[PATCH 2/3] drm/i915: Move releasing of the GEM request from free to retire/cancel

From: Chris Wilson <chris@chris-wilson.co.uk>
To: intel-gfx@lists.freedesktop.org
Subject: [PATCH 2/3] drm/i915: Move releasing of the GEM request from free to retire/cancel
Date: Sat, 12 Dec 2015 15:34:32 +0000	[thread overview]
Message-ID: <1449934473-24902-2-git-send-email-chris@chris-wilson.co.uk> (raw)
In-Reply-To: <1449934473-24902-1-git-send-email-chris@chris-wilson.co.uk>

If we move the release of the GEM request (i.e. decoupling it from the
various lists used for client and context tracking) after it is complete
(either by the GPU retiring the request, or by the caller cancelling the
request), we can remove the requirement that the final unreference of
the GEM request need to be under the struct_mutex.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_gem.c          |  4 +--
 drivers/gpu/drm/i915/i915_gem_request.c  | 54 +++++++++++++++-----------------
 drivers/gpu/drm/i915/i915_gem_request.h  | 14 ---------
 drivers/gpu/drm/i915/intel_breadcrumbs.c |  2 +-
 drivers/gpu/drm/i915/intel_display.c     |  2 +-
 drivers/gpu/drm/i915/intel_pm.c          |  2 +-
 6 files changed, 30 insertions(+), 48 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index a23dea27f272..d92950b56f2d 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2676,7 +2676,7 @@ i915_gem_wait_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
 			ret = __i915_wait_request(req[i], true,
 						  args->timeout_ns > 0 ? &args->timeout_ns : NULL,
 						  to_rps_client(file));
-		i915_gem_request_unreference__unlocked(req[i]);
+		i915_gem_request_unreference(req[i]);
 	}
 	return ret;
 
@@ -3688,7 +3688,7 @@ i915_gem_ring_throttle(struct drm_device *dev, struct drm_file *file)
 	if (ret == 0)
 		queue_delayed_work(dev_priv->wq, &dev_priv->mm.retire_work, 0);
 
-	i915_gem_request_unreference__unlocked(target);
+	i915_gem_request_unreference(target);
 
 	return ret;
 }
diff --git a/drivers/gpu/drm/i915/i915_gem_request.c b/drivers/gpu/drm/i915/i915_gem_request.c
index 28435c8d7b1f..bb88146dd90c 100644
--- a/drivers/gpu/drm/i915/i915_gem_request.c
+++ b/drivers/gpu/drm/i915/i915_gem_request.c
@@ -73,6 +73,7 @@ int i915_gem_request_alloc(struct intel_engine_cs *ring,
 		goto err;
 
 	kref_init(&req->ref);
+	INIT_LIST_HEAD(&req->list);
 	req->i915 = dev_priv;
 	req->ring = ring;
 	req->reset_counter = reset_counter;
@@ -117,13 +118,6 @@ err:
 	return ret;
 }
 
-void i915_gem_request_cancel(struct drm_i915_gem_request *req)
-{
-	intel_ring_reserved_space_cancel(req->ringbuf);
-
-	i915_gem_request_unreference(req);
-}
-
 int i915_gem_request_add_to_client(struct drm_i915_gem_request *req,
 				   struct drm_file *file)
 {
@@ -168,6 +162,27 @@ i915_gem_request_remove_from_client(struct drm_i915_gem_request *request)
 	request->pid = NULL;
 }
 
+static void __i915_gem_request_release(struct drm_i915_gem_request *request)
+{
+	list_del_init(&request->list);
+
+	i915_gem_request_remove_from_client(request);
+
+	if (i915.enable_execlists) {
+		if (request->ctx != request->ring->default_context)
+			intel_lr_context_unpin(request);
+	}
+	i915_gem_context_unreference(request->ctx);
+
+	i915_gem_request_unreference(request);
+}
+
+void i915_gem_request_cancel(struct drm_i915_gem_request *req)
+{
+	intel_ring_reserved_space_cancel(req->ringbuf);
+	__i915_gem_request_release(req);
+}
+
 static void i915_gem_request_retire(struct drm_i915_gem_request *request)
 {
 	trace_i915_gem_request_retire(request);
@@ -181,11 +196,7 @@ static void i915_gem_request_retire(struct drm_i915_gem_request *request)
 	 * completion order.
 	 */
 	request->ringbuf->last_retired_head = request->postfix;
-
-	list_del_init(&request->list);
-	i915_gem_request_remove_from_client(request);
-
-	i915_gem_request_unreference(request);
+	__i915_gem_request_release(request);
 }
 
 void
@@ -492,22 +503,7 @@ i915_wait_request(struct drm_i915_gem_request *req)
 
 void i915_gem_request_free(struct kref *req_ref)
 {
-	struct drm_i915_gem_request *req = container_of(req_ref,
-						 typeof(*req), ref);
-	struct intel_context *ctx = req->ctx;
-
-	if (req->file_priv)
-		i915_gem_request_remove_from_client(req);
-
-	if (ctx) {
-		if (i915.enable_execlists) {
-			if (ctx != req->ring->default_context)
-				intel_lr_context_unpin(req);
-		}
-
-		i915_gem_context_unreference(ctx);
-	}
-
+	struct drm_i915_gem_request *req =
+		container_of(req_ref, typeof(*req), ref);
 	kmem_cache_free(req->i915->requests, req);
 }
-
diff --git a/drivers/gpu/drm/i915/i915_gem_request.h b/drivers/gpu/drm/i915/i915_gem_request.h
index 75c9015c19dc..b19160a1511a 100644
--- a/drivers/gpu/drm/i915/i915_gem_request.h
+++ b/drivers/gpu/drm/i915/i915_gem_request.h
@@ -155,23 +155,9 @@ i915_gem_request_reference(struct drm_i915_gem_request *req)
 static inline void
 i915_gem_request_unreference(struct drm_i915_gem_request *req)
 {
-	WARN_ON(!mutex_is_locked(&req->ring->dev->struct_mutex));
 	kref_put(&req->ref, i915_gem_request_free);
 }
 
-static inline void
-i915_gem_request_unreference__unlocked(struct drm_i915_gem_request *req)
-{
-	struct drm_device *dev;
-
-	if (!req)
-		return;
-
-	dev = req->ring->dev;
-	if (kref_put_mutex(&req->ref, i915_gem_request_free, &dev->struct_mutex))
-		mutex_unlock(&dev->struct_mutex);
-}
-
 static inline void i915_gem_request_assign(struct drm_i915_gem_request **pdst,
 					   struct drm_i915_gem_request *src)
 {
diff --git a/drivers/gpu/drm/i915/intel_breadcrumbs.c b/drivers/gpu/drm/i915/intel_breadcrumbs.c
index 82e4d15b6c18..d916e1325bd4 100644
--- a/drivers/gpu/drm/i915/intel_breadcrumbs.c
+++ b/drivers/gpu/drm/i915/intel_breadcrumbs.c
@@ -324,7 +324,7 @@ static int intel_breadcrumbs_signaller(void *arg)
 		if (signal_complete(signal)) {
 			intel_engine_remove_wait(engine, &signal->wait);
 
-			i915_gem_request_unreference__unlocked(signal->request);
+			i915_gem_request_unreference(signal->request);
 
 			spin_lock(&engine->breadcrumbs.lock);
 			rb_erase(&signal->node, &engine->breadcrumbs.signals);
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 3c3766eab5c4..031830e87f8f 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -11367,7 +11367,7 @@ static void intel_mmio_flip_work_func(struct work_struct *work)
 		WARN_ON(__i915_wait_request(mmio_flip->req,
 					    false, NULL,
 					    &mmio_flip->i915->rps.mmioflips));
-		i915_gem_request_unreference__unlocked(mmio_flip->req);
+		i915_gem_request_unreference(mmio_flip->req);
 	}
 
 	/* For framebuffer backed by dmabuf, wait for fence */
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index f543f897c516..f972078290b6 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -7196,7 +7196,7 @@ static void __intel_rps_boost_work(struct work_struct *work)
 		gen6_rps_boost(to_i915(req->ring->dev), NULL,
 			       req->emitted_jiffies);
 
-	i915_gem_request_unreference__unlocked(req);
+	i915_gem_request_unreference(req);
 	kfree(boost);
 }
 
-- 
2.6.3

_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/intel-gfx
