load average calculation failing

load average calculation failing

[Mark Geisert]

I've recently noticed that the 'xload' I routinely run shows zero load 
even with compute-bound processes running.  This is on both Cygwin 
pre-3.4.0 as well as 3.3.4.  A test program, shown below, indicates that 
getloadavg() is returning with 0 status, i.e. not an error but no elems
of the passed-in array updated.

Stepping with gdb through the test program seems weird within the 
loadavginfo::load_init method.  Single-stepping at line loadavg.cc:68 goes 
to strace.h:52 and then to _sigbe ?!

I had recently updated both Cygwin and Windows 10 to latest at the same 
time so I cannot say when the failure started.  Last day or two at most.

..mark

-------------------
#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>

int
main (int argc, char **argv)
{
     double loadavg[3];

     int res = getloadavg (loadavg, 3);
     if (res == -1)
         return 0xFF;
     if (res > 0)
         for (int i = 0; i < res; i++)
             printf ("%f.2 ", loadavg[i]);

     return res;
}