linux-kernel - [PATCH 4/4] KVM: MMU: lower the aduit frequency

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Date:	Sat, 28 Aug 2010 20:03:00 +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 4/4] 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_debug.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kvm/mmu_debug.c b/arch/x86/kvm/mmu_debug.c
index c4ebe6a..bc61b3d 100644
--- a/arch/x86/kvm/mmu_debug.c
+++ b/arch/x86/kvm/mmu_debug.c
@@ -18,6 +18,7 @@
  */
 
 #include <linux/debugfs.h>
+#include <linux/ratelimit.h>
 
 static struct dentry *debugfs_file;
 static bool mmu_debug;
@@ -233,6 +234,11 @@ static void audit_vcpu_spte(struct kvm_vcpu *vcpu)
 
 static void kvm_mmu_audit(void *ignore, struct kvm_vcpu *vcpu, const char *msg)
 {
+	static DEFINE_RATELIMIT_STATE(ratelimit_state, 5 * HZ, 10);
+
+	if (!__ratelimit(&ratelimit_state))
+		return;
+
 	audit_msg = msg;
 	audit_all_active_sps(vcpu->kvm);
 	audit_vcpu_spte(vcpu);
-- 
1.7.0.4

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