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| author | Teresa Johnson <tejohnson@google.com> | 2018-08-17 13:19:36 +0000 |
|---|---|---|
| committer | Teresa Johnson <tejohnson@google.com> | 2018-08-17 13:19:36 +0000 |
| commit | c9818ebc02b9ae0ef5cee50a9fb60a9626c6274e (patch) | |
| tree | 2aacb04147706e7627a49c0221000362749ab48c /clang/docs/ThinLTO.rst | |
| parent | 16a2f54eee3bfd7844ac6d1fde1abdd0be4c471f (diff) | |
| download | bcm5719-llvm-c9818ebc02b9ae0ef5cee50a9fb60a9626c6274e.tar.gz bcm5719-llvm-c9818ebc02b9ae0ef5cee50a9fb60a9626c6274e.zip | |
[ThinLTO] Correct documentation on default number of threads
Summary:
The number of threads used for ThinLTO backend parallelism was
dropped to the number of cores in r284618 to avoid oversubscribing
physical cores due to hyperthreading. This updates the documentation
to reflect that change.
Fixes PR38610.
Reviewers: pcc
Subscribers: mehdi_amini, inglorion, eraman, steven_wu, dexonsmith, cfe-commits
Differential Revision: https://reviews.llvm.org/D50882
llvm-svn: 340021
Diffstat (limited to 'clang/docs/ThinLTO.rst')
| -rw-r--r-- | clang/docs/ThinLTO.rst | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/clang/docs/ThinLTO.rst b/clang/docs/ThinLTO.rst index 38873f464c2..05a0b67dbab 100644 --- a/clang/docs/ThinLTO.rst +++ b/clang/docs/ThinLTO.rst @@ -105,7 +105,9 @@ Controlling Backend Parallelism ------------------------------- .. _parallelism: -By default, the ThinLTO link step will launch up to +By default, the ThinLTO link step will launch as many +threads in parallel as there are cores. If the number of +cores can't be computed for the architecture, then it will launch ``std::thread::hardware_concurrency`` number of threads in parallel. For machines with hyper-threading, this is the total number of virtual cores. For some applications and machine configurations this |
