On Thu, 2011-08-11 at 12:25 -0700, Turquette, Mike wrote: > On Thu, Aug 11, 2011 at 11:30 AM, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote: > > On Wed, 2011-08-10 at 13:03 -0700, Mike Turquette wrote: > >> This patch series introduces a new cpumask which tracks CPUs that > >> support hotplugging. The purpose of this patch series is to provide a > >> simple method for kernel code to know which CPUs can be hotplugged and > >> which ones cannot. Potential users of this code might be a thermal > >> mitigation technique which uses hotplug to lower temperature, or a power > >> capping mechanism which uses hotplug to lower power consumption. > >> > >> All the of usual cpumask helper functions are created for this new mask. > >> The second patch in this series simply sets the bit for elligible CPUs > >> while they are being registered. The cpumask itself is static after > >> boot and should not change (like the possbile mask). > > > > I still most strongly object to people using hotplug for these goals. > > > > Why do you need to go through the entire dance of hotplug just to idle a > > cpu? Hotplug not only idles the cpu but tears down (and rebuilds) an > > insane amount of resources associated with the cpu. > > I think you're nacking the wrong series. This patchset simply allows > kernel space to know which CPUs can go offline and which one can't, > which seems pretty innocuous. Are you fundamentally opposed to the > kernel having better accessor functions to this data? Yeah, people might think its sane to use it.. > I'll soon be posting some code which does implement hotplug as a > power-capping feature. I think *that* is the patch that you'll want > to nack. That too of course.. _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
