Re: [PATCH -v7][RFC]: mutex: implement adaptive spinning

Linus Torvalds
2009-01-10T05:29:27Z

On Fri, 9 Jan 2009, H. Peter Anvin wrote:
>
> I was thinking about experimenting with this, to see what level of
> upside it might add. Ingo showed me numbers which indicate that a
> fairly significant fraction of the cases where removing inline helps is
> in .h files, which would require code movement to fix. Hence to see if
> it can be automated.

We _definitely_ have too many inline functions in headers. They usually
start out small, and then they grow. And even after they've grown big,
it's usually not at all clear exactly where else they should go, so even
when you realize that "that shouldn't be inlined", moving them and making
them uninlined is not obvious.

And quite often, some of them go away - or at least shrink a lot - when
some config option or other isn't set. So sometimes it's an inline because
a certain class of people really want it inlined, simply because for
_them_ it makes sense, but when you enable debugging or something, it
absolutely explodes.

Linus