On Wed, Jun 13, 2018 at 11:26:41AM +0100, Dr. David Alan Gilbert (git) wrote:
[...]
> @@ -2932,10 +2943,24 @@ static void *migration_thread(void *opaque)
>
> migration_update_counters(s, current_time);
>
> + urgent = false;
> if (qemu_file_rate_limit(s->to_dst_file)) {
> - /* usleep expects microseconds */
> - g_usleep((s->iteration_start_time + BUFFER_DELAY -
> - current_time) * 1000);
> + /* Wait for a delay to do rate limiting OR
> + * something urgent to post the semaphore.
> + */
> + int ms = s->iteration_start_time + BUFFER_DELAY - current_time;
> + trace_migration_thread_ratelimit_pre(ms);
> + if (qemu_sem_timedwait(&s->rate_limit_sem, ms) == 0) {
> + /* We were worken by one or more urgent things but
> + * the timedwait will have consumed one of them.
> + * The service routine for the urgent wake will dec
> + * the semaphore itself for each item it consumes,
> + * so add this one we just eat back.
> + */
> + qemu_sem_post(&s->rate_limit_sem);
Is it possible that we just avoid eating that in the next patch? Then
we only provide a helper to "trigger an urgent request" but we only
consume the point here?
--
Peter Xu
