From: Idan Horowitz <idan.horowitz@gmail.com>
To: qemu-devel@nongnu.org
Cc: richard.henderson@linaro.org,
Idan Horowitz <idan.horowitz@gmail.com>,
pbonzini@redhat.com
Subject: [PATCH 2/2] qemu-timer: Skip empty timer lists before locking in qemu_clock_deadline_ns_all
Date: Fri, 14 Jan 2022 02:43:58 +0200 [thread overview]
Message-ID: <20220114004358.299534-2-idan.horowitz@gmail.com> (raw)
In-Reply-To: <20220114004358.299534-1-idan.horowitz@gmail.com>
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 <idan.horowitz@gmail.com>
---
util/qemu-timer.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/util/qemu-timer.c b/util/qemu-timer.c
index f36c75e594..e56895ef55 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 */
--
2.34.1
next prev parent reply other threads:[~2022-01-14 0:54 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-14 0:43 [PATCH 1/2] softmmu/cpus: Check if the cpu work list is empty atomically Idan Horowitz
2022-01-14 0:43 ` Idan Horowitz [this message]
2022-01-26 21:43 ` [PATCH 2/2] qemu-timer: Skip empty timer lists before locking in qemu_clock_deadline_ns_all Richard Henderson
2022-06-19 8:54 ` Idan Horowitz
2022-06-21 16:25 ` Richard Henderson
2022-01-26 21:40 ` [PATCH 1/2] softmmu/cpus: Check if the cpu work list is empty atomically Richard Henderson
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