[Intel-gfx] [PATCH 17/42] drm/i915: Pass around sg_table to get_pages/put_pages backend

[Chris Wilson]

On Fri, Oct 14, 2016 at 10:28:42AM +0100, Tvrtko Ursulin wrote:
>  diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
>  index 3c22d49005fe..271e63c8f037 100644
>  --- a/drivers/gpu/drm/i915/i915_drv.h
>  +++ b/drivers/gpu/drm/i915/i915_drv.h
>  @@ -2175,8 +2175,8 @@ struct drm_i915_gem_object_ops {
>           * being released or under memory pressure (where we attempt to
>           * reap pages for the shrinker).
>           */
>  -       int (*get_pages)(struct drm_i915_gem_object *);
>  -       void (*put_pages)(struct drm_i915_gem_object *);
>  +       struct sg_table *(*get_pages)(struct drm_i915_gem_object *);
>  +       void (*put_pages)(struct drm_i915_gem_object *, struct sg_table *);
> 
>    Idea is that put_pages vfunc does not need struct mutex?  Or it acquires
>    it on demand inside it, which means struct mutex will nest inside the
>    mm.lock?

Right, it loses the mutex within get/put pages and I am no longer
concerned about the number of workers. Though that is mainly because of
another patch to improve execbuf + userptr workloads.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre