1366156 - Child INPUT_EVENT_RESPONSE_MS p50 regressed from 9.28 to 10.22ms on 2017-05-06 build

Status: RESOLVED INCOMPLETE

(Core :: General, defect)

Description

[(no longer active)]

Telemetry: https://mzl.la/2rp2aeP

Comment 1

[(no longer active)]

Andreas, I think the telemetry collection code in bug 1322184 may be the reason for this regression...

The good news is that if this is the case, AutoCollectVsyncTelemetry automatically turns itself off for the release channel, so we can just ignore the regression.  But we should verify whether this is really the regression we are looking at.  I would like to disable this probe for a few days and watch INPUT_EVENT_RESPONSE_MS to see if it drops down and in that case, mark this bug as WONTFIX and move on!

Comment 2

[(no longer active)]

Attachment: Temporarily disable the collection of content js delay event telemetry probes to investigate whether they are the cause of child process INPUT_EVENT_RESPONSE_MS regressions

Comment 3

[Andreas Farre [:farre]]

Sorry, shouldn't have set the checkin-needed flag there. Don't know what happened.

Comment 4

[Andreas Farre [:farre]]

Attachment: 0001-Bug-1366156-Temporarily-stop-recording-vsync-message.patch

What I should've said is that we should probably do this as well.

Comment 5

[(no longer active)]

Comment on attachment 8869396 [details] [diff] [review]
0001-Bug-1366156-Temporarily-stop-recording-vsync-message.patch

Yeah makes sense.  I'll fold this into my patch to make it easier to back the whole thing out after a few days.  Thanks!

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/dfdebc342d2e
Temporarily disable the collection of content js delay event telemetry probes to investigate whether they are the cause of child process INPUT_EVENT_RESPONSE_MS regressions; r=farre

Comment 7

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/dfdebc342d2e

Comment 8

[(no longer active)]

Comment on attachment 8869307 [details] [diff] [review]
Temporarily disable the collection of content js delay event telemetry probes to investigate whether they are the cause of child process INPUT_EVENT_RESPONSE_MS regressions

It doesn't look like this has caused any measurable change in the INPUT_EVENT_RESPONSE_MS telemetry probe.  I'm going to revert this patch now...

Comment 9

[(no longer active)]

(In reply to :Ehsan Akhgari (super long backlog, slow to respond) from comment #8)
> Comment on attachment 8869307 [details] [diff] [review]
> Temporarily disable the collection of content js delay event telemetry
> probes to investigate whether they are the cause of child process
> INPUT_EVENT_RESPONSE_MS regressions
> 
> It doesn't look like this has caused any measurable change in the
> INPUT_EVENT_RESPONSE_MS telemetry probe.  I'm going to revert this patch
> now...

https://hg.mozilla.org/integration/mozilla-inbound/rev/1658b1c63226

Comment 10

[Ryan VanderMeulen [:RyanVM]]

Merge of backout:
https://hg.mozilla.org/mozilla-central/rev/1658b1c63226

Comment 11

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Backed out bug 1352889 today to see whether it is the cause.

Comment 12

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

The backout of bug 1352889 didn't make any difference.  I'm going to reland it, but that means you need to look for a different culprit here.

Comment 13

[Kan-Ru Chen [:kanru] (UTC+9)]

See bug 1362094 comment 25. We decided this bug is INCOMPLETE due to the limitation of the probes.

Comment 14

[Firefox Bug Husbandry Bot]

Removing leave-open keyword from resolved bugs, per :sylvestre.