1958441 - 75% tenuring rate on opening a large gecko profile

Status: NEW

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

Description

[Mayank Bansal]

Gecko/samply profile: https://profiler.firefox.com/public/fd0csrmc01c9ktds4rpdzpt8m1q6g9m5j96s7a0/calltree/?globalTrackOrder=0wDb&symbolServer=http%3A%2F%2F127.0.0.1%3A3000%2F27na21nsk5x7xgrs9p7gmfjqj54hh1cfvzp7jd3&thread=zPr&v=10

Profile of capturing the profile: https://share.firefox.dev/3FOupPA (14s)
Chrome: https://share.firefox.dev/4clY8LR (9s)

Comment 1

[Iain Ireland [:iain]]

Many of the minor GCs seem to be triggered by allocating lambdas using NewFunctionClone, which does not do pretenuring.

I also see some GCs triggered via CallObject::createWithShape, which similarly does not pretenure.

Comment 2

[Mayank Bansal]

Bug 1898270 has some ideas on pretenuring lambdas.