780336 - BrowserElementScrolling cosumes 7% of profile time on gaia homescreen, but isn't used

Status: RESOLVED FIXED

(Firefox OS Graveyard :: General, defect)

Description

[Chris Jones [:cjones] inactive; ni?/f?/r? if you need me]

The homescreen implements its own panning physics, but the BrowserElementScrolling fallback is still kicking in and apparently having its values stomped by the homescreen's.  It's using 7% of profile time which corresponds to a nontrivial framerate difference.

There may be something we can do to make the BrowserElementScrolling code cheaper, or maybe we need to stopPropagation() or something in gaia.  Though it seems that the gaia code runs after BES or the gaia stuff wouldn't "win".

Comment 1

[Chris Jones [:cjones] inactive; ni?/f?/r? if you need me]

Early-returning from ContentPanning.handleEvent() buys us 3-4fps.

Comment 2

[Vivien Nicolas (:vingtetun) (:21) - (NOT reading bugmails, needinfo? please)]

Attachment: Do not generate a callback to scroll the window if there is nothing to scroll

This patch should force an early return in onTouchMove if there is nothing to scroll. (Thanks a lot for the profiling information!)

Comment 3

[Mounir Lamouri (:mounir)]

Sent to try:
http://tbpl.mozilla.org/?tree=Try&rev=034dbbabe904

Comment 4

[Mounir Lamouri (:mounir)]

https://hg.mozilla.org/integration/mozilla-inbound/rev/bd8ac25f41c4

Comment 5

[Ed Morley [:emorley]]

https://hg.mozilla.org/mozilla-central/rev/bd8ac25f41c4