linux-kernel - [PATCH v2 5/5] KVM: MMU: lower the aduit frequency

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Date:	Mon, 30 Aug 2010 18:26:33 +0800
From:	Xiao Guangrong <xiaoguangrong@...fujitsu.com>
To:	Avi Kivity <avi@...hat.com>
CC:	Marcelo Tosatti <mtosatti@...hat.com>,
	LKML <linux-kernel@...r.kernel.org>, KVM <kvm@...r.kernel.org>
Subject: [PATCH v2 5/5] KVM: MMU: lower the aduit frequency

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

Signed-off-by: Xiao Guangrong <xiaoguangrong@...fujitsu.com>
---
 arch/x86/kvm/mmu_audit.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kvm/mmu_audit.c b/arch/x86/kvm/mmu_audit.c
index 3bde186..bd2b1be 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);
-- 
1.7.0.4

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