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| author | Hayato Ohhashi <o8@vmm.dev> | 2020-07-21 16:12:31 +0000 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2020-07-25 15:49:41 +0200 |
| commit | 898ec52d2ba05915aaedcdb21bff2e944c883cb8 (patch) | |
| tree | ffbc8924e513eb3f801698cea48b127c8f64839f | |
| parent | 23ee3e4e5bd27bdbc0f1785eef7209ce872794c7 (diff) | |
| download | lwn-898ec52d2ba05915aaedcdb21bff2e944c883cb8.tar.gz lwn-898ec52d2ba05915aaedcdb21bff2e944c883cb8.zip | |
x86/xen/time: Set the X86_FEATURE_TSC_KNOWN_FREQ flag in xen_tsc_khz()
If the TSC frequency is known from the pvclock page,
the TSC frequency does not need to be recalibrated.
We can avoid recalibration by setting X86_FEATURE_TSC_KNOWN_FREQ.
Signed-off-by: Hayato Ohhashi <o8@vmm.dev>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: https://lore.kernel.org/r/20200721161231.6019-1-o8@vmm.dev
| -rw-r--r-- | arch/x86/xen/time.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c index c8897aad13cd..91f5b330dcc6 100644 --- a/arch/x86/xen/time.c +++ b/arch/x86/xen/time.c @@ -39,6 +39,7 @@ static unsigned long xen_tsc_khz(void) struct pvclock_vcpu_time_info *info = &HYPERVISOR_shared_info->vcpu_info[0].time; + setup_force_cpu_cap(X86_FEATURE_TSC_KNOWN_FREQ); return pvclock_tsc_khz(info); } |