It is useful to assert that if the object is bound, then it must have its pages pinned to prevent the shrinker from reaping its backing store. This is even more useful with the introduction of real-ppgtt whereupon we may have the object bound into several vma, with each instance pinning the backing store. This assertion breaks down during unbind where we unpinned the backing store before decoupling the vma binding. This can be fixed with a trivial reording of the unbind sequence, which reinforces the pin pages bind to vma ... unbind from vma unpin pages concept. v2: Bonus comment Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Cc: Ben Widawsky <ben@xxxxxxxxxxxx> Reviewed-by: Ben Widawsky <ben@xxxxxxxxxxxx> Tested-by: Ben Widawsky <ben@xxxxxxxxxxxx> --- drivers/gpu/drm/i915/i915_gem.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 6312d61f5198..9b805f0e8387 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -2755,7 +2755,6 @@ int i915_vma_unbind(struct i915_vma *vma) vma->unbind_vma(vma); i915_gem_gtt_finish_object(obj); - i915_gem_object_unpin_pages(obj); list_del(&vma->mm_list); /* Avoid an unnecessary call to unbind on rebind. */ @@ -2763,7 +2762,6 @@ int i915_vma_unbind(struct i915_vma *vma) obj->map_and_fenceable = true; drm_mm_remove_node(&vma->node); - i915_gem_vma_destroy(vma); /* Since the unbound list is global, only move to that list if @@ -2771,6 +2769,12 @@ int i915_vma_unbind(struct i915_vma *vma) if (list_empty(&obj->vma_list)) list_move_tail(&obj->global_list, &dev_priv->mm.unbound_list); + /* And finally now the object is completely decoupled from this vma, + * we can drop its hold on the backing storage and allow it to be + * reaped by the shrinker. + */ + i915_gem_object_unpin_pages(obj); + return 0; } -- 1.8.5 _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
