src/proc_diskstats.c

   1 #include "common.h"
   2
   3 #define RRD_TYPE_DISK "disk"
   4
   5 #define DISK_TYPE_PHYSICAL  1
   6 #define DISK_TYPE_PARTITION 2
   7 #define DISK_TYPE_CONTAINER 3
   8
   9 static struct disk {
  10     char *disk;             // the name of the disk (sda, sdb, etc)
  11     unsigned long major;
  12     unsigned long minor;
  13     int sector_size;
  14     int type;
  15
  16     char *mount_point;
  17
  18     // disk options caching
  19     int configured;
  20     int do_io;
  21     int do_ops;
  22     int do_mops;
  23     int do_iotime;
  24     int do_qops;
  25     int do_util;
  26     int do_backlog;
  27
  28     struct disk *next;
  29 } *disk_root = NULL;
  30
  31 static struct disk *get_disk(unsigned long major, unsigned long minor, char *disk) {
  32     static char path_to_get_hw_sector_size[FILENAME_MAX + 1] = "";
  33     static char path_to_get_hw_sector_size_partitions[FILENAME_MAX + 1] = "";
  34     static char path_find_block_device[FILENAME_MAX + 1] = "";
  35     static struct mountinfo *disk_mountinfo_root = NULL;
  36
  37     struct disk *d;
  38
  39     // search for it in our RAM list.
  40     // this is sequential, but since we just walk through
  41     // and the number of disks / partitions in a system
  42     // should not be that many, it should be acceptable
  43     for(d = disk_root; d ; d = d->next)
  44         if(unlikely(d->major == major && d->minor == minor))
  45             return d;
  46
  47     // not found
  48     // create a new disk structure
  49     d = (struct disk *)mallocz(sizeof(struct disk));
  50
  51     d->disk = strdupz(disk);
  52     d->major = major;
  53     d->minor = minor;
  54     d->type = DISK_TYPE_PHYSICAL; // Default type. Changed later if not correct.
  55     d->configured = 0;
  56     d->sector_size = 512; // the default, will be changed below
  57     d->next = NULL;
  58
  59     // append it to the list
  60     if(unlikely(!disk_root))
  61         disk_root = d;
  62     else {
  63         struct disk *last;
  64         for(last = disk_root; last->next ;last = last->next);
  65         last->next = d;
  66     }
  67
  68     // ------------------------------------------------------------------------
  69     // find the type of the device
  70
  71     char buffer[FILENAME_MAX + 1];
  72
  73     // get the default path for finding info about the block device
  74     if(unlikely(!path_find_block_device[0])) {
  75         snprintfz(buffer, FILENAME_MAX, "%s%s", netdata_configured_host_prefix, "/sys/dev/block/%lu:%lu/%s");
  76         snprintfz(path_find_block_device, FILENAME_MAX, "%s", config_get("plugin:proc:/proc/diskstats", "path to get block device infos", buffer));
  77     }
  78
  79     // find if it is a partition
  80     // by checking if /sys/dev/block/MAJOR:MINOR/partition is readable.
  81     snprintfz(buffer, FILENAME_MAX, path_find_block_device, major, minor, "partition");
  82     if(likely(access(buffer, R_OK) == 0)) {
  83         d->type = DISK_TYPE_PARTITION;
  84     }
  85     else {
  86         // find if it is a container
  87         // by checking if /sys/dev/block/MAJOR:MINOR/slaves has entries
  88         snprintfz(buffer, FILENAME_MAX, path_find_block_device, major, minor, "slaves/");
  89         DIR *dirp = opendir(buffer);
  90         if(likely(dirp != NULL)) {
  91             struct dirent *dp;
  92             while( (dp = readdir(dirp)) ) {
  93                 // . and .. are also files in empty folders.
  94                 if(unlikely(strcmp(dp->d_name, ".") == 0 || strcmp(dp->d_name, "..") == 0)) {
  95                     continue;
  96                 }
  97
  98                 d->type = DISK_TYPE_CONTAINER;
  99
 100                 // Stop the loop after we found one file.
 101                 break;
 102             }
 103             if(unlikely(closedir(dirp) == -1))
 104                 error("Unable to close dir %s", buffer);
 105         }
 106     }
 107
 108     // ------------------------------------------------------------------------
 109     // check if we can find its mount point
 110
 111     // mountinfo_find() can be called with NULL disk_mountinfo_root
 112     struct mountinfo *mi = mountinfo_find(disk_mountinfo_root, d->major, d->minor);
 113     if(unlikely(!mi)) {
 114         // mountinfo_free can be called with NULL
 115         mountinfo_free(disk_mountinfo_root);
 116         disk_mountinfo_root = mountinfo_read(0);
 117         mi = mountinfo_find(disk_mountinfo_root, d->major, d->minor);
 118     }
 119
 120     if(unlikely(mi))
 121         d->mount_point = strdupz(mi->mount_point);
 122     else
 123         d->mount_point = NULL;
 124
 125     // ------------------------------------------------------------------------
 126     // find the disk sector size
 127
 128     if(unlikely(!path_to_get_hw_sector_size[0])) {
 129         snprintfz(buffer, FILENAME_MAX, "%s%s", netdata_configured_host_prefix, "/sys/block/%s/queue/hw_sector_size");
 130         snprintfz(path_to_get_hw_sector_size, FILENAME_MAX, "%s", config_get("plugin:proc:/proc/diskstats", "path to get h/w sector size", buffer));
 131     }
 132     if(unlikely(!path_to_get_hw_sector_size_partitions[0])) {
 133         snprintfz(buffer, FILENAME_MAX, "%s%s", netdata_configured_host_prefix, "/sys/dev/block/%lu:%lu/subsystem/%s/../queue/hw_sector_size");
 134         snprintfz(path_to_get_hw_sector_size_partitions, FILENAME_MAX, "%s", config_get("plugin:proc:/proc/diskstats", "path to get h/w sector size for partitions", buffer));
 135     }
 136
 137     {
 138         char tf[FILENAME_MAX + 1], *t;
 139         strncpyz(tf, d->disk, FILENAME_MAX);
 140
 141         // replace all / with !
 142         for(t = tf; *t ;t++)
 143             if(unlikely(*t == '/')) *t = '!';
 144
 145         if(likely(d->type == DISK_TYPE_PARTITION))
 146             snprintfz(buffer, FILENAME_MAX, path_to_get_hw_sector_size_partitions, d->major, d->minor, tf);
 147         else
 148             snprintfz(buffer, FILENAME_MAX, path_to_get_hw_sector_size, tf);
 149
 150         FILE *fpss = fopen(buffer, "r");
 151         if(likely(fpss)) {
 152             char buffer2[1024 + 1];
 153             char *tmp = fgets(buffer2, 1024, fpss);
 154
 155             if(likely(tmp)) {
 156                 d->sector_size = str2i(tmp);
 157                 if(unlikely(d->sector_size <= 0)) {
 158                     error("Invalid sector size %d for device %s in %s. Assuming 512.", d->sector_size, d->disk, buffer);
 159                     d->sector_size = 512;
 160                 }
 161             }
 162             else error("Cannot read data for sector size for device %s from %s. Assuming 512.", d->disk, buffer);
 163
 164             fclose(fpss);
 165         }
 166         else error("Cannot read sector size for device %s from %s. Assuming 512.", d->disk, buffer);
 167     }
 168
 169     return d;
 170 }
 171
 172 static inline int is_major_enabled(int major) {
 173     static int8_t *major_configs = NULL;
 174     static size_t major_size = 0;
 175
 176     if(major < 0) return 1;
 177
 178     size_t wanted_size = (size_t)major + 1;
 179
 180     if(major_size < wanted_size) {
 181         major_configs = reallocz(major_configs, wanted_size * sizeof(int8_t));
 182
 183         size_t i;
 184         for(i = major_size; i < wanted_size ; i++)
 185             major_configs[i] = -1;
 186
 187         major_size = wanted_size;
 188     }
 189
 190     if(major_configs[major] == -1) {
 191         char buffer[CONFIG_MAX_NAME + 1];
 192         snprintfz(buffer, CONFIG_MAX_NAME, "performance metrics for disks with major %d", major);
 193         major_configs[major] = (char)config_get_boolean("plugin:proc:/proc/diskstats", buffer, 1);
 194     }
 195
 196     return (int)major_configs[major];
 197 }
 198
 199 int do_proc_diskstats(int update_every, usec_t dt) {
 200     static procfile *ff = NULL;
 201     static int  global_enable_new_disks_detected_at_runtime = CONFIG_ONDEMAND_YES,
 202                 global_enable_performance_for_physical_disks = CONFIG_ONDEMAND_ONDEMAND,
 203                 global_enable_performance_for_virtual_disks = CONFIG_ONDEMAND_ONDEMAND,
 204                 global_enable_performance_for_partitions = CONFIG_ONDEMAND_NO,
 205                 global_do_io = CONFIG_ONDEMAND_ONDEMAND,
 206                 global_do_ops = CONFIG_ONDEMAND_ONDEMAND,
 207                 global_do_mops = CONFIG_ONDEMAND_ONDEMAND,
 208                 global_do_iotime = CONFIG_ONDEMAND_ONDEMAND,
 209                 global_do_qops = CONFIG_ONDEMAND_ONDEMAND,
 210                 global_do_util = CONFIG_ONDEMAND_ONDEMAND,
 211                 global_do_backlog = CONFIG_ONDEMAND_ONDEMAND,
 212                 globals_initialized = 0;
 213
 214     if(unlikely(!globals_initialized)) {
 215         global_enable_new_disks_detected_at_runtime = config_get_boolean("plugin:proc:/proc/diskstats", "enable new disks detected at runtime", global_enable_new_disks_detected_at_runtime);
 216
 217         global_enable_performance_for_physical_disks = config_get_boolean_ondemand("plugin:proc:/proc/diskstats", "performance metrics for physical disks", global_enable_performance_for_physical_disks);
 218         global_enable_performance_for_virtual_disks = config_get_boolean_ondemand("plugin:proc:/proc/diskstats", "performance metrics for virtual disks", global_enable_performance_for_virtual_disks);
 219         global_enable_performance_for_partitions = config_get_boolean_ondemand("plugin:proc:/proc/diskstats", "performance metrics for partitions", global_enable_performance_for_partitions);
 220
 221         global_do_io      = config_get_boolean_ondemand("plugin:proc:/proc/diskstats", "bandwidth for all disks", global_do_io);
 222         global_do_ops     = config_get_boolean_ondemand("plugin:proc:/proc/diskstats", "operations for all disks", global_do_ops);
 223         global_do_mops    = config_get_boolean_ondemand("plugin:proc:/proc/diskstats", "merged operations for all disks", global_do_mops);
 224         global_do_iotime  = config_get_boolean_ondemand("plugin:proc:/proc/diskstats", "i/o time for all disks", global_do_iotime);
 225         global_do_qops    = config_get_boolean_ondemand("plugin:proc:/proc/diskstats", "queued operations for all disks", global_do_qops);
 226         global_do_util    = config_get_boolean_ondemand("plugin:proc:/proc/diskstats", "utilization percentage for all disks", global_do_util);
 227         global_do_backlog = config_get_boolean_ondemand("plugin:proc:/proc/diskstats", "backlog for all disks", global_do_backlog);
 228
 229         globals_initialized = 1;
 230     }
 231
 232     // --------------------------------------------------------------------------
 233
 234     if(unlikely(!ff)) {
 235         char filename[FILENAME_MAX + 1];
 236         snprintfz(filename, FILENAME_MAX, "%s%s", netdata_configured_host_prefix, "/proc/diskstats");
 237         ff = procfile_open(config_get("plugin:proc:/proc/diskstats", "filename to monitor", filename), " \t", PROCFILE_FLAG_DEFAULT);
 238     }
 239     if(unlikely(!ff)) return 0;
 240
 241     ff = procfile_readall(ff);
 242     if(unlikely(!ff)) return 0; // we return 0, so that we will retry to open it next time
 243
 244     size_t lines = procfile_lines(ff), l;
 245
 246     for(l = 0; l < lines ;l++) {
 247         // --------------------------------------------------------------------------
 248         // Read parameters
 249
 250         char *disk;
 251         unsigned long       major = 0, minor = 0;
 252
 253         collected_number    reads = 0,  mreads = 0,  readsectors = 0,  readms = 0,
 254                             writes = 0, mwrites = 0, writesectors = 0, writems = 0,
 255                             queued_ios = 0, busy_ms = 0, backlog_ms = 0;
 256
 257         collected_number    last_reads = 0,  last_readsectors = 0,  last_readms = 0,
 258                             last_writes = 0, last_writesectors = 0, last_writems = 0,
 259                             last_busy_ms = 0;
 260
 261         size_t words = procfile_linewords(ff, l);
 262         if(unlikely(words < 14)) continue;
 263
 264         major           = str2ul(procfile_lineword(ff, l, 0));
 265         minor           = str2ul(procfile_lineword(ff, l, 1));
 266         disk            = procfile_lineword(ff, l, 2);
 267
 268         // # of reads completed # of writes completed
 269         // This is the total number of reads or writes completed successfully.
 270         reads           = str2ull(procfile_lineword(ff, l, 3));  // rd_ios
 271         writes          = str2ull(procfile_lineword(ff, l, 7));  // wr_ios
 272
 273         // # of reads merged # of writes merged
 274         // Reads and writes which are adjacent to each other may be merged for
 275         // efficiency.  Thus two 4K reads may become one 8K read before it is
 276         // ultimately handed to the disk, and so it will be counted (and queued)
 277         mreads          = str2ull(procfile_lineword(ff, l, 4));  // rd_merges_or_rd_sec
 278         mwrites         = str2ull(procfile_lineword(ff, l, 8));  // wr_merges
 279
 280         // # of sectors read # of sectors written
 281         // This is the total number of sectors read or written successfully.
 282         readsectors     = str2ull(procfile_lineword(ff, l, 5));  // rd_sec_or_wr_ios
 283         writesectors    = str2ull(procfile_lineword(ff, l, 9));  // wr_sec
 284
 285         // # of milliseconds spent reading # of milliseconds spent writing
 286         // This is the total number of milliseconds spent by all reads or writes (as
 287         // measured from __make_request() to end_that_request_last()).
 288         readms          = str2ull(procfile_lineword(ff, l, 6));  // rd_ticks_or_wr_sec
 289         writems         = str2ull(procfile_lineword(ff, l, 10)); // wr_ticks
 290
 291         // # of I/Os currently in progress
 292         // The only field that should go to zero. Incremented as requests are
 293         // given to appropriate struct request_queue and decremented as they finish.
 294         queued_ios      = str2ull(procfile_lineword(ff, l, 11)); // ios_pgr
 295
 296         // # of milliseconds spent doing I/Os
 297         // This field increases so long as field queued_ios is nonzero.
 298         busy_ms         = str2ull(procfile_lineword(ff, l, 12)); // tot_ticks
 299
 300         // weighted # of milliseconds spent doing I/Os
 301         // This field is incremented at each I/O start, I/O completion, I/O
 302         // merge, or read of these stats by the number of I/Os in progress
 303         // (field queued_ios) times the number of milliseconds spent doing I/O since the
 304         // last update of this field.  This can provide an easy measure of both
 305         // I/O completion time and the backlog that may be accumulating.
 306         backlog_ms      = str2ull(procfile_lineword(ff, l, 13)); // rq_ticks
 307
 308
 309         // --------------------------------------------------------------------------
 310         // remove slashes from disk names
 311         char *s;
 312         for(s = disk; *s ;s++)
 313             if(*s == '/') *s = '_';
 314
 315         // --------------------------------------------------------------------------
 316         // get a disk structure for the disk
 317
 318         struct disk *d = get_disk(major, minor, disk);
 319
 320
 321         // --------------------------------------------------------------------------
 322         // Set its family based on mount point
 323
 324         char *family = d->mount_point;
 325         if(!family) family = disk;
 326
 327
 328         // --------------------------------------------------------------------------
 329         // Check the configuration for the device
 330
 331         if(unlikely(!d->configured)) {
 332             char var_name[4096 + 1];
 333             snprintfz(var_name, 4096, "plugin:proc:/proc/diskstats:%s", disk);
 334
 335             int def_enable = config_get_boolean_ondemand(var_name, "enable", global_enable_new_disks_detected_at_runtime);
 336             if(unlikely(def_enable == CONFIG_ONDEMAND_NO)) {
 337                 // the user does not want any metrics for this disk
 338                 d->do_io = CONFIG_ONDEMAND_NO;
 339                 d->do_ops = CONFIG_ONDEMAND_NO;
 340                 d->do_mops = CONFIG_ONDEMAND_NO;
 341                 d->do_iotime = CONFIG_ONDEMAND_NO;
 342                 d->do_qops = CONFIG_ONDEMAND_NO;
 343                 d->do_util = CONFIG_ONDEMAND_NO;
 344                 d->do_backlog = CONFIG_ONDEMAND_NO;
 345             }
 346             else {
 347                 // this disk is enabled
 348                 // check its direct settings
 349
 350                 int def_performance = CONFIG_ONDEMAND_ONDEMAND;
 351
 352                 // since this is 'on demand' we can figure the performance settings
 353                 // based on the type of disk
 354
 355                 switch(d->type) {
 356                     case DISK_TYPE_PHYSICAL:
 357                         def_performance = global_enable_performance_for_physical_disks;
 358                         break;
 359
 360                     case DISK_TYPE_PARTITION:
 361                         def_performance = global_enable_performance_for_partitions;
 362                         break;
 363
 364                     case DISK_TYPE_CONTAINER:
 365                         def_performance = global_enable_performance_for_virtual_disks;
 366                         break;
 367                 }
 368
 369                 // check if we have to disable performance for this disk
 370                 if(def_performance)
 371                     def_performance = is_major_enabled((int)major);
 372
 373                 // ------------------------------------------------------------
 374                 // now we have def_performance and def_space
 375                 // to work further
 376
 377                 // def_performance
 378                 // check the user configuration (this will also show our 'on demand' decision)
 379                 def_performance = config_get_boolean_ondemand(var_name, "enable performance metrics", def_performance);
 380
 381                 int ddo_io = CONFIG_ONDEMAND_NO,
 382                     ddo_ops = CONFIG_ONDEMAND_NO,
 383                     ddo_mops = CONFIG_ONDEMAND_NO,
 384                     ddo_iotime = CONFIG_ONDEMAND_NO,
 385                     ddo_qops = CONFIG_ONDEMAND_NO,
 386                     ddo_util = CONFIG_ONDEMAND_NO,
 387                     ddo_backlog = CONFIG_ONDEMAND_NO;
 388
 389                 // we enable individual performance charts only when def_performance is not disabled
 390                 if(unlikely(def_performance != CONFIG_ONDEMAND_NO)) {
 391                     ddo_io = global_do_io,
 392                     ddo_ops = global_do_ops,
 393                     ddo_mops = global_do_mops,
 394                     ddo_iotime = global_do_iotime,
 395                     ddo_qops = global_do_qops,
 396                     ddo_util = global_do_util,
 397                     ddo_backlog = global_do_backlog;
 398                 }
 399
 400                 d->do_io      = config_get_boolean_ondemand(var_name, "bandwidth", ddo_io);
 401                 d->do_ops     = config_get_boolean_ondemand(var_name, "operations", ddo_ops);
 402                 d->do_mops    = config_get_boolean_ondemand(var_name, "merged operations", ddo_mops);
 403                 d->do_iotime  = config_get_boolean_ondemand(var_name, "i/o time", ddo_iotime);
 404                 d->do_qops    = config_get_boolean_ondemand(var_name, "queued operations", ddo_qops);
 405                 d->do_util    = config_get_boolean_ondemand(var_name, "utilization percentage", ddo_util);
 406                 d->do_backlog = config_get_boolean_ondemand(var_name, "backlog", ddo_backlog);
 407             }
 408
 409             d->configured = 1;
 410         }
 411
 412         RRDSET *st;
 413
 414         // --------------------------------------------------------------------------
 415         // Do performance metrics
 416
 417         if(d->do_io == CONFIG_ONDEMAND_YES || (d->do_io == CONFIG_ONDEMAND_ONDEMAND && (readsectors || writesectors))) {
 418             d->do_io = CONFIG_ONDEMAND_YES;
 419
 420             st = rrdset_find_bytype(RRD_TYPE_DISK, disk);
 421             if(unlikely(!st)) {
 422                 st = rrdset_create(RRD_TYPE_DISK, disk, NULL, family, "disk.io", "Disk I/O Bandwidth", "kilobytes/s", 2000, update_every, RRDSET_TYPE_AREA);
 423
 424                 rrddim_add(st, "reads", NULL, d->sector_size, 1024, RRDDIM_INCREMENTAL);
 425                 rrddim_add(st, "writes", NULL, d->sector_size * -1, 1024, RRDDIM_INCREMENTAL);
 426             }
 427             else rrdset_next(st);
 428
 429             last_readsectors  = rrddim_set(st, "reads", readsectors);
 430             last_writesectors = rrddim_set(st, "writes", writesectors);
 431             rrdset_done(st);
 432         }
 433
 434         // --------------------------------------------------------------------
 435
 436         if(d->do_ops == CONFIG_ONDEMAND_YES || (d->do_ops == CONFIG_ONDEMAND_ONDEMAND && (reads || writes))) {
 437             d->do_ops = CONFIG_ONDEMAND_YES;
 438
 439             st = rrdset_find_bytype("disk_ops", disk);
 440             if(unlikely(!st)) {
 441                 st = rrdset_create("disk_ops", disk, NULL, family, "disk.ops", "Disk Completed I/O Operations", "operations/s", 2001, update_every, RRDSET_TYPE_LINE);
 442                 st->isdetail = 1;
 443
 444                 rrddim_add(st, "reads", NULL, 1, 1, RRDDIM_INCREMENTAL);
 445                 rrddim_add(st, "writes", NULL, -1, 1, RRDDIM_INCREMENTAL);
 446             }
 447             else rrdset_next(st);
 448
 449             last_reads  = rrddim_set(st, "reads", reads);
 450             last_writes = rrddim_set(st, "writes", writes);
 451             rrdset_done(st);
 452         }
 453
 454         // --------------------------------------------------------------------
 455
 456         if(d->do_qops == CONFIG_ONDEMAND_YES || (d->do_qops == CONFIG_ONDEMAND_ONDEMAND && queued_ios)) {
 457             d->do_qops = CONFIG_ONDEMAND_YES;
 458
 459             st = rrdset_find_bytype("disk_qops", disk);
 460             if(unlikely(!st)) {
 461                 st = rrdset_create("disk_qops", disk, NULL, family, "disk.qops", "Disk Current I/O Operations", "operations", 2002, update_every, RRDSET_TYPE_LINE);
 462                 st->isdetail = 1;
 463
 464                 rrddim_add(st, "operations", NULL, 1, 1, RRDDIM_ABSOLUTE);
 465             }
 466             else rrdset_next(st);
 467
 468             rrddim_set(st, "operations", queued_ios);
 469             rrdset_done(st);
 470         }
 471
 472         // --------------------------------------------------------------------
 473
 474         if(d->do_backlog == CONFIG_ONDEMAND_YES || (d->do_backlog == CONFIG_ONDEMAND_ONDEMAND && backlog_ms)) {
 475             d->do_backlog = CONFIG_ONDEMAND_YES;
 476
 477             st = rrdset_find_bytype("disk_backlog", disk);
 478             if(unlikely(!st)) {
 479                 st = rrdset_create("disk_backlog", disk, NULL, family, "disk.backlog", "Disk Backlog", "backlog (ms)", 2003, update_every, RRDSET_TYPE_AREA);
 480                 st->isdetail = 1;
 481
 482                 rrddim_add(st, "backlog", NULL, 1, 10, RRDDIM_INCREMENTAL);
 483             }
 484             else rrdset_next(st);
 485
 486             rrddim_set(st, "backlog", backlog_ms);
 487             rrdset_done(st);
 488         }
 489
 490         // --------------------------------------------------------------------
 491
 492         if(d->do_util == CONFIG_ONDEMAND_YES || (d->do_util == CONFIG_ONDEMAND_ONDEMAND && busy_ms)) {
 493             d->do_util = CONFIG_ONDEMAND_YES;
 494
 495             st = rrdset_find_bytype("disk_util", disk);
 496             if(unlikely(!st)) {
 497                 st = rrdset_create("disk_util", disk, NULL, family, "disk.util", "Disk Utilization Time", "% of time working", 2004, update_every, RRDSET_TYPE_AREA);
 498                 st->isdetail = 1;
 499
 500                 rrddim_add(st, "utilization", NULL, 1, 10, RRDDIM_INCREMENTAL);
 501             }
 502             else rrdset_next(st);
 503
 504             last_busy_ms = rrddim_set(st, "utilization", busy_ms);
 505             rrdset_done(st);
 506         }
 507
 508         // --------------------------------------------------------------------
 509
 510         if(d->do_mops == CONFIG_ONDEMAND_YES || (d->do_mops == CONFIG_ONDEMAND_ONDEMAND && (mreads || mwrites))) {
 511             d->do_mops = CONFIG_ONDEMAND_YES;
 512
 513             st = rrdset_find_bytype("disk_mops", disk);
 514             if(unlikely(!st)) {
 515                 st = rrdset_create("disk_mops", disk, NULL, family, "disk.mops", "Disk Merged Operations", "merged operations/s", 2021, update_every, RRDSET_TYPE_LINE);
 516                 st->isdetail = 1;
 517
 518                 rrddim_add(st, "reads", NULL, 1, 1, RRDDIM_INCREMENTAL);
 519                 rrddim_add(st, "writes", NULL, -1, 1, RRDDIM_INCREMENTAL);
 520             }
 521             else rrdset_next(st);
 522
 523             rrddim_set(st, "reads", mreads);
 524             rrddim_set(st, "writes", mwrites);
 525             rrdset_done(st);
 526         }
 527
 528         // --------------------------------------------------------------------
 529
 530         if(d->do_iotime == CONFIG_ONDEMAND_YES || (d->do_iotime == CONFIG_ONDEMAND_ONDEMAND && (readms || writems))) {
 531             d->do_iotime = CONFIG_ONDEMAND_YES;
 532
 533             st = rrdset_find_bytype("disk_iotime", disk);
 534             if(unlikely(!st)) {
 535                 st = rrdset_create("disk_iotime", disk, NULL, family, "disk.iotime", "Disk Total I/O Time", "milliseconds/s", 2022, update_every, RRDSET_TYPE_LINE);
 536                 st->isdetail = 1;
 537
 538                 rrddim_add(st, "reads", NULL, 1, 1, RRDDIM_INCREMENTAL);
 539                 rrddim_add(st, "writes", NULL, -1, 1, RRDDIM_INCREMENTAL);
 540             }
 541             else rrdset_next(st);
 542
 543             last_readms  = rrddim_set(st, "reads", readms);
 544             last_writems = rrddim_set(st, "writes", writems);
 545             rrdset_done(st);
 546         }
 547
 548         // --------------------------------------------------------------------
 549         // calculate differential charts
 550         // only if this is not the first time we run
 551
 552         if(likely(dt)) {
 553             if( (d->do_iotime == CONFIG_ONDEMAND_YES || (d->do_iotime == CONFIG_ONDEMAND_ONDEMAND && (readms || writems))) &&
 554                 (d->do_ops    == CONFIG_ONDEMAND_YES || (d->do_ops    == CONFIG_ONDEMAND_ONDEMAND && (reads || writes)))) {
 555                 st = rrdset_find_bytype("disk_await", disk);
 556                 if(unlikely(!st)) {
 557                     st = rrdset_create("disk_await", disk, NULL, family, "disk.await", "Average Completed I/O Operation Time", "ms per operation", 2005, update_every, RRDSET_TYPE_LINE);
 558                     st->isdetail = 1;
 559
 560                     rrddim_add(st, "reads", NULL, 1, 1, RRDDIM_ABSOLUTE);
 561                     rrddim_add(st, "writes", NULL, -1, 1, RRDDIM_ABSOLUTE);
 562                 }
 563                 else rrdset_next(st);
 564
 565                 rrddim_set(st, "reads", (reads - last_reads) ? (readms - last_readms) / (reads - last_reads) : 0);
 566                 rrddim_set(st, "writes", (writes - last_writes) ? (writems - last_writems) / (writes - last_writes) : 0);
 567                 rrdset_done(st);
 568             }
 569
 570             if( (d->do_io  == CONFIG_ONDEMAND_YES || (d->do_io  == CONFIG_ONDEMAND_ONDEMAND && (readsectors || writesectors))) &&
 571                 (d->do_ops == CONFIG_ONDEMAND_YES || (d->do_ops == CONFIG_ONDEMAND_ONDEMAND && (reads || writes)))) {
 572                 st = rrdset_find_bytype("disk_avgsz", disk);
 573                 if(unlikely(!st)) {
 574                     st = rrdset_create("disk_avgsz", disk, NULL, family, "disk.avgsz", "Average Completed I/O Operation Bandwidth", "kilobytes per operation", 2006, update_every, RRDSET_TYPE_AREA);
 575                     st->isdetail = 1;
 576
 577                     rrddim_add(st, "reads", NULL, d->sector_size, 1024, RRDDIM_ABSOLUTE);
 578                     rrddim_add(st, "writes", NULL, d->sector_size * -1, 1024, RRDDIM_ABSOLUTE);
 579                 }
 580                 else rrdset_next(st);
 581
 582                 rrddim_set(st, "reads", (reads - last_reads) ? (readsectors - last_readsectors) / (reads - last_reads) : 0);
 583                 rrddim_set(st, "writes", (writes - last_writes) ? (writesectors - last_writesectors) / (writes - last_writes) : 0);
 584                 rrdset_done(st);
 585             }
 586
 587             if( (d->do_util == CONFIG_ONDEMAND_YES || (d->do_util == CONFIG_ONDEMAND_ONDEMAND && busy_ms)) &&
 588                 (d->do_ops  == CONFIG_ONDEMAND_YES || (d->do_ops  == CONFIG_ONDEMAND_ONDEMAND && (reads || writes)))) {
 589                 st = rrdset_find_bytype("disk_svctm", disk);
 590                 if(unlikely(!st)) {
 591                     st = rrdset_create("disk_svctm", disk, NULL, family, "disk.svctm", "Average Service Time", "ms per operation", 2007, update_every, RRDSET_TYPE_LINE);
 592                     st->isdetail = 1;
 593
 594                     rrddim_add(st, "svctm", NULL, 1, 1, RRDDIM_ABSOLUTE);
 595                 }
 596                 else rrdset_next(st);
 597
 598                 rrddim_set(st, "svctm", ((reads - last_reads) + (writes - last_writes)) ? (busy_ms - last_busy_ms) / ((reads - last_reads) + (writes - last_writes)) : 0);
 599                 rrdset_done(st);
 600             }
 601         }
 602     }
 603
 604     return 0;
 605 }