Commit | Line | Data |
---|---|---|
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> | |
f3cef7a9 | 21 | #include <linux/tsacct_kern.h> |
6f44993f | 22 | #include <linux/delayacct.h> |
9acc1853 | 23 | #include <linux/tsacct_kern.h> |
f9fd8914 SN |
24 | #include <linux/cpumask.h> |
25 | #include <linux/percpu.h> | |
c757249a SN |
26 | #include <net/genetlink.h> |
27 | #include <asm/atomic.h> | |
28 | ||
f9fd8914 SN |
29 | /* |
30 | * Maximum length of a cpumask that can be specified in | |
31 | * the TASKSTATS_CMD_ATTR_REGISTER/DEREGISTER_CPUMASK attribute | |
32 | */ | |
33 | #define TASKSTATS_CPUMASK_MAXLEN (100+6*NR_CPUS) | |
34 | ||
c757249a SN |
35 | static DEFINE_PER_CPU(__u32, taskstats_seqnum) = { 0 }; |
36 | static int family_registered; | |
37 | kmem_cache_t *taskstats_cache; | |
c757249a SN |
38 | |
39 | static struct genl_family family = { | |
40 | .id = GENL_ID_GENERATE, | |
41 | .name = TASKSTATS_GENL_NAME, | |
42 | .version = TASKSTATS_GENL_VERSION, | |
43 | .maxattr = TASKSTATS_CMD_ATTR_MAX, | |
44 | }; | |
45 | ||
46 | static struct nla_policy taskstats_cmd_get_policy[TASKSTATS_CMD_ATTR_MAX+1] | |
47 | __read_mostly = { | |
48 | [TASKSTATS_CMD_ATTR_PID] = { .type = NLA_U32 }, | |
49 | [TASKSTATS_CMD_ATTR_TGID] = { .type = NLA_U32 }, | |
f9fd8914 SN |
50 | [TASKSTATS_CMD_ATTR_REGISTER_CPUMASK] = { .type = NLA_STRING }, |
51 | [TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK] = { .type = NLA_STRING },}; | |
52 | ||
53 | struct listener { | |
54 | struct list_head list; | |
55 | pid_t pid; | |
bb129994 | 56 | char valid; |
c757249a SN |
57 | }; |
58 | ||
f9fd8914 SN |
59 | struct listener_list { |
60 | struct rw_semaphore sem; | |
61 | struct list_head list; | |
62 | }; | |
63 | static DEFINE_PER_CPU(struct listener_list, listener_array); | |
64 | ||
65 | enum actions { | |
66 | REGISTER, | |
67 | DEREGISTER, | |
68 | CPU_DONT_CARE | |
69 | }; | |
c757249a SN |
70 | |
71 | static int prepare_reply(struct genl_info *info, u8 cmd, struct sk_buff **skbp, | |
72 | void **replyp, size_t size) | |
73 | { | |
74 | struct sk_buff *skb; | |
75 | void *reply; | |
76 | ||
77 | /* | |
78 | * If new attributes are added, please revisit this allocation | |
79 | */ | |
3d8334de ON |
80 | size = nlmsg_total_size(genlmsg_total_size(size)); |
81 | skb = nlmsg_new(size, GFP_KERNEL); | |
c757249a SN |
82 | if (!skb) |
83 | return -ENOMEM; | |
84 | ||
85 | if (!info) { | |
86 | int seq = get_cpu_var(taskstats_seqnum)++; | |
87 | put_cpu_var(taskstats_seqnum); | |
88 | ||
89 | reply = genlmsg_put(skb, 0, seq, | |
90 | family.id, 0, 0, | |
91 | cmd, family.version); | |
92 | } else | |
93 | reply = genlmsg_put(skb, info->snd_pid, info->snd_seq, | |
94 | family.id, 0, 0, | |
95 | cmd, family.version); | |
96 | if (reply == NULL) { | |
97 | nlmsg_free(skb); | |
98 | return -EINVAL; | |
99 | } | |
100 | ||
101 | *skbp = skb; | |
102 | *replyp = reply; | |
103 | return 0; | |
104 | } | |
105 | ||
f9fd8914 SN |
106 | /* |
107 | * Send taskstats data in @skb to listener with nl_pid @pid | |
108 | */ | |
109 | static int send_reply(struct sk_buff *skb, pid_t pid) | |
c757249a SN |
110 | { |
111 | struct genlmsghdr *genlhdr = nlmsg_data((struct nlmsghdr *)skb->data); | |
f9fd8914 | 112 | void *reply = genlmsg_data(genlhdr); |
c757249a SN |
113 | int rc; |
114 | ||
c757249a SN |
115 | rc = genlmsg_end(skb, reply); |
116 | if (rc < 0) { | |
117 | nlmsg_free(skb); | |
118 | return rc; | |
119 | } | |
120 | ||
c757249a SN |
121 | return genlmsg_unicast(skb, pid); |
122 | } | |
123 | ||
f9fd8914 SN |
124 | /* |
125 | * Send taskstats data in @skb to listeners registered for @cpu's exit data | |
126 | */ | |
d94a0415 | 127 | static void send_cpu_listeners(struct sk_buff *skb, unsigned int cpu) |
f9fd8914 SN |
128 | { |
129 | struct genlmsghdr *genlhdr = nlmsg_data((struct nlmsghdr *)skb->data); | |
130 | struct listener_list *listeners; | |
131 | struct listener *s, *tmp; | |
132 | struct sk_buff *skb_next, *skb_cur = skb; | |
133 | void *reply = genlmsg_data(genlhdr); | |
d94a0415 | 134 | int rc, delcount = 0; |
f9fd8914 SN |
135 | |
136 | rc = genlmsg_end(skb, reply); | |
137 | if (rc < 0) { | |
138 | nlmsg_free(skb); | |
d94a0415 | 139 | return; |
f9fd8914 SN |
140 | } |
141 | ||
142 | rc = 0; | |
143 | listeners = &per_cpu(listener_array, cpu); | |
bb129994 | 144 | down_read(&listeners->sem); |
d94a0415 | 145 | list_for_each_entry(s, &listeners->list, list) { |
f9fd8914 SN |
146 | skb_next = NULL; |
147 | if (!list_is_last(&s->list, &listeners->list)) { | |
148 | skb_next = skb_clone(skb_cur, GFP_KERNEL); | |
d94a0415 | 149 | if (!skb_next) |
f9fd8914 | 150 | break; |
f9fd8914 | 151 | } |
d94a0415 SN |
152 | rc = genlmsg_unicast(skb_cur, s->pid); |
153 | if (rc == -ECONNREFUSED) { | |
bb129994 SN |
154 | s->valid = 0; |
155 | delcount++; | |
f9fd8914 SN |
156 | } |
157 | skb_cur = skb_next; | |
158 | } | |
bb129994 | 159 | up_read(&listeners->sem); |
f9fd8914 | 160 | |
d94a0415 SN |
161 | if (skb_cur) |
162 | nlmsg_free(skb_cur); | |
163 | ||
bb129994 | 164 | if (!delcount) |
d94a0415 | 165 | return; |
bb129994 SN |
166 | |
167 | /* Delete invalidated entries */ | |
168 | down_write(&listeners->sem); | |
169 | list_for_each_entry_safe(s, tmp, &listeners->list, list) { | |
170 | if (!s->valid) { | |
171 | list_del(&s->list); | |
172 | kfree(s); | |
173 | } | |
174 | } | |
175 | up_write(&listeners->sem); | |
f9fd8914 SN |
176 | } |
177 | ||
a98b6094 | 178 | static int fill_pid(pid_t pid, struct task_struct *tsk, |
c757249a SN |
179 | struct taskstats *stats) |
180 | { | |
7d94dddd | 181 | int rc = 0; |
c757249a | 182 | |
a98b6094 ON |
183 | if (!tsk) { |
184 | rcu_read_lock(); | |
c757249a | 185 | tsk = find_task_by_pid(pid); |
a98b6094 ON |
186 | if (tsk) |
187 | get_task_struct(tsk); | |
188 | rcu_read_unlock(); | |
189 | if (!tsk) | |
c757249a | 190 | return -ESRCH; |
c757249a SN |
191 | } else |
192 | get_task_struct(tsk); | |
193 | ||
194 | /* | |
195 | * Each accounting subsystem adds calls to its functions to | |
196 | * fill in relevant parts of struct taskstsats as follows | |
197 | * | |
7d94dddd | 198 | * per-task-foo(stats, tsk); |
c757249a SN |
199 | */ |
200 | ||
7d94dddd | 201 | delayacct_add_tsk(stats, tsk); |
f3cef7a9 JL |
202 | |
203 | /* fill in basic acct fields */ | |
6f44993f | 204 | stats->version = TASKSTATS_VERSION; |
f3cef7a9 | 205 | bacct_add_tsk(stats, tsk); |
6f44993f | 206 | |
9acc1853 JL |
207 | /* fill in extended acct fields */ |
208 | xacct_add_tsk(stats, tsk); | |
209 | ||
6f44993f | 210 | /* Define err: label here if needed */ |
c757249a SN |
211 | put_task_struct(tsk); |
212 | return rc; | |
213 | ||
214 | } | |
215 | ||
a98b6094 | 216 | static int fill_tgid(pid_t tgid, struct task_struct *first, |
c757249a SN |
217 | struct taskstats *stats) |
218 | { | |
a98b6094 | 219 | struct task_struct *tsk; |
ad4ecbcb | 220 | unsigned long flags; |
a98b6094 | 221 | int rc = -ESRCH; |
c757249a | 222 | |
ad4ecbcb SN |
223 | /* |
224 | * Add additional stats from live tasks except zombie thread group | |
225 | * leaders who are already counted with the dead tasks | |
226 | */ | |
a98b6094 ON |
227 | rcu_read_lock(); |
228 | if (!first) | |
c757249a | 229 | first = find_task_by_pid(tgid); |
ad4ecbcb | 230 | |
a98b6094 ON |
231 | if (!first || !lock_task_sighand(first, &flags)) |
232 | goto out; | |
ad4ecbcb | 233 | |
a98b6094 ON |
234 | if (first->signal->stats) |
235 | memcpy(stats, first->signal->stats, sizeof(*stats)); | |
fca178c0 | 236 | |
a98b6094 | 237 | tsk = first; |
c757249a | 238 | do { |
d7c3f5f2 | 239 | if (tsk->exit_state) |
ad4ecbcb | 240 | continue; |
c757249a | 241 | /* |
ad4ecbcb | 242 | * Accounting subsystem can call its functions here to |
c757249a SN |
243 | * fill in relevant parts of struct taskstsats as follows |
244 | * | |
ad4ecbcb | 245 | * per-task-foo(stats, tsk); |
c757249a | 246 | */ |
ad4ecbcb | 247 | delayacct_add_tsk(stats, tsk); |
6f44993f | 248 | |
c757249a | 249 | } while_each_thread(first, tsk); |
6f44993f | 250 | |
a98b6094 ON |
251 | unlock_task_sighand(first, &flags); |
252 | rc = 0; | |
253 | out: | |
254 | rcu_read_unlock(); | |
255 | ||
256 | stats->version = TASKSTATS_VERSION; | |
c757249a | 257 | /* |
ad4ecbcb SN |
258 | * Accounting subsytems can also add calls here to modify |
259 | * fields of taskstats. | |
c757249a | 260 | */ |
a98b6094 | 261 | return rc; |
ad4ecbcb SN |
262 | } |
263 | ||
264 | ||
265 | static void fill_tgid_exit(struct task_struct *tsk) | |
266 | { | |
267 | unsigned long flags; | |
268 | ||
b8534d7b | 269 | spin_lock_irqsave(&tsk->sighand->siglock, flags); |
ad4ecbcb SN |
270 | if (!tsk->signal->stats) |
271 | goto ret; | |
272 | ||
273 | /* | |
274 | * Each accounting subsystem calls its functions here to | |
275 | * accumalate its per-task stats for tsk, into the per-tgid structure | |
276 | * | |
277 | * per-task-foo(tsk->signal->stats, tsk); | |
278 | */ | |
279 | delayacct_add_tsk(tsk->signal->stats, tsk); | |
280 | ret: | |
b8534d7b | 281 | spin_unlock_irqrestore(&tsk->sighand->siglock, flags); |
ad4ecbcb | 282 | return; |
c757249a SN |
283 | } |
284 | ||
f9fd8914 SN |
285 | static int add_del_listener(pid_t pid, cpumask_t *maskp, int isadd) |
286 | { | |
287 | struct listener_list *listeners; | |
288 | struct listener *s, *tmp; | |
289 | unsigned int cpu; | |
290 | cpumask_t mask = *maskp; | |
ad4ecbcb | 291 | |
f9fd8914 SN |
292 | if (!cpus_subset(mask, cpu_possible_map)) |
293 | return -EINVAL; | |
294 | ||
295 | if (isadd == REGISTER) { | |
296 | for_each_cpu_mask(cpu, mask) { | |
297 | s = kmalloc_node(sizeof(struct listener), GFP_KERNEL, | |
298 | cpu_to_node(cpu)); | |
299 | if (!s) | |
300 | goto cleanup; | |
301 | s->pid = pid; | |
302 | INIT_LIST_HEAD(&s->list); | |
bb129994 | 303 | s->valid = 1; |
f9fd8914 SN |
304 | |
305 | listeners = &per_cpu(listener_array, cpu); | |
306 | down_write(&listeners->sem); | |
307 | list_add(&s->list, &listeners->list); | |
308 | up_write(&listeners->sem); | |
309 | } | |
310 | return 0; | |
311 | } | |
312 | ||
313 | /* Deregister or cleanup */ | |
314 | cleanup: | |
315 | for_each_cpu_mask(cpu, mask) { | |
316 | listeners = &per_cpu(listener_array, cpu); | |
317 | down_write(&listeners->sem); | |
318 | list_for_each_entry_safe(s, tmp, &listeners->list, list) { | |
319 | if (s->pid == pid) { | |
320 | list_del(&s->list); | |
321 | kfree(s); | |
322 | break; | |
323 | } | |
324 | } | |
325 | up_write(&listeners->sem); | |
326 | } | |
327 | return 0; | |
328 | } | |
329 | ||
330 | static int parse(struct nlattr *na, cpumask_t *mask) | |
331 | { | |
332 | char *data; | |
333 | int len; | |
334 | int ret; | |
335 | ||
336 | if (na == NULL) | |
337 | return 1; | |
338 | len = nla_len(na); | |
339 | if (len > TASKSTATS_CPUMASK_MAXLEN) | |
340 | return -E2BIG; | |
341 | if (len < 1) | |
342 | return -EINVAL; | |
343 | data = kmalloc(len, GFP_KERNEL); | |
344 | if (!data) | |
345 | return -ENOMEM; | |
346 | nla_strlcpy(data, na, len); | |
347 | ret = cpulist_parse(data, *mask); | |
348 | kfree(data); | |
349 | return ret; | |
350 | } | |
351 | ||
352 | static int taskstats_user_cmd(struct sk_buff *skb, struct genl_info *info) | |
c757249a SN |
353 | { |
354 | int rc = 0; | |
355 | struct sk_buff *rep_skb; | |
356 | struct taskstats stats; | |
357 | void *reply; | |
358 | size_t size; | |
359 | struct nlattr *na; | |
f9fd8914 SN |
360 | cpumask_t mask; |
361 | ||
362 | rc = parse(info->attrs[TASKSTATS_CMD_ATTR_REGISTER_CPUMASK], &mask); | |
363 | if (rc < 0) | |
364 | return rc; | |
365 | if (rc == 0) | |
366 | return add_del_listener(info->snd_pid, &mask, REGISTER); | |
367 | ||
368 | rc = parse(info->attrs[TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK], &mask); | |
369 | if (rc < 0) | |
370 | return rc; | |
371 | if (rc == 0) | |
372 | return add_del_listener(info->snd_pid, &mask, DEREGISTER); | |
c757249a SN |
373 | |
374 | /* | |
375 | * Size includes space for nested attributes | |
376 | */ | |
377 | size = nla_total_size(sizeof(u32)) + | |
378 | nla_total_size(sizeof(struct taskstats)) + nla_total_size(0); | |
379 | ||
380 | memset(&stats, 0, sizeof(stats)); | |
381 | rc = prepare_reply(info, TASKSTATS_CMD_NEW, &rep_skb, &reply, size); | |
382 | if (rc < 0) | |
383 | return rc; | |
384 | ||
385 | if (info->attrs[TASKSTATS_CMD_ATTR_PID]) { | |
386 | u32 pid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_PID]); | |
387 | rc = fill_pid(pid, NULL, &stats); | |
388 | if (rc < 0) | |
389 | goto err; | |
390 | ||
391 | na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_PID); | |
392 | NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_PID, pid); | |
393 | NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS, | |
394 | stats); | |
395 | } else if (info->attrs[TASKSTATS_CMD_ATTR_TGID]) { | |
396 | u32 tgid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_TGID]); | |
397 | rc = fill_tgid(tgid, NULL, &stats); | |
398 | if (rc < 0) | |
399 | goto err; | |
400 | ||
401 | na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_TGID); | |
402 | NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_TGID, tgid); | |
403 | NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS, | |
404 | stats); | |
405 | } else { | |
406 | rc = -EINVAL; | |
407 | goto err; | |
408 | } | |
409 | ||
410 | nla_nest_end(rep_skb, na); | |
411 | ||
f9fd8914 | 412 | return send_reply(rep_skb, info->snd_pid); |
c757249a SN |
413 | |
414 | nla_put_failure: | |
d46a3d0d | 415 | rc = genlmsg_cancel(rep_skb, reply); |
c757249a SN |
416 | err: |
417 | nlmsg_free(rep_skb); | |
418 | return rc; | |
419 | } | |
420 | ||
f9fd8914 SN |
421 | void taskstats_exit_alloc(struct taskstats **ptidstats, unsigned int *mycpu) |
422 | { | |
423 | struct listener_list *listeners; | |
424 | struct taskstats *tmp; | |
425 | /* | |
426 | * This is the cpu on which the task is exiting currently and will | |
427 | * be the one for which the exit event is sent, even if the cpu | |
428 | * on which this function is running changes later. | |
429 | */ | |
430 | *mycpu = raw_smp_processor_id(); | |
431 | ||
432 | *ptidstats = NULL; | |
433 | tmp = kmem_cache_zalloc(taskstats_cache, SLAB_KERNEL); | |
434 | if (!tmp) | |
435 | return; | |
436 | ||
437 | listeners = &per_cpu(listener_array, *mycpu); | |
438 | down_read(&listeners->sem); | |
439 | if (!list_empty(&listeners->list)) { | |
440 | *ptidstats = tmp; | |
441 | tmp = NULL; | |
442 | } | |
443 | up_read(&listeners->sem); | |
444 | kfree(tmp); | |
445 | } | |
446 | ||
c757249a SN |
447 | /* Send pid data out on exit */ |
448 | void taskstats_exit_send(struct task_struct *tsk, struct taskstats *tidstats, | |
f9fd8914 | 449 | int group_dead, unsigned int mycpu) |
c757249a SN |
450 | { |
451 | int rc; | |
452 | struct sk_buff *rep_skb; | |
453 | void *reply; | |
454 | size_t size; | |
455 | int is_thread_group; | |
456 | struct nlattr *na; | |
457 | ||
458 | if (!family_registered || !tidstats) | |
459 | return; | |
460 | ||
ad4ecbcb | 461 | rc = 0; |
c757249a SN |
462 | /* |
463 | * Size includes space for nested attributes | |
464 | */ | |
465 | size = nla_total_size(sizeof(u32)) + | |
466 | nla_total_size(sizeof(struct taskstats)) + nla_total_size(0); | |
467 | ||
b8534d7b | 468 | is_thread_group = (tsk->signal->stats != NULL); |
c757249a SN |
469 | if (is_thread_group) |
470 | size = 2 * size; /* PID + STATS + TGID + STATS */ | |
471 | ||
472 | rc = prepare_reply(NULL, TASKSTATS_CMD_NEW, &rep_skb, &reply, size); | |
473 | if (rc < 0) | |
474 | goto ret; | |
475 | ||
476 | rc = fill_pid(tsk->pid, tsk, tidstats); | |
477 | if (rc < 0) | |
478 | goto err_skb; | |
479 | ||
480 | na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_PID); | |
481 | NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_PID, (u32)tsk->pid); | |
482 | NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS, | |
483 | *tidstats); | |
484 | nla_nest_end(rep_skb, na); | |
485 | ||
ad4ecbcb SN |
486 | if (!is_thread_group) |
487 | goto send; | |
c757249a | 488 | |
c757249a | 489 | /* |
ad4ecbcb SN |
490 | * tsk has/had a thread group so fill the tsk->signal->stats structure |
491 | * Doesn't matter if tsk is the leader or the last group member leaving | |
c757249a | 492 | */ |
ad4ecbcb SN |
493 | |
494 | fill_tgid_exit(tsk); | |
495 | if (!group_dead) | |
496 | goto send; | |
c757249a SN |
497 | |
498 | na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_TGID); | |
499 | NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_TGID, (u32)tsk->tgid); | |
ad4ecbcb | 500 | /* No locking needed for tsk->signal->stats since group is dead */ |
c757249a | 501 | NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS, |
ad4ecbcb | 502 | *tsk->signal->stats); |
c757249a SN |
503 | nla_nest_end(rep_skb, na); |
504 | ||
ad4ecbcb | 505 | send: |
f9fd8914 | 506 | send_cpu_listeners(rep_skb, mycpu); |
ad4ecbcb | 507 | return; |
c757249a SN |
508 | |
509 | nla_put_failure: | |
510 | genlmsg_cancel(rep_skb, reply); | |
c757249a SN |
511 | err_skb: |
512 | nlmsg_free(rep_skb); | |
513 | ret: | |
c757249a SN |
514 | return; |
515 | } | |
516 | ||
517 | static struct genl_ops taskstats_ops = { | |
518 | .cmd = TASKSTATS_CMD_GET, | |
f9fd8914 | 519 | .doit = taskstats_user_cmd, |
c757249a SN |
520 | .policy = taskstats_cmd_get_policy, |
521 | }; | |
522 | ||
523 | /* Needed early in initialization */ | |
524 | void __init taskstats_init_early(void) | |
525 | { | |
f9fd8914 SN |
526 | unsigned int i; |
527 | ||
c757249a SN |
528 | taskstats_cache = kmem_cache_create("taskstats_cache", |
529 | sizeof(struct taskstats), | |
530 | 0, SLAB_PANIC, NULL, NULL); | |
f9fd8914 SN |
531 | for_each_possible_cpu(i) { |
532 | INIT_LIST_HEAD(&(per_cpu(listener_array, i).list)); | |
533 | init_rwsem(&(per_cpu(listener_array, i).sem)); | |
534 | } | |
c757249a SN |
535 | } |
536 | ||
537 | static int __init taskstats_init(void) | |
538 | { | |
539 | int rc; | |
540 | ||
541 | rc = genl_register_family(&family); | |
542 | if (rc) | |
543 | return rc; | |
544 | ||
545 | rc = genl_register_ops(&family, &taskstats_ops); | |
546 | if (rc < 0) | |
547 | goto err; | |
548 | ||
549 | family_registered = 1; | |
550 | return 0; | |
551 | err: | |
552 | genl_unregister_family(&family); | |
553 | return rc; | |
554 | } | |
555 | ||
556 | /* | |
557 | * late initcall ensures initialization of statistics collection | |
558 | * mechanisms precedes initialization of the taskstats interface | |
559 | */ | |
560 | late_initcall(taskstats_init); |