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llvm / llvm-project / b034905c821884c59a8d882a1714b7a06bbbf6f3
commitb034905c821884c59a8d882a1714b7a06bbbf6f3[log] [tgz]
authorMircea Trofin <mtrofin@google.com>Fri Mar 14 21:10:22 2025 -0700
committerGitHub <noreply@github.com>Fri Mar 14 21:10:22 2025 -0700
treeed507ad1a47f5741e6f474b5e6ec62cfc30a387f
parenta3ce1cc3b0ea307157580fbf1a59fe4615caec71 [diff]
[ctxprof] Capture sampling info for context roots (#131201)

When we collect a contextual profile, we sample the threads entering its root and only collect on one at a time (see `ContextRoot::Taken`). If we want to compare profiles between contextual profiles, and/or flat profiles, we have a problem: we don't know how to compare the counter values relative to each other. To that end, we add `ContextRoot::TotalEntries`, which is incremented every time a root is entered and serves as multiplier for the counter values collected under that root.

We expose this in the profile and leave the normalization to the user of the profile, for a few reasons:

* it's only needed if reasoning about all profiles in aggregate.
* the goal, in compiler_rt, is to flush out the profile as quickly as possible, and performing multiplications adds an overhead that may not even be necessary if the consumer of the profile doesn't care about combining profiles
* the information itself may be interesting as an indication of relative sampling of various contexts.
30 files changed
tree: ed507ad1a47f5741e6f474b5e6ec62cfc30a387f
  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.

The LLVM project has multiple components. The core of the project is itself called “LLVM”. This contains all of the tools, libraries, and header files needed to process intermediate representations and convert them into object files. Tools include an assembler, disassembler, bitcode analyzer, and bitcode optimizer.

C-like languages use the Clang frontend. This component compiles C, C++, Objective-C, and Objective-C++ code into LLVM bitcode -- and from there into object files, using LLVM.

Other components include: the libc++ C++ standard library, the LLD linker, and more.

Getting the Source Code and Building LLVM

Consult the Getting Started with LLVM page for information on building and running LLVM.

For information on how to contribute to the LLVM project, please take a look at the Contributing to LLVM guide.

Getting in touch

Join the LLVM Discourse forums, Discord chat, LLVM Office Hours or Regular sync-ups.

The LLVM project has adopted a code of conduct for participants to all modes of communication within the project.