From 8c0ff9508da5f02e8ce6580a126a2018c9bf702a Mon Sep 17 00:00:00 2001 From: Rafael Espindola Date: Wed, 4 Oct 2017 20:27:01 +0000 Subject: Bring r314809 back. But now include a check for CPU_COUNT so we still build on 10 year old versions of glibc. Original message: Use sched_getaffinity instead of std::thread::hardware_concurrency. The issue with std::thread::hardware_concurrency is that it forwards to libc and some implementations (like glibc) don't take thread affinity into consideration. With this change a llvm program that can execute in only 2 cores will use 2 threads, even if the machine has 32 cores. This makes benchmarking a lot easier, but should also help if someone doesn't want to use all cores for compilation for example. llvm-svn: 314931 --- llvm/lib/Support/Parallel.cpp | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'llvm/lib/Support/Parallel.cpp') diff --git a/llvm/lib/Support/Parallel.cpp b/llvm/lib/Support/Parallel.cpp index ab2cfdebf07..010e42916f9 100644 --- a/llvm/lib/Support/Parallel.cpp +++ b/llvm/lib/Support/Parallel.cpp @@ -9,6 +9,7 @@ #include "llvm/Support/Parallel.h" #include "llvm/Config/llvm-config.h" +#include "llvm/Support/Threading.h" #include #include @@ -70,8 +71,7 @@ Executor *Executor::getDefaultExecutor() { /// in filo order. class ThreadPoolExecutor : public Executor { public: - explicit ThreadPoolExecutor( - unsigned ThreadCount = std::thread::hardware_concurrency()) + explicit ThreadPoolExecutor(unsigned ThreadCount = hardware_concurrency()) : Done(ThreadCount) { // Spawn all but one of the threads in another thread as spawning threads // can take a while. -- cgit v1.2.3