src/proc_interrupts.c

   1 #include "common.h"
   2
   3 #define MAX_INTERRUPT_NAME 50
   4
   5 struct interrupt {
   6         int used;
   7         char *id;
   8         char name[MAX_INTERRUPT_NAME + 1];
   9         unsigned long long total;
  10         unsigned long long value[];
  11 };
  12
  13 // since each interrupt is variable in size
  14 // we use this to calculate its record size
  15 #define recordsize(cpus) (sizeof(struct interrupt) + (cpus * sizeof(unsigned long long)))
  16
  17 // given a base, get a pointer to each record
  18 #define irrindex(base, line, cpus) ((struct interrupt *)&((char *)(base))[line * recordsize(cpus)])
  19
  20 static inline struct interrupt *get_interrupts_array(int lines, int cpus) {
  21         static struct interrupt *irrs = NULL;
  22         static int allocated = 0;
  23
  24         if(lines < allocated) return irrs;
  25         else {
  26                 irrs = (struct interrupt *)reallocz(irrs, lines * recordsize(cpus));
  27                 allocated = lines;
  28         }
  29
  30         return irrs;
  31 }
  32
  33 int do_proc_interrupts(int update_every, unsigned long long dt) {
  34         static procfile *ff = NULL;
  35         static int cpus = -1, do_per_core = -1;
  36         struct interrupt *irrs = NULL;
  37
  38         if(dt) {};
  39
  40         if(do_per_core == -1) do_per_core = config_get_boolean("plugin:proc:/proc/interrupts", "interrupts per core", 1);
  41
  42         if(!ff) {
  43                 char filename[FILENAME_MAX + 1];
  44                 snprintfz(filename, FILENAME_MAX, "%s%s", global_host_prefix, "/proc/interrupts");
  45                 ff = procfile_open(config_get("plugin:proc:/proc/interrupts", "filename to monitor", filename), " \t", PROCFILE_FLAG_DEFAULT);
  46         }
  47         if(!ff) return 1;
  48
  49         ff = procfile_readall(ff);
  50         if(!ff) return 0; // we return 0, so that we will retry to open it next time
  51
  52         uint32_t lines = procfile_lines(ff), l;
  53         uint32_t words = procfile_linewords(ff, 0), w;
  54
  55         if(!lines) {
  56                 error("Cannot read /proc/interrupts, zero lines reported.");
  57                 return 1;
  58         }
  59
  60         // find how many CPUs are there
  61         if(cpus == -1) {
  62                 cpus = 0;
  63                 for(w = 0; w < words ; w++) {
  64                         if(strncmp(procfile_lineword(ff, 0, w), "CPU", 3) == 0)
  65                                 cpus++;
  66                 }
  67         }
  68
  69         if(!cpus) {
  70                 error("PLUGIN: PROC_INTERRUPTS: Cannot find the number of CPUs in /proc/interrupts");
  71                 return 1;
  72         }
  73
  74         // allocate the size we need;
  75         irrs = get_interrupts_array(lines, cpus);
  76         irrs[0].used = 0;
  77
  78         // loop through all lines
  79         for(l = 1; l < lines ;l++) {
  80                 struct interrupt *irr = irrindex(irrs, l, cpus);
  81                 irr->used = 0;
  82                 irr->total = 0;
  83
  84                 words = procfile_linewords(ff, l);
  85                 if(!words) continue;
  86
  87                 irr->id = procfile_lineword(ff, l, 0);
  88                 if(!irr->id || !irr->id[0]) continue;
  89
  90                 int idlen = strlen(irr->id);
  91                 if(irr->id[idlen - 1] == ':')
  92                         irr->id[idlen - 1] = '\0';
  93
  94                 int c;
  95                 for(c = 0; c < cpus ;c++) {
  96                         if((c + 1) < (int)words)
  97                                 irr->value[c] = strtoull(procfile_lineword(ff, l, (uint32_t)(c + 1)), NULL, 10);
  98                         else
  99                                 irr->value[c] = 0;
 100
 101                         irr->total += irr->value[c];
 102                 }
 103
 104                 if(isdigit(irr->id[0]) && (uint32_t)(cpus + 2) < words) {
 105                         strncpyz(irr->name, procfile_lineword(ff, l, words - 1), MAX_INTERRUPT_NAME);
 106                         int nlen = strlen(irr->name);
 107                         if(nlen < (MAX_INTERRUPT_NAME-1)) {
 108                                 irr->name[nlen] = '_';
 109                                 strncpyz(&irr->name[nlen + 1], irr->id, MAX_INTERRUPT_NAME - nlen);
 110                         }
 111                 }
 112                 else {
 113                         strncpyz(irr->name, irr->id, MAX_INTERRUPT_NAME);
 114                 }
 115
 116                 irr->used = 1;
 117         }
 118
 119         RRDSET *st;
 120
 121         // --------------------------------------------------------------------
 122
 123         st = rrdset_find_bytype("system", "interrupts");
 124         if(!st) {
 125                 st = rrdset_create("system", "interrupts", NULL, "interrupts", NULL, "System interrupts", "interrupts/s", 1000, update_every, RRDSET_TYPE_STACKED);
 126
 127                 for(l = 0; l < lines ;l++) {
 128                         struct interrupt *irr = irrindex(irrs, l, cpus);
 129                         if(!irr->used) continue;
 130                         rrddim_add(st, irr->id, irr->name, 1, 1, RRDDIM_INCREMENTAL);
 131                 }
 132         }
 133         else rrdset_next(st);
 134
 135         for(l = 0; l < lines ;l++) {
 136                 struct interrupt *irr = irrindex(irrs, l, cpus);
 137                 if(!irr->used) continue;
 138                 rrddim_set(st, irr->id, irr->total);
 139         }
 140         rrdset_done(st);
 141
 142         if(do_per_core) {
 143                 int c;
 144
 145                 for(c = 0; c < cpus ; c++) {
 146                         char id[256+1];
 147                         snprintfz(id, 256, "cpu%d_interrupts", c);
 148
 149                         st = rrdset_find_bytype("cpu", id);
 150                         if(!st) {
 151                                 char name[256+1], title[256+1];
 152                                 snprintfz(name, 256, "cpu%d_interrupts", c);
 153                                 snprintfz(title, 256, "CPU%d Interrupts", c);
 154                                 st = rrdset_create("cpu", id, name, "interrupts", "cpu.interrupts", title, "interrupts/s", 2000 + c, update_every, RRDSET_TYPE_STACKED);
 155
 156                                 for(l = 0; l < lines ;l++) {
 157                                         struct interrupt *irr = irrindex(irrs, l, cpus);
 158                                         if(!irr->used) continue;
 159                                         rrddim_add(st, irr->id, irr->name, 1, 1, RRDDIM_INCREMENTAL);
 160                                 }
 161                         }
 162                         else rrdset_next(st);
 163
 164                         for(l = 0; l < lines ;l++) {
 165                                 struct interrupt *irr = irrindex(irrs, l, cpus);
 166                                 if(!irr->used) continue;
 167                                 rrddim_set(st, irr->id, irr->value[c]);
 168                         }
 169                         rrdset_done(st);
 170                 }
 171         }
 172
 173         return 0;
 174 }