Subject: bug#9396: make fails with undefined reference to '__sched_cpucount'

From: Paul Eggert <[email-masked]>
Date: Sun, 28 Aug 2011 17:49:52 -0700

On 08/28/11 14:59, Feuerbacher, Alan wrote:
> I tracked the problem down to the fact that the RHEL5 system uses /lib64/libc.so.6
> which apparently is version 2.5 of the GNU C Library,
> but this version does not contain "__sched_cpucount" - whatever that is.
> Apparently only version 2.6 and later contain this stuff.

It sounds like you're compiling with glibc 2.6 headers but linking
to glibc 2.5.  If so, that'd be a definite no-no; you need to configure
and build with <= 2.5 headers if you're going to link with 2.5.

I expect that it's the 2.6 headers that #define CPU_COUNT and bring
in a reference to __sched_cpucount.