From: Ingo Molnar <mingo@kernel.org>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Ritger <aritger@nvidia.com>, Alex Goins <agoins@nvidia.com>,
Thomas Gleixner <tglx@linutronix.de>,
LKML <linux-kernel@vger.kernel.org>,
linux-rt-users@vger.kernel.org
Subject: Re: [PATCH RT] Align rt_mutex inlining with upstream behavior
Date: Sat, 11 Feb 2017 18:52:42 +0100 [thread overview]
Message-ID: <20170211175241.GA30998@gmail.com> (raw)
In-Reply-To: <20170210182807.6gzs3xn3ga727xsb@linutronix.de>
* Sebastian Andrzej Siewior <bigeasy@linutronix.de> wrote:
> 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 was…
> 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.
tglx and Peter Zijlstra are main co-authors of kernel/locking/rtmutex.c, and every
author (copyright holder) has to agree to changing a GPL export of a kernel
subsystem's API to a non-GPL export.
Thanks,
Ingo
next prev parent reply other threads:[~2017-02-11 17:52 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-25 2:45 [PATCH RT] Align rt_mutex inlining with upstream behavior Alex Goins
2017-01-26 17:01 ` Sebastian Andrzej Siewior
2017-01-30 17:35 ` Andy Ritger
2017-02-03 15:54 ` Sebastian Andrzej Siewior
2017-02-03 16:49 ` Andy Ritger
2017-02-10 17:50 ` Sebastian Andrzej Siewior
2017-02-10 18:09 ` Andy Ritger
2017-02-10 18:28 ` Sebastian Andrzej Siewior
2017-02-10 19:17 ` Alex Goins
2017-02-11 17:52 ` Ingo Molnar [this message]
2017-02-11 20:15 ` Thomas Gleixner
2017-02-13 11:20 ` Peter Zijlstra
2017-02-13 13:04 ` Sebastian Andrzej Siewior
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