60017 2011-05-03 03:14:13 -0700 PreloadScanner should fetch iframes 2012-07-09 09:00:12 -0700 1 1 1 Unclassified WebKit WebCore Misc. 528+ (Nightly build) All All NEW Performance P2 Normal --- 49246 1 tonyg webkit-unassigned ap ddkilzer koivisto simonjam skyul oldest_to_newest 397027 0 tonyg 2011-05-03 03:14:13 -0700 The PreloadScanner should fetch subdocuments (iframes). To do this, I believe we need to allow main resources in the memory cache, then the fix should be trivial. We might also explore preload scanning within the subframe. FWIW, this will also let us pass browserscope's "|| Script Iframe" test here: http://www.browserscope.org/?category=network 397145 1 ap 2011-05-03 10:01:27 -0700 Is it common that iframes contain anything worthwhile? It seems that delaying loading them might be best. 397208 2 ddkilzer 2011-05-03 11:22:00 -0700 (In reply to comment #1) > Is it common that iframes contain anything worthwhile? It seems that delaying loading them might be best. Or maybe only preload them if they're from a similar domain, or set their priority higher if they're from a similar domain? 397359 3 koivisto 2011-05-03 13:56:03 -0700 (In reply to comment #1) > Is it common that iframes contain anything worthwhile? It seems that delaying loading them might be best. Iframe content is part of the page content and we want the full content to be loaded as quickly as possible. "Worthwhile" or not, it doesn't help anyone if it loads slowly. 397373 4 ap 2011-05-03 14:07:57 -0700 Total load time is not the only metric to improve. What I'm saying is that prefetching iframes (and even more so, their subresources) has a lot of potential to significantly increase the time until the page is usable.