drm/i915: Combine unbound/bound list tracking for objects

With async binding, we don't want to manage a bound/unbound list as we
may end up running before we even acquire the pages. All that is
required is keeping track of shrinkable objects, so reduce it to the
minimum list.

Fixes: 6951e5893b48 ("drm/i915: Move GEM object domain management from struct_mutex to local")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.william.auld@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190612105720.30310-1-chris@chris-wilson.co.uk

1 files changed, 13 insertions, 17 deletions

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c b/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c
index 70a4c9d3c098..1b93bc334630 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c
@@ -69,7 +69,7 @@ static bool can_release_pages(struct drm_i915_gem_object *obj)
 	 * to the GPU, simply unbinding from the GPU is not going to succeed
 	 * in releasing our pin count on the pages themselves.
 	 */
-	if (atomic_read(&obj->mm.pages_pin_count) > obj->bind_count)
+	if (atomic_read(&obj->mm.pages_pin_count) > atomic_read(&obj->bind_count))
 		return false;
 
 	/* If any vma are "permanently" pinned, it will prevent us from
@@ -145,8 +145,10 @@ i915_gem_shrink(struct drm_i915_private *i915,
 		unsigned int bit;
 	} phases[] = {
 		{ &i915->mm.purge_list, ~0u },
-		{ &i915->mm.unbound_list, I915_SHRINK_UNBOUND },
-		{ &i915->mm.bound_list, I915_SHRINK_BOUND },
+		{
+			&i915->mm.shrink_list,
+			I915_SHRINK_BOUND | I915_SHRINK_UNBOUND
+		},
 		{ NULL, 0 },
 	}, *phase;
 	intel_wakeref_t wakeref = 0;
@@ -238,7 +240,7 @@ i915_gem_shrink(struct drm_i915_private *i915,
 				continue;
 
 			if (!(shrink & I915_SHRINK_BOUND) &&
-			    READ_ONCE(obj->bind_count))
+			    atomic_read(&obj->bind_count))
 				continue;
 
 			if (!can_release_pages(obj))
@@ -378,7 +380,7 @@ i915_gem_shrinker_oom(struct notifier_block *nb, unsigned long event, void *ptr)
 	struct drm_i915_private *i915 =
 		container_of(nb, struct drm_i915_private, mm.oom_notifier);
 	struct drm_i915_gem_object *obj;
-	unsigned long unevictable, bound, unbound, freed_pages;
+	unsigned long unevictable, available, freed_pages;
 	intel_wakeref_t wakeref;
 	unsigned long flags;
 
@@ -393,26 +395,20 @@ i915_gem_shrinker_oom(struct notifier_block *nb, unsigned long event, void *ptr)
 	 * assert that there are no objects with pinned pages that are not
 	 * being pointed to by hardware.
 	 */
-	unbound = bound = unevictable = 0;
+	available = unevictable = 0;
 	spin_lock_irqsave(&i915->mm.obj_lock, flags);
-	list_for_each_entry(obj, &i915->mm.unbound_list, mm.link) {
+	list_for_each_entry(obj, &i915->mm.shrink_list, mm.link) {
 		if (!can_release_pages(obj))
 			unevictable += obj->base.size >> PAGE_SHIFT;
 		else
-			unbound += obj->base.size >> PAGE_SHIFT;
-	}
-	list_for_each_entry(obj, &i915->mm.bound_list, mm.link) {
-		if (!can_release_pages(obj))
-			unevictable += obj->base.size >> PAGE_SHIFT;
-		else
-			bound += obj->base.size >> PAGE_SHIFT;
+			available += obj->base.size >> PAGE_SHIFT;
 	}
 	spin_unlock_irqrestore(&i915->mm.obj_lock, flags);
 
-	if (freed_pages || unbound || bound)
+	if (freed_pages || available)
 		pr_info("Purging GPU memory, %lu pages freed, "
-			"%lu pages still pinned.\n",
-			freed_pages, unevictable);
+			"%lu pages still pinned, %lu pages left available.\n",
+			freed_pages, unevictable, available);
 
 	*(unsigned long *)ptr += freed_pages;
 	return NOTIFY_DONE;