On 09/14/10 10:00, Michael Tokarev wrote: > 14.09.2010 19:51, David S. Ahern пишет: >> cat /sys/devices/system/clocksource/clocksource0/current_clocksource > > It's tsc (AthlonII CPU). Also available are hpet and acpi_pm. > Switching to hpet or acpi_pm does not have visible effect, at > least not while the guest is running. acpi_pm takes more cycles to read. On my laptop switching from hpet to acpi_pm caused the winxp VM to jump up in CPU usage. For both time sources 'perf top -p <pid of main thread>' shows timer reads as the top function for qemu-kvm (e.g., read_hpet). On a Nehalem box the clock source is TSC. 'perf top -p <pid>' for a winxp VM does not show clock reads at all. David > > Thanks! > > /mjt -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
