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kvm: kvmclock: use get_cpu() and put_cpu()

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We can use get_cpu() and put_cpu() to replace
preempt_disable()/cpu = smp_processor_id() and
preempt_enable() for slightly better code.

Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Tiejun Chen 2014-09-26 14:00:04 +08:00 committed by Paolo Bonzini
parent f30ebc312c
commit c6338ce494
1 changed files with 8 additions and 11 deletions
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19
arch/x86/kernel/kvmclock.c
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@ -59,13 +59,12 @@ static void kvm_get_wallclock(struct timespec *now)
native_write_msr(msr_kvm_wall_clock, low, high);
preempt_disable();
cpu = smp_processor_id();
cpu = get_cpu();
vcpu_time = &hv_clock[cpu].pvti;
pvclock_read_wallclock(&wall_clock, vcpu_time, now);
preempt_enable();
put_cpu();
}
static int kvm_set_wallclock(const struct timespec *now)
@ -107,11 +106,10 @@ static unsigned long kvm_get_tsc_khz(void)
int cpu;
unsigned long tsc_khz;
preempt_disable();
cpu = smp_processor_id();
cpu = get_cpu();
src = &hv_clock[cpu].pvti;
tsc_khz = pvclock_tsc_khz(src);
preempt_enable();
put_cpu();
return tsc_khz;
}
@ -284,23 +282,22 @@ int __init kvm_setup_vsyscall_timeinfo(void)
size = PAGE_ALIGN(sizeof(struct pvclock_vsyscall_time_info)*NR_CPUS);
preempt_disable();
cpu = smp_processor_id();
cpu = get_cpu();
vcpu_time = &hv_clock[cpu].pvti;
flags = pvclock_read_flags(vcpu_time);
if (!(flags & PVCLOCK_TSC_STABLE_BIT)) {
preempt_enable();
put_cpu();
return 1;
}
if ((ret = pvclock_init_vsyscall(hv_clock, size))) {
preempt_enable();
put_cpu();
return ret;
}
preempt_enable();
put_cpu();
kvm_clock.archdata.vclock_mode = VCLOCK_PVCLOCK;
#endif