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llvm / llvm-project / 14c95e0c8b25f6deba47cd279c5dcdeef3870159
commit14c95e0c8b25f6deba47cd279c5dcdeef3870159[log] [tgz]
authorWael Yehia <wmyehia2001@yahoo.com>Tue Mar 18 14:13:15 2025 -0400
committerGitHub <noreply@github.com>Tue Mar 18 14:13:15 2025 -0400
tree3c7626622e15037bf8f8b32765b0173bb875ce96
parent8cc9a485792240314ad723dcf6661490850d2c98 [diff]
 [profile] Implement a non-mmap path when reading profile files from a non-local filesystem (#131177)

On AIX, when accessing mmap'ed memory associated to a file on NFS, a
SIGBUS might be raised at random.
The problem is still in open state with the OS team.

This PR teaches the profile runtime, under certain conditions, to avoid
the mmap when reading the profile file during online merging.
This PR has no effect on any platform other than AIX because I'm not
aware of this problem on other platforms.
Other platforms can easily opt-in to this functionality in the future.

The logic in function `is_local_filesystem` was copied from
[llvm/lib/Support/Unix/Path.inc](https://github.com/llvm/llvm-project/blob/f388ca3d9d9a58e3d189458b590ba68dfd9e5a2d/llvm/lib/Support/Unix/Path.inc#L515)
(https://reviews.llvm.org/D58801), because it seems that the
compiler-rt/profile cannot reuse code from llvm except through
`InstrProfData.inc`.

Thanks to @hubert-reinterpretcast for substantial feedback downstream.

---------

Co-authored-by: Wael Yehia <wyehia@ca.ibm.com>
Co-authored-by: Hubert Tong <hubert.reinterpretcast@gmail.com>
6 files changed
tree: 3c7626622e15037bf8f8b32765b0173bb875ce96
  1. .ci/
  2. .github/
  3. bolt/
  4. clang/
  5. clang-tools-extra/
  6. cmake/
  7. compiler-rt/
  8. cross-project-tests/
  9. flang/
  10. flang-rt/
  11. libc/
  12. libclc/
  13. libcxx/
  14. libcxxabi/
  15. libunwind/
  16. lld/
  17. lldb/
  18. llvm/
  19. llvm-libgcc/
  20. mlir/
  21. offload/
  22. openmp/
  23. polly/
  24. pstl/
  25. runtimes/
  26. third-party/
  27. utils/
  28. .clang-format
  29. .clang-tidy
  30. .git-blame-ignore-revs
  31. .gitattributes
  32. .gitignore
  33. .mailmap
  34. CODE_OF_CONDUCT.md
  35. CONTRIBUTING.md
  36. LICENSE.TXT
  37. pyproject.toml
  38. README.md
  39. SECURITY.md
README.md

The LLVM Compiler Infrastructure

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Welcome to the LLVM project!

This repository contains the source code for LLVM, a toolkit for the construction of highly optimized compilers, optimizers, and run-time environments.

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