What should be in <sys/param.h>?

[H. J. Lu]

On Sun, Jul 17, 2005 at 08:57:46PM -0700, Roland McGrath wrote:
> <sys/param.h> only exists for compatibility with old applications that have
> usage predating the better ways now available to get such information.  So
> all that matters is that it has what was there in the past when that
> application could be compiled on that platform.  If you are compiling a
> program someplace it was never compiled in the past, then you should fix it
> to use the modern interfaces.

The problem is <sys/param.h> doesn't compile on ia64 due to

# define HZ     sysconf(_SC_CLK_TCK)

in <asm/param.h> on RHEL 4. RHEL 3 has

#ifdef CONFIG_IA64_HP_SIM
/*
 * Yeah, simulating stuff is slow, so let us catch some breath between
 * timer interrupts...
 */
# define HZ       32
#else
# define HZ     1024
#endif

and it is OK. You can argue that <asm/param.h> doesn't come from glibc.
But the old application only includes <sys/param.h>, which should work.
If glibc provides <sys/param.h>, it should at least compile when it is
used. 


H.J.