Re: [patch] Real-Time Preemption, -RT-2.6.9-rc4-mm1-U8

[Ingo Molnar]

* Jens Axboe <axboe@xxxxxxx> wrote:

> I didn't look at the USB code, I'm just saying that it's perfectly
> valid use of a semaphore the pattern you describe (process A holding
> it, process B releasing it).

yes, that is perfectly true, and sorry if we gave you the wrong
impression.

the goal of these patches is to do a semaphore->completion conversion in
cases where the semaphore was used for completion purposes. It's a bit
faster and more readable but not a 'bugfix' in any way. (another set of
patches are converting sleep_on() uses to wait_event*() plus waitqueues
- those can in fact be considered bugfixes in some cases.)

typically the cases where semaphores are held by one task and released
by another task happens coincide with this used-for-completion scenario.

[ the different-owner assert that triggers in my PREEMPT_REALTIME tree
is for completely different reasons and has no impact on upstream at
all. (It merely means 'Ingo does some weird stuff again, pester him, not
others'.) ]

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