From 3f42906c9ab2c777a895b48b87b8107167e4a275 Mon Sep 17 00:00:00 2001 From: Idan Horowitz Date: Fri, 14 Jan 2022 02:43:58 +0200 Subject: qemu-timer: Skip empty timer lists before locking in qemu_clock_deadline_ns_all This decreases qemu_clock_deadline_ns_all's share from 23.2% to 13% in a profile of icount-enabled aarch64-softmmu. Signed-off-by: Idan Horowitz Reviewed-by: Richard Henderson Message-Id: <20220114004358.299534-2-idan.horowitz@gmail.com> Signed-off-by: Richard Henderson --- util/qemu-timer.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'util/qemu-timer.c') diff --git a/util/qemu-timer.c b/util/qemu-timer.c index a670a57881..6a0de33dd2 100644 --- a/util/qemu-timer.c +++ b/util/qemu-timer.c @@ -261,6 +261,9 @@ int64_t qemu_clock_deadline_ns_all(QEMUClockType type, int attr_mask) } QLIST_FOREACH(timer_list, &clock->timerlists, list) { + if (!qatomic_read(&timer_list->active_timers)) { + continue; + } qemu_mutex_lock(&timer_list->active_timers_lock); ts = timer_list->active_timers; /* Skip all external timers */ -- cgit v1.2.3-55-g7522