Исходное сообщение
"В OpenBSD добавлен код программного отключения SMT (HyperThr..." Отправлено PereresusNeVlezaetBuggy, 20-Июн-18 20:50
>[оверквотинг удален] > cause performance penalties >      under certain loads, the logical CPUs can > be disabled by setting the >      machdep.hyperthreading_allowed tunable to zero. > > https://www.opennet.ru/openforum/vsluhforumID3/12174.html#13 >> 1.13, Аноним, 14:24, 08/09/2005 >> 2xXeon 2.8 >> machdep.hyperthreading_allowed=1 > ? Как минимум в том, что фряшники енто дело грохнули лет семь назад, как я понимаю: -20110608: -    The following sysctls and tunables are retired on x86 platforms: -        machdep.hlt_cpus -        machdep.hlt_logical_cpus -    The following sysctl is retired: -        machdep.hyperthreading_allowed -    The sysctls were supposed to provide a way to dynamically offline and -    online selected CPUs on x86 platforms, but the implementation has not -    been reliable especially with SCHED_ULE scheduler. -    machdep.hyperthreading_allowed tunable is still available to ignore -    hyperthreading CPUs at OS level. -    Individual CPUs can be disabled using hint.lapic.X.disabled tunable, -    where X is an APIC ID of a CPU.  Be advised, though, that disabling -    CPUs in non-uniform fashion will result in non-uniform topology and -    may lead to sub-optimal system performance with SCHED_ULE, which is -    a default scheduler. https://marc.info/?l=freebsd-commits-all&m=139939109320608&w=2