On Fri, 2009-09-25 at 12:36 +0530, Vaidyanathan Srinivasan wrote: > * Arjan van de Ven <ar...@infradead.org> [2009-09-24 14:22:28]: > > > On Thu, 24 Sep 2009 10:42:41 +0530 > > Arun R Bharadwaj <a...@linux.vnet.ibm.com> wrote: > > > > > * Arun R Bharadwaj <a...@linux.vnet.ibm.com> [2009-09-22 16:55:27]: > > > > > > Hi Len, (or other acpi folks), > > > > > > I had a question regarding ACPI-cpuidle interaction in the current > > > implementation. > > > > > > Currently, every cpu (i.e. acpi_processor) registers to cpuidle as > > > a cpuidle_device. So every cpu has to go through the process of > > > setting up the idle states and then registering as a cpuidle device. > > > > > > What exactly is the reason behind this? > > > > > > > technically a BIOS can opt to give you C states via ACPI on some cpus, > > but not on others. > > > > in practice when this happens it tends to be a bug.. but it's > > technically a valid configuration > > So we will need to keep the per-cpu registration as of now because we > may have such buggy BIOS in the field and we don't want the cpuidle > framework to malfunction there.
If the BIOS doesn't mention a certain C state on a cpu, and you try to set it anyway, does that go boom? This whole per-cpu registration thing is horridly ugly, can't you have a per-cpu C state exception mask and leave it at that -- if its really needed? _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
