C function extending postgres

#include "postgres.h"
#include "fmgr.h"
#include "proc.h"

PG_FUNCTION_INFO_V1(get_process_total);

Datum
get_process_total(PG_FUNCTION_ARGS)
{
float ret;
ret = proc_cpu_user() + proc_cpu_nice() + proc_cpu_system() -
proc_cpu_idle();
PG_RETURN_FLOAT4(ret);
}

Hi ,

I'm getting the following error when attempting to call the above
function, I have included the -I path when compiling, and have compiled a
similar function to execute and printf to linux without a problem :

Returned by postgres:

ERROR: could not load library "/usr/lib/pgsql/processinfo.so":
/usr/lib/pgsql/processinfo.so: undefined symbol: proc_cpu_idle

Compiling:
cc -g -I /usr/local/pgsql/include -I /usr/local/pgsql/include/server
-I /usr/local/include -fpic -c processinfo.c
cc -g -I /usr/local/pgsql/include -I /usr/local/pgsql/include/server
-I /usr/local/include -shared -o processinfo.so processinfo.o

Here is the postgres create function:
CREATE FUNCTION get_process_total() RETURNS float4
AS '$libdir/processinfo', 'get_process_total'
LANGUAGE 'c' STABLE STRICT;

TEST:
select * from get_process_total()

Your help would be greatly appreciated.

Theo

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