ i915_gem_request_alloc(struct intel_engine_cs *engine,
> >  	return req;
>  
>  err_ctx:
> +	/* Make sure we didn't add ourselves to external state before freeing */
> +	GEM_BUG_ON(!list_empty(&req->active_list));
> +	GEM_BUG_ON(!list_empty(&req->priotree.signalers_list));
> +	GEM_BUG_ON(!list_empty(&req->priotree.waiters_list));

This is some paranoia already, but if you managed to hit it;

Reviewed-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>

Regards, Joonas
-- 
Joonas Lahtinen
Open Source Technology Center
Intel Corporation