1888803 - On AST explorer, 85% nursery promotion rate on VUE-eslint parser

Status: RESOLVED WORKSFORME

(Core :: JavaScript Engine, task, P3)

Description

[Mayank Bansal]

Go to https://astexplorer.net/
From the top bar, select "VUE" as the input type, and " VUE-Eslint-parser" as the parser.
Copy-paste the sample text.

AR:
Senispace enabled: https://share.firefox.dev/49jAyfq
Semispace disabled: https://share.firefox.dev/49gsyfh

ER: Something to improve?

Comment 1

[Mayank Bansal]

Attachment: moz bundle.txt

Comment 2

[Matthew Gaudet (he/him) [:mgaudet]]

Jon: The pair of profiles seem to show that the semispace version is tenuring about 14% more cells than the one with semispace disabled; Not sure if this is expected or not.

Comment 3

[Jon Coppeard (:jonco)]

Semispace is an experimental feature and is not ready for performance testing. Mayank, thanks for filing this but it's not worth measuring performance with semispace enabled yet.

Probably we're tenuring more because we're using half the nursery at a time, making the max size it can grow to smaller smaller.

Comment 4

[Mayank Bansal]

Putting the semispace vs non-semiepsace was an afterthought and just as an additional data/reference point.
My original intent of filing this bug was a more general "we have high (70%-85%) tenuring rate on this testcase. Given that the intent is to usually keep it under 2%, Is there anything to improve?".

---

To rephrase the bug with my original intent:
In default Nightly with the STR: https://share.firefox.dev/49gsyfh (~70% tenuring rate).
Is this worth investigating further? If no, happy to close as WONTFIX.

(ni you so you dont miss the question).

Comment 5

[Mayank Bansal]

Profile with latest Nightly: https://share.firefox.dev/47NSJel

Comment 6

[Mayank Bansal]

not sure if this is worth relooking.