1524090 - add telemetry probe to capture GPU processing time

Status: RESOLVED FIXED

(Core :: Graphics: WebRender, enhancement)

Description

[Benjamin De Kosnik [:bdekoz]]

In discussing the WebRender status dashboard (1) with Matt Woodrow, he indicated that there are currently no probes that indicate the time where the GPU has finished processing submitted commands.

Such a probe would help improve coverage of telemetry probes over the full browser engine, and may be useful (or required?) for future W3C work on layout or navigation timing.

(1) - https://metrics.mozilla.com/webrender/dashboard.html

Comment 1

[Jeff Muizelaar [:jrmuizel]]

Attachment: A first attempt

Here's a quick patch to capture the amount of time that we spend waiting on the GPU. This approach has the advantage of not requiring any additional GPU queries to implement and ends up only recording times where were actually blocked on the GPU.

Comment 2

[Jeff Muizelaar [:jrmuizel]]

Attachment: request.md

Comment 3

[Jeff Muizelaar [:jrmuizel]]

Attachment: Bug 1524090. Add telemetry for GPU wait time.

Comment 4

[Chris H-C :chutten]

Comment on attachment 9048509 [details]
request.md

DATA COLLECTION REVIEW RESPONSE:

    Is there or will there be documentation that describes the schema for the ultimate data set available publicly, complete and accurate?

Yes. This collection is Telemetry so is documented in its definitions file [Histograms.json](https://hg.mozilla.org/mozilla-central/file/tip/toolkit/components/telemetry/Histograms.json) and the [Probe Dictionary](https://telemetry.mozilla.org/probe-dictionary/).

    Is there a control mechanism that allows the user to turn the data collection on and off?

Yes. This collection is Telemetry so can be controlled through Firefox's Preferences.

    If the request is for permanent data collection, is there someone who will monitor the data over time?

No. This collection will expire in Firefox 82.

    Using the category system of data types on the Mozilla wiki, what collection type of data do the requested measurements fall under?

Category 1, Technical.

    Is the data collection request for default-on or default-off?

Default on for all channels.

    Does the instrumentation include the addition of any new identifiers?

No.

    Is the data collection covered by the existing Firefox privacy notice?

Yes.

    Does there need to be a check-in in the future to determine whether to renew the data?

Yes. :jrmuizel is responsible for renewing or removing the collection before it expires in Firefox 82.

---
Result: datareview+

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/5b73beb33ff1
Add telemetry for GPU wait time. r=mattwoodrow,chutten

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/2b58359864c3
Add telemetry for GPU wait time. r=mattwoodrow,chutten

Comment 7

[Pulsebot]

Backout by [e-mail]:
https://hg.mozilla.org/mozilla-central/rev/2a08410b3cdc
Backed out changeset 5b73beb33ff1 as per jmuizelaar`s req. CLOSED TREE

Comment 8

[Oana Pop-Rus]

https://hg.mozilla.org/mozilla-central/rev/2b58359864c3