config: enabling madvise syscalls for user mode deallocations#138
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This config change includes madvise.o in the final build image, enabling madvise syscalls. This is necessary because MiMalloc (the allocator for OpenHCL) uses madvise syscalls to deallocate memory. Without this change, madvise is excluded from the final build image resulting in the syscalls for deallocating memory from the user mode being unrecognized by the kernel. This results in a major memory leak where no user mode process is able to free physical memory. OpenHCL builds with the kernel with this fix indicate steady memory usage in a reproduction scenario that would otherwise expose the memory leak.
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Pull request overview
This PR updates the OpenHCL kernel configuration to ensure madvise()/fadvise() syscalls (and the associated mm/madvise.o object) are included in the build, which is required for MiMalloc’s user-mode deallocation behavior.
Changes:
- Enable
CONFIG_ADVISE_SYSCALLS=yfor x64 OpenHCL kernel config. - Enable
CONFIG_ADVISE_SYSCALLS=yfor arm64 OpenHCL kernel config.
Reviewed changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.
| File | Description |
|---|---|
| Microsoft/hcl-x64.config | Enables CONFIG_ADVISE_SYSCALLS so madvise()/fadvise() syscalls are built/available on x64. |
| Microsoft/hcl-arm64.config | Enables CONFIG_ADVISE_SYSCALLS so madvise()/fadvise() syscalls are built/available on arm64. |
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This config change includes madvise.o in the final build image, enabling madvise syscalls. This is necessary because MiMalloc (the allocator for OpenHCL) uses madvise syscalls to deallocate memory. Without this change, madvise is excluded from the final build image resulting in the syscalls for deallocating memory from the user mode being unrecognized by the kernel. This results in a major memory leak where no user mode process is able to free physical memory. OpenHCL builds with the kernel with this fix indicate steady memory usage in a reproduction scenario that would otherwise expose the memory leak.