1854135 - Let `MOZ_PHC` ride the trains

Status: RESOLVED FIXED

(Core :: Memory Allocator, task, P1)

Description

[Paul Bone [:pbone]]

We want to test PHC in release. It's now controlled by a pref but we need to build support in release versions of Firefox. That means letting the configuration and #ifdef ride the trains.

We also want to set some different constants for tuning PHC on release.

Comment 1

[Paul Bone [:pbone]]

Attachment: Bug 1854135 - Set --enable-phc for release r=glandium

--enable-phc builds firefox with PHC support. It's not enabled unless the
phc pref is also set. So this change will cause PHC support to ride the
trains, but in a disabled state.

Comment 2

[Paul Bone [:pbone]]

Attachment: Bug 1854135 - Set PHC's size to limit it to 1.1MiB per process in release r=decoder

Depends on D188821

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/f98408e7e1f8
Set --enable-phc for release r=glandium
https://hg.mozilla.org/integration/autoland/rev/6d12b530a5c9
Set PHC's size to limit it to 1.1MiB per process in release r=decoder

Comment 4

[Narcis Beleuzu [:NarcisB]]

https://hg.mozilla.org/mozilla-central/rev/f98408e7e1f8
https://hg.mozilla.org/mozilla-central/rev/6d12b530a5c9

Comment 5

[Paul Bone [:pbone]]

Comment on attachment 9354318 [details]
Bug 1854135 - Set --enable-phc for release r=glandium

Beta/Release Uplift Approval Request

• User impact if declined: PHC is a feature that helps engineers debug UAF crashes. We'd like to ship the code to release behind a pref so that we can begin experiments which will help us prepare for an rollout. These patches ifdef PHC into the build in late beta and release on 64bit desktop builds.
• Is this code covered by automated tests?: Yes
• Has the fix been verified in Nightly?: Yes
• Needs manual test from QE?: No
• If yes, steps to reproduce:
• List of other uplifts needed: Bug 1859964
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): PHC has been used in Nightly for years. This patch ifdefs PHC into Firefox, but PHC is only used if a pref is set (default is off).
• String changes made/needed:
• Is Android affected?: No

Comment 6

[Dianna Smith [:diannaS]]

Comment on attachment 9354318 [details]
Bug 1854135 - Set --enable-phc for release r=glandium

Approved for 120.0b3

Comment 7

[Pulsebot]

https://hg.mozilla.org/releases/mozilla-beta/rev/9988d6c034e4
https://hg.mozilla.org/releases/mozilla-beta/rev/44ba83304566