src/proc_softirqs.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_softirqs(int update_every, unsigned long long dt) {
  34         static procfile *ff = NULL;
  35         static int cpus = -1, do_per_core = -1;
  36
  37         struct interrupt *irrs = NULL;
  38
  39         if(dt) {};
  40
  41         if(do_per_core == -1) do_per_core = config_get_boolean("plugin:proc:/proc/softirqs", "interrupts per core", 1);
  42
  43         if(!ff) {
  44                 char filename[FILENAME_MAX + 1];
  45                 snprintfz(filename, FILENAME_MAX, "%s%s", global_host_prefix, "/proc/softirqs");
  46                 ff = procfile_open(config_get("plugin:proc:/proc/softirqs", "filename to monitor", filename), " \t", PROCFILE_FLAG_DEFAULT);
  47         }
  48         if(!ff) return 1;
  49
  50         ff = procfile_readall(ff);
  51         if(!ff) return 0; // we return 0, so that we will retry to open it next time
  52
  53         uint32_t lines = procfile_lines(ff), l;
  54         uint32_t words = procfile_linewords(ff, 0), w;
  55
  56         if(!lines) {
  57                 error("Cannot read /proc/softirqs, zero lines reported.");
  58                 return 1;
  59         }
  60
  61         // find how many CPUs are there
  62         if(cpus == -1) {
  63                 cpus = 0;
  64                 for(w = 0; w < words ; w++) {
  65                         if(strncmp(procfile_lineword(ff, 0, w), "CPU", 3) == 0)
  66                                 cpus++;
  67                 }
  68         }
  69
  70         if(!cpus) {
  71                 error("PLUGIN: PROC_SOFTIRQS: Cannot find the number of CPUs in /proc/softirqs");
  72                 return 1;
  73         }
  74
  75         // allocate the size we need;
  76         irrs = get_interrupts_array(lines, cpus);
  77         irrs[0].used = 0;
  78
  79         // loop through all lines
  80         for(l = 1; l < lines ;l++) {
  81                 struct interrupt *irr = irrindex(irrs, l, cpus);
  82                 irr->used = 0;
  83                 irr->total = 0;
  84
  85                 words = procfile_linewords(ff, l);
  86                 if(!words) continue;
  87
  88                 irr->id = procfile_lineword(ff, l, 0);
  89                 if(!irr->id || !irr->id[0]) continue;
  90
  91                 int idlen = strlen(irr->id);
  92                 if(irr->id[idlen - 1] == ':')
  93                         irr->id[idlen - 1] = '\0';
  94
  95                 int c;
  96                 for(c = 0; c < cpus ;c++) {
  97                         if((c + 1) < (int)words)
  98                                 irr->value[c] = strtoull(procfile_lineword(ff, l, (uint32_t)(c + 1)), NULL, 10);
  99                         else
 100                                 irr->value[c] = 0;
 101
 102                         irr->total += irr->value[c];
 103                 }
 104
 105                 strncpyz(irr->name, irr->id, MAX_INTERRUPT_NAME);
 106
 107                 irr->used = 1;
 108         }
 109
 110         RRDSET *st;
 111
 112         // --------------------------------------------------------------------
 113
 114         st = rrdset_find_bytype("system", "softirqs");
 115         if(!st) {
 116                 st = rrdset_create("system", "softirqs", NULL, "softirqs", NULL, "System softirqs", "softirqs/s", 950, update_every, RRDSET_TYPE_STACKED);
 117
 118                 for(l = 0; l < lines ;l++) {
 119                         struct interrupt *irr = irrindex(irrs, l, cpus);
 120                         if(!irr->used) continue;
 121                         rrddim_add(st, irr->id, irr->name, 1, 1, RRDDIM_INCREMENTAL);
 122                 }
 123         }
 124         else rrdset_next(st);
 125
 126         for(l = 0; l < lines ;l++) {
 127                 struct interrupt *irr = irrindex(irrs, l, cpus);
 128                 if(!irr->used) continue;
 129                 rrddim_set(st, irr->id, irr->total);
 130         }
 131         rrdset_done(st);
 132
 133         if(do_per_core) {
 134                 int c;
 135
 136                 for(c = 0; c < cpus ; c++) {
 137                         char id[256+1];
 138                         snprintfz(id, 256, "cpu%d_softirqs", c);
 139
 140                         st = rrdset_find_bytype("cpu", id);
 141                         if(!st) {
 142                                 // find if everything is zero
 143                                 unsigned long long core_sum = 0 ;
 144                                 for(l = 0; l < lines ;l++) {
 145                                         struct interrupt *irr = irrindex(irrs, l, cpus);
 146                                         if(!irr->used) continue;
 147                                         core_sum += irr->value[c];
 148                                 }
 149                                 if(core_sum == 0) continue; // try next core
 150
 151                                 char name[256+1], title[256+1];
 152                                 snprintfz(name, 256, "cpu%d_softirqs", c);
 153                                 snprintfz(title, 256, "CPU%d softirqs", c);
 154                                 st = rrdset_create("cpu", id, name, "softirqs", "cpu.softirqs", title, "softirqs/s", 3000 + 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 }