Using some profiling and tracing, we've found that - Template/Hello World app paints two or three times (partly bug 836198) - homescreen paints 4 or 5 times - b2g process paints numerous times We need to ensure that each one is necessary and as inexpensive as possible.

(In reply to Chris Jones [:cjones] inactive; ni?/f?/r? if you need me from comment #0) > Using some profiling and tracing, we've found that > - Template/Hello World app paints two or three times (partly bug 836198) > - homescreen paints 4 or 5 times > - b2g process paints numerous times > > We need to ensure that each one is necessary and as inexpensive as possible. Given the passage of time and changes, does anyone believe this is still an issue?

(In reply to Wayne Mery (:wsmwk, NI for questions) from comment #1) > (In reply to Chris Jones [:cjones] inactive; ni?/f?/r? if you need me from > comment #0) > > Using some profiling and tracing, we've found that > > - Template/Hello World app paints two or three times (partly bug 836198) > > - homescreen paints 4 or 5 times > > - b2g process paints numerous times > > > > We need to ensure that each one is necessary and as inexpensive as possible. > > Given the passage of time and changes, does anyone believe this is still an > issue? I don't find this bug very actionable, so we could probably close it. If we paint several times during startup there will be some visible flickering, so we'll likely file bugs about the flicker (like bug 1372518) rather this generic bug. One thing I've noticed in startup profile that's kinda related to this bug is that we have the refresh driver ticks that start happening as soon as we have created a first window (typically the hidden window), and this causes useless layouts while we are not done loading the first browser window, especially if startup is slow and loading/creating that first browser window takes a while. Smaug tried to patch this a couple weeks ago to prevent the refresh driver ticks before first paint, but couldn't conclude about whether it was an actual win or not.