Re: [PATCH RT] Align rt_mutex inlining with upstream behavior

[Sebastian Andrzej Siewior]

On 2017-02-10 10:09:29 [-0800], Andy Ritger wrote:
> Is the
> 
>     WARN_ON(rt_mutex_is_locked(lock));
> 
> in rt_mutex_destroy() valuable in non-CONFIG_DEBUG_MUTEXES kernels,
> such that it would be better to always call it, and not noop away mutex_destroy()
> non-CONFIG_DEBUG_MUTEXES kernels?  I thought that was your objection to
> Alex's original patch.

It kind of wasâ
So first I removed the GPL symbol. Then I wasn't too happy about it
especially since it was not introduced as part of RT. So I reverted that
changed and aligned with mainline behaviour (the mutex_rt.h hunk). But
then I noticed that with CONFIG_DEBUG_MUTEXES=n and
CONFIG_DEBUG_RT_MUTEXES=y we still have a regression compared to !RT and
this was the initial motivation to fix things.
Then I got curious why mutex_lock() (which is essential rt_mutex_lock())
works and noticed the wrapper around it. And while looking at it I
decided to go back to strip the GPL part from export symbol instead of
adding a wrapper. And here I am.
Then I was looking at the patch and decided to align with mainline (and
keep that one hunk) in case Ingo ask for his GPL symbol.

> Thanks,
> - Andy
Sebastian