Re: Once again: test_and_set for CPUs w/o LL/SC

[Daniel Jacobowitz <dan@debian.org>]

On Mon, Oct 07, 2002 at 08:43:44PM +0200, Johannes Stezenbach wrote:
> The question is how the glibc can detect if
> a) the CPU does not have LL/SC
> b) the kernel guarantees k1 != MAGIC
> 
> I think the kernel should announce this explicitly.
> In my patch from Sep 16 I used a sysctl, but that's
> probably bad because glibc would rely on a real new
> include/linux/sysctl.h.
> 
> I need some advice on this (maybe add a line to /proc/cpuinfo,
> or create a new /proc entry? or add a sysmips call to get
> this info?).

You should be using an "aux vector"; see how PowerPC provides current
glibc with the size of a cache line.

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer