Re: [patch] Real-Time Preemption, -RT-2.6.11-rc3-V0.7.38-01

Ingo Molnar
2005-02-04T17:39:20Z

* Kevin Hilman <kevin@hilman.org> wrote:

> What I've done for now is to use sema_init_nocheck() to disable the
> checking in the case of a counting semaphore, but I remember seeing
> discussion in an earlier thread about creating a separate counting
> semaphore type. Is this still planned?

the nocheck variant is the counting semaphore in essence. I removed the
counting semaphore implementation because it caused more problems than
it solved - but it can be reintroduced later.

> [*] For example, an open semaphore being down'ed and thus acquired and
> the same thread doing a down() again before another thread has a
> chance to up() the semaphore.

yeah, these are cases where the code is better off using completions
anyway. Thomas Gleixner had a good bunch of patches to convers such
semaphore use to completions - the most necessary ones are in -RT, and i
hope he'll submit the whole bunch upstream after 2.6.11 is out :-)

Ingo