On 06/28, Steven Rostedt wrote:
> 
> I also don't see any nice API to have the priority set for a workqueue
> thread from within the kernel. Looks like one needs to be added,
> otherwise, I need to have the wrapper dig into the workqueue structs to
> find the thread that handles the workqueue.

It is not so trivial to implement properly. Note that CPU_UP creates a new
cwq->thread, so somehow workqueue should "remember" its priority. This means
we should record it in workqueue_struct. The most simple way is to add yet
another parameter to __create_workqueue(), but this is nasty.

So, perhaps we should add "long nice" to "struct workqueue_struct", and then

        void set_workqueue_nice(struct workqueue_struct *wq, long nice)
        {
                const cpumask_t *cpu_map = wq_cpu_map(wq);
                struct cpu_workqueue_struct *cwq;
                int cpu;

                wq->nice = nice;

                mutex_lock(&workqueue_mutex);

                for_each_cpu_mask(cpu, *cpu_map) {
                        cwq = per_cpu_ptr(wq->cpu_wq, cpu);
                        if (cwq->thread)
                                set_user_nice(cwq->thread, nice);
                }

                mutex_unlock(&workqueue_mutex);
        }

We could use for_each_cpu_online() instead, but then we should check
is_single_threaded().

Oleg.

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to