For llvm's internal function which retrieves the number of available

"hardware threads", use cpuset_getaffinity(2) on FreeBSD, so it will
honor processor sets configured by the cpuset(1) command.

This should make it possible to avoid e.g. lld creating a huge number of
threads on a machine with many cores, even for linking simple programs.

This will also be submitted upstream.

Submitted by:	mjg
MFC after:	1 week
This commit is contained in:
Dimitry Andric 2020-11-18 19:55:24 +00:00
parent 1463aa8cf2
commit 991f6e7534
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=367815

View File

@ -26,6 +26,10 @@
#include <pthread_np.h> // For pthread_getthreadid_np() / pthread_set_name_np()
#endif
#if defined(__FreeBSD__)
#include <sys/cpuset.h>
#endif
#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
#include <errno.h>
#include <sys/sysctl.h>
@ -282,6 +286,13 @@ SetThreadPriorityResult llvm::set_thread_priority(ThreadPriority Priority) {
#include <thread>
int computeHostNumHardwareThreads() {
#ifdef __FreeBSD__
cpuset_t mask;
CPU_ZERO(&mask);
if (cpuset_getaffinity(CPU_LEVEL_WHICH, CPU_WHICH_TID, -1, sizeof(mask),
&mask) == 0)
return CPU_COUNT(&mask);
#endif
#ifdef __linux__
cpu_set_t Set;
if (sched_getaffinity(0, sizeof(Set), &Set) == 0)