Re: [Qemu-devel] [RFC PATCH 1/3] cpus: protect queued_work_* with work_mutex.

[Frederic Konrad]

On 10/07/2015 17:22, Paolo Bonzini wrote:

On 10/07/2015 17:19, fred.kon...@greensocs.com wrote:

+    qemu_mutex_lock(&cpu->work_mutex);
      while ((wi = cpu->queued_work_first)) {
          cpu->queued_work_first = wi->next;
          wi->func(wi->data);

Please unlock the mutex while calling the callback.

Paolo

@@ -905,6 +912,8 @@ static void flush_queued_work(CPUState *cpu)
          }
      }
      cpu->queued_work_last = NULL;
+    qemu_mutex_unlock(&cpu->work_mutex);
+
      qemu_cond_broadcast(&qemu_work_cond);

I think something like that can work because we don't have two
flush_queued_work at the same time on the same CPU?

static void flush_queued_work(CPUState *cpu)
{
    struct qemu_work_item *wi;

    if (cpu->queued_work_first == NULL) {
        return;
    }

    qemu_mutex_lock(&cpu->work_mutex);
    while ((wi = cpu->queued_work_first)) {
        cpu->queued_work_first = wi->next;
        qemu_mutex_unlock(&cpu->work_mutex);
        wi->func(wi->data);
        qemu_mutex_lock(&cpu->work_mutex);
        wi->done = true;
        if (wi->free) {
            g_free(wi);
        }
    }
    cpu->queued_work_last = NULL;
    qemu_mutex_unlock(&cpu->work_mutex);

    qemu_cond_broadcast(&qemu_work_cond);
}

Fred