From: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Date: Mon, 30 Aug 2010 10:26:33 +0000 (+0800)
Subject: KVM: MMU: lower the aduit frequency
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=30644b902c5eef5328d37a2e15f1921aaca2588b;p=linux-beck.git

KVM: MMU: lower the aduit frequency

The audit is very high overhead, so we need lower the frequency to assure
the guest is running.

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
---

diff --git a/arch/x86/kvm/mmu_audit.c b/arch/x86/kvm/mmu_audit.c
index 3bde186409bf..bd2b1be7066e 100644
--- a/arch/x86/kvm/mmu_audit.c
+++ b/arch/x86/kvm/mmu_audit.c
@@ -17,6 +17,8 @@
  *
  */
 
+#include <linux/ratelimit.h>
+
 static const char *audit_msg;
 
 typedef void (*inspect_spte_fn) (struct kvm_vcpu *vcpu, u64 *sptep, int level);
@@ -228,6 +230,11 @@ static void audit_vcpu_spte(struct kvm_vcpu *vcpu)
 
 static void kvm_mmu_audit(void *ignore, struct kvm_vcpu *vcpu, int audit_point)
 {
+	static DEFINE_RATELIMIT_STATE(ratelimit_state, 5 * HZ, 10);
+
+	if (!__ratelimit(&ratelimit_state))
+		return;
+
 	audit_msg = audit_point_name[audit_point];
 	audit_all_active_sps(vcpu->kvm);
 	audit_vcpu_spte(vcpu);