Re: [PATCH 2/2 v2] sched/wait: Introduce lock breaker in wake_up_page_bit

From: Linus Torvalds
Date: Fri Aug 25 2017 - 20:32:03 EST


On Fri, Aug 25, 2017 at 4:03 PM, Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> Let this be a lesson in just *how* little tested, and *how* crap that
> patch probably still is.

I haven't had time to look at it any more (trying to merge the pull
requests that came in today instead), but the more I think about it,
the more I think it was a mistake to do that page_wait_struct
allocation on the stack.

It made it way more fragile and complicated, having to rewrite things
so carefully. A simple slab cache would likely be a lot cleaner and
simpler.

So even if that thing can be made to work, it's probably not worth the pain.

Linus