diff --git a/mozilla/tools/performance/startup/printlog.pl b/mozilla/tools/performance/startup/printlog.pl
new file mode 100644
index 00000000000..6e5aa382aef
--- /dev/null
+++ b/mozilla/tools/performance/startup/printlog.pl
@@ -0,0 +1,34 @@
+# Post processor for timeline output
+# Does a diff betn consecutive timeline outputs looking for
+# big % differences
+
+my $percent = 1; # anything over 1% of total is of interest to us
+my $ignoreDllLoads = 0; # by default dont ignore dll timings
+
+# Read in log to memory
+my @lines = <>;
+
+my $total = 0;
+# Look for main1's timing
+foreach (@lines) {
+    if (/^([0-9\.]*): \.\.\.main1/) {
+        $total = $1 + 0;
+        print "Found main1 time: $total\n";
+        last;
+    }
+}
+
+
+my $prev = 0;
+my $t = $total * $percent / 100;
+foreach (@lines) {
+    /^([0-9\.]*):/;
+    $cur = $1;
+    # if significant time elapsed print it
+    $diff = $cur - $prev;
+    if ($diff > $t && (!$ignoreDllLoads || ! /PR_LoadLibrary/)) {
+        printf "%4.2f%% %5.3f\n", $diff/$total*100, $diff;
+    }
+    print "\t$_";
+    $prev = $cur;
+}