Re: Intel P6 vs P7 system call performance

[Linus Torvalds]

On Tue, 17 Dec 2002, Ulrich Drepper wrote:
>
> If you don't like the process-global page thingy (anymore) the
> alternative would be a sysconf() system call.

Well, we do _have_ the process-global thingy now - it's the vsyscall page.
It's not settable by the process, but it's useful for information.
Together with an elf AT_ entry pointing to it, it's certainly sufficient
for this usage, and it should also be sufficient for "future use" (ie we
can add future system information in the page later: bitmaps of features
at offset "start + 128" for example).

		Linus