[Qemu-devel] [PATCH 11/18] qemu-timer: optimize timerlist_run_timers

[Paolo Bonzini <pbonzini@redhat.com>]

The case of no active timers is relatively common.  Check it
outside the lock.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 qemu-timer.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/qemu-timer.c b/qemu-timer.c
index 2463fe6..dc11ab9 100644
--- a/qemu-timer.c
+++ b/qemu-timer.c
@@ -476,6 +476,10 @@ bool timerlist_run_timers(QEMUTimerList *timer_list)
     QEMUTimerCB *cb;
     void *opaque;
 
+    if (!atomic_read(&timer_list->active_timers)) {
+        return false;
+    }
+
     qemu_event_reset(&timer_list->timers_done_ev);
     if (!timer_list->clock->enabled) {
         goto out;
-- 
2.4.3