linux-kernel - Re: [PATCH 04/13] tracing: Rename kvfree_rcu() to kvfree_rcu

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Message-ID: <8d42e647-617a-4ee9-b4d0-bc1e7bc1b732@paulmck-laptop>
Date:   Thu, 16 Mar 2023 07:56:50 -0700
From:   "Paul E. McKenney" <paulmck@...nel.org>
To:     Steven Rostedt <rostedt@...dmis.org>
Cc:     Joel Fernandes <joel@...lfernandes.org>,
        Jens Axboe <axboe@...nel.dk>,
        Uladzislau Rezki <urezki@...il.com>,
        LKML <linux-kernel@...r.kernel.org>, RCU <rcu@...r.kernel.org>,
        Oleksiy Avramchenko <oleksiy.avramchenko@...y.com>,
        Philipp Reisner <philipp.reisner@...bit.com>,
        Bryan Tan <bryantan@...are.com>,
        Eric Dumazet <edumazet@...gle.com>,
        Bob Pearson <rpearsonhpe@...il.com>,
        Ariel Levkovich <lariel@...dia.com>,
        Theodore Ts'o <tytso@....edu>, Julian Anastasov <ja@....bg>
Subject: Re: [PATCH 04/13] tracing: Rename kvfree_rcu() to
 kvfree_rcu_mightsleep()

On Thu, Mar 16, 2023 at 08:14:24AM -0400, Steven Rostedt wrote:
> On Thu, 16 Mar 2023 00:16:39 -0400
> Joel Fernandes <joel@...lfernandes.org> wrote:
> 
> > Indeed, and one could argue that "headless" sounds like something out
> > of a horror movie ;-). Which of course does match the situation when
> > the API is applied incorrectly.
> 
> Well, "headless" is a common term in IT.
> 
>    https://en.wikipedia.org/wiki/Headless_software

Indeed it is.  But RCU is incapable of headlessness, so in the
kvfree_rcu_mightsleep() case, the rcu_head is dynamically allocated.

> We could be specific to what horror movie/story, and call it:
> 
>   kvfree_rcu_sleepy_hollow()
> 
> Which will imply both headless *and* might_sleep!

Heh!  That one is almost bad enough to be good!  Almost!  ;-)

							Thanx, Paul