diff options
Diffstat (limited to 'lib/libutil/getloadavg.c')
| -rw-r--r-- | lib/libutil/getloadavg.c | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/lib/libutil/getloadavg.c b/lib/libutil/getloadavg.c new file mode 100644 index 000000000000..8f6fb0bcaa86 --- /dev/null +++ b/lib/libutil/getloadavg.c @@ -0,0 +1,93 @@ +/*- + * Copyright (c) 1989 The Regents of the University of California. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#if defined(LIBC_SCCS) && !defined(lint) +static char sccsid[] = "@(#)getloadavg.c 6.2 (Berkeley) 6/29/90"; +#endif /* LIBC_SCCS and not lint */ + +#include <sys/param.h> +#include <sys/types.h> +#include <sys/file.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; + fixpt_t averunnable[3]; + int fscale, kmemfd, i; + int alreadyopen; + + 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 *)averunnable, + sizeof(averunnable)) != sizeof(averunnable)) + goto bad; + if (kvm_read( (off_t)nl[X_FSCALE].n_value, (char *)&fscale, + sizeof(fscale)) != sizeof(fscale)) + goto bad; + nelem = MIN(nelem, sizeof(averunnable) / sizeof(averunnable[0])); + for (i = 0; i < nelem; i++) + loadavg[i] = (double) averunnable[i] / fscale; + if (!alreadyopen) + kvm_close(); + return (nelem); + +bad: + if (!alreadyopen) + kvm_close(); + return (-1); +} |