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procps/proc/sysinfo.c

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20 KiB
C
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// Copyright (C) 1992-1998 by Michael K. Johnson, johnsonm@redhat.com
// Copyright 1998-2003 Albert Cahalan
//
// This file is placed under the conditions of the GNU Library
// General Public License, version 2, or any later version.
// See file COPYING for information on distribution conditions.
/* File for parsing top-level /proc entities. */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <locale.h>
#include <unistd.h>
#include <fcntl.h>
#include "version.h"
#include "sysinfo.h" /* include self to verify prototypes */
#ifndef HZ
#include <netinet/in.h> /* htons */
#endif
long smp_num_cpus; /* number of CPUs */
#define BAD_OPEN_MESSAGE \
"Error: /proc must be mounted\n" \
" To mount /proc at boot you need an /etc/fstab line like:\n" \
" /proc /proc proc defaults\n" \
" In the meantime, mount /proc /proc -t proc\n"
#define STAT_FILE "/proc/stat"
static int stat_fd = -1;
#define UPTIME_FILE "/proc/uptime"
static int uptime_fd = -1;
#define LOADAVG_FILE "/proc/loadavg"
static int loadavg_fd = -1;
#define MEMINFO_FILE "/proc/meminfo"
static int meminfo_fd = -1;
#define VMINFO_FILE "/proc/vmstat"
static int vminfo_fd = -1;
static char buf[1024];
/* This macro opens filename only if necessary and seeks to 0 so
* that successive calls to the functions are more efficient.
* It also reads the current contents of the file into the global buf.
*/
#define FILE_TO_BUF(filename, fd) do{ \
static int local_n; \
if (fd == -1 && (fd = open(filename, O_RDONLY)) == -1) { \
fprintf(stderr, BAD_OPEN_MESSAGE); \
fflush(NULL); \
_exit(102); \
} \
lseek(fd, 0L, SEEK_SET); \
if ((local_n = read(fd, buf, sizeof buf - 1)) < 0) { \
perror(filename); \
fflush(NULL); \
_exit(103); \
} \
buf[local_n] = '\0'; \
}while(0)
/* evals 'x' twice */
#define SET_IF_DESIRED(x,y) do{ if(x) *(x) = (y); }while(0)
/***********************************************************************/
int uptime(double *restrict uptime_secs, double *restrict idle_secs) {
double up=0, idle=0;
char *restrict savelocale;
FILE_TO_BUF(UPTIME_FILE,uptime_fd);
savelocale = setlocale(LC_NUMERIC, NULL);
setlocale(LC_NUMERIC,"C");
if (sscanf(buf, "%lf %lf", &up, &idle) < 2) {
setlocale(LC_NUMERIC,savelocale);
fprintf(stderr, "bad data in " UPTIME_FILE "\n");
return 0;
}
setlocale(LC_NUMERIC,savelocale);
SET_IF_DESIRED(uptime_secs, up);
SET_IF_DESIRED(idle_secs, idle);
return up; /* assume never be zero seconds in practice */
}
/***********************************************************************
* Some values in /proc are expressed in units of 1/HZ seconds, where HZ
* is the kernel clock tick rate. One of these units is called a jiffy.
* The HZ value used in the kernel may vary according to hacker desire.
* According to Linus Torvalds, this is not true. He considers the values
* in /proc as being in architecture-dependant units that have no relation
* to the kernel clock tick rate. Examination of the kernel source code
* reveals that opinion as wishful thinking.
*
* In any case, we need the HZ constant as used in /proc. (the real HZ value
* may differ, but we don't care) There are several ways we could get HZ:
*
* 1. Include the kernel header file. If it changes, recompile this library.
* 2. Use the sysconf() function. When HZ changes, recompile the C library!
* 3. Ask the kernel. This is obviously correct...
*
* Linus Torvalds won't let us ask the kernel, because he thinks we should
* not know the HZ value. Oh well, we don't have to listen to him.
* Someone smuggled out the HZ value. :-)
*
* This code should work fine, even if Linus fixes the kernel to match his
* stated behavior. The code only fails in case of a partial conversion.
*
* Recent update: on some architectures, the 2.4 kernel provides an
* ELF note to indicate HZ. This may be for ARM or user-mode Linux
* support. This ought to be investigated. Note that sysconf() is still
* unreliable, because it doesn't return an error code when it is
* used with a kernel that doesn't support the ELF note. On some other
* architectures there may be a system call or sysctl() that will work.
*/
unsigned long long Hertz;
static void old_Hertz_hack(void){
unsigned long long user_j, nice_j, sys_j, other_j; /* jiffies (clock ticks) */
double up_1, up_2, seconds;
unsigned long long jiffies;
unsigned h;
char *restrict savelocale;
savelocale = setlocale(LC_NUMERIC, NULL);
setlocale(LC_NUMERIC, "C");
do{
FILE_TO_BUF(UPTIME_FILE,uptime_fd); sscanf(buf, "%lf", &up_1);
/* uptime(&up_1, NULL); */
FILE_TO_BUF(STAT_FILE,stat_fd);
sscanf(buf, "cpu %Lu %Lu %Lu %Lu", &user_j, &nice_j, &sys_j, &other_j);
FILE_TO_BUF(UPTIME_FILE,uptime_fd); sscanf(buf, "%lf", &up_2);
/* uptime(&up_2, NULL); */
} while((long long)( (up_2-up_1)*1000.0/up_1 )); /* want under 0.1% error */
setlocale(LC_NUMERIC, savelocale);
jiffies = user_j + nice_j + sys_j + other_j;
seconds = (up_1 + up_2) / 2;
h = (unsigned)( (double)jiffies/seconds/smp_num_cpus );
/* actual values used by 2.4 kernels: 32 64 100 128 1000 1024 1200 */
switch(h){
case 9 ... 11 : Hertz = 10; break; /* S/390 (sometimes) */
case 18 ... 22 : Hertz = 20; break; /* user-mode Linux */
case 30 ... 34 : Hertz = 32; break; /* ia64 emulator */
case 48 ... 52 : Hertz = 50; break;
case 58 ... 61 : Hertz = 60; break;
case 62 ... 65 : Hertz = 64; break; /* StrongARM /Shark */
case 95 ... 105 : Hertz = 100; break; /* normal Linux */
case 124 ... 132 : Hertz = 128; break; /* MIPS, ARM */
case 195 ... 204 : Hertz = 200; break; /* normal << 1 */
case 253 ... 260 : Hertz = 256; break;
case 393 ... 408 : Hertz = 400; break; /* normal << 2 */
case 790 ... 808 : Hertz = 800; break; /* normal << 3 */
case 990 ... 1010 : Hertz = 1000; break; /* ARM */
case 1015 ... 1035 : Hertz = 1024; break; /* Alpha, ia64 */
case 1180 ... 1220 : Hertz = 1200; break; /* Alpha */
default:
#ifdef HZ
Hertz = (unsigned long long)HZ; /* <asm/param.h> */
#else
/* If 32-bit or big-endian (not Alpha or ia64), assume HZ is 100. */
Hertz = (sizeof(long)==sizeof(int) || htons(999)==999) ? 100UL : 1024UL;
#endif
fprintf(stderr, "Unknown HZ value! (%d) Assume %Ld.\n", h, Hertz);
}
}
#ifndef AT_CLKTCK
#define AT_CLKTCK 17 /* frequency of times() */
#endif
extern char** environ;
/* for ELF executables, notes are pushed before environment and args */
static unsigned long find_elf_note(unsigned long findme){
unsigned long *ep = (unsigned long *)environ;
while(*ep++);
while(*ep){
if(ep[0]==findme) return ep[1];
ep+=2;
}
return 42;
}
static void init_libproc(void) __attribute__((constructor));
static void init_libproc(void){
/* ought to count CPUs in /proc/stat instead of relying
* on glibc, which foolishly tries to parse /proc/cpuinfo
*/
smp_num_cpus = sysconf(_SC_NPROCESSORS_CONF); // or _SC_NPROCESSORS_ONLN
if(smp_num_cpus<1) smp_num_cpus=1; /* SPARC glibc is buggy */
if(linux_version_code > LINUX_VERSION(2, 4, 0)){
Hertz = find_elf_note(AT_CLKTCK);
if(Hertz!=42) return;
fprintf(stderr, "2.4 kernel w/o ELF notes? -- report to albert@users.sf.net\n");
}
old_Hertz_hack();
}
/***********************************************************************
* The /proc filesystem calculates idle=jiffies-(user+nice+sys) and we
* recover jiffies by adding up the 4 or 5 numbers we are given. SMP kernels
* (as of pre-2.4 era) can report idle time going backwards, perhaps due
* to non-atomic reads and updates. There is no locking for these values.
*/
#ifndef NAN
#define NAN (-0.0)
#endif
#define JT unsigned long long
void five_cpu_numbers(double *restrict uret, double *restrict nret, double *restrict sret, double *restrict iret, double *restrict wret){
double tmp_u, tmp_n, tmp_s, tmp_i, tmp_w;
double scale; /* scale values to % */
static JT old_u, old_n, old_s, old_i, old_w;
JT new_u, new_n, new_s, new_i, new_w;
JT ticks_past; /* avoid div-by-0 by not calling too often :-( */
tmp_w = 0.0;
new_w = 0;
FILE_TO_BUF(STAT_FILE,stat_fd);
sscanf(buf, "cpu %Lu %Lu %Lu %Lu %Lu", &new_u, &new_n, &new_s, &new_i, &new_w);
ticks_past = (new_u+new_n+new_s+new_i+new_w)-(old_u+old_n+old_s+old_i+old_w);
if(ticks_past){
scale = 100.0 / (double)ticks_past;
tmp_u = ( (double)new_u - (double)old_u ) * scale;
tmp_n = ( (double)new_n - (double)old_n ) * scale;
tmp_s = ( (double)new_s - (double)old_s ) * scale;
tmp_i = ( (double)new_i - (double)old_i ) * scale;
tmp_w = ( (double)new_w - (double)old_w ) * scale;
}else{
tmp_u = NAN;
tmp_n = NAN;
tmp_s = NAN;
tmp_i = NAN;
tmp_w = NAN;
}
SET_IF_DESIRED(uret, tmp_u);
SET_IF_DESIRED(nret, tmp_n);
SET_IF_DESIRED(sret, tmp_s);
SET_IF_DESIRED(iret, tmp_i);
SET_IF_DESIRED(wret, tmp_w);
old_u=new_u;
old_n=new_n;
old_s=new_s;
old_i=new_i;
old_w=new_w;
}
#undef JT
/***********************************************************************/
void loadavg(double *restrict av1, double *restrict av5, double *restrict av15) {
double avg_1=0, avg_5=0, avg_15=0;
char *restrict savelocale;
FILE_TO_BUF(LOADAVG_FILE,loadavg_fd);
savelocale = setlocale(LC_NUMERIC, NULL);
setlocale(LC_NUMERIC, "C");
if (sscanf(buf, "%lf %lf %lf", &avg_1, &avg_5, &avg_15) < 3) {
fprintf(stderr, "bad data in " LOADAVG_FILE "\n");
exit(1);
}
setlocale(LC_NUMERIC, savelocale);
SET_IF_DESIRED(av1, avg_1);
SET_IF_DESIRED(av5, avg_5);
SET_IF_DESIRED(av15, avg_15);
}
/***********************************************************************/
/*
* Copyright 1999 by Albert Cahalan; all rights reserved.
* This file may be used subject to the terms and conditions of the
* GNU Library General Public License Version 2, or any later version
* at your option, as published by the Free Software Foundation.
* 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 Library General Public License for more details.
*/
typedef struct mem_table_struct {
const char *name; /* memory type name */
unsigned long *slot; /* slot in return struct */
} mem_table_struct;
static int compare_mem_table_structs(const void *a, const void *b){
return strcmp(((const mem_table_struct*)a)->name,((const mem_table_struct*)b)->name);
}
/* example data, following junk, with comments added:
*
* MemTotal: 61768 kB old
* MemFree: 1436 kB old
* MemShared: 0 kB old (now always zero; not calculated)
* Buffers: 1312 kB old
* Cached: 20932 kB old
* Active: 12464 kB new
* Inact_dirty: 7772 kB new
* Inact_clean: 2008 kB new
* Inact_target: 0 kB new
* Inact_laundry: 0 kB new, and might be missing too
* HighTotal: 0 kB
* HighFree: 0 kB
* LowTotal: 61768 kB
* LowFree: 1436 kB
* SwapTotal: 122580 kB old
* SwapFree: 60352 kB old
* Inactive: 20420 kB 2.5.41+
* Dirty: 0 kB 2.5.41+
* Writeback: 0 kB 2.5.41+
* Mapped: 9792 kB 2.5.41+
* Slab: 4564 kB 2.5.41+
* Committed_AS: 8440 kB 2.5.41+
* PageTables: 304 kB 2.5.41+
* ReverseMaps: 5738 2.5.41+
* SwapCached: 0 kB 2.5.??+
* HugePages_Total: 220 2.5.??+
* HugePages_Free: 138 2.5.??+
* Hugepagesize: 4096 kB 2.5.??+
*/
/* obsolete */
unsigned long kb_main_shared;
/* old but still kicking -- the important stuff */
unsigned long kb_main_buffers;
unsigned long kb_main_cached;
unsigned long kb_main_free;
unsigned long kb_main_total;
unsigned long kb_swap_free;
unsigned long kb_swap_total;
/* recently introduced */
unsigned long kb_high_free;
unsigned long kb_high_total;
unsigned long kb_low_free;
unsigned long kb_low_total;
/* 2.4.xx era */
unsigned long kb_active;
unsigned long kb_inact_laundry;
unsigned long kb_inact_dirty;
unsigned long kb_inact_clean;
unsigned long kb_inact_target;
unsigned long kb_swap_cached; /* late 2.4 only */
/* derived values */
unsigned long kb_swap_used;
unsigned long kb_main_used;
/* 2.5.41+ */
unsigned long kb_writeback;
unsigned long kb_slab;
unsigned long nr_reversemaps;
unsigned long kb_committed_as;
unsigned long kb_dirty;
unsigned long kb_inactive;
unsigned long kb_mapped;
unsigned long kb_pagetables;
void meminfo(void){
char namebuf[16]; /* big enough to hold any row name */
mem_table_struct findme = { namebuf, NULL};
mem_table_struct *found;
char *head;
char *tail;
static const mem_table_struct mem_table[] = {
{"Active", &kb_active}, // important
{"Buffers", &kb_main_buffers}, // important
{"Cached", &kb_main_cached}, // important
{"Committed_AS", &kb_committed_as},
{"Dirty", &kb_dirty}, // kB version of vmstat nr_dirty
{"HighFree", &kb_high_free},
{"HighTotal", &kb_high_total},
{"Inact_clean", &kb_inact_clean},
{"Inact_dirty", &kb_inact_dirty},
{"Inact_laundry",&kb_inact_laundry},
{"Inact_target", &kb_inact_target},
{"Inactive", &kb_inactive}, // important
{"LowFree", &kb_low_free},
{"LowTotal", &kb_low_total},
{"Mapped", &kb_mapped}, // kB version of vmstat nr_mapped
{"MemFree", &kb_main_free}, // important
{"MemShared", &kb_main_shared}, // important
{"MemTotal", &kb_main_total}, // important
{"PageTables", &kb_pagetables}, // kB version of vmstat nr_page_table_pages
{"ReverseMaps", &nr_reversemaps}, // same as vmstat nr_page_table_pages
{"Slab", &kb_slab}, // kB version of vmstat nr_slab
{"SwapCached", &kb_swap_cached},
{"SwapFree", &kb_swap_free}, // important
{"SwapTotal", &kb_swap_total}, // important
{"Writeback", &kb_writeback}, // kB version of vmstat nr_writeback
};
const int mem_table_count = sizeof(mem_table)/sizeof(mem_table_struct);
FILE_TO_BUF(MEMINFO_FILE,meminfo_fd);
kb_inactive = ~0UL;
head = buf;
for(;;){
tail = strchr(head, ':');
if(!tail) break;
*tail = '\0';
if(strlen(head) >= sizeof(namebuf)){
head = tail+1;
goto nextline;
}
strcpy(namebuf,head);
found = bsearch(&findme, mem_table, mem_table_count,
sizeof(mem_table_struct), compare_mem_table_structs
);
head = tail+1;
if(!found) goto nextline;
*(found->slot) = strtoul(head,&tail,10);
nextline:
tail = strchr(head, '\n');
if(!tail) break;
head = tail+1;
}
if(!kb_low_total){ /* low==main except with large-memory support */
kb_low_total = kb_main_total;
kb_low_free = kb_main_free;
}
if(kb_inactive==~0UL){
kb_inactive = kb_inact_dirty + kb_inact_clean + kb_inact_laundry;
}
kb_swap_used = kb_swap_total - kb_swap_free;
kb_main_used = kb_main_total - kb_main_free;
}
/*****************************************************************/
/* read /proc/vminfo only for 2.5.41 and above */
typedef struct vm_table_struct {
const char *name; /* VM statistic name */
unsigned long *slot; /* slot in return struct */
} vm_table_struct;
static int compare_vm_table_structs(const void *a, const void *b){
return strcmp(((const vm_table_struct*)a)->name,((const vm_table_struct*)b)->name);
}
// see include/linux/page-flags.h and mm/page_alloc.c
unsigned long vm_nr_dirty; // dirty writable pages
unsigned long vm_nr_writeback; // pages under writeback
unsigned long vm_nr_pagecache; // pages in pagecache -- gone in 2.5.66+ kernels
unsigned long vm_nr_page_table_pages;// pages used for pagetables
unsigned long vm_nr_reverse_maps; // includes PageDirect
unsigned long vm_nr_mapped; // mapped into pagetables
unsigned long vm_nr_slab; // in slab
unsigned long vm_pgpgin; // kB disk reads (same as 1st num on /proc/stat page line)
unsigned long vm_pgpgout; // kB disk writes (same as 2nd num on /proc/stat page line)
unsigned long vm_pswpin; // swap reads (same as 1st num on /proc/stat swap line)
unsigned long vm_pswpout; // swap writes (same as 2nd num on /proc/stat swap line)
unsigned long vm_pgalloc; // page allocations
unsigned long vm_pgfree; // page freeings
unsigned long vm_pgactivate; // pages moved inactive -> active
unsigned long vm_pgdeactivate; // pages moved active -> inactive
unsigned long vm_pgfault; // total faults (major+minor)
unsigned long vm_pgmajfault; // major faults
unsigned long vm_pgscan; // pages scanned by page reclaim
unsigned long vm_pgrefill; // inspected by refill_inactive_zone
unsigned long vm_pgsteal; // total pages reclaimed
unsigned long vm_kswapd_steal; // pages reclaimed by kswapd
// next 3 as defined by the 2.5.52 kernel
unsigned long vm_pageoutrun; // times kswapd ran page reclaim
unsigned long vm_allocstall; // times a page allocator ran direct reclaim
unsigned long vm_pgrotated; // pages rotated to the tail of the LRU for immediate reclaim
void vminfo(void){
char namebuf[16]; /* big enough to hold any row name */
vm_table_struct findme = { namebuf, NULL};
vm_table_struct *found;
char *head;
char *tail;
static const vm_table_struct vm_table[] = {
{"allocstall", &vm_allocstall},
{"kswapd_steal", &vm_kswapd_steal},
{"nr_dirty", &vm_nr_dirty}, // page version of meminfo Dirty
{"nr_mapped", &vm_nr_mapped}, // page version of meminfo Mapped
{"nr_page_table_pages", &vm_nr_page_table_pages},// same as meminfo PageTables
{"nr_pagecache", &vm_nr_pagecache}, // gone in 2.5.66+ kernels
{"nr_reverse_maps", &vm_nr_reverse_maps}, // page version of meminfo ReverseMaps
{"nr_slab", &vm_nr_slab}, // page version of meminfo Slab
{"nr_writeback", &vm_nr_writeback}, // page version of meminfo Writeback
{"pageoutrun", &vm_pageoutrun},
{"pgactivate", &vm_pgactivate},
{"pgalloc", &vm_pgalloc},
{"pgdeactivate", &vm_pgdeactivate},
{"pgfault", &vm_pgfault},
{"pgfree", &vm_pgfree},
{"pgmajfault", &vm_pgmajfault},
{"pgpgin", &vm_pgpgin}, // important
{"pgpgout", &vm_pgpgout}, // important
{"pgrefill", &vm_pgrefill},
{"pgrotated", &vm_pgrotated},
{"pgscan", &vm_pgscan},
{"pgsteal", &vm_pgsteal},
{"pswpin", &vm_pswpin}, // important
{"pswpout", &vm_pswpout} // important
};
const int vm_table_count = sizeof(vm_table)/sizeof(vm_table_struct);
FILE_TO_BUF(VMINFO_FILE,vminfo_fd);
head = buf;
for(;;){
tail = strchr(head, ' ');
if(!tail) break;
*tail = '\0';
if(strlen(head) >= sizeof(namebuf)){
head = tail+1;
goto nextline;
}
strcpy(namebuf,head);
found = bsearch(&findme, vm_table, vm_table_count,
sizeof(vm_table_struct), compare_vm_table_structs
);
head = tail+1;
if(!found) goto nextline;
*(found->slot) = strtoul(head,&tail,10);
nextline:
//if(found) fprintf(stderr,"%s=%d\n",found->name,*(found->slot));
//else fprintf(stderr,"%s not found\n",findme.name);
tail = strchr(head, '\n');
if(!tail) break;
head = tail+1;
}
}
/*****************************************************************/
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