> >>don't many of the multi-CPU problems with tsc go away because you've got a
> >>per-cpu physical page for the vsyscall?
> >>
> >>i.e. per-cpu tsc epoch and scaling can be set on that page.
> >
> > Problem is that cpu's can randomly drift +/- 100 clocks or so... Not
> > nice at all.
> >
>
> ญญ?100 clocks is what... ?50 ns these days? You can't get that kind of
> accuracy for anything outside the CPU core anyway...
50ns is bad enough when it makes your time go backwards.
Pavel
-- Casualities in World Trade Center: ~3k dead inside the building, cryptography in U.S.A. and free speech in Czech Republic. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/