--- a/libop/op_config.h
+++ b/libop/op_config.h
@@ -19,11 +19,37 @@
 extern "C" {
 #endif
   
+
+enum {	OPERF_SAMPLES, /**< nr. samples */
+	OPERF_KERNEL, /**< nr. kernel samples */
+	OPERF_PROCESS, /**< nr. userspace samples */
+	OPERF_INVALID_CTX, /**< nr. samples lost due to sample address not in expected range for domain */
+	OPERF_LOST_KERNEL,  /**< nr. kernel samples lost */
+	OPERF_LOST_SAMPLEFILE, /**< nr samples for which sample file can't be opened */
+	OPERF_LOST_NO_MAPPING, /**< nr samples lost due to no mapping */
+	OPERF_NO_APP_KERNEL_SAMPLE, /**<nr. user ctx kernel samples dropped due to no app context available */
+	OPERF_NO_APP_USER_SAMPLE, /**<nr. user samples dropped due to no app context available */
+	OPERF_BT_LOST_NO_MAPPING, /**<nr. backtrace samples dropped due to no mapping */
+	OPERF_LOST_INVALID_HYPERV_ADDR, /**<nr. hypervisor samples dropped due to address out-of-range */
+	OPERF_RECORD_LOST_SAMPLE, /**<nr. samples lost reported by perf_events kernel */
+	OPERF_MAX_STATS /**< end of stats */
+};
+#define OPERF_INDEX_OF_FIRST_LOST_STAT 3
+
+/* Warn on lost samples if number of lost samples is greater the this fraction
+ * of the total samples
+*/
+#define OPERF_WARN_LOST_SAMPLES_THRESHOLD   0.0001
+
+extern char * stats_filenames[];
+
 /** 
  * must be called to initialize the paths below.
  * @param session_dir  the non-NULL value of the base session directory
  */
 void init_op_config_dirs(char const * session_dir);
+
+//void init_op_stats_filenames(char const * session_dir);
 
 #define OP_SESSION_DIR_DEFAULT "/var/lib/oprofile/"