| Message ID | 1459496803-18092-2-git-send-email-joonas.lahtinen@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 01/04/16 08:46, Joonas Lahtinen wrote: > According to Chris, use of i915_vm_to_ppgtt is visible in benchmark > unless WARN_ON is removed, so lets get rid of it. > > Cc: Chris Wilson <chris@chris-wilson.co.uk> > Reported-by: Chris Wilson <chris@chris-wilson.co.uk> > Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> > Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> > --- > drivers/gpu/drm/i915/i915_drv.h | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h > index d3ebb2f..0035dc3 100644 > --- a/drivers/gpu/drm/i915/i915_drv.h > +++ b/drivers/gpu/drm/i915/i915_drv.h > @@ -3157,7 +3157,6 @@ bool i915_gem_obj_is_pinned(struct drm_i915_gem_object *obj); > static inline struct i915_hw_ppgtt * > i915_vm_to_ppgtt(struct i915_address_space *vm) > { > - WARN_ON(i915_is_ggtt(vm)); > return container_of(vm, struct i915_hw_ppgtt, base); > } I shouldn't think the actual check (i915_is_ggtt()) is slowing things down, so it must be the overhead of an unactivated WARN_ON(), which probably generates quite a bit of code and may disable optimisations, even when the code block isn't entered. As an alternative (if you *want* things to break if this is used incorrectly) you could have it return NULL for that case: static inline struct i915_hw_ppgtt * i915_vm_to_ppgtt(struct i915_address_space *vm) { return i915_is_ggtt(vm) ? NULL : container_of(vm, struct i915_hw_ppgtt, base); } Caller will then very likely get an OOPS! .Dave.
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index d3ebb2f..0035dc3 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -3157,7 +3157,6 @@ bool i915_gem_obj_is_pinned(struct drm_i915_gem_object *obj); static inline struct i915_hw_ppgtt * i915_vm_to_ppgtt(struct i915_address_space *vm) { - WARN_ON(i915_is_ggtt(vm)); return container_of(vm, struct i915_hw_ppgtt, base); }