76725 2012-01-20 12:08:27 -0800 [Regression] 2% Page Cycler Moz regression 2012-01-22 11:17:18 -0800 1 1 1 Unclassified WebKit WebCore Misc. 528+ (Nightly build) Unspecified Unspecified RESOLVED FIXED P2 Normal --- 76726 1 abarth webkit-unassigned hyatt kenrb mihnea simon.fraser thorton tony oldest_to_newest 539679 0 abarth 2012-01-20 12:08:27 -0800 Looks to be something in this range: http://trac.webkit.org/log/trunk/Source?rev=105427&stop_rev=105419&verbose=on http://build.chromium.org/f/chromium/perf/xp-release-dual-core/moz/report.html?history=150&rev=118458&graph=times 539680 1 abarth 2012-01-20 12:08:48 -0800 http://code.google.com/p/chromium/issues/detail?id=110915 539685 2 abarth 2012-01-20 12:12:07 -0800 These two look like the leading candidate for causing the regression: http://trac.webkit.org/changeset/105426/trunk/Source http://trac.webkit.org/changeset/105423/trunk/Source 539688 3 abarth 2012-01-20 12:13:13 -0800 I think we should try rolling out http://trac.webkit.org/changeset/105426 because the ChangeLog mentions there's a risk of a perf regression. 539697 4 abarth 2012-01-20 12:23:27 -0800 Tried reverting 105426 in http://trac.webkit.org/changeset/105532 539918 5 abarth 2012-01-20 16:38:44 -0800 Reverting that patch seems to have fixed the regression. http://build.chromium.org/f/chromium/perf/vista-release-webkit-latest/moz/report.html?history=150&rev=-1 540225 6 mihnea 2012-01-22 00:03:15 -0800 This is huge regression. In my tests, i have never had a regression of this scale. The initial regression introduced by the first version of the region styling patch was 2-3%. I am puzzled but i will try to take a look again at the problem. 540260 7 tony 2012-01-22 09:14:29 -0800 I think abarth just read the graph wrong. It's about 2%, like before. 540294 8 abarth 2012-01-22 11:17:18 -0800 Sorry, I was just repeating what the performance sheriff wrote.