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Commit c6338ce4 authored by Tiejun Chen's avatar Tiejun Chen Committed by Paolo Bonzini
Browse files

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



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: default avatarTiejun Chen <tiejun.chen@intel.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent f30ebc31

arch/x86/kernel/kvmclock.c

+8 −11
Original line number Diff line number Diff line
@@ -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