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| author | Joao Martins <joao.m.martins@oracle.com> | 2017-11-08 17:19:56 +0000 |
|---|---|---|
| committer | Boris Ostrovsky <boris.ostrovsky@oracle.com> | 2017-11-08 16:33:14 -0500 |
| commit | b888808093113ae7d63d213272d01fea4b8329ed (patch) | |
| tree | e580648ce8a0fa9ec3820102855c32403313df5b | |
| parent | 9f08890ab906abaf9d4c1bad8111755cbd302260 (diff) | |
| download | linux-b888808093113ae7d63d213272d01fea4b8329ed.tar.bz2 | |
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: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
| -rw-r--r-- | arch/x86/xen/time.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c index 244791ff8201..c96e61fd70e7 100644 --- a/arch/x86/xen/time.c +++ b/arch/x86/xen/time.c @@ -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(); |