[Intel-gfx] [PATCH 11/41] drm/i915: Defer active reference until required
Chris Wilson
chris at chris-wilson.co.uk
Thu Oct 20 15:03:53 UTC 2016
We only need the active reference to keep the object alive after the
handle has been deleted (so as to prevent a synchronous gem_close). Why
then pay the price of a kref on every execbuf when we can insert that
final active ref just in time for the handle deletion?
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
---
drivers/gpu/drm/i915/i915_drv.h | 28 ++++++++++++++++++++++++++++
drivers/gpu/drm/i915/i915_gem.c | 22 +++++++++++++++++++++-
drivers/gpu/drm/i915/i915_gem_batch_pool.c | 2 +-
drivers/gpu/drm/i915/i915_gem_context.c | 2 +-
drivers/gpu/drm/i915/i915_gem_execbuffer.c | 2 --
drivers/gpu/drm/i915/i915_gem_gtt.c | 7 ++++++-
drivers/gpu/drm/i915/i915_gem_render_state.c | 3 ++-
drivers/gpu/drm/i915/intel_ringbuffer.c | 15 ++++++++++++---
8 files changed, 71 insertions(+), 10 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 6a308ad5e5a6..4e93c3797d90 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2234,6 +2234,12 @@ struct drm_i915_gem_object {
((READ_ONCE((bo)->flags) >> I915_BO_ACTIVE_SHIFT) & I915_BO_ACTIVE_MASK)
/**
+ * Have we taken a reference for the object for incomplete GPU
+ * activity?
+ */
+#define I915_BO_ACTIVE_REF (I915_BO_ACTIVE_SHIFT + I915_NUM_ENGINES)
+
+ /**
* This is set if the object has been written to since last bound
* to the GTT
*/
@@ -2394,6 +2400,28 @@ i915_gem_object_has_active_engine(const struct drm_i915_gem_object *obj,
return obj->flags & BIT(engine + I915_BO_ACTIVE_SHIFT);
}
+static inline bool
+i915_gem_object_has_active_reference(const struct drm_i915_gem_object *obj)
+{
+ return test_bit(I915_BO_ACTIVE_REF, &obj->flags);
+}
+
+static inline void
+i915_gem_object_set_active_reference(struct drm_i915_gem_object *obj)
+{
+ lockdep_assert_held(&obj->base.dev->struct_mutex);
+ __set_bit(I915_BO_ACTIVE_REF, &obj->flags);
+}
+
+static inline void
+i915_gem_object_clear_active_reference(struct drm_i915_gem_object *obj)
+{
+ lockdep_assert_held(&obj->base.dev->struct_mutex);
+ __clear_bit(I915_BO_ACTIVE_REF, &obj->flags);
+}
+
+void __i915_gem_object_release_unless_active(struct drm_i915_gem_object *obj);
+
static inline unsigned int
i915_gem_object_get_tiling(struct drm_i915_gem_object *obj)
{
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 90af27d88980..ee8d1405013e 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2664,7 +2664,10 @@ i915_gem_object_retire__read(struct i915_gem_active *active,
list_move_tail(&obj->global_list,
&request->i915->mm.bound_list);
- i915_gem_object_put(obj);
+ if (i915_gem_object_has_active_reference(obj)) {
+ i915_gem_object_clear_active_reference(obj);
+ i915_gem_object_put(obj);
+ }
}
static bool i915_context_is_banned(const struct i915_gem_context *ctx)
@@ -2938,6 +2941,12 @@ void i915_gem_close_object(struct drm_gem_object *gem, struct drm_file *file)
list_for_each_entry_safe(vma, vn, &obj->vma_list, obj_link)
if (vma->vm->file == fpriv)
i915_vma_close(vma);
+
+ if (i915_gem_object_is_active(obj) &&
+ !i915_gem_object_has_active_reference(obj)) {
+ i915_gem_object_set_active_reference(obj);
+ i915_gem_object_get(obj);
+ }
mutex_unlock(&obj->base.dev->struct_mutex);
}
@@ -4476,6 +4485,17 @@ void i915_gem_free_object(struct drm_gem_object *gem_obj)
intel_runtime_pm_put(dev_priv);
}
+void __i915_gem_object_release_unless_active(struct drm_i915_gem_object *obj)
+{
+ lockdep_assert_held(&obj->base.dev->struct_mutex);
+
+ GEM_BUG_ON(i915_gem_object_has_active_reference(obj));
+ if (i915_gem_object_is_active(obj))
+ i915_gem_object_set_active_reference(obj);
+ else
+ i915_gem_object_put(obj);
+}
+
int i915_gem_suspend(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = to_i915(dev);
diff --git a/drivers/gpu/drm/i915/i915_gem_batch_pool.c b/drivers/gpu/drm/i915/i915_gem_batch_pool.c
index ed989596d9a3..cb25cad3318c 100644
--- a/drivers/gpu/drm/i915/i915_gem_batch_pool.c
+++ b/drivers/gpu/drm/i915/i915_gem_batch_pool.c
@@ -73,7 +73,7 @@ void i915_gem_batch_pool_fini(struct i915_gem_batch_pool *pool)
list_for_each_entry_safe(obj, next,
&pool->cache_list[n],
batch_pool_link)
- i915_gem_object_put(obj);
+ __i915_gem_object_release_unless_active(obj);
INIT_LIST_HEAD(&pool->cache_list[n]);
}
diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index 5dca32ac1c67..47e888cc721f 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -155,7 +155,7 @@ void i915_gem_context_free(struct kref *ctx_ref)
if (ce->ring)
intel_ring_free(ce->ring);
- i915_vma_put(ce->state);
+ __i915_gem_object_release_unless_active(ce->state->obj);
}
put_pid(ctx->pid);
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index cdd7b3d49a41..1afa6dbe8472 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -1298,8 +1298,6 @@ void i915_vma_move_to_active(struct i915_vma *vma,
* add the active reference first and queue for it to be dropped
* *last*.
*/
- if (!i915_gem_object_is_active(obj))
- i915_gem_object_get(obj);
i915_gem_object_set_active(obj, idx);
i915_gem_active_set(&obj->last_read[idx], req);
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 947d5ad51fb7..a3a364478a89 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -3734,11 +3734,16 @@ void __iomem *i915_vma_pin_iomap(struct i915_vma *vma)
void i915_vma_unpin_and_release(struct i915_vma **p_vma)
{
struct i915_vma *vma;
+ struct drm_i915_gem_object *obj;
vma = fetch_and_zero(p_vma);
if (!vma)
return;
+ obj = vma->obj;
+
i915_vma_unpin(vma);
- i915_vma_put(vma);
+ i915_vma_close(vma);
+
+ __i915_gem_object_release_unless_active(obj);
}
diff --git a/drivers/gpu/drm/i915/i915_gem_render_state.c b/drivers/gpu/drm/i915/i915_gem_render_state.c
index a98c0f42badd..e7c3dbcc6c81 100644
--- a/drivers/gpu/drm/i915/i915_gem_render_state.c
+++ b/drivers/gpu/drm/i915/i915_gem_render_state.c
@@ -224,7 +224,8 @@ int i915_gem_render_state_init(struct drm_i915_gem_request *req)
i915_vma_move_to_active(so.vma, req, 0);
err_unpin:
i915_vma_unpin(so.vma);
+ i915_vma_close(so.vma);
err_obj:
- i915_gem_object_put(obj);
+ __i915_gem_object_release_unless_active(obj);
return ret;
}
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 2396c651bd0f..e29e84813234 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -1764,14 +1764,19 @@ static void cleanup_phys_status_page(struct intel_engine_cs *engine)
static void cleanup_status_page(struct intel_engine_cs *engine)
{
struct i915_vma *vma;
+ struct drm_i915_gem_object *obj;
vma = fetch_and_zero(&engine->status_page.vma);
if (!vma)
return;
+ obj = vma->obj;
+
i915_vma_unpin(vma);
- i915_gem_object_unpin_map(vma->obj);
- i915_vma_put(vma);
+ i915_vma_close(vma);
+
+ i915_gem_object_unpin_map(obj);
+ __i915_gem_object_release_unless_active(obj);
}
static int init_status_page(struct intel_engine_cs *engine)
@@ -1969,7 +1974,11 @@ intel_engine_create_ring(struct intel_engine_cs *engine, int size)
void
intel_ring_free(struct intel_ring *ring)
{
- i915_vma_put(ring->vma);
+ struct drm_i915_gem_object *obj = ring->vma->obj;
+
+ i915_vma_close(ring->vma);
+ __i915_gem_object_release_unless_active(obj);
+
kfree(ring);
}
--
2.9.3
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