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, address@hidden 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