[PATCH 09/11] drm/i915: Release vma when the handle is closed

Chris Wilson
2015-12-14T11:38:04Z

In order to prevent a leak of the vma on shared objects, we need to
hook into the object_close callback to destroy the vma on the object for
this file. However, if we destroyed that vma immediately we may cause
unexpected application stalls as we try to unbind a busy vma - hence we
defer the unbind to when we retire the vma.

Testcase: igt/gem_ppggtt/flink-and-close-vma-leak
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com
---
drivers/gpu/drm/i915/i915_drv.c | 1 +
drivers/gpu/drm/i915/i915_drv.h | 1 +
drivers/gpu/drm/i915/i915_gem.c | 41 ++++++++++++++++++++++---------------
drivers/gpu/drm/i915/i915_gem_gtt.c | 2 ++
drivers/gpu/drm/i915/i915_gem_gtt.h | 1 +
5 files changed, 30 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index e7eef5fd6918..70979339d58a 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1656,6 +1656,7 @@ static struct drm_driver driver = {
.debugfs_init = i915_debugfs_init,
.debugfs_cleanup = i915_debugfs_cleanup,
#endif
+ .gem_close_object = i915_gem_close_object,
.gem_free_object = i915_gem_free_object,
.gem_vm_ops = &i915_gem_vm_ops,

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index eb775eb1c693..696469a06715 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2686,6 +2686,7 @@ struct drm_i915_gem_object *i915_gem_alloc_object(struct drm_device *dev,
size_t size);
struct drm_i915_gem_object *i915_gem_object_create_from_data(
struct drm_device *dev, const void *data, size_t size);
+void i915_gem_close_object(struct drm_gem_object *gem, struct drm_file *file);
void i915_gem_free_object(struct drm_gem_object *obj);
void i915_gem_vma_destroy(struct i915_vma *vma);

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 1d21c5b79215..7c13c27a6470 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2367,6 +2367,30 @@ i915_gem_object_flush_active(struct drm_i915_gem_object *obj)
return 0;
}

+static void i915_vma_close(struct i915_vma *vma)
+{
+ RQ_BUG_ON(vma->closed);
+ vma->closed = true;
+
+ list_del_init(&vma->obj_link);
+ if (!vma->active)
+ WARN_ON(i915_vma_unbind(vma));
+}
+
+void i915_gem_close_object(struct drm_gem_object *gem,
+ struct drm_file *file)
+{
+ struct drm_i915_gem_object *obj = to_intel_bo(gem);
+ struct drm_i915_file_private *fpriv = file->driver_priv;
+ struct i915_vma *vma, *vn;
+
+ mutex_lock(&obj->base.dev->struct_mutex);
+ list_for_each_entry_safe(vma, vn, &obj->vma_list, obj_link)
+ if (vma->vm->file == fpriv)
+ i915_vma_close(vma);
+ mutex_unlock(&obj->base.dev->struct_mutex);
+}
+
/**
* i915_gem_wait_ioctl - implements DRM_IOCTL_I915_GEM_WAIT
* @DRM_IOCTL_ARGS: standard ioctl arguments
@@ -2577,9 +2601,6 @@ static int __i915_vma_unbind(struct i915_vma *vma, bool wait)
RQ_BUG_ON(vma->active);
}

- if (list_empty(&vma->obj_link))
- return 0;
-
if (!drm_mm_node_allocated(&vma->node)) {
i915_gem_vma_destroy(vma);
return 0;
@@ -3792,20 +3813,8 @@ void i915_gem_free_object(struct drm_gem_object *gem_obj)
trace_i915_gem_object_destroy(obj);

list_for_each_entry_safe(vma, next, &obj->vma_list, obj_link) {
- int ret;
-
vma->pin_count = 0;
- ret = i915_vma_unbind(vma);
- if (WARN_ON(ret == -ERESTARTSYS)) {
- bool was_interruptible;
-
- was_interruptible = dev_priv->mm.interruptible;
- dev_priv->mm.interruptible = false;
-
- WARN_ON(i915_vma_unbind(vma));
-
- dev_priv->mm.interruptible = was_interruptible;
- }
+ i915_vma_close(vma);
}

/* Stolen objects don't hold a ref, but do hold pin count. Fix that up
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 5505603f52af..9f594c33bd0a 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -3240,6 +3240,8 @@ i915_vma_retire(struct drm_i915_gem_request_active *active,
return;

list_move_tail(&vma->vm_link, &vma->vm->inactive_list);
+ if (unlikely(vma->closed))
+ WARN_ON(i915_vma_unbind(vma));
}

static struct i915_vma *
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.h b/drivers/gpu/drm/i915/i915_gem_gtt.h
index c2f2c62ac88d..be7e8526b219 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.h
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.h
@@ -190,6 +190,7 @@ struct i915_vma {
unsigned int bound : 4;
unsigned int active : I915_NUM_RINGS;
bool is_ggtt : 1;
+ bool closed : 1;

/**
* Support different GGTT views into the same object.
--
2.6.4