Commit 7103f60d authored by Christian Borntraeger's avatar Christian Borntraeger Committed by Paolo Bonzini

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: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent e0ad0b47
...@@ -129,7 +129,8 @@ int vcpu_load(struct kvm_vcpu *vcpu) ...@@ -129,7 +129,8 @@ int vcpu_load(struct kvm_vcpu *vcpu)
struct pid *oldpid = vcpu->pid; struct pid *oldpid = vcpu->pid;
struct pid *newpid = get_task_pid(current, PIDTYPE_PID); struct pid *newpid = get_task_pid(current, PIDTYPE_PID);
rcu_assign_pointer(vcpu->pid, newpid); rcu_assign_pointer(vcpu->pid, newpid);
synchronize_rcu(); if (oldpid)
synchronize_rcu();
put_pid(oldpid); put_pid(oldpid);
} }
cpu = get_cpu(); cpu = get_cpu();
......
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