Re: [RFC PATCH 1/2] kernel/notifier: replace single-linked list with double-linked list for reverse traversal

Petr Mladek
2026-04-16T14:54:28Z

On Thu 2026-04-16 13:30:04, David Laight wrote:
> On Wed, 15 Apr 2026 15:01:37 +0800
> chensong_2000@189.cn wrote:
>
> > From: Song Chen <chensong_2000@189.cn>
> >
> > The current notifier chain implementation uses a single-linked list
> > (struct notifier_block *next), which only supports forward traversal
> > in priority order. This makes it difficult to handle cleanup/teardown
> > scenarios that require notifiers to be called in reverse priority order.
>
> If it is only cleanup/teardown then the list can be order-reversed
> as part of that process at the same time as the list is deleted.

Interesting idea. But it won't work in all situations.

Note that the motivation for this update are the module loader
notifiers which are called several times for each loaded/removed module.

Best Regards,
Petr