From 7a5580a2a69ae0681805638d1f5c66f544bd9c2a Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Sat, 31 Dec 2016 11:20:09 +0000 Subject: [PATCH] drm/i915: Move assert of page pin vs bind count into i915_vma_unbind 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 Cc: Daniel Vetter Reviewed-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/20161231112012.29263-1-chris@chris-wilson.co.uk --- 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 576b5718ed88..843f7c624091 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 868d061e1a11..e008e4e8b481 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))) -- 2.20.1