On Monday, November 21, 2016 9:57:51 AM CET Linus Torvalds wrote:
>
> - semaphores are "old-fashioned mutexes". A mutex is better than a
> semaphore, but a semaphore is better than just about all the other
> alternatives. There's nothing _wrong_ with using a semaphore per se.
>
> In this case, e
On Mon, Nov 21, 2016 at 8:52 AM, Arnd Bergmann wrote:
>
> Version of the series had replaced the semaphore with a completion
> here, which worked correctly, but one reviewer suggested using
> the wait_event() instead since it's confusing to have a completion
> starting out in 'completed' state.
Q
On Mon, Nov 21, 2016 at 05:52:27PM +0100, Arnd Bergmann wrote:
> I think a mutex would't work here, since fops->open() and fops->close()
> are not called from the same context and lockdep will complain
> about that.
>
> Version of the series had replaced the semaphore with a completion
> here, whi
On Monday, November 21, 2016 7:57:53 AM CET Linus Torvalds wrote:
> Don't do this.
>
> Never ever do your own locking primitives. You will get the memory ordering
> wrong. And even if you get it right, why do it?
>
> If you want to get rid of semaphores, and replace them with a mutex, that's
> OK
The semaphore 'sm_sem' is used for an exclusive ownership of the device
so model the same as an atomic variable with an associated wait_event.
Semaphores are going away in the future.
Signed-off-by: Binoy Jayan
---
drivers/infiniband/core/user_mad.c | 20 ++--
1 file changed, 14
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