Re: [PATCH 4/4] sched: Document Program-Order guarantees

From: Boqun Feng
Date: Thu Dec 03 2015 - 08:17:26 EST


On Thu, Dec 03, 2015 at 01:40:14PM +0100, Peter Zijlstra wrote:
[snip]
> + *
> + * CPU0 (schedule) CPU1 (try_to_wake_up) CPU2 (schedule)
> + *
> + * LOCK rq(0)->lock LOCK X->pi_lock
> + * dequeue X
> + * sched-out X
> + * smp_store_release(X->on_cpu, 0);
> + *
> + * smp_cond_acquire(!X->on_cpu);
> + * X->state = WAKING
> + * set_task_cpu(X,2)
> + *
> + * LOCK rq(2)->lock
> + * enqueue X
> + * X->state = RUNNING
> + * UNLOCK rq(2)->lock
> + *
> + * LOCK rq(2)->lock // orders against CPU1
> + * sched-out Z
> + * sched-in X
> + * UNLOCK rq(1)->lock
^^^^^^^^^^^^^^^

This is a typo, right? Should be "UNLOCK rq(2)->lock".

Regards,
Boqun

> + *
> + * UNLOCK X->pi_lock
> + * UNLOCK rq(0)->lock
> + *
> + *

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