summaryrefslogtreecommitdiff
path: root/library/slabinfo.c
blob: dfd3993aeab2fde2918e82ad4ec0e10ec5cf1464 (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
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
/*
 * slabinfo.c - slab pools related definitions for libproc2
 *
 * Copyright © 2011-2023 Jim Warner <james.warner@comcast.net>
 * Copyright © 2015-2023 Craig Small <csmall@dropbear.xyz>
 * Copyright © 2004-2006 Albert Cahalan
 * Copyright © 2003      Chris Rivera
 * Copyright © 2003      Fabian Frederick
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

#include <sys/stat.h>
#include <sys/types.h>

#include "procps-private.h"
#include "slabinfo.h"


#define SLABINFO_FILE        "/proc/slabinfo"
#define SLABINFO_LINE_LEN    2048
#define SLABINFO_NAME_LEN    128

#define STACKS_INCR          128         // amount reap stack allocations grow

/* ---------------------------------------------------------------------------- +
   this #define will be used to help ensure that our Item_table is synchronized |
   with all the enumerators found in the associated header file. It is intended |
   to only be defined locally (and temporarily) at some point prior to release! | */
// #define ITEMTABLE_DEBUG //-------------------------------------------------- |
// ---------------------------------------------------------------------------- +

/*
   Because 'select' could, at most, return only node[0] values and since 'reap' |
   would be forced to duplicate global slabs stuff in every node results stack, |
   the following #define can be used to enforce strictly logical return values. |
      select: allow only SLABINFO & SLABS items
      reap:   allow only SLABINFO & SLAB items
   Without the #define, these functions always return something even if just 0. |
      get:    return only SLABS results, else 0
      select: return only SLABINFO & SLABS results, else zero
      reap:   return any requested, even when duplicated in each cache's stack */
//#define ENFORCE_LOGICAL  // ensure only logical items accepted by select/reap


struct slabs_summ {
    unsigned int  nr_objs;           // number of objects, among all caches
    unsigned int  nr_active_objs;    // number of active objects, among all caches
    unsigned int  nr_pages;          // number of pages consumed by all objects
    unsigned int  nr_slabs;          // number of slabs, among all caches
    unsigned int  nr_active_slabs;   // number of active slabs, among all caches
    unsigned int  nr_caches;         // number of caches
    unsigned int  nr_active_caches;  // number of active caches
    unsigned int  avg_obj_size;      // average object size
    unsigned int  min_obj_size;      // size of smallest object
    unsigned int  max_obj_size;      // size of largest object
    unsigned long active_size;       // size of all active objects
    unsigned long total_size;        // size of all objects
};

struct slabs_node {
    char name[SLABINFO_NAME_LEN+1];  // name of this cache
    unsigned long cache_size;        // size of entire cache
    unsigned int  nr_objs;           // number of objects in this cache
    unsigned int  nr_active_objs;    // number of active objects
    unsigned int  obj_size;          // size of each object
    unsigned int  objs_per_slab;     // number of objects per slab
    unsigned int  pages_per_slab;    // number of pages per slab
    unsigned int  nr_slabs;          // number of slabs in this cache
    unsigned int  nr_active_slabs;   // number of active slabs
    unsigned int  use;               // percent full: total / active
};

struct slabs_hist {
    struct slabs_summ new;
    struct slabs_summ old;
};

struct stacks_extent {
    int ext_numstacks;
    struct stacks_extent *next;
    struct slabinfo_stack **stacks;
};

struct ext_support {
    int numitems;                    // includes 'logical_end' delimiter
    enum slabinfo_item *items;       // includes 'logical_end' delimiter
    struct stacks_extent *extents;   // anchor for these extents
#ifdef ENFORCE_LOGICAL
    enum slabinfo_item lowest;       // range of allowable enums
    enum slabinfo_item highest;
#endif
};

struct fetch_support {
    struct slabinfo_stack **anchor;  // fetch consolidated extents
    int n_alloc;                     // number of above pointers allocated
    int n_inuse;                     // number of above pointers occupied
    int n_alloc_save;                // last known reap.stacks allocation
    struct slabinfo_reaped results;  // count + stacks for return to caller
};

struct slabinfo_info {
    int refcount;
    FILE *slabinfo_fp;
    int nodes_alloc;                 // nodes alloc()ed
    int nodes_used;                  // nodes using alloced memory
    struct slabs_node *nodes;        // first slabnode of this list
    struct slabs_hist slabs;         // new/old slabs_summ data
    struct ext_support select_ext;   // supports concurrent select/reap
    struct ext_support fetch_ext;    // supports concurrent select/reap
    struct fetch_support fetch;      // support for procps_slabinfo_reap
    struct slabs_node nul_node;      // used by slabinfo_get/select
    struct slabinfo_result get_this; // used by slabinfo_get
    time_t sav_secs;                 // used by slabinfo_get
};


// ___ Results 'Set' Support ||||||||||||||||||||||||||||||||||||||||||||||||||

#define setNAME(e) set_ ## e
#define setDECL(e) static void setNAME(e) \
    (struct slabinfo_result *R, struct slabs_hist *S, struct slabs_node *N)

// regular assignment
#define REG_set(e,t,x) setDECL(e) { (void)N; R->result. t = S->new. x; }
#define NOD_set(e,t,x) setDECL(e) { (void)S; R->result. t = N-> x; }
// delta assignment
#define HST_set(e,t,x) setDECL(e) { (void)N; R->result. t = (signed long)S->new. x - S->old. x; }

setDECL(SLABINFO_noop)  { (void)R; (void)S; (void)N; }
setDECL(SLABINFO_extra) { (void)S; (void)N; R->result.ul_int = 0; }

NOD_set(SLAB_NAME,                     str,  name)
NOD_set(SLAB_NUM_OBJS,               u_int,  nr_objs)
NOD_set(SLAB_ACTIVE_OBJS,            u_int,  nr_active_objs)
NOD_set(SLAB_OBJ_SIZE,               u_int,  obj_size)
NOD_set(SLAB_OBJ_PER_SLAB,           u_int,  objs_per_slab)
NOD_set(SLAB_NUMS_SLABS,             u_int,  nr_slabs)
NOD_set(SLAB_ACTIVE_SLABS,           u_int,  nr_active_slabs)
NOD_set(SLAB_PAGES_PER_SLAB,         u_int,  pages_per_slab)
NOD_set(SLAB_PERCENT_USED,           u_int,  use)
NOD_set(SLAB_SIZE_TOTAL,            ul_int,  cache_size)

REG_set(SLABS_CACHES_TOTAL,          u_int,  nr_caches)
REG_set(SLABS_CACHES_ACTIVE,         u_int,  nr_active_caches)
REG_set(SLABS_NUM_OBJS,              u_int,  nr_objs)
REG_set(SLABS_ACTIVE_OBJS,           u_int,  nr_active_objs)
REG_set(SLABS_OBJ_SIZE_AVG,          u_int,  avg_obj_size)
REG_set(SLABS_OBJ_SIZE_MIN,          u_int,  min_obj_size)
REG_set(SLABS_OBJ_SIZE_MAX,          u_int,  max_obj_size)
REG_set(SLABS_NUMS_SLABS,            u_int,  nr_slabs)
REG_set(SLABS_ACTIVE_SLABS,          u_int,  nr_active_slabs)
REG_set(SLABS_PAGES_TOTAL,           u_int,  nr_pages)
REG_set(SLABS_SIZE_ACTIVE,          ul_int,  active_size)
REG_set(SLABS_SIZE_TOTAL,           ul_int,  total_size)

HST_set(SLABS_DELTA_CACHES_TOTAL,    s_int,  nr_caches)
HST_set(SLABS_DELTA_CACHES_ACTIVE,   s_int,  nr_active_caches)
HST_set(SLABS_DELTA_NUM_OBJS,        s_int,  nr_objs)
HST_set(SLABS_DELTA_ACTIVE_OBJS,     s_int,  nr_active_objs)
HST_set(SLABS_DELTA_OBJ_SIZE_AVG,    s_int,  avg_obj_size)
HST_set(SLABS_DELTA_OBJ_SIZE_MIN,    s_int,  min_obj_size)
HST_set(SLABS_DELTA_OBJ_SIZE_MAX,    s_int,  max_obj_size)
HST_set(SLABS_DELTA_NUMS_SLABS,      s_int,  nr_slabs)
HST_set(SLABS_DELTA_ACTIVE_SLABS,    s_int,  nr_active_slabs)
HST_set(SLABS_DELTA_PAGES_TOTAL,     s_int,  nr_pages)
HST_set(SLABS_DELTA_SIZE_ACTIVE,     s_int,  active_size)
HST_set(SLABS_DELTA_SIZE_TOTAL,      s_int,  total_size)

#undef setDECL
#undef REG_set
#undef NOD_set
#undef HST_set


// ___ Sorting Support ||||||||||||||||||||||||||||||||||||||||||||||||||||||||

struct sort_parms {
    int offset;
    enum slabinfo_sort_order order;
};

#define srtNAME(t) sort_slabinfo_ ## t
#define srtDECL(t) static int srtNAME(t) \
    (const struct slabinfo_stack **A, const struct slabinfo_stack **B, struct sort_parms *P)

srtDECL(u_int) {
    const struct slabinfo_result *a = (*A)->head + P->offset; \
    const struct slabinfo_result *b = (*B)->head + P->offset; \
    if ( a->result.u_int > b->result.u_int ) return P->order > 0 ?  1 : -1; \
    if ( a->result.u_int < b->result.u_int ) return P->order > 0 ? -1 :  1; \
    return 0;
}

srtDECL(ul_int) {
    const struct slabinfo_result *a = (*A)->head + P->offset; \
    const struct slabinfo_result *b = (*B)->head + P->offset; \
    if ( a->result.ul_int > b->result.ul_int ) return P->order > 0 ?  1 : -1; \
    if ( a->result.ul_int < b->result.ul_int ) return P->order > 0 ? -1 :  1; \
    return 0;
}

srtDECL(str) {
    const struct slabinfo_result *a = (*A)->head + P->offset;
    const struct slabinfo_result *b = (*B)->head + P->offset;
    return P->order * strcoll(a->result.str, b->result.str);
}

srtDECL(noop) { \
    (void)A; (void)B; (void)P; \
    return 0;
}

#undef srtDECL


// ___ Controlling Table ||||||||||||||||||||||||||||||||||||||||||||||||||||||

typedef void (*SET_t)(struct slabinfo_result *, struct slabs_hist *, struct slabs_node *);
#ifdef ITEMTABLE_DEBUG
#define RS(e) (SET_t)setNAME(e), e, STRINGIFY(e)
#else
#define RS(e) (SET_t)setNAME(e)
#endif

typedef int  (*QSR_t)(const void *, const void *, void *);
#define QS(t) (QSR_t)srtNAME(t)

#define TS(t) STRINGIFY(t)
#define TS_noop ""

        /*
         * Need it be said?
         * This table must be kept in the exact same order as
         * those *enum slabinfo_item* guys ! */
static struct {
    SET_t setsfunc;              // the actual result setting routine
#ifdef ITEMTABLE_DEBUG
    int   enumnumb;              // enumerator (must match position!)
    char *enum2str;              // enumerator name as a char* string
#endif
    QSR_t sortfunc;              // sort cmp func for a specific type
    char *type2str;              // the result type as a string value
} Item_table[] = {
/*  setsfunc                        sortfunc     type2str
    ------------------------------  -----------  ---------- */
  { RS(SLABINFO_noop),              QS(noop),    TS_noop    },
  { RS(SLABINFO_extra),             QS(ul_int),  TS_noop    },

  { RS(SLAB_NAME),                  QS(str),     TS(str)    },
  { RS(SLAB_NUM_OBJS),              QS(u_int),   TS(u_int)  },
  { RS(SLAB_ACTIVE_OBJS),           QS(u_int),   TS(u_int)  },
  { RS(SLAB_OBJ_SIZE),              QS(u_int),   TS(u_int)  },
  { RS(SLAB_OBJ_PER_SLAB),          QS(u_int),   TS(u_int)  },
  { RS(SLAB_NUMS_SLABS),            QS(u_int),   TS(u_int)  },
  { RS(SLAB_ACTIVE_SLABS),          QS(u_int),   TS(u_int)  },
  { RS(SLAB_PAGES_PER_SLAB),        QS(u_int),   TS(u_int)  },
  { RS(SLAB_PERCENT_USED),          QS(u_int),   TS(u_int)  },
  { RS(SLAB_SIZE_TOTAL),            QS(ul_int),  TS(ul_int) },

  { RS(SLABS_CACHES_TOTAL),         QS(noop),    TS(u_int)  },
  { RS(SLABS_CACHES_ACTIVE),        QS(noop),    TS(u_int)  },
  { RS(SLABS_NUM_OBJS),             QS(noop),    TS(u_int)  },
  { RS(SLABS_ACTIVE_OBJS),          QS(noop),    TS(u_int)  },
  { RS(SLABS_OBJ_SIZE_AVG),         QS(noop),    TS(u_int)  },
  { RS(SLABS_OBJ_SIZE_MIN),         QS(noop),    TS(u_int)  },
  { RS(SLABS_OBJ_SIZE_MAX),         QS(noop),    TS(u_int)  },
  { RS(SLABS_NUMS_SLABS),           QS(noop),    TS(u_int)  },
  { RS(SLABS_ACTIVE_SLABS),         QS(noop),    TS(u_int)  },
  { RS(SLABS_PAGES_TOTAL),          QS(noop),    TS(u_int)  },
  { RS(SLABS_SIZE_ACTIVE),          QS(noop),    TS(ul_int) },
  { RS(SLABS_SIZE_TOTAL),           QS(noop),    TS(ul_int) },

  { RS(SLABS_DELTA_CACHES_TOTAL),   QS(noop),    TS(s_int)  },
  { RS(SLABS_DELTA_CACHES_ACTIVE),  QS(noop),    TS(s_int)  },
  { RS(SLABS_DELTA_NUM_OBJS),       QS(noop),    TS(s_int)  },
  { RS(SLABS_DELTA_ACTIVE_OBJS),    QS(noop),    TS(s_int)  },
  { RS(SLABS_DELTA_OBJ_SIZE_AVG),   QS(noop),    TS(s_int)  },
  { RS(SLABS_DELTA_OBJ_SIZE_MIN),   QS(noop),    TS(s_int)  },
  { RS(SLABS_DELTA_OBJ_SIZE_MAX),   QS(noop),    TS(s_int)  },
  { RS(SLABS_DELTA_NUMS_SLABS),     QS(noop),    TS(s_int)  },
  { RS(SLABS_DELTA_ACTIVE_SLABS),   QS(noop),    TS(s_int)  },
  { RS(SLABS_DELTA_PAGES_TOTAL),    QS(noop),    TS(s_int)  },
  { RS(SLABS_DELTA_SIZE_ACTIVE),    QS(noop),    TS(s_int)  },
  { RS(SLABS_DELTA_SIZE_TOTAL),     QS(noop),    TS(s_int)  },
};

    /* please note,
     * this enum MUST be 1 greater than the highest value of any enum */
enum slabinfo_item SLABINFO_logical_end = MAXTABLE(Item_table);

#undef setNAME
#undef srtNAME
#undef RS
#undef QS


// ___ Private Functions ||||||||||||||||||||||||||||||||||||||||||||||||||||||
// --- slabnode specific support ----------------------------------------------

/* Alloc up more slabnode memory, if required
 */
static int alloc_slabnodes (
        struct slabinfo_info *info)
{
    struct slabs_node *new_nodes;
    int new_count;

    if (info->nodes_used < info->nodes_alloc)
        return 1;
    /* Increment the allocated number of slabs */
    new_count = info->nodes_alloc * 5/4+30;

    new_nodes = realloc(info->nodes, sizeof(struct slabs_node) * new_count);
    if (!new_nodes)
        return 0;
    info->nodes = new_nodes;
    info->nodes_alloc = new_count;
    return 1;
} // end: alloc_slabnodes


/*
 * get_slabnode - allocate slab_info structures using a free list
 *
 * In the fast path, we simply return a node off the free list.  In the slow
 * list, we malloc() a new node.  The free list is never automatically reaped,
 * both for simplicity and because the number of slab caches is fairly
 * constant.
 */
static int get_slabnode (
        struct slabinfo_info *info,
        struct slabs_node **node)
{
    if (info->nodes_used == info->nodes_alloc) {
        if (!alloc_slabnodes(info))
            return 0;        // here, errno was set to ENOMEM
    }
    *node = &(info->nodes[info->nodes_used++]);
    return 1;
} // end: get_slabnode


/* parse_slabinfo20:
 *
 * Actual parse routine for slabinfo 2.x (2.6 kernels)
 * Note: difference between 2.0 and 2.1 is in the ": globalstat" part where version 2.1
 * has extra column <nodeallocs>. We don't use ": globalstat" part in both versions.
 *
 * Formats (we don't use "statistics" extensions)
 *
 *  slabinfo - version: 2.1
 *  # name            <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab> \
 *  : tunables <batchcount> <limit> <sharedfactor> \
 *  : slabdata <active_slabs> <num_slabs> <sharedavail>
 *
 *  slabinfo - version: 2.1 (statistics)
 *  # name            <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab> \
 *  : tunables <batchcount> <limit> <sharedfactor> \
 *  : slabdata <active_slabs> <num_slabs> <sharedavail> \
 *  : globalstat <listallocs> <maxobjs> <grown> <reaped> <error> <maxfreeable> <freelimit> <nodeallocs> \
 *  : cpustat <allochit> <allocmiss> <freehit> <freemiss>
 *
 *  slabinfo - version: 2.0
 *  # name            <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab> \
 *  : tunables <batchcount> <limit> <sharedfactor> \
 *  : slabdata <active_slabs> <num_slabs> <sharedavail>
 *
 *  slabinfo - version: 2.0 (statistics)
 *  # name            <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab> \
 *  : tunables <batchcount> <limit> <sharedfactor> \
 *  : slabdata <active_slabs> <num_slabs> <sharedavail> \
 *  : globalstat <listallocs> <maxobjs> <grown> <reaped> <error> <maxfreeable> <freelimit> \
 *  : cpustat <allochit> <allocmiss> <freehit> <freemiss>
 */
static int parse_slabinfo20 (
        struct slabinfo_info *info)
{
    struct slabs_node *node;
    char buffer[SLABINFO_LINE_LEN];
    int page_size = getpagesize();
    struct slabs_summ *slabs = &(info->slabs.new);

    slabs->min_obj_size = INT_MAX;
    slabs->max_obj_size = 0;

    while (fgets(buffer, SLABINFO_LINE_LEN, info->slabinfo_fp )) {
        if (buffer[0] == '#')
            continue;

        if (!get_slabnode(info, &node))
            return 1;        // here, errno was set to ENOMEM

        if (sscanf(buffer,
                   "%" STRINGIFY(SLABINFO_NAME_LEN) "s" \
                   "%u %u %u %u %u : tunables %*u %*u %*u : slabdata %u %u %*u",
                   node->name,
                   &node->nr_active_objs, &node->nr_objs,
                   &node->obj_size, &node->objs_per_slab,
                   &node->pages_per_slab, &node->nr_active_slabs,
                   &node->nr_slabs) < 8) {
            errno = ERANGE;
            return 1;
        }

        if (!node->name[0])
            snprintf(node->name, sizeof(node->name), "%s", "unknown");

        if (node->obj_size < slabs->min_obj_size)
            slabs->min_obj_size = node->obj_size;
        if (node->obj_size > slabs->max_obj_size)
            slabs->max_obj_size = node->obj_size;

        node->cache_size = (unsigned long)node->nr_slabs * node->pages_per_slab * page_size;

        if (node->nr_objs) {
            node->use = (unsigned int)(100 * ((float)node->nr_active_objs / node->nr_objs));
            slabs->nr_active_caches++;
        } else
            node->use = 0;

        slabs->nr_objs += node->nr_objs;
        slabs->nr_active_objs += node->nr_active_objs;
        slabs->total_size += (unsigned long)node->nr_objs * node->obj_size;
        slabs->active_size += (unsigned long)node->nr_active_objs * node->obj_size;
        slabs->nr_pages += node->nr_slabs * node->pages_per_slab;
        slabs->nr_slabs += node->nr_slabs;
        slabs->nr_active_slabs += node->nr_active_slabs;
        slabs->nr_caches++;
    }

    if (slabs->nr_objs)
        slabs->avg_obj_size = slabs->total_size / slabs->nr_objs;

    return 0;
} // end: parse_slabinfo20


/* slabinfo_read_failed():
 *
 * Read the data out of /proc/slabinfo putting the information
 * into the supplied info container
 *
 * Returns: 0 on success, 1 on error
 */
static int slabinfo_read_failed (
        struct slabinfo_info *info)
{
    char line[SLABINFO_LINE_LEN];
    int major, minor;

    memcpy(&info->slabs.old, &info->slabs.new, sizeof(struct slabs_summ));
    memset(&(info->slabs.new), 0, sizeof(struct slabs_summ));
    if (!alloc_slabnodes(info))
        return 1;            // here, errno was set to ENOMEM

    memset(info->nodes, 0, sizeof(struct slabs_node)*info->nodes_alloc);
    info->nodes_used = 0;

    if (NULL == info->slabinfo_fp
    && (info->slabinfo_fp = fopen(SLABINFO_FILE, "r")) == NULL)
        return 1;

    if (fseek(info->slabinfo_fp, 0L, SEEK_SET) < 0)
        return 1;

    /* Parse the version string */
    if (!fgets(line, SLABINFO_LINE_LEN, info->slabinfo_fp))
        return 1;

    if (2 != sscanf(line, "slabinfo - version: %d.%d", &major, &minor)
    || (major != 2)) {
        errno = ERANGE;
        return 1;
    }

    return parse_slabinfo20(info);
} // end: slabinfo_read_failed


// ___ Private Functions ||||||||||||||||||||||||||||||||||||||||||||||||||||||
// --- generalized support ----------------------------------------------------

static inline void slabinfo_assign_results (
        struct slabinfo_stack *stack,
        struct slabs_hist *summ,
        struct slabs_node *node)
{
    struct slabinfo_result *this = stack->head;

    for (;;) {
        enum slabinfo_item item = this->item;
        if (item >= SLABINFO_logical_end)
            break;
        Item_table[item].setsfunc(this, summ, node);
        ++this;
    }
    return;
} // end: slabinfo_assign_results


static void slabinfo_extents_free_all (
        struct ext_support *this)
{
    while (this->extents) {
        struct stacks_extent *p = this->extents;
        this->extents = this->extents->next;
        free(p);
    };
} // end: slabinfo_extents_free_all


static inline struct slabinfo_result *slabinfo_itemize_stack (
        struct slabinfo_result *p,
        int depth,
        enum slabinfo_item *items)
{
    struct slabinfo_result *p_sav = p;
    int i;

    for (i = 0; i < depth; i++) {
        p->item = items[i];
        ++p;
    }
    return p_sav;
} // end: slabinfo_itemize_stack


static inline int slabinfo_items_check_failed (
        struct ext_support *this,
        enum slabinfo_item *items,
        int numitems)
{
    int i;

    /* if an enum is passed instead of an address of one or more enums, ol' gcc
     * will silently convert it to an address (possibly NULL).  only clang will
     * offer any sort of warning like the following:
     *
     * warning: incompatible integer to pointer conversion passing 'int' to parameter of type 'enum slabinfo_item *'
     * my_stack = procps_slabinfo_select(info, SLABINFO_noop, num);
     *                                         ^~~~~~~~~~~~~~~~
     */
    if (numitems < 1
    || (void *)items < (void *)(unsigned long)(2 * SLABINFO_logical_end))
        return 1;

    for (i = 0; i < numitems; i++) {
#ifdef ENFORCE_LOGICAL
        if (items[i] == SLABINFO_noop
        || (items[i] == SLABINFO_extra))
            continue;
        if (items[i] < this->lowest
        || (items[i] > this->highest))
            return 1;
#else
        // a slabinfo_item is currently unsigned, but we'll protect our future
        if (items[i] < 0)
            return 1;
        if (items[i] >= SLABINFO_logical_end)
            return 1;
        (void)this;
#endif
    }

    return 0;
} // end: slabinfo_items_check_failed


/*
 * slabinfo_stacks_alloc():
 *
 * Allocate and initialize one or more stacks each of which is anchored in an
 * associated context structure.
 *
 * All such stacks will have their result structures properly primed with
 * 'items', while the result itself will be zeroed.
 *
 * Returns a stacks_extent struct anchoring the 'heads' of each new stack.
 */
static struct stacks_extent *slabinfo_stacks_alloc (
        struct ext_support *this,
        int maxstacks)
{
    struct stacks_extent *p_blob;
    struct slabinfo_stack **p_vect;
    struct slabinfo_stack *p_head;
    size_t vect_size, head_size, list_size, blob_size;
    void *v_head, *v_list;
    int i;

    vect_size  = sizeof(void *) * maxstacks;                     // size of the addr vectors |
    vect_size += sizeof(void *);                                 // plus NULL addr delimiter |
    head_size  = sizeof(struct slabinfo_stack);                  // size of that head struct |
    list_size  = sizeof(struct slabinfo_result)*this->numitems;  // any single results stack |
    blob_size  = sizeof(struct stacks_extent);                   // the extent anchor itself |
    blob_size += vect_size;                                      // plus room for addr vects |
    blob_size += head_size * maxstacks;                          // plus room for head thing |
    blob_size += list_size * maxstacks;                          // plus room for our stacks |

    /* note: all of our memory is allocated in one single blob, facilitating a later free(). |
             as a minimum, it is important that those result structures themselves always be |
             contiguous within each stack since they are accessed through relative position. | */
    if (NULL == (p_blob = calloc(1, blob_size)))
        return NULL;

    p_blob->next = this->extents;                                // push this extent onto... |
    this->extents = p_blob;                                      // ...some existing extents |
    p_vect = (void *)p_blob + sizeof(struct stacks_extent);      // prime our vector pointer |
    p_blob->stacks = p_vect;                                     // set actual vectors start |
    v_head = (void *)p_vect + vect_size;                         // prime head pointer start |
    v_list = v_head + (head_size * maxstacks);                   // prime our stacks pointer |

    for (i = 0; i < maxstacks; i++) {
        p_head = (struct slabinfo_stack *)v_head;
        p_head->head = slabinfo_itemize_stack((struct slabinfo_result *)v_list, this->numitems, this->items);
        p_blob->stacks[i] = p_head;
        v_list += list_size;
        v_head += head_size;
    }
    p_blob->ext_numstacks = maxstacks;
    return p_blob;
} // end: slabinfo_stacks_alloc


static int slabinfo_stacks_fetch (
        struct slabinfo_info *info)
{
 #define n_alloc  info->fetch.n_alloc
 #define n_inuse  info->fetch.n_inuse
 #define n_saved  info->fetch.n_alloc_save
    struct stacks_extent *ext;

    // initialize stuff -----------------------------------
    if (!info->fetch.anchor) {
        if (!(info->fetch.anchor = calloc(sizeof(void *), STACKS_INCR)))
            return -1;
        n_alloc = STACKS_INCR;
    }
    if (!info->fetch_ext.extents) {
        if (!(ext = slabinfo_stacks_alloc(&info->fetch_ext, n_alloc)))
            return -1;       // here, errno was set to ENOMEM
        memcpy(info->fetch.anchor, ext->stacks, sizeof(void *) * n_alloc);
    }

    // iterate stuff --------------------------------------
    n_inuse = 0;
    while (n_inuse < info->nodes_used) {
        if (!(n_inuse < n_alloc)) {
            n_alloc += STACKS_INCR;
            if ((!(info->fetch.anchor = realloc(info->fetch.anchor, sizeof(void *) * n_alloc)))
            || (!(ext = slabinfo_stacks_alloc(&info->fetch_ext, STACKS_INCR))))
                return -1;   // here, errno was set to ENOMEM
            memcpy(info->fetch.anchor + n_inuse, ext->stacks, sizeof(void *) * STACKS_INCR);
        }
        slabinfo_assign_results(info->fetch.anchor[n_inuse], &info->slabs, &info->nodes[n_inuse]);
        ++n_inuse;
    }

    // finalize stuff -------------------------------------
    /* note: we go to this trouble of maintaining a duplicate of the consolidated |
             extent stacks addresses represented as our 'anchor' since these ptrs |
             are exposed to a user (um, not that we don't trust 'em or anything). |
             plus, we can NULL delimit these ptrs which we couldn't do otherwise. | */
    if (n_saved < n_inuse + 1) {
        n_saved = n_inuse + 1;
        if (!(info->fetch.results.stacks = realloc(info->fetch.results.stacks, sizeof(void *) * n_saved)))
            return -1;
    }
    memcpy(info->fetch.results.stacks, info->fetch.anchor, sizeof(void *) * n_inuse);
    info->fetch.results.stacks[n_inuse] = NULL;
    info->fetch.results.total = n_inuse;

    return n_inuse;
 #undef n_alloc
 #undef n_inuse
 #undef n_saved
} // end: slabinfo_stacks_fetch


static int slabinfo_stacks_reconfig_maybe (
        struct ext_support *this,
        enum slabinfo_item *items,
        int numitems)
{
    if (slabinfo_items_check_failed(this, items, numitems))
        return -1;
    /* is this the first time or have things changed since we were last called?
       if so, gotta' redo all of our stacks stuff ... */
    if (this->numitems != numitems + 1
    || memcmp(this->items, items, sizeof(enum slabinfo_item) * numitems)) {
        // allow for our SLABINFO_logical_end
        if (!(this->items = realloc(this->items, sizeof(enum slabinfo_item) * (numitems + 1))))
            return -1;
        memcpy(this->items, items, sizeof(enum slabinfo_item) * numitems);
        this->items[numitems] = SLABINFO_logical_end;
        this->numitems = numitems + 1;
        slabinfo_extents_free_all(this);
        return 1;
    }
    return 0;
} // end: slabinfo_stacks_reconfig_maybe


// ___ Public Functions |||||||||||||||||||||||||||||||||||||||||||||||||||||||

// --- standard required functions --------------------------------------------

/*
 * procps_slabinfo_new():
 *
 * @info: location of returned new structure
 *
 * Returns: < 0 on failure, 0 on success along with
 *          a pointer to a new context struct
 */
PROCPS_EXPORT int procps_slabinfo_new (
        struct slabinfo_info **info)
{
    struct slabinfo_info *p;

#ifdef ITEMTABLE_DEBUG
    int i, failed = 0;
    for (i = 0; i < MAXTABLE(Item_table); i++) {
        if (i != Item_table[i].enumnumb) {
            fprintf(stderr, "%s: enum/table error: Item_table[%d] was %s, but its value is %d\n"
                , __FILE__, i, Item_table[i].enum2str, Item_table[i].enumnumb);
            failed = 1;
        }
    }
    if (failed) _Exit(EXIT_FAILURE);
#endif

    if (info == NULL || *info != NULL)
        return -EINVAL;
    if (!(p = calloc(1, sizeof(struct slabinfo_info))))
        return -ENOMEM;

#ifdef ENFORCE_LOGICAL
    p->select_ext.lowest  = SLABS_CACHES_TOTAL;
    p->select_ext.highest = SLABS_DELTA_SIZE_TOTAL;
    p->fetch_ext.lowest   = SLAB_NAME;
    p->fetch_ext.highest  = SLAB_SIZE_TOTAL;
#endif

    p->refcount = 1;

    /* do a priming read here for the following potential benefits: |
         1) see if that caller's permissions were sufficient (root) |
         2) make delta results potentially useful, even if 1st time |
         3) elimnate need for history distortions 1st time 'switch' | */
    if (slabinfo_read_failed(p)) {
        procps_slabinfo_unref(&p);
        return -errno;
    }

    *info = p;
    return 0;
} // end: procps_slabinfo_new


PROCPS_EXPORT int procps_slabinfo_ref (
        struct slabinfo_info *info)
{
    if (info == NULL)
        return -EINVAL;

    info->refcount++;
    return info->refcount;
} // end: procps_slabinfo_ref


PROCPS_EXPORT int procps_slabinfo_unref (
        struct slabinfo_info **info)
{
    if (info == NULL || *info == NULL)
        return -EINVAL;

    (*info)->refcount--;

    if ((*info)->refcount < 1) {
        int errno_sav = errno;

        if ((*info)->slabinfo_fp) {
            fclose((*info)->slabinfo_fp);
            (*info)->slabinfo_fp = NULL;
        }
        if ((*info)->select_ext.extents)
            slabinfo_extents_free_all((&(*info)->select_ext));
        if ((*info)->select_ext.items)
            free((*info)->select_ext.items);

        if ((*info)->fetch.anchor)
            free((*info)->fetch.anchor);
        if ((*info)->fetch.results.stacks)
            free((*info)->fetch.results.stacks);

        if ((*info)->fetch_ext.extents)
            slabinfo_extents_free_all(&(*info)->fetch_ext);
        if ((*info)->fetch_ext.items)
            free((*info)->fetch_ext.items);

        free((*info)->nodes);

        free(*info);
        *info = NULL;

        errno = errno_sav;
        return 0;
    }
    return (*info)->refcount;
} // end: procps_slabinfo_unref


// --- variable interface functions -------------------------------------------

PROCPS_EXPORT struct slabinfo_result *procps_slabinfo_get (
        struct slabinfo_info *info,
        enum slabinfo_item item)
{
    time_t cur_secs;

    errno = EINVAL;
    if (info == NULL)
        return NULL;
    if (item < 0 || item >= SLABINFO_logical_end)
        return NULL;
    errno = 0;

    /* we will NOT read the slabinfo file with every call - rather, we'll offer
       a granularity of 1 second between reads ... */
    cur_secs = time(NULL);
    if (1 <= cur_secs - info->sav_secs) {
        if (slabinfo_read_failed(info))
            return NULL;
        info->sav_secs = cur_secs;
    }

    info->get_this.item = item;
    //  with 'get', we must NOT honor the usual 'noop' guarantee
    info->get_this.result.ul_int = 0;
    Item_table[item].setsfunc(&info->get_this, &info->slabs, &info->nul_node);

    return &info->get_this;
} // end: procps_slabinfo_get


/* procps_slabinfo_reap():
 *
 * Harvest all the requested SLAB (individual nodes) information
 * providing the result stacks along with the total number of nodes.
 *
 * Returns: pointer to a slabinfo_reaped struct on success, NULL on error.
 */
PROCPS_EXPORT struct slabinfo_reaped *procps_slabinfo_reap (
        struct slabinfo_info *info,
        enum slabinfo_item *items,
        int numitems)
{
    errno = EINVAL;
    if (info == NULL || items == NULL)
        return NULL;
    if (0 > slabinfo_stacks_reconfig_maybe(&info->fetch_ext, items, numitems))
        return NULL;         // here, errno may be overridden with ENOMEM
    errno = 0;

    if (slabinfo_read_failed(info))
        return NULL;
    if (0 > slabinfo_stacks_fetch(info))
        return NULL;

    return &info->fetch.results;
} // end: procps_slabinfo_reap


/* procps_slabinfo_select():
 *
 * Obtain all the requested SLABS (global) information then return
 * it in a single library provided results stack.
 *
 * Returns: pointer to a slabinfo_stack struct on success, NULL on error.
 */
PROCPS_EXPORT struct slabinfo_stack *procps_slabinfo_select (
        struct slabinfo_info *info,
        enum slabinfo_item *items,
        int numitems)
{
    errno = EINVAL;
    if (info == NULL || items == NULL)
        return NULL;
    if (0 > slabinfo_stacks_reconfig_maybe(&info->select_ext, items, numitems))
        return NULL;         // here, errno may be overridden with ENOMEM
    errno = 0;

    if (!info->select_ext.extents
    && (!slabinfo_stacks_alloc(&info->select_ext, 1)))
       return NULL;

    if (slabinfo_read_failed(info))
        return NULL;
    slabinfo_assign_results(info->select_ext.extents->stacks[0], &info->slabs, &info->nul_node);

    return info->select_ext.extents->stacks[0];
} // end: procps_slabinfo_select


/*
 * procps_slabinfo_sort():
 *
 * Sort stacks anchored in the passed stack pointers array
 * based on the designated sort enumerator and specified order.
 *
 * Returns those same addresses sorted.
 *
 * Note: all of the stacks must be homogeneous (of equal length and content).
 */
PROCPS_EXPORT struct slabinfo_stack **procps_slabinfo_sort (
        struct slabinfo_info *info,
        struct slabinfo_stack *stacks[],
        int numstacked,
        enum slabinfo_item sortitem,
        enum slabinfo_sort_order order)
{
    struct slabinfo_result *p;
    struct sort_parms parms;
    int offset;

    errno = EINVAL;
    if (info == NULL || stacks == NULL)
        return NULL;
    // a slabinfo_item is currently unsigned, but we'll protect our future
    if (sortitem < 0 || sortitem >= SLABINFO_logical_end)
        return NULL;
    if (order != SLABINFO_SORT_ASCEND && order != SLABINFO_SORT_DESCEND)
        return NULL;
    if (numstacked < 2)
        return stacks;

    offset = 0;
    p = stacks[0]->head;
    for (;;) {
        if (p->item == sortitem)
            break;
        ++offset;
        if (p->item >= SLABINFO_logical_end)
            return NULL;
        ++p;
    }
    errno = 0;

    parms.offset = offset;
    parms.order = order;

    qsort_r(stacks, numstacked, sizeof(void *), (QSR_t)Item_table[p->item].sortfunc, &parms);
    return stacks;
} // end: procps_slabinfo_sort


// --- special debugging function(s) ------------------------------------------
/*
 *  The following isn't part of the normal programming interface.  Rather,
 *  it exists to validate result types referenced in application programs.
 *
 *  It's used only when:
 *      1) the 'XTRA_PROCPS_DEBUG' has been defined, or
 *      2) an #include of 'xtra-procps-debug.h' is used
 */

PROCPS_EXPORT struct slabinfo_result *xtra_slabinfo_get (
        struct slabinfo_info *info,
        enum slabinfo_item actual_enum,
        const char *typestr,
        const char *file,
        int lineno)
{
    struct slabinfo_result *r = procps_slabinfo_get(info, actual_enum);

    if (actual_enum < 0 || actual_enum >= SLABINFO_logical_end) {
        fprintf(stderr, "%s line %d: invalid item = %d, type = %s\n"
            , file, lineno, actual_enum, typestr);
    }
    if (r) {
        char *str = Item_table[r->item].type2str;
        if (str[0]
        && (strcmp(typestr, str)))
            fprintf(stderr, "%s line %d: was %s, expected %s\n", file, lineno, typestr, str);
    }
    return r;
} // end: xtra_slabinfo_get_


PROCPS_EXPORT struct slabinfo_result *xtra_slabinfo_val (
        int relative_enum,
        const char *typestr,
        const struct slabinfo_stack *stack,
        struct slabinfo_info *info,
        const char *file,
        int lineno)
{
    char *str;
    int i;

    for (i = 0; stack->head[i].item < SLABINFO_logical_end; i++)
        ;
    if (relative_enum < 0 || relative_enum >= i) {
        fprintf(stderr, "%s line %d: invalid relative_enum = %d, valid range = 0-%d\n"
            , file, lineno, relative_enum, i-1);
        return NULL;
    }
    str = Item_table[stack->head[relative_enum].item].type2str;
    if (str[0]
    && (strcmp(typestr, str))) {
        fprintf(stderr, "%s line %d: was %s, expected %s\n", file, lineno, typestr, str);
    }
    return &stack->head[relative_enum];
    (void)info;
} // end: xtra_slabinfo_val