Re: [GIT PULL] Additional x86 fixes for 2.6.31-rc5

Linus Torvalds
2009-08-01T22:06:52Z

On Sat, 1 Aug 2009, H. Peter Anvin wrote:
>
> This is clearly better... now the semi-obvious question becomes if there
> is any way we can get compiler support to do better and migrate to that
> as the compiler allows.

Well, even if we had compiler support, we'd have to basically then wait
forever to make sure everybody has a supported compiler. So I think we're
better off not worrying too much about that - it's not going to happen any
time in the near future.

I've now tested my patch, and it seems to result in a working kernel too.

> In particular, if I remember right the problem with using __thread for
> percpu was exactly that the current cpuness can change almost anywhere,
> unless preemption is disabled.

That shouldn't matter. If it uses '%gs', it should all just work
automatically. But if gcc does something different for thread-local, it's
basically useless.

Linus