On 31/10/2017 12:26, Pavel Dovgalyuk wrote:
> + /* We need to drop the replay_lock so any vCPU threads woken up
> + * can finish their replay tasks
> + */
> + if (replay_mode != REPLAY_MODE_NONE) {
> + g_assert(replay_mutex_locked());
> + qemu_mutex_unlock_iothread();
> + replay_mutex_unlock();
> + qemu_mutex_lock_iothread();
> + }
The assert+unlock+lock here is unnecessary; just do
if (replay_mode != REPLAY_MODE_NONE) {
replay_mutex_unlock();
}
which according to a previous suggestion can become just
replay_mutex_unlock();
> while (!all_vcpus_paused()) {
> qemu_cond_wait(&qemu_pause_cond, &qemu_global_mutex);
> CPU_FOREACH(cpu) {
> qemu_cpu_kick(cpu);
> }
> }
> +
> + if (replay_mode != REPLAY_MODE_NONE) {
> + qemu_mutex_unlock_iothread();
> + replay_mutex_lock();
> + qemu_mutex_lock_iothread();
> + }
Likewise, this is not a fast path so:
qemu_mutex_unlock_iothread();
if (replay_mode != REPLAY_MODE_NONE) {
replay_mutex_lock();
}
qemu_mutex_lock_iothread();
or, applying the same previous suggestion,
/* Unlock iothread to preserve lock hierarchy. */
qemu_mutex_unlock_iothread();
replay_mutex_lock();
qemu_mutex_lock_iothread();
Paolo
