KVM: Note down when cpu relax intercepted or pause loop exited
Noting pause loop exited vcpu or cpu relax intercepted helps in
filtering right candidate to yield. Wrong selection of vcpu;
i.e., a vcpu that just did a pl-exit or cpu relax intercepted may
contribute to performance degradation.
Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> # on s390x
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 68dda51..0892b75 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -239,6 +239,9 @@
}
vcpu->run = page_address(page);
+ kvm_vcpu_set_in_spin_loop(vcpu, false);
+ kvm_vcpu_set_dy_eligible(vcpu, false);
+
r = kvm_arch_vcpu_init(vcpu);
if (r < 0)
goto fail_free_run;
@@ -1585,6 +1588,7 @@
int pass;
int i;
+ kvm_vcpu_set_in_spin_loop(me, true);
/*
* We boost the priority of a VCPU that is runnable but not
* currently running, because it got preempted by something
@@ -1610,6 +1614,7 @@
}
}
}
+ kvm_vcpu_set_in_spin_loop(me, false);
}
EXPORT_SYMBOL_GPL(kvm_vcpu_on_spin);