Re: Why is get_current() not const function?

[Linus Torvalds]

In article <[e-mail]>,
Jakub Jelinek  <[e-mail]> wrote:
>
>Anyone remembers why get_current function (on arches which define
>current to get_current()) is not const

Because it makes no difference at all on x86, since gcc will ignore
"const" for inline functions. At least that used to be true.

>					 and why on x86-64
>the movq %%gs:0, %0 inline asm is volatile with "memory" clobber?

Can't help you on that one, but it looks like it uses various helper
functions for doing the x86-64 per-processor data structures, and I bet
those helper functions are shared by _other_ users who definitely want
to have their data properly re-read. Ie "current()" may be constant in
process context, but that sure isn't true about a lot of other things in
the per-processor data structures.

		Linus