Chromium's V8 Optimizer toggle for disabling JavaScript JIT compilation was changed to only disable the 2 higher tiers of JIT compilation while still leaving the baseline JIT compiler enabled. This also caused the device management policy for JIT predating this to change meaning.
They did this because they decided having a toggle which breaks WebAssembly support is unacceptable. We had to revert these changes.
Microsoft Edge implemented a WebAssembly interpreter instead, but it's not open source and there's nothing like it for Chrome yet.
Vanadium disables JS JIT by default and provides a convenient per-site toggle available in the drop down menu next to the URL. We've restored the previous meaning of disabling the JIT so you'll need to add exceptions for sites requiring WebAssembly again.
In theory, we could add 4 choices instead of 2: Disabled, Baseline JIT, Baseline JIT + Tier 2 and Full JIT. However, it's likely far too complicated and we're likely going to stick with having it either enabled or disabled. Chromium will hopefully add a WASM interpreter soon...
#grapheneos
final [GrapheneOS] 📱👁️🗨️
npub1c9…7sqfm
2024-07-01 04:34:01
Author Public Key
npub1c9d95evcdeatgy6dacats5j5mfw96jcyu79579kg9qm3jtf42xzs07sqfmPublished at
2024-07-01 04:34:01Event JSON
{
"id": "9d78be3e6212edb6d01622d0a845b16eb6b99c489f7b35c18bb0deb144108569",
"pubkey": "c15a5a65986e7ab4134dee3ab85254da5c5d4b04e78b4f16c82837192d355185",
"created_at": 1719808441,
"kind": 1,
"tags": [
[
"t",
"grapheneos"
]
],
"content": "Chromium's V8 Optimizer toggle for disabling JavaScript JIT compilation was changed to only disable the 2 higher tiers of JIT compilation while still leaving the baseline JIT compiler enabled. This also caused the device management policy for JIT predating this to change meaning.\n\nThey did this because they decided having a toggle which breaks WebAssembly support is unacceptable. We had to revert these changes.\n\nMicrosoft Edge implemented a WebAssembly interpreter instead, but it's not open source and there's nothing like it for Chrome yet.\n\nVanadium disables JS JIT by default and provides a convenient per-site toggle available in the drop down menu next to the URL. We've restored the previous meaning of disabling the JIT so you'll need to add exceptions for sites requiring WebAssembly again.\n\nIn theory, we could add 4 choices instead of 2: Disabled, Baseline JIT, Baseline JIT + Tier 2 and Full JIT. However, it's likely far too complicated and we're likely going to stick with having it either enabled or disabled. Chromium will hopefully add a WASM interpreter soon...\n\n#grapheneos",
"sig": "1b768e14e47cfe0ca363f37dd322ea977a99c9f283cfc32290a9bb239eb4d9afb6db2e655ed21cf2ff46f44db91e9e18de287d0f80167e368b3dbf38daf2af53"
}