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Date:   Thu, 4 Aug 2022 01:42:25 +0100
From:   Matthew Wilcox <willy@infradead.org>
To:     Linus Torvalds <torvalds@linux-foundation.org>
Cc:     Steven Rostedt <rostedt@goodmis.org>,
        Al Viro <viro@zeniv.linux.org.uk>,
        Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
        Thomas Gleixner <tglx@linutronix.de>,
        linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
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On Wed, Aug 03, 2022 at 04:42:43PM -0700, Linus Torvalds wrote:
> On Wed, Aug 3, 2022 at 4:24 PM Matthew Wilcox <willy@infradead.org> wrote:
> >
> > On Wed, Aug 03, 2022 at 06:59:36PM -0400, Steven Rostedt wrote:
> > >
> > >       preempt_disable_inlock() ?
> >
> > preempt_disable_locked()?
> 
> Heh. Shed painting in full glory.
> 
> Let's try just "preempt_enable_under_spinlock()" and see.
> 
> It's a bit long, but it's still shorter than the existing usage pattern.
> 
> And we don't have "inlock" anywhere else, and while "locked" is a real
> pattern we have, it tends to be about other things (ie "I hold the
> lock that you need, so don't take it").
> 
> And this is _explicitly_ only about spinning locks, because sleeping
> locks don't do the preemption disable even without RT.
> 
> So let's make it verbose and clear and unambiguous. It's not like I
> expect to see a _lot_ of those. Knock wood.

Should we have it take a spinlock_t pointer?  We could have lockdep
check it is actually held.