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1 | /* | |
2 | * taskstats.c - Export per-task statistics to userland | |
3 | * | |
4 | * Copyright (C) Shailabh Nagar, IBM Corp. 2006 | |
5 | * (C) Balbir Singh, IBM Corp. 2006 | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License as published by | |
9 | * the Free Software Foundation; either version 2 of the License, or | |
10 | * (at your option) any later version. | |
11 | * | |
12 | * This program is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | * GNU General Public License for more details. | |
16 | * | |
17 | */ | |
18 | ||
19 | #include <linux/kernel.h> | |
20 | #include <linux/taskstats_kern.h> | |
21 | #include <linux/tsacct_kern.h> | |
22 | #include <linux/delayacct.h> | |
23 | #include <linux/cpumask.h> | |
24 | #include <linux/percpu.h> | |
25 | #include <linux/cgroupstats.h> | |
26 | #include <linux/cgroup.h> | |
27 | #include <linux/fs.h> | |
28 | #include <linux/file.h> | |
29 | #include <net/genetlink.h> | |
30 | #include <asm/atomic.h> | |
31 | ||
32 | /* | |
33 | * Maximum length of a cpumask that can be specified in | |
34 | * the TASKSTATS_CMD_ATTR_REGISTER/DEREGISTER_CPUMASK attribute | |
35 | */ | |
36 | #define TASKSTATS_CPUMASK_MAXLEN (100+6*NR_CPUS) | |
37 | ||
38 | static DEFINE_PER_CPU(__u32, taskstats_seqnum); | |
39 | static int family_registered; | |
40 | struct kmem_cache *taskstats_cache; | |
41 | ||
42 | static struct genl_family family = { | |
43 | .id = GENL_ID_GENERATE, | |
44 | .name = TASKSTATS_GENL_NAME, | |
45 | .version = TASKSTATS_GENL_VERSION, | |
46 | .maxattr = TASKSTATS_CMD_ATTR_MAX, | |
47 | }; | |
48 | ||
49 | static struct nla_policy taskstats_cmd_get_policy[TASKSTATS_CMD_ATTR_MAX+1] | |
50 | __read_mostly = { | |
51 | [TASKSTATS_CMD_ATTR_PID] = { .type = NLA_U32 }, | |
52 | [TASKSTATS_CMD_ATTR_TGID] = { .type = NLA_U32 }, | |
53 | [TASKSTATS_CMD_ATTR_REGISTER_CPUMASK] = { .type = NLA_STRING }, | |
54 | [TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK] = { .type = NLA_STRING },}; | |
55 | ||
56 | static struct nla_policy | |
57 | cgroupstats_cmd_get_policy[CGROUPSTATS_CMD_ATTR_MAX+1] __read_mostly = { | |
58 | [CGROUPSTATS_CMD_ATTR_FD] = { .type = NLA_U32 }, | |
59 | }; | |
60 | ||
61 | struct listener { | |
62 | struct list_head list; | |
63 | pid_t pid; | |
64 | char valid; | |
65 | }; | |
66 | ||
67 | struct listener_list { | |
68 | struct rw_semaphore sem; | |
69 | struct list_head list; | |
70 | }; | |
71 | static DEFINE_PER_CPU(struct listener_list, listener_array); | |
72 | ||
73 | enum actions { | |
74 | REGISTER, | |
75 | DEREGISTER, | |
76 | CPU_DONT_CARE | |
77 | }; | |
78 | ||
79 | static int prepare_reply(struct genl_info *info, u8 cmd, struct sk_buff **skbp, | |
80 | size_t size) | |
81 | { | |
82 | struct sk_buff *skb; | |
83 | void *reply; | |
84 | ||
85 | /* | |
86 | * If new attributes are added, please revisit this allocation | |
87 | */ | |
88 | skb = genlmsg_new(size, GFP_KERNEL); | |
89 | if (!skb) | |
90 | return -ENOMEM; | |
91 | ||
92 | if (!info) { | |
93 | int seq = get_cpu_var(taskstats_seqnum)++; | |
94 | put_cpu_var(taskstats_seqnum); | |
95 | ||
96 | reply = genlmsg_put(skb, 0, seq, &family, 0, cmd); | |
97 | } else | |
98 | reply = genlmsg_put_reply(skb, info, &family, 0, cmd); | |
99 | if (reply == NULL) { | |
100 | nlmsg_free(skb); | |
101 | return -EINVAL; | |
102 | } | |
103 | ||
104 | *skbp = skb; | |
105 | return 0; | |
106 | } | |
107 | ||
108 | /* | |
109 | * Send taskstats data in @skb to listener with nl_pid @pid | |
110 | */ | |
111 | static int send_reply(struct sk_buff *skb, struct genl_info *info) | |
112 | { | |
113 | struct genlmsghdr *genlhdr = nlmsg_data(nlmsg_hdr(skb)); | |
114 | void *reply = genlmsg_data(genlhdr); | |
115 | int rc; | |
116 | ||
117 | rc = genlmsg_end(skb, reply); | |
118 | if (rc < 0) { | |
119 | nlmsg_free(skb); | |
120 | return rc; | |
121 | } | |
122 | ||
123 | return genlmsg_reply(skb, info); | |
124 | } | |
125 | ||
126 | /* | |
127 | * Send taskstats data in @skb to listeners registered for @cpu's exit data | |
128 | */ | |
129 | static void send_cpu_listeners(struct sk_buff *skb, | |
130 | struct listener_list *listeners) | |
131 | { | |
132 | struct genlmsghdr *genlhdr = nlmsg_data(nlmsg_hdr(skb)); | |
133 | struct listener *s, *tmp; | |
134 | struct sk_buff *skb_next, *skb_cur = skb; | |
135 | void *reply = genlmsg_data(genlhdr); | |
136 | int rc, delcount = 0; | |
137 | ||
138 | rc = genlmsg_end(skb, reply); | |
139 | if (rc < 0) { | |
140 | nlmsg_free(skb); | |
141 | return; | |
142 | } | |
143 | ||
144 | rc = 0; | |
145 | down_read(&listeners->sem); | |
146 | list_for_each_entry(s, &listeners->list, list) { | |
147 | skb_next = NULL; | |
148 | if (!list_is_last(&s->list, &listeners->list)) { | |
149 | skb_next = skb_clone(skb_cur, GFP_KERNEL); | |
150 | if (!skb_next) | |
151 | break; | |
152 | } | |
153 | rc = genlmsg_unicast(&init_net, skb_cur, s->pid); | |
154 | if (rc == -ECONNREFUSED) { | |
155 | s->valid = 0; | |
156 | delcount++; | |
157 | } | |
158 | skb_cur = skb_next; | |
159 | } | |
160 | up_read(&listeners->sem); | |
161 | ||
162 | if (skb_cur) | |
163 | nlmsg_free(skb_cur); | |
164 | ||
165 | if (!delcount) | |
166 | return; | |
167 | ||
168 | /* Delete invalidated entries */ | |
169 | down_write(&listeners->sem); | |
170 | list_for_each_entry_safe(s, tmp, &listeners->list, list) { | |
171 | if (!s->valid) { | |
172 | list_del(&s->list); | |
173 | kfree(s); | |
174 | } | |
175 | } | |
176 | up_write(&listeners->sem); | |
177 | } | |
178 | ||
179 | static int fill_pid(pid_t pid, struct task_struct *tsk, | |
180 | struct taskstats *stats) | |
181 | { | |
182 | int rc = 0; | |
183 | ||
184 | if (!tsk) { | |
185 | rcu_read_lock(); | |
186 | tsk = find_task_by_vpid(pid); | |
187 | if (tsk) | |
188 | get_task_struct(tsk); | |
189 | rcu_read_unlock(); | |
190 | if (!tsk) | |
191 | return -ESRCH; | |
192 | } else | |
193 | get_task_struct(tsk); | |
194 | ||
195 | memset(stats, 0, sizeof(*stats)); | |
196 | /* | |
197 | * Each accounting subsystem adds calls to its functions to | |
198 | * fill in relevant parts of struct taskstsats as follows | |
199 | * | |
200 | * per-task-foo(stats, tsk); | |
201 | */ | |
202 | ||
203 | delayacct_add_tsk(stats, tsk); | |
204 | ||
205 | /* fill in basic acct fields */ | |
206 | stats->version = TASKSTATS_VERSION; | |
207 | stats->nvcsw = tsk->nvcsw; | |
208 | stats->nivcsw = tsk->nivcsw; | |
209 | bacct_add_tsk(stats, tsk); | |
210 | ||
211 | /* fill in extended acct fields */ | |
212 | xacct_add_tsk(stats, tsk); | |
213 | ||
214 | /* Define err: label here if needed */ | |
215 | put_task_struct(tsk); | |
216 | return rc; | |
217 | ||
218 | } | |
219 | ||
220 | static int fill_tgid(pid_t tgid, struct task_struct *first, | |
221 | struct taskstats *stats) | |
222 | { | |
223 | struct task_struct *tsk; | |
224 | unsigned long flags; | |
225 | int rc = -ESRCH; | |
226 | ||
227 | /* | |
228 | * Add additional stats from live tasks except zombie thread group | |
229 | * leaders who are already counted with the dead tasks | |
230 | */ | |
231 | rcu_read_lock(); | |
232 | if (!first) | |
233 | first = find_task_by_vpid(tgid); | |
234 | ||
235 | if (!first || !lock_task_sighand(first, &flags)) | |
236 | goto out; | |
237 | ||
238 | if (first->signal->stats) | |
239 | memcpy(stats, first->signal->stats, sizeof(*stats)); | |
240 | else | |
241 | memset(stats, 0, sizeof(*stats)); | |
242 | ||
243 | tsk = first; | |
244 | do { | |
245 | if (tsk->exit_state) | |
246 | continue; | |
247 | /* | |
248 | * Accounting subsystem can call its functions here to | |
249 | * fill in relevant parts of struct taskstsats as follows | |
250 | * | |
251 | * per-task-foo(stats, tsk); | |
252 | */ | |
253 | delayacct_add_tsk(stats, tsk); | |
254 | ||
255 | stats->nvcsw += tsk->nvcsw; | |
256 | stats->nivcsw += tsk->nivcsw; | |
257 | } while_each_thread(first, tsk); | |
258 | ||
259 | unlock_task_sighand(first, &flags); | |
260 | rc = 0; | |
261 | out: | |
262 | rcu_read_unlock(); | |
263 | ||
264 | stats->version = TASKSTATS_VERSION; | |
265 | /* | |
266 | * Accounting subsystems can also add calls here to modify | |
267 | * fields of taskstats. | |
268 | */ | |
269 | return rc; | |
270 | } | |
271 | ||
272 | ||
273 | static void fill_tgid_exit(struct task_struct *tsk) | |
274 | { | |
275 | unsigned long flags; | |
276 | ||
277 | spin_lock_irqsave(&tsk->sighand->siglock, flags); | |
278 | if (!tsk->signal->stats) | |
279 | goto ret; | |
280 | ||
281 | /* | |
282 | * Each accounting subsystem calls its functions here to | |
283 | * accumalate its per-task stats for tsk, into the per-tgid structure | |
284 | * | |
285 | * per-task-foo(tsk->signal->stats, tsk); | |
286 | */ | |
287 | delayacct_add_tsk(tsk->signal->stats, tsk); | |
288 | ret: | |
289 | spin_unlock_irqrestore(&tsk->sighand->siglock, flags); | |
290 | return; | |
291 | } | |
292 | ||
293 | static int add_del_listener(pid_t pid, const struct cpumask *mask, int isadd) | |
294 | { | |
295 | struct listener_list *listeners; | |
296 | struct listener *s, *tmp; | |
297 | unsigned int cpu; | |
298 | ||
299 | if (!cpumask_subset(mask, cpu_possible_mask)) | |
300 | return -EINVAL; | |
301 | ||
302 | if (isadd == REGISTER) { | |
303 | for_each_cpu(cpu, mask) { | |
304 | s = kmalloc_node(sizeof(struct listener), GFP_KERNEL, | |
305 | cpu_to_node(cpu)); | |
306 | if (!s) | |
307 | goto cleanup; | |
308 | s->pid = pid; | |
309 | INIT_LIST_HEAD(&s->list); | |
310 | s->valid = 1; | |
311 | ||
312 | listeners = &per_cpu(listener_array, cpu); | |
313 | down_write(&listeners->sem); | |
314 | list_add(&s->list, &listeners->list); | |
315 | up_write(&listeners->sem); | |
316 | } | |
317 | return 0; | |
318 | } | |
319 | ||
320 | /* Deregister or cleanup */ | |
321 | cleanup: | |
322 | for_each_cpu(cpu, mask) { | |
323 | listeners = &per_cpu(listener_array, cpu); | |
324 | down_write(&listeners->sem); | |
325 | list_for_each_entry_safe(s, tmp, &listeners->list, list) { | |
326 | if (s->pid == pid) { | |
327 | list_del(&s->list); | |
328 | kfree(s); | |
329 | break; | |
330 | } | |
331 | } | |
332 | up_write(&listeners->sem); | |
333 | } | |
334 | return 0; | |
335 | } | |
336 | ||
337 | static int parse(struct nlattr *na, struct cpumask *mask) | |
338 | { | |
339 | char *data; | |
340 | int len; | |
341 | int ret; | |
342 | ||
343 | if (na == NULL) | |
344 | return 1; | |
345 | len = nla_len(na); | |
346 | if (len > TASKSTATS_CPUMASK_MAXLEN) | |
347 | return -E2BIG; | |
348 | if (len < 1) | |
349 | return -EINVAL; | |
350 | data = kmalloc(len, GFP_KERNEL); | |
351 | if (!data) | |
352 | return -ENOMEM; | |
353 | nla_strlcpy(data, na, len); | |
354 | ret = cpulist_parse(data, mask); | |
355 | kfree(data); | |
356 | return ret; | |
357 | } | |
358 | ||
359 | static struct taskstats *mk_reply(struct sk_buff *skb, int type, u32 pid) | |
360 | { | |
361 | struct nlattr *na, *ret; | |
362 | int aggr; | |
363 | ||
364 | aggr = (type == TASKSTATS_TYPE_PID) | |
365 | ? TASKSTATS_TYPE_AGGR_PID | |
366 | : TASKSTATS_TYPE_AGGR_TGID; | |
367 | ||
368 | na = nla_nest_start(skb, aggr); | |
369 | if (!na) | |
370 | goto err; | |
371 | if (nla_put(skb, type, sizeof(pid), &pid) < 0) | |
372 | goto err; | |
373 | ret = nla_reserve(skb, TASKSTATS_TYPE_STATS, sizeof(struct taskstats)); | |
374 | if (!ret) | |
375 | goto err; | |
376 | nla_nest_end(skb, na); | |
377 | ||
378 | return nla_data(ret); | |
379 | err: | |
380 | return NULL; | |
381 | } | |
382 | ||
383 | static int cgroupstats_user_cmd(struct sk_buff *skb, struct genl_info *info) | |
384 | { | |
385 | int rc = 0; | |
386 | struct sk_buff *rep_skb; | |
387 | struct cgroupstats *stats; | |
388 | struct nlattr *na; | |
389 | size_t size; | |
390 | u32 fd; | |
391 | struct file *file; | |
392 | int fput_needed; | |
393 | ||
394 | na = info->attrs[CGROUPSTATS_CMD_ATTR_FD]; | |
395 | if (!na) | |
396 | return -EINVAL; | |
397 | ||
398 | fd = nla_get_u32(info->attrs[CGROUPSTATS_CMD_ATTR_FD]); | |
399 | file = fget_light(fd, &fput_needed); | |
400 | if (!file) | |
401 | return 0; | |
402 | ||
403 | size = nla_total_size(sizeof(struct cgroupstats)); | |
404 | ||
405 | rc = prepare_reply(info, CGROUPSTATS_CMD_NEW, &rep_skb, | |
406 | size); | |
407 | if (rc < 0) | |
408 | goto err; | |
409 | ||
410 | na = nla_reserve(rep_skb, CGROUPSTATS_TYPE_CGROUP_STATS, | |
411 | sizeof(struct cgroupstats)); | |
412 | stats = nla_data(na); | |
413 | memset(stats, 0, sizeof(*stats)); | |
414 | ||
415 | rc = cgroupstats_build(stats, file->f_dentry); | |
416 | if (rc < 0) { | |
417 | nlmsg_free(rep_skb); | |
418 | goto err; | |
419 | } | |
420 | ||
421 | rc = send_reply(rep_skb, info); | |
422 | ||
423 | err: | |
424 | fput_light(file, fput_needed); | |
425 | return rc; | |
426 | } | |
427 | ||
428 | static int taskstats_user_cmd(struct sk_buff *skb, struct genl_info *info) | |
429 | { | |
430 | int rc; | |
431 | struct sk_buff *rep_skb; | |
432 | struct taskstats *stats; | |
433 | size_t size; | |
434 | cpumask_var_t mask; | |
435 | ||
436 | if (!alloc_cpumask_var(&mask, GFP_KERNEL)) | |
437 | return -ENOMEM; | |
438 | ||
439 | rc = parse(info->attrs[TASKSTATS_CMD_ATTR_REGISTER_CPUMASK], mask); | |
440 | if (rc < 0) | |
441 | goto free_return_rc; | |
442 | if (rc == 0) { | |
443 | rc = add_del_listener(info->snd_pid, mask, REGISTER); | |
444 | goto free_return_rc; | |
445 | } | |
446 | ||
447 | rc = parse(info->attrs[TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK], mask); | |
448 | if (rc < 0) | |
449 | goto free_return_rc; | |
450 | if (rc == 0) { | |
451 | rc = add_del_listener(info->snd_pid, mask, DEREGISTER); | |
452 | free_return_rc: | |
453 | free_cpumask_var(mask); | |
454 | return rc; | |
455 | } | |
456 | free_cpumask_var(mask); | |
457 | ||
458 | /* | |
459 | * Size includes space for nested attributes | |
460 | */ | |
461 | size = nla_total_size(sizeof(u32)) + | |
462 | nla_total_size(sizeof(struct taskstats)) + nla_total_size(0); | |
463 | ||
464 | rc = prepare_reply(info, TASKSTATS_CMD_NEW, &rep_skb, size); | |
465 | if (rc < 0) | |
466 | return rc; | |
467 | ||
468 | rc = -EINVAL; | |
469 | if (info->attrs[TASKSTATS_CMD_ATTR_PID]) { | |
470 | u32 pid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_PID]); | |
471 | stats = mk_reply(rep_skb, TASKSTATS_TYPE_PID, pid); | |
472 | if (!stats) | |
473 | goto err; | |
474 | ||
475 | rc = fill_pid(pid, NULL, stats); | |
476 | if (rc < 0) | |
477 | goto err; | |
478 | } else if (info->attrs[TASKSTATS_CMD_ATTR_TGID]) { | |
479 | u32 tgid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_TGID]); | |
480 | stats = mk_reply(rep_skb, TASKSTATS_TYPE_TGID, tgid); | |
481 | if (!stats) | |
482 | goto err; | |
483 | ||
484 | rc = fill_tgid(tgid, NULL, stats); | |
485 | if (rc < 0) | |
486 | goto err; | |
487 | } else | |
488 | goto err; | |
489 | ||
490 | return send_reply(rep_skb, info); | |
491 | err: | |
492 | nlmsg_free(rep_skb); | |
493 | return rc; | |
494 | } | |
495 | ||
496 | static struct taskstats *taskstats_tgid_alloc(struct task_struct *tsk) | |
497 | { | |
498 | struct signal_struct *sig = tsk->signal; | |
499 | struct taskstats *stats; | |
500 | ||
501 | if (sig->stats || thread_group_empty(tsk)) | |
502 | goto ret; | |
503 | ||
504 | /* No problem if kmem_cache_zalloc() fails */ | |
505 | stats = kmem_cache_zalloc(taskstats_cache, GFP_KERNEL); | |
506 | ||
507 | spin_lock_irq(&tsk->sighand->siglock); | |
508 | if (!sig->stats) { | |
509 | sig->stats = stats; | |
510 | stats = NULL; | |
511 | } | |
512 | spin_unlock_irq(&tsk->sighand->siglock); | |
513 | ||
514 | if (stats) | |
515 | kmem_cache_free(taskstats_cache, stats); | |
516 | ret: | |
517 | return sig->stats; | |
518 | } | |
519 | ||
520 | /* Send pid data out on exit */ | |
521 | void taskstats_exit(struct task_struct *tsk, int group_dead) | |
522 | { | |
523 | int rc; | |
524 | struct listener_list *listeners; | |
525 | struct taskstats *stats; | |
526 | struct sk_buff *rep_skb; | |
527 | size_t size; | |
528 | int is_thread_group; | |
529 | ||
530 | if (!family_registered) | |
531 | return; | |
532 | ||
533 | /* | |
534 | * Size includes space for nested attributes | |
535 | */ | |
536 | size = nla_total_size(sizeof(u32)) + | |
537 | nla_total_size(sizeof(struct taskstats)) + nla_total_size(0); | |
538 | ||
539 | is_thread_group = !!taskstats_tgid_alloc(tsk); | |
540 | if (is_thread_group) { | |
541 | /* PID + STATS + TGID + STATS */ | |
542 | size = 2 * size; | |
543 | /* fill the tsk->signal->stats structure */ | |
544 | fill_tgid_exit(tsk); | |
545 | } | |
546 | ||
547 | listeners = &__raw_get_cpu_var(listener_array); | |
548 | if (list_empty(&listeners->list)) | |
549 | return; | |
550 | ||
551 | rc = prepare_reply(NULL, TASKSTATS_CMD_NEW, &rep_skb, size); | |
552 | if (rc < 0) | |
553 | return; | |
554 | ||
555 | stats = mk_reply(rep_skb, TASKSTATS_TYPE_PID, tsk->pid); | |
556 | if (!stats) | |
557 | goto err; | |
558 | ||
559 | rc = fill_pid(-1, tsk, stats); | |
560 | if (rc < 0) | |
561 | goto err; | |
562 | ||
563 | /* | |
564 | * Doesn't matter if tsk is the leader or the last group member leaving | |
565 | */ | |
566 | if (!is_thread_group || !group_dead) | |
567 | goto send; | |
568 | ||
569 | stats = mk_reply(rep_skb, TASKSTATS_TYPE_TGID, tsk->tgid); | |
570 | if (!stats) | |
571 | goto err; | |
572 | ||
573 | memcpy(stats, tsk->signal->stats, sizeof(*stats)); | |
574 | ||
575 | send: | |
576 | send_cpu_listeners(rep_skb, listeners); | |
577 | return; | |
578 | err: | |
579 | nlmsg_free(rep_skb); | |
580 | } | |
581 | ||
582 | static struct genl_ops taskstats_ops = { | |
583 | .cmd = TASKSTATS_CMD_GET, | |
584 | .doit = taskstats_user_cmd, | |
585 | .policy = taskstats_cmd_get_policy, | |
586 | }; | |
587 | ||
588 | static struct genl_ops cgroupstats_ops = { | |
589 | .cmd = CGROUPSTATS_CMD_GET, | |
590 | .doit = cgroupstats_user_cmd, | |
591 | .policy = cgroupstats_cmd_get_policy, | |
592 | }; | |
593 | ||
594 | /* Needed early in initialization */ | |
595 | void __init taskstats_init_early(void) | |
596 | { | |
597 | unsigned int i; | |
598 | ||
599 | taskstats_cache = KMEM_CACHE(taskstats, SLAB_PANIC); | |
600 | for_each_possible_cpu(i) { | |
601 | INIT_LIST_HEAD(&(per_cpu(listener_array, i).list)); | |
602 | init_rwsem(&(per_cpu(listener_array, i).sem)); | |
603 | } | |
604 | } | |
605 | ||
606 | static int __init taskstats_init(void) | |
607 | { | |
608 | int rc; | |
609 | ||
610 | rc = genl_register_family(&family); | |
611 | if (rc) | |
612 | return rc; | |
613 | ||
614 | rc = genl_register_ops(&family, &taskstats_ops); | |
615 | if (rc < 0) | |
616 | goto err; | |
617 | ||
618 | rc = genl_register_ops(&family, &cgroupstats_ops); | |
619 | if (rc < 0) | |
620 | goto err_cgroup_ops; | |
621 | ||
622 | family_registered = 1; | |
623 | printk("registered taskstats version %d\n", TASKSTATS_GENL_VERSION); | |
624 | return 0; | |
625 | err_cgroup_ops: | |
626 | genl_unregister_ops(&family, &taskstats_ops); | |
627 | err: | |
628 | genl_unregister_family(&family); | |
629 | return rc; | |
630 | } | |
631 | ||
632 | /* | |
633 | * late initcall ensures initialization of statistics collection | |
634 | * mechanisms precedes initialization of the taskstats interface | |
635 | */ | |
636 | late_initcall(taskstats_init); |