I noticed today that our time to load the full reference-workload-heavy contact list went from less than 8.5 seconds up to over 9.7 seconds. Git bisecting showed that this was due to : https://github.com/mozilla-b2g/gaia/commit/d6567edc44dea923914935b1f256c4fce67856fd Looking at the code I don't see an obvious explanation for this. As far as I can tell all of these changes are outside of the contact list. We'll need to investigate further. This may be a requirement of the new feature or perhaps its something we can work around. I'll post a patch with the code I am using to measure the time. I'd really like to setup an automated system to monitor the time so we can proactively detect changes.

This patch outputs times to logcat for both the above-the-fold event and full load from contactsAPI. The above-the-fold time is obviously important for showing a useable UI to the user quickly. The full load time dictates how soon we can use the letter group shortcuts to jump to the end of the list.

It appears that the app container is using a steady 25% CPU when idle after this change. Still need to investigate more.

This appears to be due to the pack-activity class animation running in the background. This occurs because the #throbber progress element is using visibility:hidden instead of display:none. It seems there are two straightforward ways to handle this. Either switch to using display:none or only add the pack-activity class when the progress element is displayed.

This pull request fixes the issue by using the standard hide class instead of visibility:hidden. Jose, requesting review from you because I believe Cristian is still on holiday and it would be nice to get this fixed soon. Thanks!

Comment on attachment 786288 [details] Pull request at https://github.com/mozilla-b2g/gaia/pull/11377 good work and good catch! thanks

Thanks Jose! Merged: https://github.com/mozilla-b2g/gaia/commit/a3630e49320424d63f5de0c57d48fde1494569b2