drm/i915: Stop holding a ref to the ppgtt from each vma

The context owns both the ppgtt and the vma within it, and our activity
tracking on the context ensures that we do not release active ppgtt. As
the context fulfils our obligations for active memory tracking, we can
relinquish the reference from the vma.

This fixes a silly transient refleak from closed vma being kept alive
until the entire system was idle, keeping all vm alive as well.

Reported-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Testcase: igt/gem_ctx_create/files
Fixes: 4b7c59833947 ("drm/i915: Lazily unbind vma on close")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Tested-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180816073448.19396-1-chris@chris-wilson.co.uk
(cherry picked from commit a4417b7b419a68540ad7945ac4efbb39d19afa63)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
index 11d834f942205f37c10c1a95a345b8908cb3411f..98358b4b36dea7e13177bdf38554ffaad4f994e9 100644 (file)
--- a/drivers/gpu/drm/i915/i915_vma.c
+++ b/drivers/gpu/drm/i915/i915_vma.c
@@ -199,7 +199,6 @@ vma_create(struct drm_i915_gem_object *obj,
                vma->flags |= I915_VMA_GGTT;
                list_add(&vma->obj_link, &obj->vma_list);
        } else {
-               i915_ppgtt_get(i915_vm_to_ppgtt(vm));
                list_add_tail(&vma->obj_link, &obj->vma_list);
        }
 
@@ -807,9 +806,6 @@ static void __i915_vma_destroy(struct i915_vma *vma)
        if (vma->obj)
                rb_erase(&vma->obj_node, &vma->obj->vma_tree);
 
-       if (!i915_vma_is_ggtt(vma))
-               i915_ppgtt_put(i915_vm_to_ppgtt(vma->vm));
-
        rbtree_postorder_for_each_entry_safe(iter, n, &vma->active, node) {
                GEM_BUG_ON(i915_gem_active_isset(&iter->base));
                kfree(iter);