Re: [PATCH] kvm: Drop obsolete cpu_get/put in make_all_cpus_request

[Andrea Arcangeli <aarcange@redhat.com>]

Hi,

I suggested this too first time around when I've seen the patch but
they reminded it's needed to make life easier to preempt-rt...

On Mon, Jul 20, 2009 at 11:30:12AM +0200, Jan Kiszka wrote:
> spin_lock disables preemption, so we can simply read the current cpu.
> 
> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> ---
> 
>  virt/kvm/kvm_main.c |    3 +--
>  1 files changed, 1 insertions(+), 2 deletions(-)
> 
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index 7cd1c10..98e4ec8 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -741,8 +741,8 @@ static bool make_all_cpus_request(struct kvm *kvm, unsigned int req)
>  	if (alloc_cpumask_var(&cpus, GFP_ATOMIC))
>  		cpumask_clear(cpus);
>  
> -	me = get_cpu();
>  	spin_lock(&kvm->requests_lock);
> +	me = smp_processor_id();
>  	kvm_for_each_vcpu(i, vcpu, kvm) {
>  		if (test_and_set_bit(req, &vcpu->requests))
>  			continue;
> @@ -757,7 +757,6 @@ static bool make_all_cpus_request(struct kvm *kvm, unsigned int req)
>  	else
>  		called = false;
>  	spin_unlock(&kvm->requests_lock);
> -	put_cpu();
>  	free_cpumask_var(cpus);
>  	return called;
>  }
> --
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