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Commit b8888080 authored by Joao Martins's avatar Joao Martins Committed by Boris Ostrovsky
Browse files

x86/xen/time: set pvclock flags on xen_time_init() 



Specifically check for PVCLOCK_TSC_STABLE_BIT and if this bit is set,
then set it too on pvclock flags. This allows Xen clocksource to use it
and thus speeding up xen_clocksource_read() callers (i.e. sched_clock())

Signed-off-by: default avatarJoao Martins <joao.m.martins@oracle.com>
Reviewed-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
parent 9f08890a

arch/x86/xen/time.c

+9 −0
Original line number Diff line number Diff line
@@ -372,6 +372,7 @@ static const struct pv_time_ops xen_time_ops __initconst = { 


static void __init xen_time_init(void)

{

	struct pvclock_vcpu_time_info *pvti;

	int cpu = smp_processor_id();

	struct timespec tp;
@@ -395,6 +396,14 @@ static void __init xen_time_init(void) 


	setup_force_cpu_cap(X86_FEATURE_TSC);



	/*

	 * We check ahead on the primary time info if this

	 * bit is supported hence speeding up Xen clocksource.

	 */

	pvti = &__this_cpu_read(xen_vcpu)->time;

	if (pvti->flags & PVCLOCK_TSC_STABLE_BIT)

		pvclock_set_flags(PVCLOCK_TSC_STABLE_BIT);



	xen_setup_runstate_info(cpu);

	xen_setup_timer(cpu);

	xen_setup_cpu_clockevents();