Index: mapiproxy/modules/mpm_cache.c
===================================================================
--- mapiproxy/modules/mpm_cache.c	(revision 943)
+++ mapiproxy/modules/mpm_cache.c	(working copy)
@@ -75,8 +75,6 @@
 {
 	TALLOC_CTX	*mem_ctx;
 	struct timeval	tv_end;
-	uint64_t       	sec;
-	uint64_t       	usec;
 	char		*name;
 	const char	*stage;
 
@@ -96,17 +94,7 @@
 	}
 
 	gettimeofday(&tv_end, NULL);
-	sec = tv_end.tv_sec - stream->tv_start.tv_sec;
-	if ((tv_end.tv_usec - stream->tv_start.tv_usec) < 0) {
-		sec -= 1;
-		usec = tv_end.tv_usec + stream->tv_start.tv_usec;
-		while (usec > 1000000) {
-			usec -= 1000000;
-			sec += 1;
-		}
-	} else {
-		usec = tv_end.tv_usec - stream->tv_start.tv_usec;
-	}
+	timersub(&tv_end, &stream->tv_start, &tv_end);
 
 	if (stream->ahead == true) {
 		stage = "[read ahead]";
@@ -117,7 +105,7 @@
 	}
 
 	DEBUG(1, ("STATISTIC: %-20s %s The difference is %ld seconds %ld microseconds\n", 
-		  stage, name, (long int)sec, (long int)usec));
+		  stage, name, (long int)tv_end.tv_sec, (long int)tv_end.tv_usec));
 	talloc_free(name);
 }