Changeset 65940 in webkit

Timestamp:

Aug 24, 2010 3:22:14 PM (14 years ago)

Author:

ojan@chromium.org

Message:

2010-08-24 Ojan Vafai <​ojan@chromium.org>

Reviewed by Tony Chang.

perf tests are flaky
​https://bugs.webkit.org/show_bug.cgi?id=44199

Speculative fix for perf test flakiness. Use chromium.Interval
to get a microsecond granularity timer. If this does end up
reducing flakiness, then we can expose something similar for
JSC and/or layoutTestController.

• resources/magnitude-perf.js: (Magnitude._runIteration): (Magnitude):

Location:

trunk/LayoutTests

Files:

• ChangeLog (modified) (1 diff)
• resources/magnitude-perf.js (modified) (1 diff)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2010-08-24  Ojan Vafai  <ojan@chromium.org>
+
+        Reviewed by Tony Chang.
+
+        perf tests are flaky
+        https://bugs.webkit.org/show_bug.cgi?id=44199
+
+        Speculative fix for perf test flakiness. Use chromium.Interval
+        to get a microsecond granularity timer. If this does end up
+        reducing flakiness, then we can expose something similar for
+        JSC and/or layoutTestController.
+
+        * resources/magnitude-perf.js:
+        (Magnitude._runIteration):
+        (Magnitude):
+
 2010-08-24  Pavel Podivilov  <podivilov@chromium.org>
 

trunk/LayoutTests/resources/magnitude-perf.js

@@ -204 +204 @@
     setup(magnitude);
 
-    var start = Date.now();
     var iterations = 0;
-    while (Date.now() - start < milliseconds) {
-        // Loop runsPerIteration times to reduce errors due to the overhead and granularity of the Date object.
-        for (var i = 0; i < runsPerIteration; i++) {
-            test(magnitude);
-        }
-        iterations++;
+    if (window.chromium) {
+      // FIXME: If using microseconds turns out to be less flaky, expose microseconds
+      // from JSC or layoutTestController and use them. Otherwise, get rid of this block.
+      var microseconds = milliseconds * 1000;
+      var interval = new chromium.Interval();
+      interval.start();
+      while (interval.microseconds() < microseconds) {
+          // Loop runsPerIteration times to reduce errors due to the overhead and granularity of the Date object.
+          for (var i = 0; i < runsPerIteration; i++) {
+              test(magnitude);
+          }
+          iterations++;
+      }
+      interval.stop();
+    } else {
+      var start = Date.now();
+      while (Date.now() - start < milliseconds) {
+          // Loop runsPerIteration times to reduce errors due to the overhead and granularity of the Date object.
+          for (var i = 0; i < runsPerIteration; i++) {
+              test(magnitude);
+          }
+          iterations++;
+      }
     }
     return iterations;