On Wed, Mar 22, 2017 at 10:10:05AM -0400, Gabriel L. Somlo wrote: > On Wed, Mar 22, 2017 at 03:35:18PM +0200, Michael S. Tsirkin wrote: > > On Tue, Mar 21, 2017 at 05:02:25PM -0700, Nadav Amit wrote: > > > > > > > On Mar 21, 2017, at 3:51 PM, Gabriel Somlo <gsomlo@xxxxxxxxx> wrote: > > > > > > > > And I get the exact same results on the MacBookAir4,2 (which exhibits > > > > no freezing or extreme sluggishness when running OS X 10.7 smp with > > > > Michael's KVM MWAIT-in-L1 patch)... > > > > > > Sorry for my confusion. I didn’t read the entire thread and thought that > > > the problem is spurious wake-ups. > > > > > > Since that is not the case, I would just suggest two things that you can > > > freely ignore: > > > > > > 1. According to the SDM, when an interrupt is delivered, the interrupt > > > is only delivered on the following instruction, so you may consider > > > skipping the MWAIT first. > > > > > > 2. Perhaps the CPU changes for some reason GUEST_ACTIVITY_STATE (which > > > is not according to the SDM). > > > > > > That is it. No more BS from me. > > > > > > Nadav > > > > Intersting. I found this errata: > > A REP STOS/MOVS to a MONITOR/MWAIT Address Range May Prevent Triggering of > > the Monitoring Hardware > > Any way to tell if they mean that for L0, or L>=1, or all of them? > > > Could the macbook CPU be affected? > > I ran a grep on the log file I collected when disassembling > AppleIntelCPUPowerManagement.kext (where the MWAIT-based idle > thread lives) a few days ago, and didn't find any "rep stos" or > "rep movs" instances. > Right but that would be on the waking side, not the one that does mwait. -- MST
