summaryrefslogtreecommitdiffstats
path: root/collectors/slabinfo.plugin/slabinfo.c
blob: 00e0d39134ceba12705be3fdf00336b521d808f2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
// SPDX-License-Identifier: GPL-3.0-or-later

#include "libnetdata/libnetdata.h"
#include "daemon/common.h"

#define PLUGIN_SLABINFO_NAME "slabinfo.plugin"
#define PLUGIN_SLABINFO_PROCFILE "/proc/slabinfo"

#define CHART_TYPE "mem"
#define CHART_FAMILY "slab"
#define CHART_PRIO 3000

// #define slabdebug(...) if (debug) { fprintf(stderr, __VA_ARGS__); }
#define slabdebug(args...) if (debug) { \
    fprintf(stderr, "slabinfo.plugin DEBUG (%04d@%-10.10s:%-15.15s)::", __LINE__, __FILE__, __FUNCTION__); \
    fprintf(stderr, ##args); \
    fprintf(stderr, "\n"); }


// ----------------------------------------------------------------------------

// callback required by fatal()
void netdata_cleanup_and_exit(int ret) {
    exit(ret);
}

void send_statistics(const char *action, const char *action_result, const char *action_data) {
    (void) action;
    (void) action_result;
    (void) action_data;
    return;
}

// callbacks required by popen()
void signals_block(void) {};
void signals_unblock(void) {};
void signals_reset(void) {};

// callback required by eval()
int health_variable_lookup(const char *variable, uint32_t hash, struct rrdcalc *rc, calculated_number *result) {
    (void)variable;
    (void)hash;
    (void)rc;
    (void)result;
    return 0;
};

// required by get_system_cpus()
char *netdata_configured_host_prefix = "";


int running = 1;
int debug = 0;

// ----------------------------------------------------------------------------

// Slabinfo format :
// format 2.1 Was provided by 57ed3eda977a215f054102b460ab0eb5d8d112e6 (2.6.24-rc6) as:
// seq_puts(m, "# name  <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab>");
// seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
// seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
//
// With max values:
// seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
//   cache_name(s), sinfo.active_objs, sinfo.num_objs, s->size, sinfo.objects_per_slab, (1 << sinfo.cache_order));
// seq_printf(m, " : tunables %4u %4u %4u",
//   sinfo.limit, sinfo.batchcount, sinfo.shared);
// seq_printf(m, " : slabdata %6lu %6lu %6lu",
//   sinfo.active_slabs, sinfo.num_slabs, sinfo.shared_avail);
//
// If CONFIG_DEBUG_SLAB is set, it will also add columns from slabinfo_show_stats (for SLAB only):
// seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu %4lu %4lu %4lu %4lu %4lu",
//   allocs, high, grown, reaped, errors, max_freeable, node_allocs, node_frees, overflows);
// seq_printf(m, " : cpustat %6lu %6lu %6lu %6lu",
//   allochit, allocmiss, freehit, freemiss);
//
// Implementation choices:
// - Iterates through a linked list of kmem_cache.
// - Name is a char* from struct kmem_cache (mm/slab.h).
// - max name size found is 24:
//     grep -roP 'kmem_cache_create\(".+"'| awk '{split($0,a,"\""); print a[2],length(a[2]); }' | sort -k2 -n
// - Using uint64 everywhere, as types fits and allows to use standard helpers

struct slabinfo {
    // procfile fields
    const char *name;
    uint64_t active_objs;
    uint64_t num_objs;
    uint64_t obj_size;
    uint64_t obj_per_slab;
    uint64_t pages_per_slab;
    uint64_t tune_limit;
    uint64_t tune_batchcnt;
    uint64_t tune_shared_factor;
    uint64_t data_active_slabs;
    uint64_t data_num_slabs;
    uint64_t data_shared_avail;

    // Calculated fields
    uint64_t mem_usage;
    uint64_t mem_waste;
    uint8_t  obj_filling;

    uint32_t hash;
    struct slabinfo *next;
} *slabinfo_root = NULL, *slabinfo_next = NULL, *slabinfo_last_used = NULL;

// The code is very inspired from "proc_net_dev.c" and "perf_plugin.c"

// Get the existing object, or create a new one
static struct slabinfo *get_slabstruct(const char *name) {
    struct slabinfo *s;

    slabdebug("--> Requested slabstruct %s", name);

    uint32_t hash = simple_hash(name);

    // Search it, from the next to the end
    for (s = slabinfo_next; s; s = s->next) {
        if ((hash = s->hash) && !strcmp(name, s->name)) {
            slabdebug("<-- Found existing slabstruct after %s", slabinfo_last_used->name);
            // Prepare the next run
            slabinfo_next = s->next;
            slabinfo_last_used = s;
            return s;
        }
    }

    // Search it from the begining to the last position we used
    for (s = slabinfo_root; s != slabinfo_last_used; s = s->next) {
        if (hash == s->hash && !strcmp(name, s->name)) {
            slabdebug("<-- Found existing slabstruct after root %s", slabinfo_root->name);
            slabinfo_next = s->next;
            slabinfo_last_used = s;
            return s;
        }
    }

    // Create a new one
    s = callocz(1, sizeof(struct slabinfo));
    s->name = strdupz(name);
    s->hash = hash;

    // Add it to the current postion
    if (slabinfo_root) {
        slabdebug("<-- Creating new slabstruct after %s", slabinfo_last_used->name);
        s->next = slabinfo_last_used->next;
        slabinfo_last_used->next = s;
        slabinfo_last_used = s;
    }
    else {
        slabdebug("<-- Creating new slabstruct as root");
        slabinfo_root = slabinfo_last_used = s;
    }

    return s;
}


// Read a full pass of slabinfo to update the structs
struct slabinfo *read_file_slabinfo() {

    slabdebug("-> Reading procfile %s", PLUGIN_SLABINFO_PROCFILE);

    static procfile *ff = NULL;
    static long slab_pagesize = 0;

    if (unlikely(!slab_pagesize)) {
        slab_pagesize = sysconf(_SC_PAGESIZE);
        slabdebug("   Discovered pagesize: %ld", slab_pagesize);
    }

    if(unlikely(!ff)) {
        ff = procfile_reopen(ff, PLUGIN_SLABINFO_PROCFILE, " ,:" , PROCFILE_FLAG_DEFAULT);
        if(unlikely(!ff)) {
            error("<- Cannot open file '%s", PLUGIN_SLABINFO_PROCFILE);
            exit(1);
        }
    }

    ff = procfile_readall(ff);
    if(unlikely(!ff)) {
        error("<- Cannot read file '%s'", PLUGIN_SLABINFO_PROCFILE);
        exit(0);
    }


    // Iterate on all lines to populate / update the slabinfo struct
    size_t lines = procfile_lines(ff), l;

    slabdebug("   Read %lu lines from procfile", (unsigned long)lines);
    for(l = 2; l < lines; l++) {
        if (unlikely(procfile_linewords(ff, l) < 14)) {
            slabdebug("    Line %zu has only %zu words, skipping", l, procfile_linewords(ff,l));
            continue;
        }

        char *name = procfile_lineword(ff, l, 0);
        struct slabinfo *s = get_slabstruct(name);

        s->active_objs    = str2uint64_t(procfile_lineword(ff, l, 1));
        s->num_objs       = str2uint64_t(procfile_lineword(ff, l, 2));
        s->obj_size       = str2uint64_t(procfile_lineword(ff, l, 3));
        s->obj_per_slab   = str2uint64_t(procfile_lineword(ff, l, 4));
        s->pages_per_slab = str2uint64_t(procfile_lineword(ff, l, 5));

        s->tune_limit     = str2uint64_t(procfile_lineword(ff, l, 7));
        s->tune_batchcnt  = str2uint64_t(procfile_lineword(ff, l, 8));
        s->tune_shared_factor = str2uint64_t(procfile_lineword(ff, l, 9));

        s->data_active_slabs = str2uint64_t(procfile_lineword(ff, l, 11));
        s->data_num_slabs    = str2uint64_t(procfile_lineword(ff, l, 12));
        s->data_shared_avail = str2uint64_t(procfile_lineword(ff, l, 13));

        uint32_t memperslab = s->pages_per_slab * slab_pagesize;
        // Internal fragmentation: loss per slab, due to objects not being a multiple of pagesize
        //uint32_t lossperslab = memperslab - s->obj_per_slab * s->obj_size;

        // Total usage = slabs * pages per slab * page size
        s->mem_usage = (uint64_t)(s->data_num_slabs * memperslab);

        // Wasted memory (filling): slabs allocated but not filled: sum total slab - sum total objects
        s->mem_waste = s->mem_usage - (uint64_t)(s->active_objs * s->obj_size);
        //if (s->data_num_slabs > 1)
        //    s->mem_waste += s->data_num_slabs * lossperslab;


        // Slab filling efficiency
        if (s->num_objs > 0)
            s->obj_filling = 100 * s->active_objs / s->num_objs;
        else
            s->obj_filling = 0;

        slabdebug("    Updated slab %s: %"PRIu64" %"PRIu64" %"PRIu64" %"PRIu64" %"PRIu64" / %"PRIu64" %"PRIu64" %"PRIu64" / %"PRIu64" %"PRIu64" %"PRIu64" / %"PRIu64" %"PRIu64" %hhu",
            name, s->active_objs, s->num_objs, s->obj_size, s->obj_per_slab, s->pages_per_slab,
            s->tune_limit, s->tune_batchcnt, s->tune_shared_factor,
            s->data_active_slabs, s->data_num_slabs, s->data_shared_avail,
            s->mem_usage, s->mem_waste, s->obj_filling);
    }

    return slabinfo_root;
}



unsigned int do_slab_stats(int update_every) {

    static unsigned int loops = 0;
    struct slabinfo *sactive = NULL, *s = NULL;

    // Main processing loop
    while (running) {

        sactive = read_file_slabinfo();

        // Init Charts
        if (unlikely(loops == 0)) {
            // Memory Usage
            printf("CHART %s.%s '' 'Memory Usage' 'B' '%s' '' line %d %d %s\n"
                , CHART_TYPE
                , "slabmemory"
                , CHART_FAMILY
                , CHART_PRIO
                , update_every
                , PLUGIN_SLABINFO_NAME
            );
            for (s = sactive; s; s = s->next) {
                printf("DIMENSION %s '' absolute 1 1\n", s->name);
            }

            // Slab active usage (filling)
            printf("CHART %s.%s '' 'Object Filling' '%%' '%s' '' line %d %d %s\n"
                , CHART_TYPE
                , "slabfilling"
                , CHART_FAMILY
                , CHART_PRIO + 1
                , update_every
                , PLUGIN_SLABINFO_NAME
            );
            for (s = sactive; s; s = s->next) {
                printf("DIMENSION %s '' absolute 1 1\n", s->name);
            }

            // Memory waste
            printf("CHART %s.%s '' 'Memory waste' 'B' '%s' '' line %d %d %s\n"
                , CHART_TYPE
                , "slabwaste"
                , CHART_FAMILY
                , CHART_PRIO + 2
                , update_every
                , PLUGIN_SLABINFO_NAME
            );
            for (s = sactive; s; s = s->next) {
                printf("DIMENSION %s '' absolute 1 1\n", s->name);
            }
        }


        //
        // Memory usage
        //
        printf("BEGIN %s.%s\n"
            , CHART_TYPE
            , "slabmemory"
        );
        for (s = sactive; s; s = s->next) {
            printf("SET %s = %"PRIu64"\n"
                , s->name
                , s->mem_usage
            );
        }
        printf("END\n");

        //
        // Slab active usage
        //
        printf("BEGIN %s.%s\n"
            , CHART_TYPE
            , "slabfilling"
        );
        for (s = sactive; s; s = s->next) {
            printf("SET %s = %u\n"
                , s->name
                , s->obj_filling
            );
        }
        printf("END\n");

        //
        // Memory waste
        //
        printf("BEGIN %s.%s\n"
            , CHART_TYPE
            , "slabwaste"
        );
        for (s = sactive; s; s = s->next) {
            printf("SET %s = %"PRIu64"\n"
                , s->name
                , s->mem_waste
            );
        }
        printf("END\n");


        loops++;

        sleep(update_every);
    }

    return loops;
}




// ----------------------------------------------------------------------------
// main

void usage(void) {
    fprintf(stderr, "%s\n", program_name);
    exit(1);
}

int main(int argc, char **argv) {

    program_name = argv[0];
    program_version = "0.1";
    error_log_syslog = 0;

    int update_every = 1, i, n, freq = 0;

    for (i = 1; i < argc; i++) {
        // Frequency parsing
        if(isdigit(*argv[i]) && !freq) {
            n = (int) str2l(argv[i]);
            if (n > 0) {
                if (n >= UPDATE_EVERY_MAX) {
                    error("Invalid interval value: %s", argv[i]);
                    exit(1);
                }
                freq = n;
            }
        }
        else if (strcmp("debug", argv[i]) == 0) {
            debug = 1;
            continue;
        }
        else {
            fprintf(stderr,
                "netdata slabinfo.plugin %s\n"
                "This program is a data collector plugin for netdata.\n"
                "\n"
                "Available command line options:\n"
                "\n"
                "  COLLECTION_FREQUENCY    data collection frequency in seconds\n"
                "                          minimum: %d\n"
                "\n"
                "  debug                   enable verbose output\n"
                "                          default: disabled\n"
                "\n",
                program_version,
                update_every
            );
            exit(1);
        }
    }

    if(freq >= update_every)
        update_every = freq;
    else if(freq)
        error("update frequency %d seconds is too small for slabinfo. Using %d.", freq, update_every);


    // Call the main function. Time drift to be added
    do_slab_stats(update_every);

    return 0;
}