See cairo mailing list 15-10-2007 patch by Soeren Sandmann.
Fixes unreliable results for cairo-perf.

diff --git a/perf/cairo-perf.c b/perf/cairo-perf.c
index 360f2dd..a8d7abc 100644
--- a/perf/cairo-perf.c
+++ b/perf/cairo-perf.c
@@ -166,22 +166,11 @@ cairo_perf_run (cairo_perf_t		*perf,
 			cairo_perf_ticks_per_second () / 1000.0);
 	    printf (" %lld", times[i]);
 	} else {
-	    if (i > 0) {
-		_cairo_stats_compute (&stats, times, i+1);
-
-		if (stats.std_dev <= CAIRO_PERF_LOW_STD_DEV &&
-		    ! perf->exact_iterations)
-		{
-		    low_std_dev_count++;
-		    if (low_std_dev_count >= CAIRO_PERF_STABLE_STD_DEV_COUNT)
-			break;
-		} else {
-		    low_std_dev_count = 0;
-		}
-	    }
 	}
     }
 
+    _cairo_stats_compute (&stats, times, i+1);
+	    
     if (perf->raw) {
 	printf ("\n");
     } else {
diff --git a/perf/cairo-stats.c b/perf/cairo-stats.c