From: "Palik, Imre" <[email protected]> In Dom0's the use of the TSC clocksource (whenever it is stable enough to be used) instead of the Xen clocksource should not cause any issues, as Dom0 VMs never live-migrated. The TSC clocksource is somewhat more efficient than the Xen paravirtualised clocksource, thus it should have higher rating.
This patch decreases the rating of the Xen clocksource in Dom0s to 275. Which is half-way between the rating of the TSC clocksource (300) and the hpet clocksource (250). Cc: Anthony Liguori <[email protected]> Signed-off-by: Imre Palik <[email protected]> --- arch/x86/xen/time.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c index f473d26..c768726 100644 --- a/arch/x86/xen/time.c +++ b/arch/x86/xen/time.c @@ -487,6 +487,10 @@ static void __init xen_time_init(void) int cpu = smp_processor_id(); struct timespec tp; + /* As Dom0 is never moved, no penalty on using TSC there */ + if (xen_initial_domain()) + xen_clocksource.rating = 275; + clocksource_register_hz(&xen_clocksource, NSEC_PER_SEC); if (HYPERVISOR_vcpu_op(VCPUOP_stop_periodic_timer, cpu, NULL) == 0) { -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
