Don't oversubscribe cores for framework crossgen on macOS; raise single-assembly timeout - #130261
#130261Merged
jtschuster merged 1 commit intoJul 7, 2026
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Don't oversubscribe cores for framework crossgen on macOS; raise single-assembly timeout#130261jtschuster merged 1 commit intodotnet:maindotnet/runtime:mainfrom jtschuster:jtschuster-crossgen2-parallelism-testjtschuster/runtime:jtschuster-crossgen2-parallelism-testCopy head branch name to clipboard
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…le-assembly timeout The Generate CORE_ROOT step compiles each framework assembly with a separate single-threaded crossgen2 process (-dop N --crossgen2-parallelism 1). On macOS the process count was cores+1, which oversubscribes and steals cycles from the critical-path System.Private.CoreLib compile, slowing the whole step. Use exactly the core count instead. Also raise the non-composite compilation timeout from 10 to 15 minutes so System.Private.CoreLib stops timing out on slower CI machines. Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
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Pull request overview
Adjusts framework crossgen2 orchestration used by src/tests/build.sh to avoid oversubscribing CPU cores on macOS and reduces spurious failures by increasing the default single-assembly compilation timeout used by the r2rtest process runner.
Changes:
- Update macOS processor-count detection to use the online core count exactly (removes the historical
+1). - Increase
r2rtest’s default non-composite compilation timeout from 10 to 15 minutes and document the rationale.
Reviewed changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.
| File | Description |
|---|---|
| src/tests/build.sh | Use getconf _NPROCESSORS_ONLN (no +1) for macOS when computing NUMBER_OF_PROCESSORS passed to build.proj / crossgen2 -dop. |
| src/coreclr/tools/r2rtest/ProcessRunner.cs | Raise DefaultIlcTimeout to 15 minutes and add explanatory comment for large single-assembly compiles. |
davidwrighton
approved these changes
Jul 6, 2026
eiriktsarpalis
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Jul 15, 2026
…le-assembly timeout (#130261) The Generate CORE_ROOT step compiles each framework assembly with a separate single-threaded crossgen2 process (`-dop N --crossgen2-parallelism 1`). On macOS the process count was `cores+1`, which oversubscribes and steals cycles from the critical-path `System.Private.CoreLib` compile, slowing the whole step. This uses exactly the core count instead. Also raises the non-composite compilation timeout from 10 to 15 minutes so `System.Private.CoreLib` stops timing out on slower Mac CI machines. Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
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The Generate CORE_ROOT step compiles each framework assembly with a separate single-threaded crossgen2 process (
-dop N --crossgen2-parallelism 1). On macOS the process count wascores+1, which oversubscribes and steals cycles from the critical-pathSystem.Private.CoreLibcompile, slowing the whole step. This uses exactly the core count instead.Also raises the non-composite compilation timeout from 10 to 15 minutes so
System.Private.CoreLibstops timing out on slower Mac CI machines.Note
This PR was generated with the assistance of GitHub Copilot.