move from sys to gen

[unix-history] / usr / src / lib / libc / gen / getloadavg.c

/*-
* Copyright (c) 1989 The Regents of the University of California.
* All rights reserved.
*
* %sccs.include.redist.c%
*/

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)getloadavg.c        6.4 (Berkeley) %G%";
#endif /* LIBC_SCCS and not lint */

#include <sys/param.h>
#include <sys/types.h>
#include <sys/file.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <vm/vm_param.h>
#include <nlist.h>

static struct nlist nl[] = {
       { "_averunnable" },
#define X_AVERUNNABLE   0
       { "_fscale" },
#define X_FSCALE        1
       { "" },
};

/*
*  getloadavg() -- Get system load averages.
*
*  Put `nelem' samples into `loadavg' array.
*  Return number of samples retrieved, or -1 on error.
*/
getloadavg(loadavg, nelem)
       double loadavg[];
       int nelem;
{
       static int need_nlist = 1;
       struct loadavg loadinfo;
       int size, kmemfd, i;
       int alreadyopen = 1;
       int mib[2], fscale;

       size = sizeof(loadinfo);
       mib[0] = CTL_VM;
       mib[1] = VM_LOADAVG;
       if (sysctl(mib, 2, &loadinfo, &size, NULL, 0) < 0) {
               if ((alreadyopen = kvm_openfiles(NULL, NULL, NULL)) == -1)
                       return (-1);
               /* 
                * cache nlist 
                */
               if (need_nlist) {
                       if (kvm_nlist(nl) != 0)
                               goto bad;
                       need_nlist = 0;
               }
               if (kvm_read((off_t)nl[X_AVERUNNABLE].n_value,
                   (char *)&loadinfo, sizeof(loadinfo)) != size)
                       goto bad;
               /*
                * Old kernel have fscale separately; if not found assume
                * running new format.
                */
               if (kvm_read( (off_t)nl[X_FSCALE].n_value, (char *)&fscale, 
                   sizeof(fscale)) == sizeof(fscale))
                       loadinfo.fscale = fscale;
       }
       nelem = MIN(nelem, sizeof(loadinfo.ldavg) / sizeof(fixpt_t));
       for (i = 0; i < nelem; i++)
               loadavg[i] = (double) loadinfo.ldavg[i] / loadinfo.fscale;
       if (!alreadyopen)
               kvm_close();
       return (nelem);

bad:
       if (!alreadyopen)
               kvm_close();
       return (-1);
}