aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorIdan Horowitz <idan.horowitz@gmail.com>2022-01-14 02:43:57 +0200
committerRichard Henderson <richard.henderson@linaro.org>2022-02-09 08:55:02 +1100
commit25e82fb769eddb83e0b68487b8b08d9426704d54 (patch)
treebf541bd2cd78e26e5350a2473d89a152e1b8b7d7
parentcfc2a2d69d59f02b32df3098ce17e10ab86d43c6 (diff)
softmmu/cpus: Check if the cpu work list is empty atomically
Instead of taking the lock of the cpu work list in order to check if it's empty, we can just read the head pointer atomically. This decreases cpu_work_list_empty's share from 5% to 1.3% in a profile of icount-enabled aarch64-softmmu. Signed-off-by: Idan Horowitz <idan.horowitz@gmail.com> Message-Id: <20220114004358.299534-1-idan.horowitz@gmail.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
-rw-r--r--softmmu/cpus.c7
1 files changed, 1 insertions, 6 deletions
diff --git a/softmmu/cpus.c b/softmmu/cpus.c
index 23bca46b07..035395ae13 100644
--- a/softmmu/cpus.c
+++ b/softmmu/cpus.c
@@ -73,12 +73,7 @@ bool cpu_is_stopped(CPUState *cpu)
bool cpu_work_list_empty(CPUState *cpu)
{
- bool ret;
-
- qemu_mutex_lock(&cpu->work_mutex);
- ret = QSIMPLEQ_EMPTY(&cpu->work_list);
- qemu_mutex_unlock(&cpu->work_mutex);
- return ret;
+ return QSIMPLEQ_EMPTY_ATOMIC(&cpu->work_list);
}
bool cpu_thread_is_idle(CPUState *cpu)