Re: finding out the value of HZ from userspace

[Peter Williams]

Albert Cahalan wrote:
> On Sat, 2004-03-20 at 04:56, Arjan van de Ven wrote:
>
> > On Tue, Mar 16, 2004 at 11:14:59AM -0500, Albert Cahalan wrote:
> >
> > > > there is one. Nothing uses it
> > > > (sysconf() provides this info)
> > >
> > > If you have a recent glibc on a recent kernel, it might.
> > > You could also get a -1 or a supposed ABI value that
> > > has nothing to do with the kernel currently running.
> > > The most reliable way is to first look around on the
> > > stack in search of ELF notes, and then fall back to
> > > some horribly gross hacks as needed.
> >
> > eh sysconf() is the nice way to get to the ELF notes
> > instead of having to grovel yourself.
>
>
> Unless there is some hidden feature that lets
> me specify the ELF note number directly, no way.
>
> The sysconf(_SC_CLK_TCK) call does not return an
> error code when used on a 2.2.xx i386 kernel.
> You get an arbitrary value that fails for ARM,
> Alpha, and any system with modified HZ.

As Linux is supposed to be POSIX compliant this is a bug and should be 
fixed.

Peter
--
Dr Peter Williams, Chief Scientist                peterw@xxxxxxxxxx
Aurema Pty Limited                                Tel:+61 2 9698 2322
PO Box 305, Strawberry Hills NSW 2012, Australia  Fax:+61 2 9699 9174
79 Myrtle Street, Chippendale NSW 2008, Australia http://www.aurema.com

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