X-Git-Url: http://git.lttng.org./?a=blobdiff_plain;f=src%2Flttng-event-notifier-notification.c;h=52b5593ac9325b5324c9169f72ff736044a49cac;hb=4a7d870a981874db47b3c3b94f913fdd57bf19d6;hp=f675de4b1dbddbf6522928d79e810fe2323172dc;hpb=99d223adfae9b68800e91bda470c92acb14efae6;p=lttng-modules.git

diff --git a/src/lttng-event-notifier-notification.c b/src/lttng-event-notifier-notification.c
index f675de4b..52b5593a 100644
--- a/src/lttng-event-notifier-notification.c
+++ b/src/lttng-event-notifier-notification.c
@@ -11,10 +11,15 @@
 #include <lttng/events.h>
 #include <lttng/msgpack.h>
 #include <lttng/event-notifier-notification.h>
+#include <wrapper/barrier.h>
 
 /*
- * FIXME: this probably too low but it needs to be below 1024 bytes to avoid
- * the frame to be larger than the 1024 limit enforced by the kernel.
+ * The capture buffer size needs to be below 1024 bytes to avoid the
+ * frame to be larger than the 1024 limit enforced by the kernel. If we
+ * ever need to increase it, we will need to use a memory allocation
+ * scheme which allows allocating temporary memory chunks from the
+ * instrumentation sites. This could be done by adapting lttng
+ * tp-mempool to become nmi-safe and lock-free.
  */
 #define CAPTURE_BUFFER_SIZE 512
 
@@ -343,6 +348,33 @@ end:
 	return ret;
 }
 
+static
+void record_error(struct lttng_event_notifier *event_notifier)
+{
+
+	struct lttng_event_notifier_group *event_notifier_group = event_notifier->group;
+	struct lttng_counter *error_counter;
+	size_t dimension_index[1];
+	int ret;
+
+	/*
+	 * lttng_smp_load_acquire paired with lttng_smp_store_release orders
+	 * creation of the error counter and setting error_counter_len
+	 * before the error_counter is used.
+	 */
+	error_counter = lttng_smp_load_acquire(&event_notifier_group->error_counter);
+	/* This group may not have an error counter attached to it. */
+	if (!error_counter)
+		return;
+
+	dimension_index[0] = event_notifier->error_counter_index;
+
+	ret = error_counter->ops->counter_add(error_counter->counter,
+			dimension_index, 1);
+	if (ret)
+		WARN_ON_ONCE(1);
+}
+
 static
 void notification_send(struct lttng_event_notifier_notification *notif,
 		struct lttng_event_notifier *event_notifier)
@@ -371,9 +403,7 @@ void notification_send(struct lttng_event_notifier_notification *notif,
 			lttng_alignof(kernel_notif), -1);
 	ret = event_notifier_group->ops->event_reserve(&ctx, 0);
 	if (ret < 0) {
-		//TODO: error handling with counter maps
-		//silently drop for now.
-		WARN_ON_ONCE(1);
+		record_error(event_notifier);
 		return;
 	}