On Wed, Jun 26, 2019 at 05:43:55PM +0800, Wanpeng Li wrote: > Hi all, > > After exposing mwait/monitor into kvm guest, the guest can make > physical cpu enter deeper cstate through mwait instruction, however, > the top command on host still observe 100% cpu utilization since qemu > process is running even though guest who has the power management > capability executes mwait. Actually we can observe the physical cpu > has already enter deeper cstate by powertop on host. Could we take > cstate into consideration when accounting cputime etc? Either we account runtime on the CPU itself, in which case it will not be in a C state due to actually running an interrupt that does accounting, or we do it remote (NOHZ_FULL case) and there is no way to know what C state, if any, that CPU is in.
