diff options
| author | Christian Borntraeger <borntraeger@de.ibm.com> | 2014-08-19 16:45:56 +0200 |
|---|---|---|
| committer | Christoffer Dall <christoffer.dall@linaro.org> | 2014-10-02 17:19:10 +0200 |
| commit | 7fdbe25673a0bcd4c38968ec2cd048a21f1fbb93 (patch) | |
| tree | 1067d0a66a99822d018843eab298950db1c0b388 | |
| parent | 57f984d2c64c8c1e597d021567a379f4f3920b35 (diff) | |
KVM: avoid unnecessary synchronize_rcu
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 <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 7103f60de8bed21a0ad5d15d2ad5b7a333dda201)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
| -rw-r--r-- | virt/kvm/kvm_main.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 50f947301fa7..aa5057e7a1b9 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(); |