Re: [PATCH -v8][RFC] mutex: implement adaptive spinning

Linus Torvalds
2009-01-12T16:04:22Z

On Mon, 12 Jan 2009, Peter Zijlstra wrote:
>
> Change mutex contention behaviour such that it will sometimes busy wait on
> acquisition - moving its behaviour closer to that of spinlocks.

This version seems worse in so many ways.

You made the mutex bigger, for no obvious reason.

You made it back into the locked version.

You have unnecessary preempt_enable/preempt_disable calls in functions
that need to be called (and are called) with preemption already disabled.

Things seem to be going backwards.

Linus