[PATCH 09/45] KVM: Wake up waitqueue before calling get_cpu()

From: Avi Kivity
Date: Sun May 24 2009 - 12:01:58 EST


From: Jan Blunck <jblunck@xxxxxxx>

This moves the get_cpu() call down to be called after we wake up the
waiters. Therefore the waitqueue locks can safely be rt mutex.

Signed-off-by: Jan Blunck <jblunck@xxxxxxx>
Signed-off-by: Sven-Thorsten Dietrich <sven@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Marcelo Tosatti <mtosatti@xxxxxxxxxx>
Signed-off-by: Avi Kivity <avi@xxxxxxxxxx>
---
arch/x86/kvm/x86.c | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 8f4dc86..c92d42b 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4565,7 +4565,7 @@ static void vcpu_kick_intr(void *info)
void kvm_vcpu_kick(struct kvm_vcpu *vcpu)
{
int ipi_pcpu = vcpu->cpu;
- int cpu = get_cpu();
+ int cpu;

if (waitqueue_active(&vcpu->wq)) {
wake_up_interruptible(&vcpu->wq);
@@ -4575,6 +4575,7 @@ void kvm_vcpu_kick(struct kvm_vcpu *vcpu)
* We may be called synchronously with irqs disabled in guest mode,
* So need not to call smp_call_function_single() in that case.
*/
+ cpu = get_cpu();
if (vcpu->guest_mode && vcpu->cpu != cpu)
smp_call_function_single(ipi_pcpu, vcpu_kick_intr, vcpu, 0);
put_cpu();
--
1.6.0.6

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