Robert Watson wrote:
In the mean time, it sounds like the sysctl does need to be reimplemented or removed, but one question is how far to take it -- caches are shared to varying degrees at varying levels of the topology. However, I believe the recommendation has generally moved to disabling hyperthreading using the BIOS, as that uses the vendor's notion of hyperthreading. The idea of changing the setting at run-time is currently untenable because we don't have the OS infrastructure to take CPUs out of service, although growing it would be useful in order to support virtual machine dynamic CPU reconfiguration.
Well, as far as I know, what SCHED_4BSD does is simply stopping scheduling threads to the logical core(s). One doesn't need infrastructure to take CPU off-line for doing the same in SCHED_ULE.
Unfortunately access to BIOS is not always an option and also some BIOSes don't even provide a feature to turn HTT off.
-Maxim _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
