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/*
* lbcd kernel code for IRIX.
*
* Use utmpx to get the system boot time as the method used to get kernel
* addresses doesn't seem to work for the time of the last reboot.
*
* Written by Russ Allbery <eagle@eyrie.org>
* Copyright 2000, 2009, 2012
* The Board of Trustees of the Leland Stanford Junior University
*
* See LICENSE for licensing terms.
*/
#include <config.h>
#include <portable/system.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/sysmp.h>
#include <sys/time.h>
#include <time.h>
#include <utmpx.h>
#include <server/internal.h>
#include <util/messages.h>
/* Whether we've opened the kernel already. */
static int kernel_init = 0;
/* The file descriptor of /dev/kmem, which we hold open. */
static int kmem_fd = -1;
/* The offset in /dev/kmem where the load average is stored. */
static long kmem_offset = -1;
/*
* Sets up for later queries. Open the kernel memory file and find the
* address of the necessary variable. Exits on error.
*/
static int
kernel_open(void)
{
int ldav_off;
kmem_fd = open("/dev/kmem", O_RDONLY);
if (kmem_fd < 0)
sysdie("cannot open /dev/kmem");
ldav_off = sysmp(MP_KERNADDR, MPKA_AVENRUN);
if (ldav_off < 0)
sysdie("sysmp failed");
kernel_offset = (long) ldav_off & 0x7fffffff;
kernel_init = 1;
}
/*
* Close and free any resources for querying the kernel.
*/
static int
kernel_close(void)
{
if (!kernel_init)
return 0;
return close(kmem_fd);
}
/*
* Get the current load average from the kernel and return the one minute,
* five minute, and fifteen minute averages in the given parameters. Returns
* 0 on success and -1 on failure.
*/
int
kernel_getload(double *load1, double *load5, double *load15)
{
int status, load[3];
static long offset = -1;
if (!kernel_init)
kernel_open();
if (lseek(kmem_fd, offset, 0) < 0)
sysdie("cannot lseek in /dev/kmem");
status = read(kmem_fd, (void *) load, sizeof(load));
if (status != sizeof(load))
sysdie("kernel read failed");
*load1 = (double) load[0] / 1000.0;
*load5 = (double) load[1] / 1000.0;
*load15 = (double) load[2] / 1000.0;
return 0;
}
/*
* Get the system uptime and return it in the boottime parameter. Returns 0
* on success and -1 on failure.
*/
int
kernel_getboottime(time_t *boottime)
{
struct utmpx query, *result;
query.ut_type = BOOT_TIME;
setutxent();
result = getutxid(&query);
endutxent();
if (result == NULL) {
syswarn("getutxid failed to find BOOT_TIME");
return -1;
}
*boottime = result->ut_tv.tv_sec;
return 0;
}
/*
* Test routine.
*/
#ifdef MAIN
int
main(void)
{
double l1, l5, l15;
time_t boottime;
if (kernel_getload(&l1, &l5, &l15) == 0)
printf("load %.02f %.02f %.02f\n", l1, l5, l15);
if (kernel_getboottime(&boottime) == 0)
printf("booted at %s", ctime(&boottime));
return 0;
}
#endif
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