Re: [PATCH 00/13] Rename k[v]free_rcu() single argument to k[v]free_rcu_mightsleep()
From: Jens Axboe
Date: Thu Feb 23 2023 - 09:57:20 EST
On 2/1/23 8:08 AM, Uladzislau Rezki (Sony) wrote:
> This small series is based on Paul's "dev" branch. Head is 6002817348a1c610dc1b1c01ff81654cdec12be4
> it renames a single argument of k[v]free_rcu() to its new k[v]free_rcu_mightsleep() name.
>
> 1.
> The problem is that, recently we have run into a precedent when
> a user intended to give a second argument to kfree_rcu() API but
> forgot to do it in a code so a call became as a single argument
> of kfree_rcu() API.
>
> 2.
> Such mistyping can lead to hidden bags where sleeping is forbidden.
>
> 3.
> _mightsleep() prefix gives much more information for which contexts
> it can be used for.
This patchset seems weird to me. We have a LOT of calls that might
sleep, yet we don't suffix them all with _mightsleep(). Why is this
any different? Why isn't this just a might_sleep() call in the
actual helper, which will suffice for checkers and catch it at
runtime as well.
--
Jens Axboe