apic: Don't iterate past last used apic
local_apics are allocated sequentially and never removed, so
we can stop any iterations that go to MAX_APICS as soon as we
hit the first NULL. Looking at a small guest running a virtio-net
workload with oprofile, this drops apic_get_delivery_bitmask()
from #3 in the profile to down in the noise.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/hw/apic.c b/hw/apic.c
index 63d62c7..5f4a87c 100644
--- a/hw/apic.c
+++ b/hw/apic.c
@@ -437,6 +437,8 @@
apic = local_apics[i];
if (apic && apic->id == dest)
return i;
+ if (!apic)
+ break;
}
return -1;
@@ -472,6 +474,8 @@
set_bit(deliver_bitmask, i);
}
}
+ } else {
+ break;
}
}
}