Comment 9 for bug 1352826

Zhang Hua and Nobuto, thanks for your testing! Patch set 2 is enough for improving the performance, and it is safe. The complexity of patch set 5 is almost same with patch set 2, in fact I have not carefully measured which one is faster. Now patch set 5 is not fully tested. I hope more stackers can have a try and give me feedback.
Thanks again!