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.william...@redhat.com> --- hw/apic.c | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-) 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 @@ static int apic_find_dest(uint8_t dest) apic = local_apics[i]; if (apic && apic->id == dest) return i; + if (!apic) + break; } return -1; @@ -472,6 +474,8 @@ static void apic_get_delivery_bitmask(uint32_t *deliver_bitmask, set_bit(deliver_bitmask, i); } } + } else { + break; } } }