Re: Intel P6 vs P7 system call performance

Kai Henningsen
2002-12-18T08:38:52Z

torvalds@transmeta.com (Linus Torvalds) wrote on 17.12.02 in <Pine.LNX.4.44.0212171157050.1095-100000@home.transmeta.com>:

> On Tue, 17 Dec 2002, Richard B. Johnson wrote:
> >
> > You can call intersegment with a full pointer. I don't know how
> > expensive that is.
>
> It's so expensive as to not be worth it, it's cheaper to load a register
> or something, i eyou can do
>
> pushl $0xfffff000
> call *(%esp)
>
> faster than doing a far call.

Hmm ...

How expensive would it be to have a special virtual DSO built into ld.so
which exported this (and any other future entry points), to be linked
against like any other DSO? That way, the *actual* interface would only be
between the kernel and ld.so.

MfG Kai