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| author | Lasse Collin <lasse.collin@tukaani.org> | 2022-10-20 20:22:50 +0300 |
|---|---|---|
| committer | Lasse Collin <lasse.collin@tukaani.org> | 2022-11-11 13:28:56 +0200 |
| commit | 5daa40454b63c4eb04ab5caeb339eddc95c94bb1 (patch) | |
| tree | f541d54a2f0842572db81a16db095b6fff658ed4 | |
| parent | NEWS: Omit the extra copy of 5.2.5 NEWS. (diff) | |
| download | xz-5daa40454b63c4eb04ab5caeb339eddc95c94bb1.tar.xz | |
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.
| -rw-r--r-- | m4/tuklib_cpucores.m4 | 5 | ||||
| -rw-r--r-- | src/common/tuklib_cpucores.c | 9 |
2 files changed, 14 insertions, 0 deletions
diff --git a/m4/tuklib_cpucores.m4 b/m4/tuklib_cpucores.m4 index a2b09a72..c5cee23e 100644 --- a/m4/tuklib_cpucores.m4 +++ b/m4/tuklib_cpucores.m4 @@ -103,7 +103,12 @@ compile error int main(void) { +#ifdef HW_NCPUONLINE + /* This is preferred on OpenBSD, see tuklib_cpucores.c. */ + int name[2] = { CTL_HW, HW_NCPUONLINE }; +#else int name[2] = { CTL_HW, HW_NCPU }; +#endif int cpus; size_t cpus_size = sizeof(cpus); sysctl(name, 2, &cpus, &cpus_size, NULL, 0); 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 |