[PATCH 14/18] KVM: VMX: Avoid unnecessary vcpu_load()/vcpu_put() cycles

From: Avi Kivity
Date: Thu Apr 26 2007 - 05:25:24 EST

From: Eddie Dong <eddie.dong@xxxxxxxxx>

By checking if a reschedule is needed, we avoid dropping the vcpu.

[With changes by me, based on Anthony Liguori's observations]

Signed-off-by: Avi Kivity <avi@xxxxxxxxxxxx>
drivers/kvm/kvm_main.c | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 03c0ee7..f535635 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -1590,6 +1590,8 @@ static int set_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data)

void kvm_resched(struct kvm_vcpu *vcpu)
+ if (!need_resched())
+ return;

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