| 1 | // SPDX-License-Identifier: GPL-3.0-or-later |
| 2 | |
| 3 | #include "database/rrd.h" |
| 4 | |
| 5 | #define PLUGIN_SLABINFO_NAME "slabinfo.plugin" |
| 6 | #define PLUGIN_SLABINFO_PROCFILE "/proc/slabinfo" |
| 7 | |
| 8 | #define CHART_TYPE "mem" |
| 9 | #define CHART_FAMILY "slab" |
| 10 | #define CHART_PRIO 3000 |
| 11 | |
| 12 | // #define slabdebug(...) if (debug) { fprintf(stderr, __VA_ARGS__); } |
| 13 | #define slabdebug(args...) do { \ |
| 14 | if (debug) { \ |
| 15 | fprintf(stderr, "slabinfo.plugin DEBUG (%04d@%-10.10s:%-15.15s)::", __LINE__, __FILE__, __FUNCTION__); \ |
| 16 | fprintf(stderr, ##args); \ |
| 17 | fprintf(stderr, "\n"); \ |
| 18 | } \ |
| 19 | } while(0) |
| 20 | |
| 21 | int running = 1; |
| 22 | int debug = 0; |
| 23 | size_t lines_discovered = 0; |
| 24 | int redraw_chart = 0; |
| 25 | |
| 26 | // ---------------------------------------------------------------------------- |
| 27 | |
| 28 | // Slabinfo format : |
| 29 | // format 2.1 Was provided by 57ed3eda977a215f054102b460ab0eb5d8d112e6 (2.6.24-rc6) as: |
| 30 | // seq_puts(m, "# name <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab>"); |
| 31 | // seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>"); |
| 32 | // seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>"); |
| 33 | // |
| 34 | // With max values: |
| 35 | // seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d", |
| 36 | // cache_name(s), sinfo.active_objs, sinfo.num_objs, s->size, sinfo.objects_per_slab, (1 << sinfo.cache_order)); |
| 37 | // seq_printf(m, " : tunables %4u %4u %4u", |
| 38 | // sinfo.limit, sinfo.batchcount, sinfo.shared); |
| 39 | // seq_printf(m, " : slabdata %6lu %6lu %6lu", |
| 40 | // sinfo.active_slabs, sinfo.num_slabs, sinfo.shared_avail); |
| 41 | // |
| 42 | // If CONFIG_DEBUG_SLAB is set, it will also add columns from slabinfo_show_stats (for SLAB only): |
| 43 | // seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu %4lu %4lu %4lu %4lu %4lu", |
| 44 | // allocs, high, grown, reaped, errors, max_freeable, node_allocs, node_frees, overflows); |
| 45 | // seq_printf(m, " : cpustat %6lu %6lu %6lu %6lu", |
| 46 | // allochit, allocmiss, freehit, freemiss); |
| 47 | // |
| 48 | // Implementation choices: |
| 49 | // - Iterates through a linked list of kmem_cache. |
| 50 | // - Name is a char* from struct kmem_cache (mm/slab.h). |
| 51 | // - max name size found is 24: |
| 52 | // grep -roP 'kmem_cache_create\(".+"'| awk '{split($0,a,"\""); print a[2],length(a[2]); }' | sort -k2 -n |
| 53 | // - Using uint64 everywhere, as types fits and allows to use standard helpers |
| 54 | |
| 55 | struct slabinfo { |
| 56 | // procfile fields |
| 57 | const char *name; |
| 58 | uint64_t active_objs; |
| 59 | uint64_t num_objs; |
| 60 | uint64_t obj_size; |
| 61 | uint64_t obj_per_slab; |
| 62 | uint64_t pages_per_slab; |
| 63 | uint64_t tune_limit; |
| 64 | uint64_t tune_batchcnt; |
| 65 | uint64_t tune_shared_factor; |
| 66 | uint64_t data_active_slabs; |
| 67 | uint64_t data_num_slabs; |
| 68 | uint64_t data_shared_avail; |
| 69 | |
| 70 | // Calculated fields |
| 71 | uint64_t mem_usage; |
| 72 | uint64_t mem_waste; |
| 73 | uint8_t obj_filling; |
| 74 | |
| 75 | uint32_t hash; |
| 76 | struct slabinfo *next; |
| 77 | } *slabinfo_root = NULL, *slabinfo_next = NULL, *slabinfo_last_used = NULL; |
| 78 | |
| 79 | // The code is very inspired from "proc_net_dev.c" and "perf_plugin.c" |
| 80 | |
| 81 | // Get the existing object, or create a new one |
| 82 | static struct slabinfo *get_slabstruct(const char *name) { |
| 83 | struct slabinfo *s; |
| 84 | |
| 85 | slabdebug("--> Requested slabstruct %s", name); |
| 86 | |
| 87 | uint32_t hash = simple_hash(name); |
| 88 | |
| 89 | // Search it, from the next to the end |
| 90 | for (s = slabinfo_next; s; s = s->next) { |
| 91 | if ((hash = s->hash) && !strcmp(name, s->name)) { |
| 92 | slabdebug("<-- Found existing slabstruct after %s", slabinfo_last_used->name); |
| 93 | // Prepare the next run |
| 94 | slabinfo_next = s->next; |
| 95 | slabinfo_last_used = s; |
| 96 | return s; |
| 97 | } |
| 98 | } |
| 99 | |
| 100 | // Search it from the beginning to the last position we used |
| 101 | for (s = slabinfo_root; s != slabinfo_last_used; s = s->next) { |
| 102 | if (hash == s->hash && !strcmp(name, s->name)) { |
| 103 | slabdebug("<-- Found existing slabstruct after root %s", slabinfo_root->name); |
| 104 | slabinfo_next = s->next; |
| 105 | slabinfo_last_used = s; |
| 106 | return s; |
| 107 | } |
| 108 | } |
| 109 | |
| 110 | // Create a new one |
| 111 | s = callocz(1, sizeof(struct slabinfo)); |
| 112 | s->name = strdupz(name); |
| 113 | s->hash = hash; |
| 114 | |
| 115 | // Add it to the current position |
| 116 | if (slabinfo_root) { |
| 117 | slabdebug("<-- Creating new slabstruct after %s", slabinfo_last_used->name); |
| 118 | s->next = slabinfo_last_used->next; |
| 119 | slabinfo_last_used->next = s; |
| 120 | slabinfo_last_used = s; |
| 121 | } |
| 122 | else { |
| 123 | slabdebug("<-- Creating new slabstruct as root"); |
| 124 | slabinfo_root = slabinfo_last_used = s; |
| 125 | } |
| 126 | |
| 127 | return s; |
| 128 | } |
| 129 | |
| 130 | |
| 131 | // Read a full pass of slabinfo to update the structs |
| 132 | struct slabinfo *read_file_slabinfo() { |
| 133 | |
| 134 | slabdebug("-> Reading procfile %s", PLUGIN_SLABINFO_PROCFILE); |
| 135 | |
| 136 | static procfile *ff = NULL; |
| 137 | static long slab_pagesize = 0; |
| 138 | |
| 139 | if (unlikely(!slab_pagesize)) { |
| 140 | slab_pagesize = sysconf(_SC_PAGESIZE); |
| 141 | slabdebug(" Discovered pagesize: %ld", slab_pagesize); |
| 142 | } |
| 143 | |
| 144 | if(unlikely(!ff)) { |
| 145 | ff = procfile_reopen(ff, PLUGIN_SLABINFO_PROCFILE, " ,:" , PROCFILE_FLAG_DEFAULT); |
| 146 | if(unlikely(!ff)) { |
| 147 | collector_error("<- Cannot open file '%s", PLUGIN_SLABINFO_PROCFILE); |
| 148 | exit(1); |
| 149 | } |
| 150 | } |
| 151 | |
| 152 | ff = procfile_readall(ff); |
| 153 | if(unlikely(!ff)) { |
| 154 | collector_error("<- Cannot read file '%s'", PLUGIN_SLABINFO_PROCFILE); |
| 155 | exit(0); |
| 156 | } |
| 157 | |
| 158 | |
| 159 | // Iterate on all lines to populate / update the slabinfo struct |
| 160 | size_t lines = procfile_lines(ff), l; |
| 161 | if (unlikely(lines != lines_discovered)) { |
| 162 | lines_discovered = lines; |
| 163 | redraw_chart = 1; |
| 164 | } |
| 165 | |
| 166 | slabdebug(" Read %lu lines from procfile", (unsigned long)lines); |
| 167 | for(l = 2; l < lines; l++) { |
| 168 | if (unlikely(procfile_linewords(ff, l) < 14)) { |
| 169 | slabdebug(" Line %zu has only %zu words, skipping", l, (size_t)procfile_linewords(ff,l)); |
| 170 | continue; |
| 171 | } |
| 172 | |
| 173 | char *name = procfile_lineword(ff, l, 0); |
| 174 | struct slabinfo *s = get_slabstruct(name); |
| 175 | |
| 176 | s->active_objs = str2uint64_t(procfile_lineword(ff, l, 1), NULL); |
| 177 | s->num_objs = str2uint64_t(procfile_lineword(ff, l, 2), NULL); |
| 178 | s->obj_size = str2uint64_t(procfile_lineword(ff, l, 3), NULL); |
| 179 | s->obj_per_slab = str2uint64_t(procfile_lineword(ff, l, 4), NULL); |
| 180 | s->pages_per_slab = str2uint64_t(procfile_lineword(ff, l, 5), NULL); |
| 181 | |
| 182 | s->tune_limit = str2uint64_t(procfile_lineword(ff, l, 7), NULL); |
| 183 | s->tune_batchcnt = str2uint64_t(procfile_lineword(ff, l, 8), NULL); |
| 184 | s->tune_shared_factor = str2uint64_t(procfile_lineword(ff, l, 9), NULL); |
| 185 | |
| 186 | s->data_active_slabs = str2uint64_t(procfile_lineword(ff, l, 11), NULL); |
| 187 | s->data_num_slabs = str2uint64_t(procfile_lineword(ff, l, 12), NULL); |
| 188 | s->data_shared_avail = str2uint64_t(procfile_lineword(ff, l, 13), NULL); |
| 189 | |
| 190 | uint32_t memperslab = s->pages_per_slab * slab_pagesize; |
| 191 | // Internal fragmentation: loss per slab, due to objects not being a multiple of pagesize |
| 192 | //uint32_t lossperslab = memperslab - s->obj_per_slab * s->obj_size; |
| 193 | |
| 194 | // Total usage = slabs * pages per slab * page size |
| 195 | s->mem_usage = (uint64_t)(s->data_num_slabs * memperslab); |
| 196 | |
| 197 | // Wasted memory (filling): slabs allocated but not filled: sum total slab - sum total objects |
| 198 | s->mem_waste = s->mem_usage - (uint64_t)(s->active_objs * s->obj_size); |
| 199 | //if (s->data_num_slabs > 1) |
| 200 | // s->mem_waste += s->data_num_slabs * lossperslab; |
| 201 | |
| 202 | |
| 203 | // Slab filling efficiency |
| 204 | if (s->num_objs > 0) |
| 205 | s->obj_filling = 100 * s->active_objs / s->num_objs; |
| 206 | else |
| 207 | s->obj_filling = 0; |
| 208 | |
| 209 | slabdebug(" Updated slab %s: %"PRIu64" %"PRIu64" %"PRIu64" %"PRIu64" %"PRIu64" / %"PRIu64" %"PRIu64" %"PRIu64" / %"PRIu64" %"PRIu64" %"PRIu64" / %"PRIu64" %"PRIu64" %hhu", |
| 210 | name, s->active_objs, s->num_objs, s->obj_size, s->obj_per_slab, s->pages_per_slab, |
| 211 | s->tune_limit, s->tune_batchcnt, s->tune_shared_factor, |
| 212 | s->data_active_slabs, s->data_num_slabs, s->data_shared_avail, |
| 213 | s->mem_usage, s->mem_waste, s->obj_filling); |
| 214 | } |
| 215 | |
| 216 | return slabinfo_root; |
| 217 | } |
| 218 | |
| 219 | |
| 220 | |
| 221 | unsigned int do_slab_stats(int update_every) { |
| 222 | |
| 223 | static unsigned int loops = 0; |
| 224 | struct slabinfo *sactive = NULL, *s = NULL; |
| 225 | |
| 226 | // Main processing loop |
| 227 | while (running) { |
| 228 | |
| 229 | sactive = read_file_slabinfo(); |
| 230 | |
| 231 | // Init Charts |
| 232 | if (unlikely(redraw_chart)) { |
| 233 | redraw_chart = 0; |
| 234 | // Memory Usage |
| 235 | printf("CHART %s.%s '' 'Memory Usage' 'B' '%s' '' line %d %d %s\n" |
| 236 | , CHART_TYPE |
| 237 | , "slabmemory" |
| 238 | , CHART_FAMILY |
| 239 | , CHART_PRIO |
| 240 | , update_every |
| 241 | , PLUGIN_SLABINFO_NAME |
| 242 | ); |
| 243 | for (s = sactive; s; s = s->next) { |
| 244 | printf("DIMENSION %s '' absolute 1 1\n", s->name); |
| 245 | } |
| 246 | |
| 247 | // Slab active usage (filling) |
| 248 | printf("CHART %s.%s '' 'Object Filling' '%%' '%s' '' line %d %d %s\n" |
| 249 | , CHART_TYPE |
| 250 | , "slabfilling" |
| 251 | , CHART_FAMILY |
| 252 | , CHART_PRIO + 1 |
| 253 | , update_every |
| 254 | , PLUGIN_SLABINFO_NAME |
| 255 | ); |
| 256 | for (s = sactive; s; s = s->next) { |
| 257 | printf("DIMENSION %s '' absolute 1 1\n", s->name); |
| 258 | } |
| 259 | |
| 260 | // Memory waste |
| 261 | printf("CHART %s.%s '' 'Memory waste' 'B' '%s' '' line %d %d %s\n" |
| 262 | , CHART_TYPE |
| 263 | , "slabwaste" |
| 264 | , CHART_FAMILY |
| 265 | , CHART_PRIO + 2 |
| 266 | , update_every |
| 267 | , PLUGIN_SLABINFO_NAME |
| 268 | ); |
| 269 | for (s = sactive; s; s = s->next) { |
| 270 | printf("DIMENSION %s '' absolute 1 1\n", s->name); |
| 271 | } |
| 272 | } |
| 273 | |
| 274 | |
| 275 | // |
| 276 | // Memory usage |
| 277 | // |
| 278 | printf("BEGIN %s.%s\n" |
| 279 | , CHART_TYPE |
| 280 | , "slabmemory" |
| 281 | ); |
| 282 | for (s = sactive; s; s = s->next) { |
| 283 | printf("SET %s = %"PRIu64"\n" |
| 284 | , s->name |
| 285 | , s->mem_usage |
| 286 | ); |
| 287 | } |
| 288 | printf("END\n"); |
| 289 | |
| 290 | // |
| 291 | // Slab active usage |
| 292 | // |
| 293 | printf("BEGIN %s.%s\n" |
| 294 | , CHART_TYPE |
| 295 | , "slabfilling" |
| 296 | ); |
| 297 | for (s = sactive; s; s = s->next) { |
| 298 | printf("SET %s = %u\n" |
| 299 | , s->name |
| 300 | , s->obj_filling |
| 301 | ); |
| 302 | } |
| 303 | printf("END\n"); |
| 304 | |
| 305 | // |
| 306 | // Memory waste |
| 307 | // |
| 308 | printf("BEGIN %s.%s\n" |
| 309 | , CHART_TYPE |
| 310 | , "slabwaste" |
| 311 | ); |
| 312 | for (s = sactive; s; s = s->next) { |
| 313 | printf("SET %s = %"PRIu64"\n" |
| 314 | , s->name |
| 315 | , s->mem_waste |
| 316 | ); |
| 317 | } |
| 318 | printf("END\n"); |
| 319 | |
| 320 | fprintf(stdout, "\n"); |
| 321 | fflush(stdout); |
| 322 | if (ferror(stdout) && errno == EPIPE) { |
| 323 | netdata_log_error("error writing to stdout: EPIPE. Exiting..."); |
| 324 | return loops; |
| 325 | } |
| 326 | |
| 327 | loops++; |
| 328 | |
| 329 | sleep(update_every); |
| 330 | } |
| 331 | |
| 332 | return loops; |
| 333 | } |
| 334 | |
| 335 | |
| 336 | |
| 337 | |
| 338 | // ---------------------------------------------------------------------------- |
| 339 | // main |
| 340 | |
| 341 | void usage(void) { |
| 342 | fprintf(stderr, "%s\n", program_name); |
| 343 | exit(1); |
| 344 | } |
| 345 | |
| 346 | int main(int argc, char **argv) { |
| 347 | nd_log_initialize_for_external_plugins("slabinfo.plugin"); |
| 348 | netdata_threads_init_for_external_plugins(0); |
| 349 | |
| 350 | program_name = argv[0]; |
| 351 | int update_every = 1, i, n, freq = 0; |
| 352 | |
| 353 | for (i = 1; i < argc; i++) { |
| 354 | // Frequency parsing |
| 355 | if(isdigit(*argv[i]) && !freq) { |
| 356 | n = (int) str2l(argv[i]); |
| 357 | if (n > 0) { |
| 358 | if (n >= UPDATE_EVERY_MAX) { |
| 359 | collector_error("Invalid interval value: %s", argv[i]); |
| 360 | exit(1); |
| 361 | } |
| 362 | freq = n; |
| 363 | } |
| 364 | } |
| 365 | else if (strcmp("debug", argv[i]) == 0) { |
| 366 | debug = 1; |
| 367 | continue; |
| 368 | } |
| 369 | else { |
| 370 | fprintf(stderr, |
| 371 | "netdata slabinfo.plugin %s\n" |
| 372 | "This program is a data collector plugin for netdata.\n" |
| 373 | "\n" |
| 374 | "Available command line options:\n" |
| 375 | "\n" |
| 376 | " COLLECTION_FREQUENCY data collection frequency in seconds\n" |
| 377 | " minimum: %d\n" |
| 378 | "\n" |
| 379 | " debug enable verbose output\n" |
| 380 | " default: disabled\n" |
| 381 | "\n", |
| 382 | NETDATA_VERSION, |
| 383 | update_every |
| 384 | ); |
| 385 | exit(1); |
| 386 | } |
| 387 | } |
| 388 | |
| 389 | if(freq >= update_every) |
| 390 | update_every = freq; |
| 391 | else if(freq) |
| 392 | collector_error("update frequency %d seconds is too small for slabinfo. Using %d.", freq, update_every); |
| 393 | |
| 394 | |
| 395 | // Call the main function. Time drift to be added |
| 396 | do_slab_stats(update_every); |
| 397 | |
| 398 | return 0; |
| 399 | } |