From 274dd10230eef97714a2a283ecd8a8ce2ecbf687 Mon Sep 17 00:00:00 2001 From: tangbinzy Date: Mon, 6 Nov 2023 07:28:31 +0000 Subject: [PATCH] qemu-timer: Skip empty timer lists before locking in qemu_clock_deadline_ns_all mainline inclusion commit 3f42906c9ab2c777a895b48b87b8107167e4a275 category: bugfix --------------------------------------------------------------- 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 Signed-off-by: tangbinzy --- util/qemu-timer.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/util/qemu-timer.c b/util/qemu-timer.c index 40e8c83722..c5b6dc987c 100644 --- a/util/qemu-timer.c +++ b/util/qemu-timer.c @@ -330,6 +330,9 @@ 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 */ -- 2.27.0