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From:   Linus Torvalds <torvalds@linux-foundation.org>
Date:   Wed, 3 Aug 2022 16:42:43 -0700
Message-ID: <CAHk-=wh6VSqsnANHkQpw=yD-Hkt90Y1LX=ad9+r+SusfriUOfA@mail.gmail.com>
Subject: Re: [git pull] vfs.git pile 3 - dcache
To:     Matthew Wilcox <willy@infradead.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 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.

We had a handful of those things before (in mm/vmstat, and now added
another case to the dentry code. So it has become a pattern, but I
really really hope it's not exactly a common pattern.

And so because it's not common, typing a bit more is a good idea - and
making it really clear is probably also a good idea.

                Linus