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Commit | Line | Data |
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c757249a SN |
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> | |
6f44993f | 21 | #include <linux/delayacct.h> |
f9fd8914 SN |
22 | #include <linux/cpumask.h> |
23 | #include <linux/percpu.h> | |
c757249a SN |
24 | #include <net/genetlink.h> |
25 | #include <asm/atomic.h> | |
26 | ||
f9fd8914 SN |
27 | /* |
28 | * Maximum length of a cpumask that can be specified in | |
29 | * the TASKSTATS_CMD_ATTR_REGISTER/DEREGISTER_CPUMASK attribute | |
30 | */ | |
31 | #define TASKSTATS_CPUMASK_MAXLEN (100+6*NR_CPUS) | |
32 | ||
c757249a SN |
33 | static DEFINE_PER_CPU(__u32, taskstats_seqnum) = { 0 }; |
34 | static int family_registered; | |
35 | kmem_cache_t *taskstats_cache; | |
c757249a SN |
36 | |
37 | static struct genl_family family = { | |
38 | .id = GENL_ID_GENERATE, | |
39 | .name = TASKSTATS_GENL_NAME, | |
40 | .version = TASKSTATS_GENL_VERSION, | |
41 | .maxattr = TASKSTATS_CMD_ATTR_MAX, | |
42 | }; | |
43 | ||
44 | static struct nla_policy taskstats_cmd_get_policy[TASKSTATS_CMD_ATTR_MAX+1] | |
45 | __read_mostly = { | |
46 | [TASKSTATS_CMD_ATTR_PID] = { .type = NLA_U32 }, | |
47 | [TASKSTATS_CMD_ATTR_TGID] = { .type = NLA_U32 }, | |
f9fd8914 SN |
48 | [TASKSTATS_CMD_ATTR_REGISTER_CPUMASK] = { .type = NLA_STRING }, |
49 | [TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK] = { .type = NLA_STRING },}; | |
50 | ||
51 | struct listener { | |
52 | struct list_head list; | |
53 | pid_t pid; | |
bb129994 | 54 | char valid; |
c757249a SN |
55 | }; |
56 | ||
f9fd8914 SN |
57 | struct listener_list { |
58 | struct rw_semaphore sem; | |
59 | struct list_head list; | |
60 | }; | |
61 | static DEFINE_PER_CPU(struct listener_list, listener_array); | |
62 | ||
63 | enum actions { | |
64 | REGISTER, | |
65 | DEREGISTER, | |
66 | CPU_DONT_CARE | |
67 | }; | |
c757249a SN |
68 | |
69 | static int prepare_reply(struct genl_info *info, u8 cmd, struct sk_buff **skbp, | |
70 | void **replyp, size_t size) | |
71 | { | |
72 | struct sk_buff *skb; | |
73 | void *reply; | |
74 | ||
75 | /* | |
76 | * If new attributes are added, please revisit this allocation | |
77 | */ | |
78 | skb = nlmsg_new(size); | |
79 | if (!skb) | |
80 | return -ENOMEM; | |
81 | ||
82 | if (!info) { | |
83 | int seq = get_cpu_var(taskstats_seqnum)++; | |
84 | put_cpu_var(taskstats_seqnum); | |
85 | ||
86 | reply = genlmsg_put(skb, 0, seq, | |
87 | family.id, 0, 0, | |
88 | cmd, family.version); | |
89 | } else | |
90 | reply = genlmsg_put(skb, info->snd_pid, info->snd_seq, | |
91 | family.id, 0, 0, | |
92 | cmd, family.version); | |
93 | if (reply == NULL) { | |
94 | nlmsg_free(skb); | |
95 | return -EINVAL; | |
96 | } | |
97 | ||
98 | *skbp = skb; | |
99 | *replyp = reply; | |
100 | return 0; | |
101 | } | |
102 | ||
f9fd8914 SN |
103 | /* |
104 | * Send taskstats data in @skb to listener with nl_pid @pid | |
105 | */ | |
106 | static int send_reply(struct sk_buff *skb, pid_t pid) | |
c757249a SN |
107 | { |
108 | struct genlmsghdr *genlhdr = nlmsg_data((struct nlmsghdr *)skb->data); | |
f9fd8914 | 109 | void *reply = genlmsg_data(genlhdr); |
c757249a SN |
110 | int rc; |
111 | ||
c757249a SN |
112 | rc = genlmsg_end(skb, reply); |
113 | if (rc < 0) { | |
114 | nlmsg_free(skb); | |
115 | return rc; | |
116 | } | |
117 | ||
c757249a SN |
118 | return genlmsg_unicast(skb, pid); |
119 | } | |
120 | ||
f9fd8914 SN |
121 | /* |
122 | * Send taskstats data in @skb to listeners registered for @cpu's exit data | |
123 | */ | |
124 | static int send_cpu_listeners(struct sk_buff *skb, unsigned int cpu) | |
125 | { | |
126 | struct genlmsghdr *genlhdr = nlmsg_data((struct nlmsghdr *)skb->data); | |
127 | struct listener_list *listeners; | |
128 | struct listener *s, *tmp; | |
129 | struct sk_buff *skb_next, *skb_cur = skb; | |
130 | void *reply = genlmsg_data(genlhdr); | |
bb129994 | 131 | int rc, ret, delcount = 0; |
f9fd8914 SN |
132 | |
133 | rc = genlmsg_end(skb, reply); | |
134 | if (rc < 0) { | |
135 | nlmsg_free(skb); | |
136 | return rc; | |
137 | } | |
138 | ||
139 | rc = 0; | |
140 | listeners = &per_cpu(listener_array, cpu); | |
bb129994 | 141 | down_read(&listeners->sem); |
f9fd8914 SN |
142 | list_for_each_entry_safe(s, tmp, &listeners->list, list) { |
143 | skb_next = NULL; | |
144 | if (!list_is_last(&s->list, &listeners->list)) { | |
145 | skb_next = skb_clone(skb_cur, GFP_KERNEL); | |
146 | if (!skb_next) { | |
147 | nlmsg_free(skb_cur); | |
148 | rc = -ENOMEM; | |
149 | break; | |
150 | } | |
151 | } | |
152 | ret = genlmsg_unicast(skb_cur, s->pid); | |
153 | if (ret == -ECONNREFUSED) { | |
bb129994 SN |
154 | s->valid = 0; |
155 | delcount++; | |
f9fd8914 SN |
156 | rc = ret; |
157 | } | |
158 | skb_cur = skb_next; | |
159 | } | |
bb129994 | 160 | up_read(&listeners->sem); |
f9fd8914 | 161 | |
bb129994 SN |
162 | if (!delcount) |
163 | return rc; | |
164 | ||
165 | /* Delete invalidated entries */ | |
166 | down_write(&listeners->sem); | |
167 | list_for_each_entry_safe(s, tmp, &listeners->list, list) { | |
168 | if (!s->valid) { | |
169 | list_del(&s->list); | |
170 | kfree(s); | |
171 | } | |
172 | } | |
173 | up_write(&listeners->sem); | |
f9fd8914 SN |
174 | return rc; |
175 | } | |
176 | ||
c757249a SN |
177 | static int fill_pid(pid_t pid, struct task_struct *pidtsk, |
178 | struct taskstats *stats) | |
179 | { | |
7d94dddd | 180 | int rc = 0; |
c757249a SN |
181 | struct task_struct *tsk = pidtsk; |
182 | ||
183 | if (!pidtsk) { | |
184 | read_lock(&tasklist_lock); | |
185 | tsk = find_task_by_pid(pid); | |
186 | if (!tsk) { | |
187 | read_unlock(&tasklist_lock); | |
188 | return -ESRCH; | |
189 | } | |
190 | get_task_struct(tsk); | |
191 | read_unlock(&tasklist_lock); | |
192 | } else | |
193 | get_task_struct(tsk); | |
194 | ||
195 | /* | |
196 | * Each accounting subsystem adds calls to its functions to | |
197 | * fill in relevant parts of struct taskstsats as follows | |
198 | * | |
7d94dddd | 199 | * per-task-foo(stats, tsk); |
c757249a SN |
200 | */ |
201 | ||
7d94dddd | 202 | delayacct_add_tsk(stats, tsk); |
6f44993f SN |
203 | stats->version = TASKSTATS_VERSION; |
204 | ||
205 | /* Define err: label here if needed */ | |
c757249a SN |
206 | put_task_struct(tsk); |
207 | return rc; | |
208 | ||
209 | } | |
210 | ||
211 | static int fill_tgid(pid_t tgid, struct task_struct *tgidtsk, | |
212 | struct taskstats *stats) | |
213 | { | |
c757249a | 214 | struct task_struct *tsk, *first; |
ad4ecbcb | 215 | unsigned long flags; |
c757249a | 216 | |
ad4ecbcb SN |
217 | /* |
218 | * Add additional stats from live tasks except zombie thread group | |
219 | * leaders who are already counted with the dead tasks | |
220 | */ | |
c757249a | 221 | first = tgidtsk; |
c757249a | 222 | if (!first) { |
ad4ecbcb | 223 | read_lock(&tasklist_lock); |
c757249a SN |
224 | first = find_task_by_pid(tgid); |
225 | if (!first) { | |
226 | read_unlock(&tasklist_lock); | |
227 | return -ESRCH; | |
228 | } | |
ad4ecbcb SN |
229 | get_task_struct(first); |
230 | read_unlock(&tasklist_lock); | |
231 | } else | |
232 | get_task_struct(first); | |
233 | ||
234 | /* Start with stats from dead tasks */ | |
235 | spin_lock_irqsave(&first->signal->stats_lock, flags); | |
236 | if (first->signal->stats) | |
237 | memcpy(stats, first->signal->stats, sizeof(*stats)); | |
238 | spin_unlock_irqrestore(&first->signal->stats_lock, flags); | |
239 | ||
c757249a | 240 | tsk = first; |
ad4ecbcb | 241 | read_lock(&tasklist_lock); |
c757249a | 242 | do { |
ad4ecbcb SN |
243 | if (tsk->exit_state == EXIT_ZOMBIE && thread_group_leader(tsk)) |
244 | continue; | |
c757249a | 245 | /* |
ad4ecbcb | 246 | * Accounting subsystem can call its functions here to |
c757249a SN |
247 | * fill in relevant parts of struct taskstsats as follows |
248 | * | |
ad4ecbcb | 249 | * per-task-foo(stats, tsk); |
c757249a | 250 | */ |
ad4ecbcb | 251 | delayacct_add_tsk(stats, tsk); |
6f44993f | 252 | |
c757249a SN |
253 | } while_each_thread(first, tsk); |
254 | read_unlock(&tasklist_lock); | |
6f44993f SN |
255 | stats->version = TASKSTATS_VERSION; |
256 | ||
c757249a | 257 | /* |
ad4ecbcb SN |
258 | * Accounting subsytems can also add calls here to modify |
259 | * fields of taskstats. | |
c757249a SN |
260 | */ |
261 | ||
ad4ecbcb SN |
262 | return 0; |
263 | } | |
264 | ||
265 | ||
266 | static void fill_tgid_exit(struct task_struct *tsk) | |
267 | { | |
268 | unsigned long flags; | |
269 | ||
270 | spin_lock_irqsave(&tsk->signal->stats_lock, flags); | |
271 | if (!tsk->signal->stats) | |
272 | goto ret; | |
273 | ||
274 | /* | |
275 | * Each accounting subsystem calls its functions here to | |
276 | * accumalate its per-task stats for tsk, into the per-tgid structure | |
277 | * | |
278 | * per-task-foo(tsk->signal->stats, tsk); | |
279 | */ | |
280 | delayacct_add_tsk(tsk->signal->stats, tsk); | |
281 | ret: | |
282 | spin_unlock_irqrestore(&tsk->signal->stats_lock, flags); | |
283 | return; | |
c757249a SN |
284 | } |
285 | ||
f9fd8914 SN |
286 | static int add_del_listener(pid_t pid, cpumask_t *maskp, int isadd) |
287 | { | |
288 | struct listener_list *listeners; | |
289 | struct listener *s, *tmp; | |
290 | unsigned int cpu; | |
291 | cpumask_t mask = *maskp; | |
ad4ecbcb | 292 | |
f9fd8914 SN |
293 | if (!cpus_subset(mask, cpu_possible_map)) |
294 | return -EINVAL; | |
295 | ||
296 | if (isadd == REGISTER) { | |
297 | for_each_cpu_mask(cpu, mask) { | |
298 | s = kmalloc_node(sizeof(struct listener), GFP_KERNEL, | |
299 | cpu_to_node(cpu)); | |
300 | if (!s) | |
301 | goto cleanup; | |
302 | s->pid = pid; | |
303 | INIT_LIST_HEAD(&s->list); | |
bb129994 | 304 | s->valid = 1; |
f9fd8914 SN |
305 | |
306 | listeners = &per_cpu(listener_array, cpu); | |
307 | down_write(&listeners->sem); | |
308 | list_add(&s->list, &listeners->list); | |
309 | up_write(&listeners->sem); | |
310 | } | |
311 | return 0; | |
312 | } | |
313 | ||
314 | /* Deregister or cleanup */ | |
315 | cleanup: | |
316 | for_each_cpu_mask(cpu, mask) { | |
317 | listeners = &per_cpu(listener_array, cpu); | |
318 | down_write(&listeners->sem); | |
319 | list_for_each_entry_safe(s, tmp, &listeners->list, list) { | |
320 | if (s->pid == pid) { | |
321 | list_del(&s->list); | |
322 | kfree(s); | |
323 | break; | |
324 | } | |
325 | } | |
326 | up_write(&listeners->sem); | |
327 | } | |
328 | return 0; | |
329 | } | |
330 | ||
331 | static int parse(struct nlattr *na, cpumask_t *mask) | |
332 | { | |
333 | char *data; | |
334 | int len; | |
335 | int ret; | |
336 | ||
337 | if (na == NULL) | |
338 | return 1; | |
339 | len = nla_len(na); | |
340 | if (len > TASKSTATS_CPUMASK_MAXLEN) | |
341 | return -E2BIG; | |
342 | if (len < 1) | |
343 | return -EINVAL; | |
344 | data = kmalloc(len, GFP_KERNEL); | |
345 | if (!data) | |
346 | return -ENOMEM; | |
347 | nla_strlcpy(data, na, len); | |
348 | ret = cpulist_parse(data, *mask); | |
349 | kfree(data); | |
350 | return ret; | |
351 | } | |
352 | ||
353 | static int taskstats_user_cmd(struct sk_buff *skb, struct genl_info *info) | |
c757249a SN |
354 | { |
355 | int rc = 0; | |
356 | struct sk_buff *rep_skb; | |
357 | struct taskstats stats; | |
358 | void *reply; | |
359 | size_t size; | |
360 | struct nlattr *na; | |
f9fd8914 SN |
361 | cpumask_t mask; |
362 | ||
363 | rc = parse(info->attrs[TASKSTATS_CMD_ATTR_REGISTER_CPUMASK], &mask); | |
364 | if (rc < 0) | |
365 | return rc; | |
366 | if (rc == 0) | |
367 | return add_del_listener(info->snd_pid, &mask, REGISTER); | |
368 | ||
369 | rc = parse(info->attrs[TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK], &mask); | |
370 | if (rc < 0) | |
371 | return rc; | |
372 | if (rc == 0) | |
373 | return add_del_listener(info->snd_pid, &mask, DEREGISTER); | |
c757249a SN |
374 | |
375 | /* | |
376 | * Size includes space for nested attributes | |
377 | */ | |
378 | size = nla_total_size(sizeof(u32)) + | |
379 | nla_total_size(sizeof(struct taskstats)) + nla_total_size(0); | |
380 | ||
381 | memset(&stats, 0, sizeof(stats)); | |
382 | rc = prepare_reply(info, TASKSTATS_CMD_NEW, &rep_skb, &reply, size); | |
383 | if (rc < 0) | |
384 | return rc; | |
385 | ||
386 | if (info->attrs[TASKSTATS_CMD_ATTR_PID]) { | |
387 | u32 pid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_PID]); | |
388 | rc = fill_pid(pid, NULL, &stats); | |
389 | if (rc < 0) | |
390 | goto err; | |
391 | ||
392 | na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_PID); | |
393 | NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_PID, pid); | |
394 | NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS, | |
395 | stats); | |
396 | } else if (info->attrs[TASKSTATS_CMD_ATTR_TGID]) { | |
397 | u32 tgid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_TGID]); | |
398 | rc = fill_tgid(tgid, NULL, &stats); | |
399 | if (rc < 0) | |
400 | goto err; | |
401 | ||
402 | na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_TGID); | |
403 | NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_TGID, tgid); | |
404 | NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS, | |
405 | stats); | |
406 | } else { | |
407 | rc = -EINVAL; | |
408 | goto err; | |
409 | } | |
410 | ||
411 | nla_nest_end(rep_skb, na); | |
412 | ||
f9fd8914 | 413 | return send_reply(rep_skb, info->snd_pid); |
c757249a SN |
414 | |
415 | nla_put_failure: | |
416 | return genlmsg_cancel(rep_skb, reply); | |
417 | err: | |
418 | nlmsg_free(rep_skb); | |
419 | return rc; | |
420 | } | |
421 | ||
f9fd8914 SN |
422 | void taskstats_exit_alloc(struct taskstats **ptidstats, unsigned int *mycpu) |
423 | { | |
424 | struct listener_list *listeners; | |
425 | struct taskstats *tmp; | |
426 | /* | |
427 | * This is the cpu on which the task is exiting currently and will | |
428 | * be the one for which the exit event is sent, even if the cpu | |
429 | * on which this function is running changes later. | |
430 | */ | |
431 | *mycpu = raw_smp_processor_id(); | |
432 | ||
433 | *ptidstats = NULL; | |
434 | tmp = kmem_cache_zalloc(taskstats_cache, SLAB_KERNEL); | |
435 | if (!tmp) | |
436 | return; | |
437 | ||
438 | listeners = &per_cpu(listener_array, *mycpu); | |
439 | down_read(&listeners->sem); | |
440 | if (!list_empty(&listeners->list)) { | |
441 | *ptidstats = tmp; | |
442 | tmp = NULL; | |
443 | } | |
444 | up_read(&listeners->sem); | |
445 | kfree(tmp); | |
446 | } | |
447 | ||
c757249a SN |
448 | /* Send pid data out on exit */ |
449 | void taskstats_exit_send(struct task_struct *tsk, struct taskstats *tidstats, | |
f9fd8914 | 450 | int group_dead, unsigned int mycpu) |
c757249a SN |
451 | { |
452 | int rc; | |
453 | struct sk_buff *rep_skb; | |
454 | void *reply; | |
455 | size_t size; | |
456 | int is_thread_group; | |
457 | struct nlattr *na; | |
ad4ecbcb | 458 | unsigned long flags; |
c757249a SN |
459 | |
460 | if (!family_registered || !tidstats) | |
461 | return; | |
462 | ||
ad4ecbcb SN |
463 | spin_lock_irqsave(&tsk->signal->stats_lock, flags); |
464 | is_thread_group = tsk->signal->stats ? 1 : 0; | |
465 | spin_unlock_irqrestore(&tsk->signal->stats_lock, flags); | |
c757249a | 466 | |
ad4ecbcb | 467 | rc = 0; |
c757249a SN |
468 | /* |
469 | * Size includes space for nested attributes | |
470 | */ | |
471 | size = nla_total_size(sizeof(u32)) + | |
472 | nla_total_size(sizeof(struct taskstats)) + nla_total_size(0); | |
473 | ||
474 | if (is_thread_group) | |
475 | size = 2 * size; /* PID + STATS + TGID + STATS */ | |
476 | ||
477 | rc = prepare_reply(NULL, TASKSTATS_CMD_NEW, &rep_skb, &reply, size); | |
478 | if (rc < 0) | |
479 | goto ret; | |
480 | ||
481 | rc = fill_pid(tsk->pid, tsk, tidstats); | |
482 | if (rc < 0) | |
483 | goto err_skb; | |
484 | ||
485 | na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_PID); | |
486 | NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_PID, (u32)tsk->pid); | |
487 | NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS, | |
488 | *tidstats); | |
489 | nla_nest_end(rep_skb, na); | |
490 | ||
ad4ecbcb SN |
491 | if (!is_thread_group) |
492 | goto send; | |
c757249a | 493 | |
c757249a | 494 | /* |
ad4ecbcb SN |
495 | * tsk has/had a thread group so fill the tsk->signal->stats structure |
496 | * Doesn't matter if tsk is the leader or the last group member leaving | |
c757249a | 497 | */ |
ad4ecbcb SN |
498 | |
499 | fill_tgid_exit(tsk); | |
500 | if (!group_dead) | |
501 | goto send; | |
c757249a SN |
502 | |
503 | na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_TGID); | |
504 | NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_TGID, (u32)tsk->tgid); | |
ad4ecbcb | 505 | /* No locking needed for tsk->signal->stats since group is dead */ |
c757249a | 506 | NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS, |
ad4ecbcb | 507 | *tsk->signal->stats); |
c757249a SN |
508 | nla_nest_end(rep_skb, na); |
509 | ||
ad4ecbcb | 510 | send: |
f9fd8914 | 511 | send_cpu_listeners(rep_skb, mycpu); |
ad4ecbcb | 512 | return; |
c757249a SN |
513 | |
514 | nla_put_failure: | |
515 | genlmsg_cancel(rep_skb, reply); | |
516 | goto ret; | |
517 | err_skb: | |
518 | nlmsg_free(rep_skb); | |
519 | ret: | |
c757249a SN |
520 | return; |
521 | } | |
522 | ||
523 | static struct genl_ops taskstats_ops = { | |
524 | .cmd = TASKSTATS_CMD_GET, | |
f9fd8914 | 525 | .doit = taskstats_user_cmd, |
c757249a SN |
526 | .policy = taskstats_cmd_get_policy, |
527 | }; | |
528 | ||
529 | /* Needed early in initialization */ | |
530 | void __init taskstats_init_early(void) | |
531 | { | |
f9fd8914 SN |
532 | unsigned int i; |
533 | ||
c757249a SN |
534 | taskstats_cache = kmem_cache_create("taskstats_cache", |
535 | sizeof(struct taskstats), | |
536 | 0, SLAB_PANIC, NULL, NULL); | |
f9fd8914 SN |
537 | for_each_possible_cpu(i) { |
538 | INIT_LIST_HEAD(&(per_cpu(listener_array, i).list)); | |
539 | init_rwsem(&(per_cpu(listener_array, i).sem)); | |
540 | } | |
c757249a SN |
541 | } |
542 | ||
543 | static int __init taskstats_init(void) | |
544 | { | |
545 | int rc; | |
546 | ||
547 | rc = genl_register_family(&family); | |
548 | if (rc) | |
549 | return rc; | |
550 | ||
551 | rc = genl_register_ops(&family, &taskstats_ops); | |
552 | if (rc < 0) | |
553 | goto err; | |
554 | ||
555 | family_registered = 1; | |
556 | return 0; | |
557 | err: | |
558 | genl_unregister_family(&family); | |
559 | return rc; | |
560 | } | |
561 | ||
562 | /* | |
563 | * late initcall ensures initialization of statistics collection | |
564 | * mechanisms precedes initialization of the taskstats interface | |
565 | */ | |
566 | late_initcall(taskstats_init); |