[PATCH 15/17] drm/i915: Flush the freed object list on file close

Chris Wilson
2019-07-30T13:48:30Z

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
drivers/gpu/drm/i915/gem/i915_gem_object.c | 38 +++-------------------
drivers/gpu/drm/i915/i915_drv.c | 3 ++
drivers/gpu/drm/i915/i915_drv.h | 1 -
drivers/gpu/drm/i915/i915_gem.c | 1 -
4 files changed, 7 insertions(+), 36 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.c b/drivers/gpu/drm/i915/gem/i915_gem_object.c
index 4ea97fca9c35..19d55115747c 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object.c
@@ -211,48 +211,18 @@ static void __i915_gem_free_objects(struct drm_i915_private *i915,

void i915_gem_flush_free_objects(struct drm_i915_private *i915)
{
- struct llist_node *freed;
-
- /* Free the oldest, most stale object to keep the free_list short */
- freed = NULL;
- if (!llist_empty(&i915->mm.free_list)) { /* quick test for hotpath */
- /* Only one consumer of llist_del_first() allowed */
- spin_lock(&i915->mm.free_lock);
- freed = llist_del_first(&i915->mm.free_list);
- spin_unlock(&i915->mm.free_lock);
- }
- if (unlikely(freed)) {
- freed->next = NULL;
+ struct llist_node *freed = llist_del_all(&i915->mm.free_list);
+
+ if (unlikely(freed))
__i915_gem_free_objects(i915, freed);
- }
}

static void __i915_gem_free_work(struct work_struct *work)
{
struct drm_i915_private *i915 =
container_of(work, struct drm_i915_private, mm.free_work);
- struct llist_node *freed;
-
- /*
- * All file-owned VMA should have been released by this point through
- * i915_gem_close_object(), or earlier by i915_gem_context_close().
- * However, the object may also be bound into the global GTT (e.g.
- * older GPUs without per-process support, or for direct access through
- * the GTT either for the user or for scanout). Those VMA still need to
- * unbound now.
- */
-
- spin_lock(&i915->mm.free_lock);
- while ((freed = llist_del_all(&i915->mm.free_list))) {
- spin_unlock(&i915->mm.free_lock);

- __i915_gem_free_objects(i915, freed);
- if (need_resched())
- return;
-
- spin_lock(&i915->mm.free_lock);
- }
- spin_unlock(&i915->mm.free_lock);
+ i915_gem_flush_free_objects(i915);
}

void i915_gem_free_object(struct drm_gem_object *gem_obj)
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index a0e484760329..cb42d44ca328 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1893,6 +1893,9 @@ static void i915_driver_postclose(struct drm_device *dev, struct drm_file *file)
mutex_unlock(&dev->struct_mutex);

kfree(file_priv);
+
+ /* Catch up with all the deferred frees from "this" client */
+ i915_gem_flush_free_objects(to_i915(dev));
}

static void intel_suspend_encoders(struct drm_i915_private *dev_priv)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index d420b0fa0d04..326908a4bdb1 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -767,7 +767,6 @@ struct i915_gem_mm {
*/
struct llist_head free_list;
struct work_struct free_work;
- spinlock_t free_lock;
/**
* Count of objects pending destructions. Used to skip needlessly
* waiting on an RCU barrier if no objects are waiting to be freed.
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 5eeb7404a362..0e0b54abde48 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1653,7 +1653,6 @@ void i915_gem_init_mmio(struct drm_i915_private *i915)
static void i915_gem_init__mm(struct drm_i915_private *i915)
{
spin_lock_init(&i915->mm.obj_lock);
- spin_lock_init(&i915->mm.free_lock);

init_llist_head(&i915->mm.free_list);

--
2.22.0