Re: [patch] spinlocks: remove 'volatile'

Ingo Molnar
2006-07-06T08:27:40Z

* Ingo Molnar <mingo@elte.hu> wrote:

> * Linus Torvalds <torvalds@osdl.org> wrote:
>
> > I wonder if we should remove the "volatile". There really isn't
> > anything _good_ that gcc can do with it, but we've seen gcc code
> > generation do stupid things before just because "volatile" seems to
> > just disable even proper normal working.
>
> yeah. I tried this and it indeed slashed 42K off text size (0.2%):
>
> text data bss dec filename
> 20779489 6073834 3075176 29928499 vmlinux.volatile
> 20736884 6073834 3075176 29885894 vmlinux.non-volatile
>
> i booted the resulting allyesconfig bzImage and everything seems to be
> working fine. Find patch below.

btw., this effect accounted for roughly half of the per-callsite win of
the wait.h uninlining patch. That still leaves 18 bytes of per-callsite
win - i'll send that patch next.

Ingo