src/proc_softirqs.c

   1 #ifdef HAVE_CONFIG_H
   2 #include <config.h>
   3 #endif
   4 #include <stdio.h>
   5 #include <stdlib.h>
   6 #include <string.h>
   7 #include <ctype.h>
   8
   9 #include "common.h"
  10 #include "appconfig.h"
  11 #include "procfile.h"
  12 #include "rrd.h"
  13 #include "plugin_proc.h"
  14 #include "log.h"
  15
  16 #define MAX_INTERRUPT_NAME 50
  17
  18 struct interrupt {
  19         int used;
  20         char *id;
  21         char name[MAX_INTERRUPT_NAME + 1];
  22         unsigned long long total;
  23         unsigned long long value[];
  24 };
  25
  26 // since each interrupt is variable in size
  27 // we use this to calculate its record size
  28 #define recordsize(cpus) (sizeof(struct interrupt) + (cpus * sizeof(unsigned long long)))
  29
  30 // given a base, get a pointer to each record
  31 #define irrindex(base, line, cpus) ((struct interrupt *)&((char *)(base))[line * recordsize(cpus)])
  32
  33 static inline struct interrupt *get_interrupts_array(int lines, int cpus) {
  34         static struct interrupt *irrs = NULL;
  35         static int allocated = 0;
  36
  37         if(lines < allocated) return irrs;
  38         else {
  39                 irrs = (struct interrupt *)realloc(irrs, lines * recordsize(cpus));
  40                 if(!irrs)
  41                         fatal("Cannot allocate memory for %d interrupts", lines);
  42
  43                 allocated = lines;
  44         }
  45
  46         return irrs;
  47 }
  48
  49 int do_proc_softirqs(int update_every, unsigned long long dt) {
  50         static procfile *ff = NULL;
  51         static int cpus = -1, do_per_core = -1;
  52
  53         struct interrupt *irrs = NULL;
  54
  55         if(dt) {};
  56
  57         if(do_per_core == -1) do_per_core = config_get_boolean("plugin:proc:/proc/softirqs", "interrupts per core", 1);
  58
  59         if(!ff) {
  60                 char filename[FILENAME_MAX + 1];
  61                 snprintfz(filename, FILENAME_MAX, "%s%s", global_host_prefix, "/proc/softirqs");
  62                 ff = procfile_open(config_get("plugin:proc:/proc/softirqs", "filename to monitor", filename), " \t", PROCFILE_FLAG_DEFAULT);
  63         }
  64         if(!ff) return 1;
  65
  66         ff = procfile_readall(ff);
  67         if(!ff) return 0; // we return 0, so that we will retry to open it next time
  68
  69         uint32_t lines = procfile_lines(ff), l;
  70         uint32_t words = procfile_linewords(ff, 0), w;
  71
  72         if(!lines) {
  73                 error("Cannot read /proc/softirqs, zero lines reported.");
  74                 return 1;
  75         }
  76
  77         // find how many CPUs are there
  78         if(cpus == -1) {
  79                 cpus = 0;
  80                 for(w = 0; w < words ; w++) {
  81                         if(strncmp(procfile_lineword(ff, 0, w), "CPU", 3) == 0)
  82                                 cpus++;
  83                 }
  84         }
  85
  86         if(!cpus) {
  87                 error("PLUGIN: PROC_SOFTIRQS: Cannot find the number of CPUs in /proc/softirqs");
  88                 return 1;
  89         }
  90
  91         // allocate the size we need;
  92         irrs = get_interrupts_array(lines, cpus);
  93         irrs[0].used = 0;
  94
  95         // loop through all lines
  96         for(l = 1; l < lines ;l++) {
  97                 struct interrupt *irr = irrindex(irrs, l, cpus);
  98                 irr->used = 0;
  99                 irr->total = 0;
 100
 101                 words = procfile_linewords(ff, l);
 102                 if(!words) continue;
 103
 104                 irr->id = procfile_lineword(ff, l, 0);
 105                 if(!irr->id || !irr->id[0]) continue;
 106
 107                 int idlen = strlen(irr->id);
 108                 if(irr->id[idlen - 1] == ':')
 109                         irr->id[idlen - 1] = '\0';
 110
 111                 int c;
 112                 for(c = 0; c < cpus ;c++) {
 113                         if((c + 1) < (int)words)
 114                                 irr->value[c] = strtoull(procfile_lineword(ff, l, (uint32_t)(c + 1)), NULL, 10);
 115                         else
 116                                 irr->value[c] = 0;
 117
 118                         irr->total += irr->value[c];
 119                 }
 120
 121                 strncpyz(irr->name, irr->id, MAX_INTERRUPT_NAME);
 122
 123                 irr->used = 1;
 124         }
 125
 126         RRDSET *st;
 127
 128         // --------------------------------------------------------------------
 129
 130         st = rrdset_find_bytype("system", "softirqs");
 131         if(!st) {
 132                 st = rrdset_create("system", "softirqs", NULL, "softirqs", NULL, "System softirqs", "softirqs/s", 950, update_every, RRDSET_TYPE_STACKED);
 133
 134                 for(l = 0; l < lines ;l++) {
 135                         struct interrupt *irr = irrindex(irrs, l, cpus);
 136                         if(!irr->used) continue;
 137                         rrddim_add(st, irr->id, irr->name, 1, 1, RRDDIM_INCREMENTAL);
 138                 }
 139         }
 140         else rrdset_next(st);
 141
 142         for(l = 0; l < lines ;l++) {
 143                 struct interrupt *irr = irrindex(irrs, l, cpus);
 144                 if(!irr->used) continue;
 145                 rrddim_set(st, irr->id, irr->total);
 146         }
 147         rrdset_done(st);
 148
 149         if(do_per_core) {
 150                 int c;
 151
 152                 for(c = 0; c < cpus ; c++) {
 153                         char id[256+1];
 154                         snprintfz(id, 256, "cpu%d_softirqs", c);
 155
 156                         st = rrdset_find_bytype("cpu", id);
 157                         if(!st) {
 158                                 // find if everything is zero
 159                                 unsigned long long core_sum = 0 ;
 160                                 for(l = 0; l < lines ;l++) {
 161                                         struct interrupt *irr = irrindex(irrs, l, cpus);
 162                                         if(!irr->used) continue;
 163                                         core_sum += irr->value[c];
 164                                 }
 165                                 if(core_sum == 0) continue; // try next core
 166
 167                                 char name[256+1], title[256+1];
 168                                 snprintfz(name, 256, "cpu%d_softirqs", c);
 169                                 snprintfz(title, 256, "CPU%d softirqs", c);
 170                                 st = rrdset_create("cpu", id, name, "softirqs", "cpu.softirqs", title, "softirqs/s", 3000 + c, update_every, RRDSET_TYPE_STACKED);
 171
 172                                 for(l = 0; l < lines ;l++) {
 173                                         struct interrupt *irr = irrindex(irrs, l, cpus);
 174                                         if(!irr->used) continue;
 175                                         rrddim_add(st, irr->id, irr->name, 1, 1, RRDDIM_INCREMENTAL);
 176                                 }
 177                         }
 178                         else rrdset_next(st);
 179
 180                         for(l = 0; l < lines ;l++) {
 181                                 struct interrupt *irr = irrindex(irrs, l, cpus);
 182                                 if(!irr->used) continue;
 183                                 rrddim_set(st, irr->id, irr->value[c]);
 184                         }
 185                         rrdset_done(st);
 186                 }
 187         }
 188
 189         return 0;
 190 }