Re: finding out the value of HZ from userspace

From: Arjan van de Ven
Date: Thu Apr 01 2004 - 11:04:30 EST


On Thu, Apr 01, 2004 at 04:54:20PM +0100, Jamie Lokier wrote:
> Albert Cahalan wrote:
> > If you rely on sysconf(_SC_CLK_TCK) to work, then
> > your software will support:
> >
> > * all systems with a 2.6.xx kernel
> > * all systems with a 2.4.xx kernel and recent glibc
> > * all i386 systems running with the default HZ
> >
> > That's quite a bit I suppose. Maybe you have no
> > interest in supporting a 1200 HZ Alpha with an old
> > kernel or glibc. Maybe you don't care about somebody
> > running a 2.2.xx kernel with modified HZ.
>
> I'm still unclear. Does sysconf(_SC_CLK_TCK), when it is reliable,
> return HZ or USER_HZ?

USER_HZ; the value all the userspace interfaces are in.
HZ doesn't mean nothing, esp when we go to a tickless kernel...

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