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Diffstat (limited to 'getloadavg.c')
| -rw-r--r-- | getloadavg.c | 737 |
1 files changed, 737 insertions, 0 deletions
diff --git a/getloadavg.c b/getloadavg.c new file mode 100644 index 0000000..7c1c317 --- /dev/null +++ b/getloadavg.c @@ -0,0 +1,737 @@ +/* Get the system load averages. + Copyright (C) 1985, 86, 87, 88, 89, 91, 92, 93 + Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2, or (at your option) + any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ + +/* Compile-time symbols that this file uses: + + FIXUP_KERNEL_SYMBOL_ADDR() Adjust address in returned struct nlist. + KERNEL_FILE Pathname of the kernel to nlist. + LDAV_CVT() Scale the load average from the kernel. + Returns a double. + LDAV_SYMBOL Name of kernel symbol giving load average. + LOAD_AVE_TYPE Type of the load average array in the kernel. + Must be defined unless one of + apollo, DGUX, NeXT, or UMAX is defined; + otherwise, no load average is available. + NLIST_STRUCT Include nlist.h, not a.out.h, and + the nlist n_name element is a pointer, + not an array. + NLIST_NAME_UNION struct nlist has an n_un member, not n_name. + LINUX_LDAV_FILE [LINUX]: Name of file containing load averages. + + Specific system predefines this file uses, aside from setting + default values if not emacs: + + apollo + BSD Real BSD, not just BSD-like. + DGUX + eunice UNIX emulator under VMS. + hpux + NeXT + sgi + sequent Sequent Dynix 3.x.x (BSD) + _SEQUENT_ Sequent DYNIX/ptx 1.x.x (SYSV) + sony_news NEWS-OS (works at least for 4.1C) + UMAX + UMAX4_3 + VMS + LINUX Linux: assumes /proc filesystem mounted. + Support from Michael K. Johnson. + + In addition, to avoid nesting many #ifdefs, we internally set + LDAV_DONE to indicate that the load average has been computed. + + We also #define LDAV_PRIVILEGED if a program will require + special installation to be able to call getloadavg. */ + +#include <sys/types.h> + +/* Both the Emacs and non-Emacs sections want this. Some + configuration files' definitions for the LOAD_AVE_CVT macro (like + sparc.h's) use macros like FSCALE, defined here. */ +#ifdef unix +#include <sys/param.h> +#endif + + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +/* The existing Emacs configuration files define a macro called + LOAD_AVE_CVT, which accepts a value of type LOAD_AVE_TYPE, and + returns the load average multiplied by 100. What we actually want + is a macro called LDAV_CVT, which returns the load average as an + unmultiplied double. + + For backwards compatibility, we'll define LDAV_CVT in terms of + LOAD_AVE_CVT, but future machine config files should just define + LDAV_CVT directly. */ + +#if !defined(LDAV_CVT) && defined(LOAD_AVE_CVT) +#define LDAV_CVT(n) (LOAD_AVE_CVT (n) / 100.0) +#endif + +#if !defined (BSD) && defined (ultrix) +/* Ultrix behaves like BSD on Vaxen. */ +#define BSD +#endif + +#ifdef NeXT +/* NeXT in the 2.{0,1,2} releases defines BSD in <sys/param.h>, which + conflicts with the definition understood in this file, that this + really is BSD. */ +#undef BSD + +/* NeXT defines FSCALE in <sys/param.h>. However, we take FSCALE being + defined to mean that the nlist method should be used, which is not true. */ +#undef FSCALE +#endif + +/* Set values that are different from the defaults, which are + set a little farther down with #ifndef. */ + + +/* Some shorthands. */ + +#if defined (HPUX) && !defined (hpux) +#define hpux +#endif + +#if defined(hp300) && !defined(hpux) +#define MORE_BSD +#endif + +#if defined(ultrix) && defined(mips) +#define decstation +#endif + +#if defined(sun) && defined(SVR4) +#define SUNOS_5 +#endif + +#if defined (__osf__) && defined (__alpha__) +#define OSF_ALPHA +#endif + +#if defined (__osf__) && (defined (mips) || defined (__mips__)) +#define OSF_MIPS +#include <sys/table.h> +#endif + +/* UTek's /bin/cc on the 4300 has no architecture specific cpp define by + default, but _MACH_IND_SYS_TYPES is defined in <sys/types.h>. Combine + that with a couple of other things and we'll have a unique match. */ +#if !defined (tek4300) && defined (unix) && defined (m68k) && defined (mc68000) && defined (mc68020) && defined (_MACH_IND_SYS_TYPES) +#define tek4300 /* Define by emacs, but not by other users. */ +#endif + + +/* VAX C can't handle multi-line #ifs. */ +#if (defined(MORE_BSD) || defined(sun) || defined(decstation) || defined(_SEQUENT_) || defined(sgi) || defined(SVR4) || defined(sony_news) || defined(sequent) || defined (OSF_ALPHA) || (defined (ardent) && defined (titan)) || defined (tek4300)) +#define LOAD_AVE_TYPE long +#endif + + +#ifndef FSCALE + +/* SunOS and some others define FSCALE in sys/param.h. */ + +#ifdef MORE_BSD +#define FSCALE 2048.0 +#endif + +#if defined(MIPS) || defined(SVR4) || defined(decstation) +#define FSCALE 256 +#endif + +#if defined (sgi) || defined (sequent) +#define FSCALE 1000.0 +#endif + +#if defined (ardent) && defined (titan) +#define FSCALE 65536.0 +#endif + +#ifdef tek4300 +#define FSCALE 100.0 +#endif + +#endif /* Not FSCALE. */ + +#if !defined (LDAV_CVT) && defined (FSCALE) +#define LDAV_CVT(n) (((double) (n)) / FSCALE) +#endif + +/* VAX C can't handle multi-line #ifs. */ +#if !defined(NLIST_STRUCT) && (defined(MORE_BSD) || defined(sun) || defined(decstation) || defined(hpux) || defined(_SEQUENT_) || defined(sequent) || defined(sgi) || defined(SVR4) || defined(sony_news) || defined (OSF_ALPHA) || (defined (ardent) && defined (titan)) || defined (tek4300) || defined (butterfly)) +#define NLIST_STRUCT +#endif + + +#if defined(sgi) || (defined(mips) && !defined(BSD)) +#define FIXUP_KERNEL_SYMBOL_ADDR(nl) ((nl)[0].n_value &= ~(1 << 31)) +#endif + + +#if !defined (KERNEL_FILE) && defined (sequent) +#define KERNEL_FILE "/dynix" +#endif + +#if !defined (KERNEL_FILE) && defined (hpux) +#define KERNEL_FILE "/hp-ux" +#endif + +#if !defined(KERNEL_FILE) && (defined(_SEQUENT_) || defined(MIPS) || defined(SVR4) || defined(ISC) || defined (sgi) || defined(SVR4) || (defined (ardent) && defined (titan))) +#define KERNEL_FILE "/unix" +#endif + + +#if !defined (LDAV_SYMBOL) && defined (alliant) +#define LDAV_SYMBOL "_Loadavg" +#endif + +#if !defined(LDAV_SYMBOL) && ((defined(hpux) && !defined(hp9000s300)) || defined(_SEQUENT_) || defined(SVR4) || defined(ISC) || defined(sgi) || (defined (ardent) && defined (titan))) +#define LDAV_SYMBOL "avenrun" +#endif + +#ifdef HAVE_UNISTD_H +#include <unistd.h> +#endif + +#include <stdio.h> +#include <errno.h> + +#ifndef errno +extern int errno; +#endif + +/* LOAD_AVE_TYPE should only get defined if we're going to use the + nlist method. */ +#if !defined(LOAD_AVE_TYPE) && (defined(BSD) || defined(LDAV_CVT) || defined(KERNEL_FILE) || defined(LDAV_SYMBOL)) +#define LOAD_AVE_TYPE double +#endif + +#ifdef LOAD_AVE_TYPE + +#ifndef VMS +#ifndef NLIST_STRUCT +#include <a.out.h> +#else /* NLIST_STRUCT */ +#include <nlist.h> +#endif /* NLIST_STRUCT */ + +#ifdef SUNOS_5 +#include <fcntl.h> +#include <kvm.h> +#endif + +#ifndef KERNEL_FILE +#define KERNEL_FILE "/vmunix" +#endif /* KERNEL_FILE */ + +#ifndef LDAV_SYMBOL +#define LDAV_SYMBOL "_avenrun" +#endif /* LDAV_SYMBOL */ + +#else /* VMS */ + +#ifndef eunice +#include <iodef.h> +#include <descrip.h> +#else /* eunice */ +#include <vms/iodef.h> +#endif /* eunice */ +#endif /* VMS */ + +#ifndef LDAV_CVT +#define LDAV_CVT(n) ((double) (n)) +#endif /* !LDAV_CVT */ + +#endif /* LOAD_AVE_TYPE */ + +#ifdef NeXT +#ifdef HAVE_MACH_MACH_H +#include <mach/mach.h> +#else +#include <mach.h> +#endif +#endif /* NeXT */ + +#ifdef sgi +#include <sys/sysmp.h> +#endif /* sgi */ + +#ifdef UMAX +#include <stdio.h> +#include <signal.h> +#include <sys/time.h> +#include <sys/wait.h> +#include <sys/syscall.h> + +#ifdef UMAX_43 +#include <machine/cpu.h> +#include <inq_stats/statistics.h> +#include <inq_stats/sysstats.h> +#include <inq_stats/cpustats.h> +#include <inq_stats/procstats.h> +#else /* Not UMAX_43. */ +#include <sys/sysdefs.h> +#include <sys/statistics.h> +#include <sys/sysstats.h> +#include <sys/cpudefs.h> +#include <sys/cpustats.h> +#include <sys/procstats.h> +#endif /* Not UMAX_43. */ +#endif /* UMAX */ + +#ifdef DGUX +#include <sys/dg_sys_info.h> +#endif + +#if defined(HAVE_FCNTL_H) || defined(_POSIX_VERSION) +#include <fcntl.h> +#else +#include <sys/file.h> +#endif + +/* Avoid static vars inside a function since in HPUX they dump as pure. */ + +#ifdef NeXT +static processor_set_t default_set; +static int getloadavg_initialized; +#endif /* NeXT */ + +#ifdef UMAX +static unsigned int cpus = 0; +static unsigned int samples; +#endif /* UMAX */ + +#ifdef DGUX +static struct dg_sys_info_load_info load_info; /* what-a-mouthful! */ +#endif /* DGUX */ + +#ifdef LOAD_AVE_TYPE +/* File descriptor open to /dev/kmem or VMS load ave driver. */ +static int channel; +/* Nonzero iff channel is valid. */ +static int getloadavg_initialized; +/* Offset in kmem to seek to read load average, or 0 means invalid. */ +static long offset; + +#if !defined(VMS) && !defined(sgi) +static struct nlist nl[2]; +#endif /* Not VMS or sgi */ + +#ifdef SUNOS_5 +static kvm_t *kd; +#endif /* SUNOS_5 */ + +#endif /* LOAD_AVE_TYPE */ + +/* Put the 1 minute, 5 minute and 15 minute load averages + into the first NELEM elements of LOADAVG. + Return the number written (never more than 3), + or -1 if an error occurred. */ + +int +getloadavg (loadavg, nelem) + double loadavg[]; + int nelem; +{ + int elem = 0; /* Return value. */ + +#if !defined (LDAV_DONE) && defined (LINUX) +#define LDAV_DONE +#undef LOAD_AVE_TYPE + +#ifndef LINUX_LDAV_FILE +#define LINUX_LDAV_FILE "/proc/loadavg" +#endif + + char ldavgbuf[40]; + double load_ave[3]; + int fd, count; + + fd = open (LINUX_LDAV_FILE, O_RDONLY); + if (fd == -1) + return -1; + count = read (fd, ldavgbuf, 40); + (void) close (fd); + if (count <= 0) + return -1; + + count = sscanf (ldavgbuf, "%lf %lf %lf", + &load_ave[0], &load_ave[1], &load_ave[2]); + if (count < 1) + return -1; + + for (elem = 0; elem < nelem && elem < count; elem++) + loadavg[elem] = load_ave[elem]; + + return elem; + +#endif /* LINUX */ + +#if !defined (LDAV_DONE) && defined (NeXT) +#define LDAV_DONE + /* The NeXT code was adapted from iscreen 3.2. */ + + host_t host; + struct processor_set_basic_info info; + unsigned info_count; + + if (nelem > 1) + { + /* We only know how to get the 1-minute average for this system. */ + errno = EINVAL; + return -1; + } + + if (!getloadavg_initialized) + { + if (processor_set_default (host_self (), &default_set) == KERN_SUCCESS) + getloadavg_initialized = 1; + } + + if (getloadavg_initialized) + { + info_count = PROCESSOR_SET_BASIC_INFO_COUNT; + if (processor_set_info (default_set, PROCESSOR_SET_BASIC_INFO, &host, + (processor_set_info_t) &info, &info_count) + != KERN_SUCCESS) + getloadavg_initialized = 0; + else + { + if (nelem > 0) + loadavg[elem++] = (double) info.load_average / LOAD_SCALE; + } + } + + if (!getloadavg_initialized) + return -1; +#endif /* NeXT */ + +#if !defined (LDAV_DONE) && defined (UMAX) +#define LDAV_DONE +/* UMAX 4.2, which runs on the Encore Multimax multiprocessor, does not + have a /dev/kmem. Information about the workings of the running kernel + can be gathered with inq_stats system calls. + We only know how to get the 1-minute average for this system. */ + + struct proc_summary proc_sum_data; + struct stat_descr proc_info; + double load; + register unsigned int i, j; + + if (cpus == 0) + { + register unsigned int c, i; + struct cpu_config conf; + struct stat_descr desc; + + desc.sd_next = 0; + desc.sd_subsys = SUBSYS_CPU; + desc.sd_type = CPUTYPE_CONFIG; + desc.sd_addr = (char *) &conf; + desc.sd_size = sizeof conf; + + if (inq_stats (1, &desc)) + return -1; + + c = 0; + for (i = 0; i < conf.config_maxclass; ++i) + { + struct class_stats stats; + bzero ((char *) &stats, sizeof stats); + + desc.sd_type = CPUTYPE_CLASS; + desc.sd_objid = i; + desc.sd_addr = (char *) &stats; + desc.sd_size = sizeof stats; + + if (inq_stats (1, &desc)) + return -1; + + c += stats.class_numcpus; + } + cpus = c; + samples = cpus < 2 ? 3 : (2 * cpus / 3); + } + + proc_info.sd_next = 0; + proc_info.sd_subsys = SUBSYS_PROC; + proc_info.sd_type = PROCTYPE_SUMMARY; + proc_info.sd_addr = (char *) &proc_sum_data; + proc_info.sd_size = sizeof (struct proc_summary); + proc_info.sd_sizeused = 0; + + if (inq_stats (1, &proc_info) != 0) + return -1; + + load = proc_sum_data.ps_nrunnable; + j = 0; + for (i = samples - 1; i > 0; --i) + { + load += proc_sum_data.ps_nrun[j]; + if (j++ == PS_NRUNSIZE) + j = 0; + } + + if (nelem > 0) + loadavg[elem++] = load / samples / cpus; +#endif /* UMAX */ + +#if !defined (LDAV_DONE) && defined (DGUX) +#define LDAV_DONE + /* This call can return -1 for an error, but with good args + it's not supposed to fail. The first argument is for no + apparent reason of type `long int *'. */ + dg_sys_info ((long int *) &load_info, + DG_SYS_INFO_LOAD_INFO_TYPE, + DG_SYS_INFO_LOAD_VERSION_0); + + if (nelem > 0) + loadavg[elem++] = load_info.one_minute; + if (nelem > 1) + loadavg[elem++] = load_info.five_minute; + if (nelem > 2) + loadavg[elem++] = load_info.fifteen_minute; +#endif /* DGUX */ + +#if !defined (LDAV_DONE) && defined (apollo) +#define LDAV_DONE +/* Apollo code from lisch@mentorg.com (Ray Lischner). + + This system call is not documented. The load average is obtained as + three long integers, for the load average over the past minute, + five minutes, and fifteen minutes. Each value is a scaled integer, + with 16 bits of integer part and 16 bits of fraction part. + + I'm not sure which operating system first supported this system call, + but I know that SR10.2 supports it. */ + + extern void proc1_$get_loadav (); + unsigned long load_ave[3]; + + proc1_$get_loadav (load_ave); + + if (nelem > 0) + loadavg[elem++] = load_ave[0] / 65536.0; + if (nelem > 1) + loadavg[elem++] = load_ave[1] / 65536.0; + if (nelem > 2) + loadavg[elem++] = load_ave[2] / 65536.0; +#endif /* apollo */ + +#if !defined (LDAV_DONE) && defined (OSF_MIPS) +#define LDAV_DONE +#define LDAV_PRIVILEGED + + struct tbl_loadavg load_ave; + table (TBL_LOADAVG, 0, &load_ave, 1, sizeof (load_ave)); + loadavg[elem++] = (load_ave.tl_lscale == 0 + ? load_ave.tl_avenrun.d[0] + : (load_ave.tl_avenrun.l[0] / load_ave.tl_lscale)); +#endif /* OSF_MIPS */ + +#if !defined (LDAV_DONE) && defined (VMS) + /* VMS specific code -- read from the Load Ave driver. */ + + LOAD_AVE_TYPE load_ave[3]; + static int getloadavg_initialized = 0; +#ifdef eunice + struct + { + int dsc$w_length; + char *dsc$a_pointer; + } descriptor; +#endif + + /* Ensure that there is a channel open to the load ave device. */ + if (!getloadavg_initialized) + { + /* Attempt to open the channel. */ +#ifdef eunice + descriptor.dsc$w_length = 18; + descriptor.dsc$a_pointer = "$$VMS_LOAD_AVERAGE"; +#else + $DESCRIPTOR (descriptor, "LAV0:"); +#endif + if (sys$assign (&descriptor, &channel, 0, 0) & 1) + getloadavg_initialized = 1; + } + + /* Read the load average vector. */ + if (getloadavg_initialized + && !(sys$qiow (0, channel, IO$_READVBLK, 0, 0, 0, + load_ave, 12, 0, 0, 0, 0) & 1)) + { + sys$dassgn (channel); + getloadavg_initialized = 0; + } + + if (!getloadavg_initialized) + return -1; +#endif /* VMS */ + +#if !defined (LDAV_DONE) && defined(LOAD_AVE_TYPE) && !defined(VMS) + + /* UNIX-specific code -- read the average from /dev/kmem. */ + +#define LDAV_PRIVILEGED /* This code requires special installation. */ + + LOAD_AVE_TYPE load_ave[3]; + + /* Get the address of LDAV_SYMBOL. */ + if (offset == 0) + { +#ifndef SUNOS_5 +#ifndef sgi +#ifndef NLIST_STRUCT + strcpy (nl[0].n_name, LDAV_SYMBOL); + strcpy (nl[1].n_name, ""); +#else /* NLIST_STRUCT */ +#ifdef NLIST_NAME_UNION + nl[0].n_un.n_name = LDAV_SYMBOL; + nl[1].n_un.n_name = 0; +#else /* not NLIST_NAME_UNION */ + nl[0].n_name = LDAV_SYMBOL; + nl[1].n_name = 0; +#endif /* not NLIST_NAME_UNION */ +#endif /* NLIST_STRUCT */ + + if (nlist (KERNEL_FILE, nl) >= 0) + /* Omit "&& nl[0].n_type != 0 " -- it breaks on Sun386i. */ + { +#ifdef FIXUP_KERNEL_SYMBOL_ADDR + FIXUP_KERNEL_SYMBOL_ADDR (nl); +#endif + offset = nl[0].n_value; + } +#else /* sgi */ + int ldav_off; + + ldav_off = sysmp (MP_KERNADDR, MPKA_AVENRUN); + if (ldav_off != -1) + offset = (long) ldav_off & 0x7fffffff; +#endif /* sgi */ +#endif /* !SUNOS_5 */ + } + + /* Make sure we have /dev/kmem open. */ + if (!getloadavg_initialized) + { +#ifndef SUNOS_5 + channel = open ("/dev/kmem", 0); + if (channel >= 0) + getloadavg_initialized = 1; +#else /* SUNOS_5 */ + kd = kvm_open (0, 0, 0, O_RDONLY, 0); + if (kd != 0) + { + kvm_nlist (kd, nl); + getloadavg_initialized = 1; + } +#endif /* SUNOS_5 */ + } + + /* If we can, get the load average values. */ + if (offset && getloadavg_initialized) + { + /* Try to read the load. */ +#ifndef SUNOS_5 + if (lseek (channel, offset, 0) == -1L + || read (channel, (char *) load_ave, sizeof (load_ave)) + != sizeof (load_ave)) + { + close (channel); + getloadavg_initialized = 0; + } +#else /* SUNOS_5 */ + if (kvm_read (kd, offset, (char *) load_ave, sizeof (load_ave)) + != sizeof (load_ave)) + { + kvm_close (kd); + getloadavg_initialized = 0; + } +#endif /* SUNOS_5 */ + } + + if (offset == 0 || !getloadavg_initialized) + return -1; +#endif /* LOAD_AVE_TYPE and not VMS */ + +#if !defined (LDAV_DONE) && defined (LOAD_AVE_TYPE) /* Including VMS. */ + if (nelem > 0) + loadavg[elem++] = LDAV_CVT (load_ave[0]); + if (nelem > 1) + loadavg[elem++] = LDAV_CVT (load_ave[1]); + if (nelem > 2) + loadavg[elem++] = LDAV_CVT (load_ave[2]); + +#define LDAV_DONE +#endif /* !LDAV_DONE && LOAD_AVE_TYPE */ + +#ifdef LDAV_DONE + return elem; +#else + /* Set errno to zero to indicate that there was no particular error; + this function just can't work at all on this system. */ + errno = 0; + return -1; +#endif +} + +#ifdef TEST +void +main (argc, argv) + int argc; + char **argv; +{ + int naptime = 0; + + if (argc > 1) + naptime = atoi (argv[1]); + + if (naptime == 0) + naptime = 5; + + while (1) + { + double avg[3]; + int loads; + + errno = 0; /* Don't be misled if it doesn't set errno. */ + loads = getloadavg (avg, 3); + if (loads == -1) + { + perror ("Error getting load average"); + exit (1); + } + if (loads > 0) + printf ("1-minute: %f ", avg[0]); + if (loads > 1) + printf ("5-minute: %f ", avg[1]); + if (loads > 2) + printf ("15-minute: %f ", avg[2]); + if (loads > 0) + putchar ('\n'); + sleep (naptime); + } +} +#endif /* TEST */ |