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
|
/* SPDX-License-Identifier: GPL-2.0 */
/*
* linux/cgroup-defs.h - basic definitions for cgroup
*
* This file provides basic type and interface. Include this file directly
* only if necessary to avoid cyclic dependencies.
*/
#ifndef _LINUX_CGROUP_DEFS_H
#define _LINUX_CGROUP_DEFS_H
#include <linux/limits.h>
#include <linux/list.h>
#include <linux/idr.h>
#include <linux/wait.h>
#include <linux/mutex.h>
#include <linux/rcupdate.h>
#include <linux/refcount.h>
#include <linux/percpu-refcount.h>
#include <linux/percpu-rwsem.h>
#include <linux/u64_stats_sync.h>
#include <linux/workqueue.h>
#include <linux/bpf-cgroup.h>
#include <linux/psi_types.h>
#ifdef CONFIG_CGROUPS
struct cgroup;
struct cgroup_root;
struct cgroup_subsys;
struct cgroup_taskset;
struct kernfs_node;
struct kernfs_ops;
struct kernfs_open_file;
struct seq_file;
struct poll_table_struct;
#define MAX_CGROUP_TYPE_NAMELEN 32
#define MAX_CGROUP_ROOT_NAMELEN 64
#define MAX_CFTYPE_NAME 64
/* define the enumeration of all cgroup subsystems */
#define SUBSYS(_x) _x ## _cgrp_id,
enum cgroup_subsys_id {
#include <linux/cgroup_subsys.h>
CGROUP_SUBSYS_COUNT,
};
#undef SUBSYS
/* bits in struct cgroup_subsys_state flags field */
enum {
CSS_NO_REF = (1 << 0), /* no reference counting for this css */
CSS_ONLINE = (1 << 1), /* between ->css_online() and ->css_offline() */
CSS_RELEASED = (1 << 2), /* refcnt reached zero, released */
CSS_VISIBLE = (1 << 3), /* css is visible to userland */
CSS_DYING = (1 << 4), /* css is dying */
};
/* bits in struct cgroup flags field */
enum {
/* Control Group requires release notifications to userspace */
CGRP_NOTIFY_ON_RELEASE,
/*
* Clone the parent's configuration when creating a new child
* cpuset cgroup. For historical reasons, this option can be
* specified at mount time and thus is implemented here.
*/
CGRP_CPUSET_CLONE_CHILDREN,
/* Control group has to be frozen. */
CGRP_FREEZE,
/* Cgroup is frozen. */
CGRP_FROZEN,
};
/* cgroup_root->flags */
enum {
CGRP_ROOT_NOPREFIX = (1 << 1), /* mounted subsystems have no named prefix */
CGRP_ROOT_XATTR = (1 << 2), /* supports extended attributes */
/*
* Consider namespaces as delegation boundaries. If this flag is
* set, controller specific interface files in a namespace root
* aren't writeable from inside the namespace.
*/
CGRP_ROOT_NS_DELEGATE = (1 << 3),
/*
* Enable cpuset controller in v1 cgroup to use v2 behavior.
*/
CGRP_ROOT_CPUSET_V2_MODE = (1 << 4),
/*
* Enable legacy local memory.events.
*/
CGRP_ROOT_MEMORY_LOCAL_EVENTS = (1 << 5),
};
/* cftype->flags */
enum {
CFTYPE_ONLY_ON_ROOT = (1 << 0), /* only create on root cgrp */
CFTYPE_NOT_ON_ROOT = (1 << 1), /* don't create on root cgrp */
CFTYPE_NS_DELEGATABLE = (1 << 2), /* writeable beyond delegation boundaries */
CFTYPE_NO_PREFIX = (1 << 3), /* (DON'T USE FOR NEW FILES) no subsys prefix */
CFTYPE_WORLD_WRITABLE = (1 << 4), /* (DON'T USE FOR NEW FILES) S_IWUGO */
CFTYPE_DEBUG = (1 << 5), /* create when cgroup_debug */
/* internal flags, do not use outside cgroup core proper */
__CFTYPE_ONLY_ON_DFL = (1 << 16), /* only on default hierarchy */
__CFTYPE_NOT_ON_DFL = (1 << 17), /* not on default hierarchy */
};
/*
* cgroup_file is the handle for a file instance created in a cgroup which
* is used, for example, to generate file changed notifications. This can
* be obtained by setting cftype->file_offset.
*/
struct cgroup_file {
/* do not access any fields from outside cgroup core */
struct kernfs_node *kn;
unsigned long notified_at;
struct timer_list notify_timer;
};
/*
* Per-subsystem/per-cgroup state maintained by the system. This is the
* fundamental structural building block that controllers deal with.
*
* Fields marked with "PI:" are public and immutable and may be accessed
* directly without synchronization.
*/
struct cgroup_subsys_state {
/* PI: the cgroup that this css is attached to */
struct cgroup *cgroup;
/* PI: the cgroup subsystem that this css is attached to */
struct cgroup_subsys *ss;
/* reference count - access via css_[try]get() and css_put() */
struct percpu_ref refcnt;
/* siblings list anchored at the parent's ->children */
struct list_head sibling;
struct list_head children;
/* flush target list anchored at cgrp->rstat_css_list */
struct list_head rstat_css_node;
/*
* PI: Subsys-unique ID. 0 is unused and root is always 1. The
* matching css can be looked up using css_from_id().
*/
int id;
unsigned int flags;
/*
* Monotonically increasing unique serial number which defines a
* uniform order among all csses. It's guaranteed that all
* ->children lists are in the ascending order of ->serial_nr and
* used to allow interrupting and resuming iterations.
*/
u64 serial_nr;
/*
* Incremented by online self and children. Used to guarantee that
* parents are not offlined before their children.
*/
atomic_t online_cnt;
/* percpu_ref killing and RCU release */
struct work_struct destroy_work;
struct rcu_work destroy_rwork;
/*
* PI: the parent css. Placed here for cache proximity to following
* fields of the containing structure.
*/
struct cgroup_subsys_state *parent;
};
/*
* A css_set is a structure holding pointers to a set of
* cgroup_subsys_state objects. This saves space in the task struct
* object and speeds up fork()/exit(), since a single inc/dec and a
* list_add()/del() can bump the reference count on the entire cgroup
* set for a task.
*/
struct css_set {
/*
* Set of subsystem states, one for each subsystem. This array is
* immutable after creation apart from the init_css_set during
* subsystem registration (at boot time).
*/
struct cgroup_subsys_state *subsys[CGROUP_SUBSYS_COUNT];
/* reference count */
refcount_t refcount;
/*
* For a domain cgroup, the following points to self. If threaded,
* to the matching cset of the nearest domain ancestor. The
* dom_cset provides access to the domain cgroup and its csses to
* which domain level resource consumptions should be charged.
*/
struct css_set *dom_cset;
/* the default cgroup associated with this css_set */
struct cgroup *dfl_cgrp;
/* internal task count, protected by css_set_lock */
int nr_tasks;
/*
* Lists running through all tasks using this cgroup group.
* mg_tasks lists tasks which belong to this cset but are in the
* process of being migrated out or in. Protected by
* css_set_rwsem, but, during migration, once tasks are moved to
* mg_tasks, it can be read safely while holding cgroup_mutex.
*/
struct list_head tasks;
struct list_head mg_tasks;
struct list_head dying_tasks;
/* all css_task_iters currently walking this cset */
struct list_head task_iters;
/*
* On the default hierarhcy, ->subsys[ssid] may point to a css
* attached to an ancestor instead of the cgroup this css_set is
* associated with. The following node is anchored at
* ->subsys[ssid]->cgroup->e_csets[ssid] and provides a way to
* iterate through all css's attached to a given cgroup.
*/
struct list_head e_cset_node[CGROUP_SUBSYS_COUNT];
/* all threaded csets whose ->dom_cset points to this cset */
struct list_head threaded_csets;
struct list_head threaded_csets_node;
/*
* List running through all cgroup groups in the same hash
* slot. Protected by css_set_lock
*/
struct hlist_node hlist;
/*
* List of cgrp_cset_links pointing at cgroups referenced from this
* css_set. Protected by css_set_lock.
*/
struct list_head cgrp_links;
/*
* List of csets participating in the on-going migration either as
* source or destination. Protected by cgroup_mutex.
*/
struct list_head mg_preload_node;
struct list_head mg_node;
/*
* If this cset is acting as the source of migration the following
* two fields are set. mg_src_cgrp and mg_dst_cgrp are
* respectively the source and destination cgroups of the on-going
* migration. mg_dst_cset is the destination cset the target tasks
* on this cset should be migrated to. Protected by cgroup_mutex.
*/
struct cgroup *mg_src_cgrp;
struct cgroup *mg_dst_cgrp;
struct css_set *mg_dst_cset;
/* dead and being drained, ignore for migration */
bool dead
|