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: 3365e2268b6b ("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

diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
index 274fd2a7bcb66ad7fec27adc93407c93b145183b..31efc971a3a83897b545c49142fc0e1366641521 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);
        }
 
@@ -810,9 +809,6 @@ 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);