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

[Boqun Feng <boqun.feng@gmail.com>]

[-- Attachment #1: Type: text/plain, Size: 1043 bytes --]

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
> + *
> + *

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 473 bytes --]