1443765 - Fennec: Form changes invoke SessionStore more-or-less immediately causing low Speedometer scores

Status: RESOLVED FIXED

(Firefox for Android Graveyard :: Session Restore, defect, P2)

Description

[Randell Jesup [:jesup] (needinfo me)]

Speedometer 2.0 frequently changes 100 checkboxes all at once (completeAllItems()).  On fennec (but not on focus-android with klarGeckoArm/x86Debug) this causes a very large amount of CPU time to be spent in collect() in SessionStore, gathering form data.  (75% of the time in a profile of the running portion of the test, excluding the refreshdriver section).

This is seen in the InteractiveRunner.html test of speedometer in the "completeAllItems(sync)" case.  This also causes a high variation in scores.

For Vanilla-ToDoMVC, on a Galaxy S7, focus-Gecko takes 100-200ms for completeAllItems(sync); fennec takes 1-2 seconds, 10x worse.  With Sessionstore neutered with a 'return' in handleEvent, it takes 200-300ms.

I presume sessionstore could be delayed and batched for a short period, or deferred until idle with some maximum, etc.  Users rarely change many form controls at once, but JS on a page might (SelectAll or UncheckAll, etc).  Even for the 1-element case it might have some impact on responsiveness of the browser to react to an input change.

Comment 1

[Randell Jesup [:jesup] (needinfo me)]

Attachment: delay SessionStore for Fennec on input events

This also implies that a series of events (like UnselectAll for checkboxes)
will be batched.

Comment 2

[Randell Jesup [:jesup] (needinfo me)]

Note: still need to verify it's saving dynamically

Comment 3

[Randell Jesup [:jesup] (needinfo me)]

Attachment: delay SessionStore for Fennec on input events

fix 1-char typo.  Note that test_session_form_data.html will need to be adjusted; it assumes synchronous saving.

Comment 4

[Randell Jesup [:jesup] (needinfo me)]

Attachment: Update android formdata sessionstore test for delayed save

passes test locally; pushing try for verification

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/f34ad0155500
delay SessionStore for Fennec on input events r=snorp
https://hg.mozilla.org/integration/mozilla-inbound/rev/c1152eaf2036
Update android formdata sessionstore test for delayed save r=snorp

Comment 6

[Andreea Pavel [:apavel]]

https://hg.mozilla.org/mozilla-central/rev/f34ad0155500
https://hg.mozilla.org/mozilla-central/rev/c1152eaf2036