diff options
| author | Tiejun Chen <tiejun.chen@intel.com> | 2014-09-26 08:00:04 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2014-11-03 12:07:33 +0100 |
| commit | c6338ce494456ed9c92ef10f63c0a8408bfeac6d (patch) | |
| tree | 0ed47a0d66df4ea344cc9c96760a816b3c75069e /arch/x86/kernel/kvmclock.c | |
| parent | KVM: x86: optimize some accesses to LVTT and SPIV (diff) | |
| download | linux-c6338ce494456ed9c92ef10f63c0a8408bfeac6d.tar.xz linux-c6338ce494456ed9c92ef10f63c0a8408bfeac6d.zip | |
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.c | 19 |
1 files changed, 8 insertions, 11 deletions
diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c index d9156ceecdff..0bf3467d7f30 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 |