kern/evcnt: new evcnt_read function

1 files changed, 14 insertions, 4 deletions

diff --git a/kern/evcnt.h b/kern/evcnt.h
index aa49ca2b..33e6b398 100644
--- a/kern/evcnt.h
+++ b/kern/evcnt.h
@@ -56,10 +56,7 @@ void evcnt_register(struct evcnt *evcnt, const char *name);
  * Increment the given counter.
  *
  * It is the responsibility of the caller to synchronize access to the
- * counter. In addition, since counters are 64-bits wide, retrieving them
- * on 32-bits systems might return invalid values, although this should be
- * very rare. As long as users don't rely on them for critical operations,
- * this is completely harmless.
+ * counter.
  */
 static inline void
 evcnt_inc(struct evcnt *evcnt)
@@ -68,6 +65,19 @@ evcnt_inc(struct evcnt *evcnt)
 }
 
 /*
+ * Obtain the current value of the given counter.
+ *
+ * Since counters are 64-bits wide, retrieving them on 32-bits systems might
+ * return invalid values, although this should be very rare. As long as users
+ * don't rely on them for critical operations, this is completely harmless.
+ */
+static inline unsigned long long
+evcnt_read(const struct evcnt *evcnt)
+{
+    return evcnt->count;
+}
+
+/*
  * Display the registered event counters.
  */
 void evcnt_info(void);