From 2611c4d90535652d3eb7ef4a026a6691276fab43 Mon Sep 17 00:00:00 2001 From: Lasse Collin Date: Thu, 20 Oct 2022 20:22:50 +0300 Subject: tuklib_cpucores: Use HW_NCPUONLINE on OpenBSD. On OpenBSD the number of cores online is often less than what HW_NCPU would return because OpenBSD disables simultaneous multi-threading (SMT) by default. Thanks to Christian Weisgerber. --- src/common/tuklib_cpucores.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'src/common') diff --git a/src/common/tuklib_cpucores.c b/src/common/tuklib_cpucores.c index cc968dd2..bb3f2f75 100644 --- a/src/common/tuklib_cpucores.c +++ b/src/common/tuklib_cpucores.c @@ -72,7 +72,16 @@ tuklib_cpucores(void) } #elif defined(TUKLIB_CPUCORES_SYSCTL) + // On OpenBSD HW_NCPUONLINE tells the number of processor cores that + // are online so it is preferred over HW_NCPU which also counts cores + // that aren't currently available. The number of cores online is + // often less than HW_NCPU because OpenBSD disables simultaneous + // multi-threading (SMT) by default. +# ifdef HW_NCPUONLINE + int name[2] = { CTL_HW, HW_NCPUONLINE }; +# else int name[2] = { CTL_HW, HW_NCPU }; +# endif int cpus; size_t cpus_size = sizeof(cpus); if (sysctl(name, 2, &cpus, &cpus_size, NULL, 0) != -1 -- cgit v1.2.3