925348 - contacts list doRenderTimer() can take >30ms while scrolling

Status: RESOLVED FIXED

(Firefox OS Graveyard :: Gaia::Contacts, defect, P1)

Description

[Ben Kelly [:bkelly, not reviewing]]

Profiling contacts app list scroll immediately after load shows that the doRenderTimer() function is taking >30ms.  Given that our scrolling frame budget is ~16ms, this is too long.

See the profile here at time range 37750 to 37866:

http://people.mozilla.org/~bgirard/cleopatra/#report=6d2d991883a5597684e0c09fe7fa88deb5dea891

Its unclear if we can make the work performed by doRenderTimer() more efficient, but we might be able to spread it out more to avoid computation spikes.

Comment 1

[Ben Kelly [:bkelly, not reviewing]]

Attachment: Pull request at https://github.com/mozilla-b2g/gaia/pull/12778

This pull request spreads out the contact rendering work during scrolling by adjusting the tag_visibility_monitor parameters.  The new parameters result in more frequent updates from the monitor.  This comes at a slight overhead cost, but avoids large spikes of modifications at a single time.

Overall I think this is probably better than limiting the loop in doRenderTimer() since it avoids creating another layer of code to perform throttling.

Comment 2

[Ben Kelly [:bkelly, not reviewing]]

Nom koi? because this blocks a blocker.

Comment 3

[Joe Cheng [:jcheng] (please needinfo)]

Triage: Comms team would not block: New perf requirements (see enhancements) 
but since the contacts performance bug is koi+ by the perf team, letting perf team make the call on this one

Comment 4

[Jose Manuel Cantera]

Comment on attachment 815554 [details]
Pull request at https://github.com/mozilla-b2g/gaia/pull/12778

handing over the review to Francisco as next week I will be on PTO

Comment 5

[Francisco Jordano [:arcturus] [:francisco]]

Comment on attachment 815554 [details]
Pull request at https://github.com/mozilla-b2g/gaia/pull/12778

Simple change, tried on the phone and working fine.

Thanks Ben!

Comment 6

[Ben Kelly [:bkelly, not reviewing]]

Thanks!  Merged:

  https://github.com/mozilla-b2g/gaia/commit/01e5ae83a57ac5df4e173edb83c2ad2e2d8dfec0

Comment 7

[John Ford [:jhford] CET/CEST Berlin Time]

Uplifted 01e5ae83a57ac5df4e173edb83c2ad2e2d8dfec0 to:
v1.2: 46b38f71c65d8bc2a9c5078c6bcca9de79f977a5