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authorTiejun Chen <tiejun.chen@intel.com>2014-09-26 06:00:04 (GMT)
committerPaolo Bonzini <pbonzini@redhat.com>2014-11-03 11:07:33 (GMT)
commitc6338ce494456ed9c92ef10f63c0a8408bfeac6d (patch)
tree0ed47a0d66df4ea344cc9c96760a816b3c75069e /arch/x86/kernel/kvmclock.c
parentf30ebc312ca9def25650b4e1d01cdb425c310dca (diff)
downloadlinux-c6338ce494456ed9c92ef10f63c0a8408bfeac6d.tar.xz
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: Tiejun Chen <tiejun.chen@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kernel/kvmclock.c')
-rw-r--r--arch/x86/kernel/kvmclock.c19
1 files changed, 8 insertions, 11 deletions
diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
index d9156ce..0bf3467 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -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