Re: [PATCH] RT: Add priority-queuing and priority-inheritance to workqueue infrastructure

From: Oleg Nesterov
Date: Wed Aug 01 2007 - 16:32:22 EST


On 08/02, Oleg Nesterov wrote:
>
> And I don't understand why rt_mutex_setprio() is called just before
> calling work->func(). This means that a high-priority work could
> be delayed by the low-priority ->current_work.

Aha, I missed the rt_mutex_setprio() in insert_work().

This is not good either. Suppose we have

void work_handler(struct work_struct *self)
{
if (!try_lock()) {
// try again later...
queue_work(wq, self);
return;
}

do_the_work();
}

What if that work was queued by the low-priority thread, and
then a high-priority thread inserts a new work when work_handler()
is running?

Oleg.

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