2011/5/28 Attilio Rao <[email protected]>: > 2011/5/25 Andriy Gapon <[email protected]>: >> on 23/05/2011 19:28 Andriy Gapon said the following: >>> I propose the following path for moving forward. >>> - use hint.lapic.X.disabled to disable individual CPUs by their APIC ID >>> - use machdep.hyperthreading_allowed tunable to disable second logical CPU >>> on each >>> real core >>> >>> The above should already work as expected. One thing is that currently we >>> have >>> handling of machdep.hyperthreading_allowed tunable under SCHED_ULE. I plan >>> to >>> make it unconditional. >>> >>> Things to remove: >>> - all the related sysctls for dynamic onlining/offlining >>> - machdep.hlt_logical_cpus tunable (it duplicates hint.lapic.X.disabled) >>> >>> It's possible to keep machdep.hlt_logical_cpus and just add some code to >>> convert >>> hlt_logical_cpus mask to a set of individual hint.lapic.X.disabled, but I >>> don't >>> see very much value in that. But if there is a good reason to keep that >>> tunable, >>> I am prepared to jump through this hoop. >>> >>> If no one objects to this proposal, I will provide a patch soon. >> >> The patch is here: >> http://people.freebsd.org/~avg/cpu-offline-sysctl.diff >> It should implement the strategy described above. >> > > I don't see the point in keeping alive mp_grab_cpu_hlt() and > supporting, actually. > > On the top of your patch I made some modifies that use directly > ap_watchdog() in cpu_idle() which I think is better for the time > being: > http://www.freebsd.org/~attilio/avg_rem_cpuhlt.diff > > If you are happy with it, just commit as long as Garrett tests that. > > On a second round of changes we can discuss mp_watchdog and eventual > removal / improvements to it.
I almost forgot: this change would also require an UPDATE entry, where you explicitly mention the "new" way to deal with CPUs. Use your prefer wording. Attilio -- Peace can only be achieved by understanding - A. Einstein _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "[email protected]"
