drm/i915: Reduce amount of duplicate buffer information captured on error

When capturing the error state, we do not need to know about every
address space - just those that are related to the error. We know which
context is active at the time, therefore we know which VM are implicated
in the error. We can then restrict the VM which we report to the
relevant subset.

v2: s/i/count_active/ (and similar)
    Rewrite label generation for "Buffers"
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471254551-25805-2-git-send-email-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/i915_drv.h

@@ -517,6 +517,7 @@ struct drm_i915_error_state {
 		int num_waiters;
 		int hangcheck_score;
 		enum intel_engine_hangcheck_action hangcheck_action;
+		struct i915_address_space *vm;
 		int num_requests;
 
 		/* our own tracking of ring head and tail */
@@ -587,17 +588,15 @@ struct drm_i915_error_state {
 		u32 read_domains;
 		u32 write_domain;
 		s32 fence_reg:I915_MAX_NUM_FENCE_BITS;
-		s32 pinned:2;
 		u32 tiling:2;
 		u32 dirty:1;
 		u32 purgeable:1;
 		u32 userptr:1;
 		s32 engine:4;
 		u32 cache_level:3;
-	} **active_bo, **pinned_bo;
-
-	u32 *active_bo_count, *pinned_bo_count;
-	u32 vm_count;
+	} *active_bo[I915_NUM_ENGINES], *pinned_bo;
+	u32 active_bo_count[I915_NUM_ENGINES], pinned_bo_count;
+	struct i915_address_space *active_vm[I915_NUM_ENGINES];
 };
 
 struct intel_connector;

drivers/gpu/drm/i915/i915_gpu_error.c

@@ -42,16 +42,6 @@ static const char *engine_str(int engine)
 	}
 }
 
-static const char *pin_flag(int pinned)
-{
-	if (pinned > 0)
-		return " P";
-	else if (pinned < 0)
-		return " p";
-	else
-		return "";
-}
-
 static const char *tiling_flag(int tiling)
 {
 	switch (tiling) {
@@ -189,7 +179,7 @@ static void print_error_buffers(struct drm_i915_error_state_buf *m,
 {
 	int i;
 
-	err_printf(m, "  %s [%d]:\n", name, count);
+	err_printf(m, "%s [%d]:\n", name, count);
 
 	while (count--) {
 		err_printf(m, "    %08x_%08x %8u %02x %02x [ ",
@@ -202,7 +192,6 @@ static void print_error_buffers(struct drm_i915_error_state_buf *m,
 			err_printf(m, "%02x ", err->rseqno[i]);
 
 		err_printf(m, "] %02x", err->wseqno);
-		err_puts(m, pin_flag(err->pinned));
 		err_puts(m, tiling_flag(err->tiling));
 		err_puts(m, dirty_flag(err->dirty));
 		err_puts(m, purgeable_flag(err->purgeable));
@@ -414,18 +403,33 @@ int i915_error_state_to_str(struct drm_i915_error_state_buf *m,
 			error_print_engine(m, &error->engine[i]);
 	}
 
-	for (i = 0; i < error->vm_count; i++) {
-		err_printf(m, "vm[%d]\n", i);
+	for (i = 0; i < ARRAY_SIZE(error->active_vm); i++) {
+		char buf[128];
+		int len, first = 1;
 
-		print_error_buffers(m, "Active",
+		if (!error->active_vm[i])
+			break;
+
+		len = scnprintf(buf, sizeof(buf), "Active (");
+		for (j = 0; j < ARRAY_SIZE(error->engine); j++) {
+			if (error->engine[j].vm != error->active_vm[i])
+				continue;
+
+			len += scnprintf(buf + len, sizeof(buf), "%s%s",
+					 first ? "" : ", ",
+					 dev_priv->engine[j].name);
+			first = 0;
+		}
+		scnprintf(buf + len, sizeof(buf), ")");
+		print_error_buffers(m, buf,
 				    error->active_bo[i],
 				    error->active_bo_count[i]);
-
-		print_error_buffers(m, "Pinned",
-				    error->pinned_bo[i],
-				    error->pinned_bo_count[i]);
 	}
 
+	print_error_buffers(m, "Pinned (global)",
+			    error->pinned_bo,
+			    error->pinned_bo_count);
+
 	for (i = 0; i < ARRAY_SIZE(error->engine); i++) {
 		struct drm_i915_error_engine *ee = &error->engine[i];
 
@@ -627,13 +631,10 @@ static void i915_error_state_free(struct kref *error_ref)
 
 	i915_error_object_free(error->semaphore_obj);
 
-	for (i = 0; i < error->vm_count; i++)
+	for (i = 0; i < ARRAY_SIZE(error->active_bo); i++)
 		kfree(error->active_bo[i]);
-
-	kfree(error->active_bo);
-	kfree(error->active_bo_count);
 	kfree(error->pinned_bo);
-	kfree(error->pinned_bo_count);
+
 	kfree(error->overlay);
 	kfree(error->display);
 	kfree(error);
@@ -779,9 +780,6 @@ static void capture_bo(struct drm_i915_error_buffer *err,
 	err->read_domains = obj->base.read_domains;
 	err->write_domain = obj->base.write_domain;
 	err->fence_reg = obj->fence_reg;
-	err->pinned = 0;
-	if (i915_gem_obj_is_pinned(obj))
-		err->pinned = 1;
 	err->tiling = i915_gem_object_get_tiling(obj);
 	err->dirty = obj->dirty;
 	err->purgeable = obj->madv != I915_MADV_WILLNEED;
@@ -789,13 +787,17 @@ static void capture_bo(struct drm_i915_error_buffer *err,
 	err->cache_level = obj->cache_level;
 }
 
-static u32 capture_active_bo(struct drm_i915_error_buffer *err,
-			     int count, struct list_head *head)
+static u32 capture_error_bo(struct drm_i915_error_buffer *err,
+			    int count, struct list_head *head,
+			    bool pinned_only)
 {
 	struct i915_vma *vma;
 	int i = 0;
 
 	list_for_each_entry(vma, head, vm_link) {
+		if (pinned_only && !i915_vma_is_pinned(vma))
+			continue;
+
 		capture_bo(err++, vma);
 		if (++i == count)
 			break;
@@ -804,28 +806,6 @@ static u32 capture_active_bo(struct drm_i915_error_buffer *err,
 	return i;
 }
 
-static u32 capture_pinned_bo(struct drm_i915_error_buffer *err,
-			     int count, struct list_head *head,
-			     struct i915_address_space *vm)
-{
-	struct drm_i915_gem_object *obj;
-	struct drm_i915_error_buffer * const first = err;
-	struct drm_i915_error_buffer * const last = err + count;
-
-	list_for_each_entry(obj, head, global_list) {
-		struct i915_vma *vma;
-
-		if (err == last)
-			break;
-
-		list_for_each_entry(vma, &obj->vma_list, obj_link)
-			if (vma->vm == vm && i915_vma_is_pinned(vma))
-				capture_bo(err++, vma);
-	}
-
-	return err - first;
-}
-
 /* Generate a semi-unique error code. The code is not meant to have meaning, The
  * code's only purpose is to try to prevent false duplicated bug reports by
  * grossly estimating a GPU error state.
@@ -1063,7 +1043,6 @@ static void error_record_engine_registers(struct drm_i915_error_state *error,
 	}
 }
 
-
 static void i915_gem_record_active_context(struct intel_engine_cs *engine,
 					   struct drm_i915_error_state *error,
 					   struct drm_i915_error_engine *ee)
@@ -1116,10 +1095,9 @@ static void i915_gem_record_rings(struct drm_i915_private *dev_priv,
 
 		request = i915_gem_find_active_request(engine);
 		if (request) {
-			struct i915_address_space *vm;
 			struct intel_ring *ring;
 
-			vm = request->ctx->ppgtt ?
+			ee->vm = request->ctx->ppgtt ?
 				&request->ctx->ppgtt->base : &ggtt->base;
 
 			/* We need to copy these to an anonymous buffer
@@ -1129,7 +1107,7 @@ static void i915_gem_record_rings(struct drm_i915_private *dev_priv,
 			ee->batchbuffer =
 				i915_error_object_create(dev_priv,
 							 request->batch_obj,
-							 vm);
+							 ee->vm);
 
 			if (HAS_BROKEN_CS_TLB(dev_priv))
 				ee->wa_batchbuffer =
@@ -1212,89 +1190,88 @@ static void i915_gem_record_rings(struct drm_i915_private *dev_priv,
 	}
 }
 
-/* FIXME: Since pin count/bound list is global, we duplicate what we capture per
- * VM.
- */
 static void i915_gem_capture_vm(struct drm_i915_private *dev_priv,
 				struct drm_i915_error_state *error,
 				struct i915_address_space *vm,
-				const int ndx)
+				int idx)
 {
-	struct drm_i915_error_buffer *active_bo = NULL, *pinned_bo = NULL;
-	struct drm_i915_gem_object *obj;
+	struct drm_i915_error_buffer *active_bo;
 	struct i915_vma *vma;
-	int i;
+	int count;
 
-	i = 0;
+	count = 0;
 	list_for_each_entry(vma, &vm->active_list, vm_link)
-		i++;
-	error->active_bo_count[ndx] = i;
-
-	list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list) {
-		list_for_each_entry(vma, &obj->vma_list, obj_link)
-			if (vma->vm == vm && i915_vma_is_pinned(vma))
-				i++;
-	}
-	error->pinned_bo_count[ndx] = i - error->active_bo_count[ndx];
-
-	if (i) {
-		active_bo = kcalloc(i, sizeof(*active_bo), GFP_ATOMIC);
-		if (active_bo)
-			pinned_bo = active_bo + error->active_bo_count[ndx];
-	}
+		count++;
 
+	active_bo = NULL;
+	if (count)
+		active_bo = kcalloc(count, sizeof(*active_bo), GFP_ATOMIC);
 	if (active_bo)
-		error->active_bo_count[ndx] =
-			capture_active_bo(active_bo,
-					  error->active_bo_count[ndx],
-					  &vm->active_list);
-
-	if (pinned_bo)
-		error->pinned_bo_count[ndx] =
-			capture_pinned_bo(pinned_bo,
-					  error->pinned_bo_count[ndx],
-					  &dev_priv->mm.bound_list, vm);
-	error->active_bo[ndx] = active_bo;
-	error->pinned_bo[ndx] = pinned_bo;
+		count = capture_error_bo(active_bo, count, &vm->active_list, false);
+	else
+		count = 0;
+
+	error->active_vm[idx] = vm;
+	error->active_bo[idx] = active_bo;
+	error->active_bo_count[idx] = count;
 }
 
-static void i915_gem_capture_buffers(struct drm_i915_private *dev_priv,
-				     struct drm_i915_error_state *error)
+static void i915_capture_active_buffers(struct drm_i915_private *dev_priv,
+					struct drm_i915_error_state *error)
 {
-	struct i915_address_space *vm;
-	int cnt = 0, i = 0;
-
-	list_for_each_entry(vm, &dev_priv->vm_list, global_link)
-		cnt++;
-
-	error->active_bo = kcalloc(cnt, sizeof(*error->active_bo), GFP_ATOMIC);
-	error->pinned_bo = kcalloc(cnt, sizeof(*error->pinned_bo), GFP_ATOMIC);
-	error->active_bo_count = kcalloc(cnt, sizeof(*error->active_bo_count),
-					 GFP_ATOMIC);
-	error->pinned_bo_count = kcalloc(cnt, sizeof(*error->pinned_bo_count),
-					 GFP_ATOMIC);
-
-	if (error->active_bo == NULL ||
-	    error->pinned_bo == NULL ||
-	    error->active_bo_count == NULL ||
-	    error->pinned_bo_count == NULL) {
-		kfree(error->active_bo);
-		kfree(error->active_bo_count);
-		kfree(error->pinned_bo);
-		kfree(error->pinned_bo_count);
-
-		error->active_bo = NULL;
-		error->active_bo_count = NULL;
-		error->pinned_bo = NULL;
-		error->pinned_bo_count = NULL;
-	} else {
-		list_for_each_entry(vm, &dev_priv->vm_list, global_link)
-			i915_gem_capture_vm(dev_priv, error, vm, i++);
+	int cnt = 0, i, j;
+
+	BUILD_BUG_ON(ARRAY_SIZE(error->engine) > ARRAY_SIZE(error->active_bo));
+	BUILD_BUG_ON(ARRAY_SIZE(error->active_bo) != ARRAY_SIZE(error->active_vm));
+	BUILD_BUG_ON(ARRAY_SIZE(error->active_bo) != ARRAY_SIZE(error->active_bo_count));
+
+	/* Scan each engine looking for unique active contexts/vm */
+	for (i = 0; i < ARRAY_SIZE(error->engine); i++) {
+		struct drm_i915_error_engine *ee = &error->engine[i];
+		bool found;
+
+		if (!ee->vm)
+			continue;
 
-		error->vm_count = cnt;
+		found = false;
+		for (j = 0; j < i && !found; j++)
+			found = error->engine[j].vm == ee->vm;
+		if (!found)
+			i915_gem_capture_vm(dev_priv, error, ee->vm, cnt++);
 	}
 }
 
+static void i915_capture_pinned_buffers(struct drm_i915_private *dev_priv,
+					struct drm_i915_error_state *error)
+{
+	struct i915_address_space *vm = &dev_priv->ggtt.base;
+	struct drm_i915_error_buffer *bo;
+	struct i915_vma *vma;
+	int count_inactive, count_active;
+
+	count_inactive = 0;
+	list_for_each_entry(vma, &vm->active_list, vm_link)
+		count_inactive++;
+
+	count_active = 0;
+	list_for_each_entry(vma, &vm->inactive_list, vm_link)
+		count_active++;
+
+	bo = NULL;
+	if (count_inactive + count_active)
+		bo = kcalloc(count_inactive + count_active,
+			     sizeof(*bo), GFP_ATOMIC);
+	if (!bo)
+		return;
+
+	count_inactive = capture_error_bo(bo, count_inactive,
+					  &vm->active_list, true);
+	count_active = capture_error_bo(bo + count_inactive, count_active,
+					&vm->inactive_list, true);
+	error->pinned_bo_count = count_inactive + count_active;
+	error->pinned_bo = bo;
+}
+
 /* Capture all registers which don't fit into another category. */
 static void i915_capture_reg_state(struct drm_i915_private *dev_priv,
 				   struct drm_i915_error_state *error)
@@ -1438,9 +1415,10 @@ void i915_capture_error_state(struct drm_i915_private *dev_priv,
 
 	i915_capture_gen_state(dev_priv, error);
 	i915_capture_reg_state(dev_priv, error);
-	i915_gem_capture_buffers(dev_priv, error);
 	i915_gem_record_fences(dev_priv, error);
 	i915_gem_record_rings(dev_priv, error);
+	i915_capture_active_buffers(dev_priv, error);
+	i915_capture_pinned_buffers(dev_priv, error);
 
 	do_gettimeofday(&error->time);