We dont have to wait for a grace period if there is no oldpid that
we are going to free. putpid also checks for NULL, so this patch
only fences synchronize_rcu.
Signed-off-by: Christian Borntraeger <borntrae...@de.ibm.com>
---
virt/kvm/kvm_main.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 33712fb..39b1603 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -129,7 +129,8 @@ int vcpu_load(struct kvm_vcpu *vcpu)
struct pid *oldpid = vcpu->pid;
struct pid *newpid = get_task_pid(current, PIDTYPE_PID);
rcu_assign_pointer(vcpu->pid, newpid);
- synchronize_rcu();
+ if (oldpid)
+ synchronize_rcu();
put_pid(oldpid);
}
cpu = get_cpu();
--
1.8.4.2
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