1817741 - Add telemetry for parallel marking

Status: RESOLVED FIXED

(Core :: JavaScript: GC, task, P3)

Description

[Jon Coppeard (:jonco)]

From the recent experiment it looks like parallel marking is going to be a useful improvement. We will need some telemetry to track improvements and identify regressions.

Comment 1

[Jon Coppeard (:jonco)]

Attachment: Bug 1817741 - Part 1: Add stats phases and telemetry for parallel marking r?sfink

This adds a stast phase PARALLEL_MARK which is used for total time on both main
and helper threads. Addtionally, helper threads record PARALLEL_MARK_MARK and
PARALLEL_MARK_WAIT.

The patch also adds three telemetry probes related to parallel marking:

• GC_PARALLEL_MARK_SPEEDUP - Ratio of total helper thread time spent marking to main thread time
• GC_PARALLEL_MARK_UTILIZATION - Ratio of helper thread time spent marking to total helper thread time
• GC_PARALLEL_MARK_INTERRUPTIONS - Number of interruptions/donations per slice

Comment 2

[Jon Coppeard (:jonco)]

Attachment: Bug 1817741 - Part 2: Add gecko profiler markers for parallel marking events r?sfink

Depends on D170379

Comment 3

[Jon Coppeard (:jonco)]

Attachment: data_collection_request.txt

Comment 4

[Travis Long [:travis_]]

Comment on attachment 9318798 [details]
data_collection_request.txt

Data Review

1. Is there or will there be documentation that describes the schema for the ultimate data set in a public, complete, and accurate way?

Yes, through the definitions files and the Probe Dictionary.

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

Yes, through the standard telemetry preferences in the application settings.

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

Permanent collection to be monitored by Jon Coppeard

4. 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 data

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

Default-on

6. Does the instrumentation include the addition of any new identifiers (whether anonymous or otherwise; e.g., username, random IDs, etc. See the appendix for more details)?

No

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

Yes

8. Does the data collection use a third-party collection tool?

No

Result

data-review+

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/d55afed085e2
Part 1: Add stats phases and telemetry for parallel marking r=sfink
https://hg.mozilla.org/integration/autoland/rev/214b5a1cdc71
Part 2: Add gecko profiler markers for parallel marking events r=canaltinova

Comment 6

[Marian-Vasile Laza]

https://hg.mozilla.org/mozilla-central/rev/d55afed085e2
https://hg.mozilla.org/mozilla-central/rev/214b5a1cdc71

Comment 7

[Jon Coppeard (:jonco)]

Attachment: Bug 1817741 - Fix missed code review comment r?sfink

This was picked up in code review but I forgot to fix it before landing. This
code should have been moved to a later patch, as the comment said.

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/4fcbcad85235
Fix missed code review comment r=sfink

Comment 9

[BugBot [:suhaib / :marco/ :calixte]]

A patch has been attached on this bug, which was already closed. Filing a separate bug will ensure better tracking. If this was not by mistake and further action is needed, please alert the appropriate party. (Or: if the patch doesn't change behavior -- e.g. landing a test case, or fixing a typo -- then feel free to disregard this message)

Comment 10

[Marian-Vasile Laza]

https://hg.mozilla.org/mozilla-central/rev/4fcbcad85235