On Thu, 2011-10-20 at 15:34 +0800, Alex,Shi wrote:
> percpu_xxx funcs are duplicated with this_cpu_xxx funcs, so replace them
> for further code clean up.
>
> And in preempt safe scenario, __this_cpu_xxx funcs has a bit better
> performance since __this_cpu_xxx has no redundant preempt_disable()
>
Avi:
Would you like to give some comments of this?
> Signed-off-by: Alex Shi <alex.shi@xxxxxxxxx>
> ---
> arch/x86/kvm/x86.c | 14 +++++++-------
> 1 files changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 84a28ea..432c4bc 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -5024,15 +5024,15 @@ static DEFINE_PER_CPU(struct kvm_vcpu *, current_vcpu);
>
> static int kvm_is_in_guest(void)
> {
> - return percpu_read(current_vcpu) != NULL;
> + return __this_cpu_read(current_vcpu) != NULL;
> }
>
> static int kvm_is_user_mode(void)
> {
> int user_mode = 3;
>
> - if (percpu_read(current_vcpu))
> - user_mode = kvm_x86_ops->get_cpl(percpu_read(current_vcpu));
> + if (__this_cpu_read(current_vcpu))
> + user_mode = kvm_x86_ops->get_cpl(__this_cpu_read(current_vcpu));
>
> return user_mode != 0;
> }
> @@ -5041,8 +5041,8 @@ static unsigned long kvm_get_guest_ip(void)
> {
> unsigned long ip = 0;
>
> - if (percpu_read(current_vcpu))
> - ip = kvm_rip_read(percpu_read(current_vcpu));
> + if (__this_cpu_read(current_vcpu))
> + ip = kvm_rip_read(__this_cpu_read(current_vcpu));
>
> return ip;
> }
> @@ -5055,13 +5055,13 @@ static struct perf_guest_info_callbacks kvm_guest_cbs = {
>
> void kvm_before_handle_nmi(struct kvm_vcpu *vcpu)
> {
> - percpu_write(current_vcpu, vcpu);
> + __this_cpu_write(current_vcpu, vcpu);
> }
> EXPORT_SYMBOL_GPL(kvm_before_handle_nmi);
>
> void kvm_after_handle_nmi(struct kvm_vcpu *vcpu)
> {
> - percpu_write(current_vcpu, NULL);
> + __this_cpu_write(current_vcpu, NULL);
> }
> EXPORT_SYMBOL_GPL(kvm_after_handle_nmi);
>
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
