[release/7.0] Support multiple processor groups for NativeAOT #75174
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Backport of #75165 to release/7.0
/cc @AntonLapounov
Customer Impact
NativeAOT does not account for availability of multiple processor groups on Windows. That may lead to unexpected drops in performance. For instance, on an 80 core Ampere machine with Windows Server 2022, about a half of NativeAOT processes would start with
Environment.ProcessorCount
equal to 16 and only 16 server GC heaps.Risk
For CoreCLR, the risk is very low as its code is only minimally affected. For NativeAOT, there is a little risk that enabling multiple processor groups may hit some issues on previously unexecuted (by NativeAOT) code paths in GC. However, this risk is limited to Windows 11/Windows Server 2022 machines with multiple processor groups (typically, that means 65 or more processors).