Commit 91ab933f authored by Li RongQing's avatar Li RongQing Committed by Paolo Bonzini
Browse files

KVM: VMX: clean up pi_wakeup_handler 



Passing per_cpu() to list_for_each_entry() causes the macro to be
evaluated N+1 times for N sleeping vCPUs.  This is a very small
inefficiency, and the code is cleaner if the address of the per-CPU
variable is loaded earlier.  Do this for both the list and the spinlock.

Signed-off-by: default avatarLi RongQing <lirongqing@baidu.com>
Message-Id: <1649244302-6777-1-git-send-email-lirongqing@baidu.com>
Reviewed-by: default avatarSean Christopherson <seanjc@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 33fbe6be

arch/x86/kvm/vmx/posted_intr.c

+5 −4
Original line number Diff line number Diff line
@@ -202,16 +202,17 @@ void vmx_vcpu_pi_put(struct kvm_vcpu *vcpu) 
void pi_wakeup_handler(void)

{

	int cpu = smp_processor_id();

	struct list_head *wakeup_list = &per_cpu(wakeup_vcpus_on_cpu, cpu);

	raw_spinlock_t *spinlock = &per_cpu(wakeup_vcpus_on_cpu_lock, cpu);

	struct vcpu_vmx *vmx;



	raw_spin_lock(&per_cpu(wakeup_vcpus_on_cpu_lock, cpu));

	list_for_each_entry(vmx, &per_cpu(wakeup_vcpus_on_cpu, cpu),

			    pi_wakeup_list) {

	raw_spin_lock(spinlock);

	list_for_each_entry(vmx, wakeup_list, pi_wakeup_list) {



		if (pi_test_on(&vmx->pi_desc))

			kvm_vcpu_wake_up(&vmx->vcpu);

	}

	raw_spin_unlock(&per_cpu(wakeup_vcpus_on_cpu_lock, cpu));

	raw_spin_unlock(spinlock);

}



void __init pi_init_cpu(int cpu)