Re: [rfc] "fair" rw spinlocks

Linus Torvalds
2009-11-30T22:12:53Z

On Mon, 30 Nov 2009, Thomas Gleixner wrote:
>
> Yeah, forgot to mention sched.c, but that's solvable

It should be fairly easy to add a few 'spin_lock(&tasklist_lock)' around
stuff that really depended on exclusion from writers. That should
_hopefully_ be the rare case.

The biggest problem is that there will almost inevitably be things that
get missed, and any races exposed by lacking locking will be _very_ hard
to debug and trigger. So what I'd be worried about is not getting to a
"practically working" state, but any really subtle cases that nobody
really hits in practice.

Linus