| Message ID | 20161230173314.29157-1-chris@chris-wilson.co.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Dec 30, 2016 at 05:33:14PM +0000, Chris Wilson wrote: > The read of the page pin count and the bind count are unordered, > presenting races in the assert and it firing off incorrectly. Prevent > this by restricting the assert to the vma bind/unbind routines where we > have local cpu ordering between the two. > > Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> > Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Fun. Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> > --- > drivers/gpu/drm/i915/i915_drv.h | 1 - > drivers/gpu/drm/i915/i915_vma.c | 1 + > 2 files changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h > index 00ecbb4da25e..1aa33444115a 100644 > --- a/drivers/gpu/drm/i915/i915_drv.h > +++ b/drivers/gpu/drm/i915/i915_drv.h > @@ -3291,7 +3291,6 @@ __i915_gem_object_unpin_pages(struct drm_i915_gem_object *obj) > GEM_BUG_ON(!obj->mm.pages); > > atomic_dec(&obj->mm.pages_pin_count); > - GEM_BUG_ON(atomic_read(&obj->mm.pages_pin_count) < obj->bind_count); > } > > static inline void > diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c > index 414f0f7f5059..d48c68214611 100644 > --- a/drivers/gpu/drm/i915/i915_vma.c > +++ b/drivers/gpu/drm/i915/i915_vma.c > @@ -640,6 +640,7 @@ int i915_vma_unbind(struct i915_vma *vma) > * reaped by the shrinker. > */ > i915_gem_object_unpin_pages(obj); > + GEM_BUG_ON(atomic_read(&obj->mm.pages_pin_count) < obj->bind_count); > > destroy: > if (unlikely(i915_vma_is_closed(vma))) > -- > 2.11.0 >
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 00ecbb4da25e..1aa33444115a 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -3291,7 +3291,6 @@ __i915_gem_object_unpin_pages(struct drm_i915_gem_object *obj) GEM_BUG_ON(!obj->mm.pages); atomic_dec(&obj->mm.pages_pin_count); - GEM_BUG_ON(atomic_read(&obj->mm.pages_pin_count) < obj->bind_count); } static inline void diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c index 414f0f7f5059..d48c68214611 100644 --- a/drivers/gpu/drm/i915/i915_vma.c +++ b/drivers/gpu/drm/i915/i915_vma.c @@ -640,6 +640,7 @@ int i915_vma_unbind(struct i915_vma *vma) * reaped by the shrinker. */ i915_gem_object_unpin_pages(obj); + GEM_BUG_ON(atomic_read(&obj->mm.pages_pin_count) < obj->bind_count); destroy: if (unlikely(i915_vma_is_closed(vma)))
The read of the page pin count and the bind count are unordered, presenting races in the assert and it firing off incorrectly. Prevent this by restricting the assert to the vma bind/unbind routines where we have local cpu ordering between the two. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> --- drivers/gpu/drm/i915/i915_drv.h | 1 - drivers/gpu/drm/i915/i915_vma.c | 1 + 2 files changed, 1 insertion(+), 1 deletion(-)