1433266 - Add a telemetry probe for count of tile jobs queued to PaintThread in transaction

Status: RESOLVED WONTFIX

(Core :: Graphics: Layers, enhancement, P3)

Description

[Ryan Hunt [:rhunt]]

This would be nice to know to have a grasp on how much work we can expect to be parallelized with tiled OMTP.

Comment 1

[Ryan Hunt [:rhunt]]

Attachment: omtp-telemetry.patch

From brief testing, I rarely see counts of over 50 jobs queued so I think 100 is an okay limit. I'll flag this for data-review if there are no changes we want to make to what we collect.

Comment 2

[Milan Sreckovic [:milan] (needinfo for best results)]

Comment on attachment 8945591 [details] [diff] [review]
omtp-telemetry.patch

Review of attachment 8945591 [details] [diff] [review]:
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This should get a data review as well.

Comment 3

[[e-mail]]

:milan, do we have answers to the data review request form listed here? 

https://github.com/mozilla/data-review/blob/master/request.md

Comment 4

[Ryan Hunt [:rhunt]]

1. What questions will you answer with this data?

Should we increase the amount of tiles we use when painting to improve performance with parallel OMTP?

2. Why does Mozilla need to answer these questions? Are there benefits for users? Do we need this information to address product or business requirements? Some example responses:

It will help guide us in making this performance sensitive decision, which could improve product quality.

3. What alternative methods did you consider to answer these questions? Why were they not sufficient?

I considered local testing with this probe, but my local browsing is most likely not representative of our actual users, which could skew the decision.

4. Can current instrumentation answer these questions?

No.

5. List all proposed measurements and indicate the category of data collection for each measurement, using the Firefox data collection categories on the found on the Mozilla wiki.

Measurement Description: Amount of tiles painted in a frame
Data Collection Category: Technical data
Tracking Bug #: This bug, bug 1433266

6. How long will this data be collected? Choose one of the following:

This is only needed for a short period to collect data for this decision, I plan to remove it by the end of this 61 nightly cycle.

7. What populations will you measure?

Nightly

8. If this data collection is default on, what is the opt-out mechanism for users?

This will be in nightly so it will be opt-out like the other extended telemetry probes

9. Please provide a general description of how you will analyze this data.

I plan on comparing this distribution with the distribution of cpu_cores

10. Where do you intend to share the results of your analysis?

Internally in discussions about this decision

Comment 5

[Ryan Hunt [:rhunt]]

I don't really have strong plans to continue with this. It's unclear whether this probe would give us actionable information for tiling or paint worker count. Closing this for now.