[6/7] drm/i915: find guilty batch buffer on ring resets

Commit Message

Mika Kuoppala June 12, 2013, 9:35 a.m. UTC

After hang check timer has declared gpu to be hang,
rings are reset. In ring reset, when clearing
request list, do post mortem analysis to find out
the guilty batch buffer.

Select requests for further analysis by inspecting
the completed sequence number which has been updated
into the HWS page. If request was completed, it can't
be related to the hang.

For noncompleted requests mark the batch as guilty
if the ring was not waiting and the ring head was
stuck inside the buffer object or in the flush region
right after the batch. For everything else, mark
them as innocents.

v2: Fixed a typo in commit message (Ville Syrjälä)

Signed-off-by: Mika Kuoppala <[e-mail]>
---
 drivers/gpu/drm/i915/i915_gem.c |   88 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 88 insertions(+)

Comments

Chris Wilson June 12, 2013, 10:17 a.m. UTC | #1

On Wed, Jun 12, 2013 at 12:35:33PM +0300, Mika Kuoppala wrote:
> After hang check timer has declared gpu to be hang,
s/hang/hung/ :-p

> rings are reset. In ring reset, when clearing
> request list, do post mortem analysis to find out
> the guilty batch buffer.
> 
> Select requests for further analysis by inspecting
> the completed sequence number which has been updated
> into the HWS page. If request was completed, it can't
> be related to the hang.
> 
> For noncompleted requests mark the batch as guilty
> if the ring was not waiting and the ring head was
> stuck inside the buffer object or in the flush region
> right after the batch. For everything else, mark
> them as innocents.
> 
> v2: Fixed a typo in commit message (Ville Syrjälä)
> 
> Signed-off-by: Mika Kuoppala <[e-mail]>
> ---

> +static bool i915_head_inside_request(u32 acthd, u32 rs, u32 re)
> +{

Be kind to your reader and use request_start, request_end or just start,
end.
-Chris

Patch

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 5be7846..6144f0b 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2103,6 +2103,85 @@  i915_gem_request_remove_from_client(struct drm_i915_gem_request *request)
 	spin_unlock(&file_priv->mm.lock);
 }
 
+static bool i915_head_inside_object(u32 acthd, struct drm_i915_gem_object *obj)
+{
+	if (acthd >= obj->gtt_offset &&
+	    acthd < obj->gtt_offset + obj->base.size)
+		return true;
+
+	return false;
+}
+
+static bool i915_head_inside_request(u32 acthd, u32 rs, u32 re)
+{
+	if (rs < re) {
+		if (acthd >= rs && acthd < re)
+			return true;
+	} else if (rs > re) {
+		if (acthd >= rs || acthd < re)
+			return true;
+	}
+
+	return false;
+}
+
+static bool i915_request_guilty(struct drm_i915_gem_request *request,
+				const u32 acthd, bool *inside)
+{
+	if (request->batch_obj) {
+		if (i915_head_inside_object(acthd, request->batch_obj)) {
+			*inside = true;
+			return true;
+		}
+	}
+
+	if (i915_head_inside_request(acthd, request->head, request->tail)) {
+		*inside = false;
+		return true;
+	}
+
+	return false;
+}
+
+static void i915_set_reset_status(struct intel_ring_buffer *ring,
+				  struct drm_i915_gem_request *request,
+				  u32 acthd)
+{
+	struct i915_ctx_hang_stats *hs = NULL;
+	bool inside, guilty;
+
+	/* Innocent until proven guilty */
+	guilty = false;
+
+	if (ring->hangcheck.last_action != wait &&
+	    i915_request_guilty(request, acthd, &inside)) {
+		DRM_ERROR("%s hung %s bo (0x%x ctx %d) at 0x%x\n",
+			  ring->name,
+			  inside ? "inside" : "flushing",
+			  request->batch_obj ?
+			  request->batch_obj->gtt_offset : 0,
+			  request->ctx ? request->ctx->id : 0,
+			  acthd);
+
+		guilty = true;
+	}
+
+	/* If contexts are disabled or this is the default context, use
+	 * file_priv->reset_state
+	 */
+	if (request->ctx && request->ctx->id != DEFAULT_CONTEXT_ID)
+		hs = &request->ctx->hang_stats;
+	else if (request->file_priv)
+		hs = &request->file_priv->hang_stats;
+
+	if (hs) {
+		if (guilty)
+			hs->batch_active++;
+		else
+			hs->batch_pending++;
+	}
+}
+
 static void i915_gem_free_request(struct drm_i915_gem_request *request)
 {
 	list_del(&request->list);
@@ -2117,6 +2196,12 @@  static void i915_gem_free_request(struct drm_i915_gem_request *request)
 static void i915_gem_reset_ring_lists(struct drm_i915_private *dev_priv,
 				      struct intel_ring_buffer *ring)
 {
+	u32 completed_seqno;
+	u32 acthd;
+
+	acthd = intel_ring_get_active_head(ring);
+	completed_seqno = ring->get_seqno(ring, false);
+
 	while (!list_empty(&ring->request_list)) {
 		struct drm_i915_gem_request *request;
 
@@ -2124,6 +2209,9 @@  static void i915_gem_reset_ring_lists(struct drm_i915_private *dev_priv,
 					   struct drm_i915_gem_request,
 					   list);
 
+		if (request->seqno > completed_seqno)
+			i915_set_reset_status(ring, request, acthd);
+
 		i915_gem_free_request(request);
 	}