blob: cbb387a265db01a7bde8d6576316cdeffa6f1103
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/slab.h> |
26 | #include <linux/cgroupstats.h> |
27 | #include <linux/cgroup.h> |
28 | #include <linux/fs.h> |
29 | #include <linux/file.h> |
30 | #include <linux/pid_namespace.h> |
31 | #include <net/genetlink.h> |
32 | #include <linux/atomic.h> |
33 | |
34 | /* |
35 | * Maximum length of a cpumask that can be specified in |
36 | * the TASKSTATS_CMD_ATTR_REGISTER/DEREGISTER_CPUMASK attribute |
37 | */ |
38 | #define TASKSTATS_CPUMASK_MAXLEN (100+6*NR_CPUS) |
39 | |
40 | static DEFINE_PER_CPU(__u32, taskstats_seqnum); |
41 | static int family_registered; |
42 | struct kmem_cache *taskstats_cache; |
43 | |
44 | static struct genl_family family = { |
45 | .id = GENL_ID_GENERATE, |
46 | .name = TASKSTATS_GENL_NAME, |
47 | .version = TASKSTATS_GENL_VERSION, |
48 | .maxattr = TASKSTATS_CMD_ATTR_MAX, |
49 | }; |
50 | |
51 | static const struct nla_policy taskstats_cmd_get_policy[TASKSTATS_CMD_ATTR_MAX+1] = { |
52 | [TASKSTATS_CMD_ATTR_PID] = { .type = NLA_U32 }, |
53 | [TASKSTATS_CMD_ATTR_TGID] = { .type = NLA_U32 }, |
54 | [TASKSTATS_CMD_ATTR_REGISTER_CPUMASK] = { .type = NLA_STRING }, |
55 | [TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK] = { .type = NLA_STRING },}; |
56 | |
57 | /* |
58 | * We have to use TASKSTATS_CMD_ATTR_MAX here, it is the maxattr in the family. |
59 | * Make sure they are always aligned. |
60 | */ |
61 | static const struct nla_policy cgroupstats_cmd_get_policy[TASKSTATS_CMD_ATTR_MAX+1] = { |
62 | [CGROUPSTATS_CMD_ATTR_FD] = { .type = NLA_U32 }, |
63 | }; |
64 | |
65 | struct listener { |
66 | struct list_head list; |
67 | pid_t pid; |
68 | char valid; |
69 | }; |
70 | |
71 | struct listener_list { |
72 | struct rw_semaphore sem; |
73 | struct list_head list; |
74 | }; |
75 | static DEFINE_PER_CPU(struct listener_list, listener_array); |
76 | |
77 | enum actions { |
78 | REGISTER, |
79 | DEREGISTER, |
80 | CPU_DONT_CARE |
81 | }; |
82 | |
83 | static int prepare_reply(struct genl_info *info, u8 cmd, struct sk_buff **skbp, |
84 | size_t size) |
85 | { |
86 | struct sk_buff *skb; |
87 | void *reply; |
88 | |
89 | /* |
90 | * If new attributes are added, please revisit this allocation |
91 | */ |
92 | skb = genlmsg_new(size, GFP_KERNEL); |
93 | if (!skb) |
94 | return -ENOMEM; |
95 | |
96 | if (!info) { |
97 | int seq = this_cpu_inc_return(taskstats_seqnum) - 1; |
98 | |
99 | reply = genlmsg_put(skb, 0, seq, &family, 0, cmd); |
100 | } else |
101 | reply = genlmsg_put_reply(skb, info, &family, 0, cmd); |
102 | if (reply == NULL) { |
103 | nlmsg_free(skb); |
104 | return -EINVAL; |
105 | } |
106 | |
107 | *skbp = skb; |
108 | return 0; |
109 | } |
110 | |
111 | /* |
112 | * Send taskstats data in @skb to listener with nl_pid @pid |
113 | */ |
114 | static int send_reply(struct sk_buff *skb, struct genl_info *info) |
115 | { |
116 | struct genlmsghdr *genlhdr = nlmsg_data(nlmsg_hdr(skb)); |
117 | void *reply = genlmsg_data(genlhdr); |
118 | |
119 | genlmsg_end(skb, reply); |
120 | |
121 | return genlmsg_reply(skb, info); |
122 | } |
123 | |
124 | /* |
125 | * Send taskstats data in @skb to listeners registered for @cpu's exit data |
126 | */ |
127 | static void send_cpu_listeners(struct sk_buff *skb, |
128 | struct listener_list *listeners) |
129 | { |
130 | struct genlmsghdr *genlhdr = nlmsg_data(nlmsg_hdr(skb)); |
131 | struct listener *s, *tmp; |
132 | struct sk_buff *skb_next, *skb_cur = skb; |
133 | void *reply = genlmsg_data(genlhdr); |
134 | int rc, delcount = 0; |
135 | |
136 | genlmsg_end(skb, reply); |
137 | |
138 | rc = 0; |
139 | down_read(&listeners->sem); |
140 | list_for_each_entry(s, &listeners->list, list) { |
141 | skb_next = NULL; |
142 | if (!list_is_last(&s->list, &listeners->list)) { |
143 | skb_next = skb_clone(skb_cur, GFP_KERNEL); |
144 | if (!skb_next) |
145 | break; |
146 | } |
147 | rc = genlmsg_unicast(&init_net, skb_cur, s->pid); |
148 | if (rc == -ECONNREFUSED) { |
149 | s->valid = 0; |
150 | delcount++; |
151 | } |
152 | skb_cur = skb_next; |
153 | } |
154 | up_read(&listeners->sem); |
155 | |
156 | if (skb_cur) |
157 | nlmsg_free(skb_cur); |
158 | |
159 | if (!delcount) |
160 | return; |
161 | |
162 | /* Delete invalidated entries */ |
163 | down_write(&listeners->sem); |
164 | list_for_each_entry_safe(s, tmp, &listeners->list, list) { |
165 | if (!s->valid) { |
166 | list_del(&s->list); |
167 | kfree(s); |
168 | } |
169 | } |
170 | up_write(&listeners->sem); |
171 | } |
172 | |
173 | static void fill_stats(struct user_namespace *user_ns, |
174 | struct pid_namespace *pid_ns, |
175 | struct task_struct *tsk, struct taskstats *stats) |
176 | { |
177 | memset(stats, 0, sizeof(*stats)); |
178 | /* |
179 | * Each accounting subsystem adds calls to its functions to |
180 | * fill in relevant parts of struct taskstsats as follows |
181 | * |
182 | * per-task-foo(stats, tsk); |
183 | */ |
184 | |
185 | delayacct_add_tsk(stats, tsk); |
186 | |
187 | /* fill in basic acct fields */ |
188 | stats->version = TASKSTATS_VERSION; |
189 | stats->nvcsw = tsk->nvcsw; |
190 | stats->nivcsw = tsk->nivcsw; |
191 | bacct_add_tsk(user_ns, pid_ns, stats, tsk); |
192 | |
193 | /* fill in extended acct fields */ |
194 | xacct_add_tsk(stats, tsk); |
195 | } |
196 | |
197 | static int fill_stats_for_pid(pid_t pid, struct taskstats *stats) |
198 | { |
199 | struct task_struct *tsk; |
200 | |
201 | rcu_read_lock(); |
202 | tsk = find_task_by_vpid(pid); |
203 | if (tsk) |
204 | get_task_struct(tsk); |
205 | rcu_read_unlock(); |
206 | if (!tsk) |
207 | return -ESRCH; |
208 | fill_stats(current_user_ns(), task_active_pid_ns(current), tsk, stats); |
209 | put_task_struct(tsk); |
210 | return 0; |
211 | } |
212 | |
213 | static int fill_stats_for_tgid(pid_t tgid, struct taskstats *stats) |
214 | { |
215 | struct task_struct *tsk, *first; |
216 | unsigned long flags; |
217 | int rc = -ESRCH; |
218 | |
219 | /* |
220 | * Add additional stats from live tasks except zombie thread group |
221 | * leaders who are already counted with the dead tasks |
222 | */ |
223 | rcu_read_lock(); |
224 | first = find_task_by_vpid(tgid); |
225 | |
226 | if (!first || !lock_task_sighand(first, &flags)) |
227 | goto out; |
228 | |
229 | if (first->signal->stats) |
230 | memcpy(stats, first->signal->stats, sizeof(*stats)); |
231 | else |
232 | memset(stats, 0, sizeof(*stats)); |
233 | |
234 | tsk = first; |
235 | do { |
236 | if (tsk->exit_state) |
237 | continue; |
238 | /* |
239 | * Accounting subsystem can call its functions here to |
240 | * fill in relevant parts of struct taskstsats as follows |
241 | * |
242 | * per-task-foo(stats, tsk); |
243 | */ |
244 | delayacct_add_tsk(stats, tsk); |
245 | |
246 | stats->nvcsw += tsk->nvcsw; |
247 | stats->nivcsw += tsk->nivcsw; |
248 | } while_each_thread(first, tsk); |
249 | |
250 | unlock_task_sighand(first, &flags); |
251 | rc = 0; |
252 | out: |
253 | rcu_read_unlock(); |
254 | |
255 | stats->version = TASKSTATS_VERSION; |
256 | /* |
257 | * Accounting subsystems can also add calls here to modify |
258 | * fields of taskstats. |
259 | */ |
260 | return rc; |
261 | } |
262 | |
263 | static void fill_tgid_exit(struct task_struct *tsk) |
264 | { |
265 | unsigned long flags; |
266 | |
267 | spin_lock_irqsave(&tsk->sighand->siglock, flags); |
268 | if (!tsk->signal->stats) |
269 | goto ret; |
270 | |
271 | /* |
272 | * Each accounting subsystem calls its functions here to |
273 | * accumalate its per-task stats for tsk, into the per-tgid structure |
274 | * |
275 | * per-task-foo(tsk->signal->stats, tsk); |
276 | */ |
277 | delayacct_add_tsk(tsk->signal->stats, tsk); |
278 | ret: |
279 | spin_unlock_irqrestore(&tsk->sighand->siglock, flags); |
280 | return; |
281 | } |
282 | |
283 | static int add_del_listener(pid_t pid, const struct cpumask *mask, int isadd) |
284 | { |
285 | struct listener_list *listeners; |
286 | struct listener *s, *tmp, *s2; |
287 | unsigned int cpu; |
288 | int ret = 0; |
289 | |
290 | if (!cpumask_subset(mask, cpu_possible_mask)) |
291 | return -EINVAL; |
292 | |
293 | if (current_user_ns() != &init_user_ns) |
294 | return -EINVAL; |
295 | |
296 | if (task_active_pid_ns(current) != &init_pid_ns) |
297 | return -EINVAL; |
298 | |
299 | if (isadd == REGISTER) { |
300 | for_each_cpu(cpu, mask) { |
301 | s = kmalloc_node(sizeof(struct listener), |
302 | GFP_KERNEL, cpu_to_node(cpu)); |
303 | if (!s) { |
304 | ret = -ENOMEM; |
305 | goto cleanup; |
306 | } |
307 | s->pid = pid; |
308 | s->valid = 1; |
309 | |
310 | listeners = &per_cpu(listener_array, cpu); |
311 | down_write(&listeners->sem); |
312 | list_for_each_entry(s2, &listeners->list, list) { |
313 | if (s2->pid == pid && s2->valid) |
314 | goto exists; |
315 | } |
316 | list_add(&s->list, &listeners->list); |
317 | s = NULL; |
318 | exists: |
319 | up_write(&listeners->sem); |
320 | kfree(s); /* nop if NULL */ |
321 | } |
322 | return 0; |
323 | } |
324 | |
325 | /* Deregister or cleanup */ |
326 | cleanup: |
327 | for_each_cpu(cpu, mask) { |
328 | listeners = &per_cpu(listener_array, cpu); |
329 | down_write(&listeners->sem); |
330 | list_for_each_entry_safe(s, tmp, &listeners->list, list) { |
331 | if (s->pid == pid) { |
332 | list_del(&s->list); |
333 | kfree(s); |
334 | break; |
335 | } |
336 | } |
337 | up_write(&listeners->sem); |
338 | } |
339 | return ret; |
340 | } |
341 | |
342 | static int parse(struct nlattr *na, struct cpumask *mask) |
343 | { |
344 | char *data; |
345 | int len; |
346 | int ret; |
347 | |
348 | if (na == NULL) |
349 | return 1; |
350 | len = nla_len(na); |
351 | if (len > TASKSTATS_CPUMASK_MAXLEN) |
352 | return -E2BIG; |
353 | if (len < 1) |
354 | return -EINVAL; |
355 | data = kmalloc(len, GFP_KERNEL); |
356 | if (!data) |
357 | return -ENOMEM; |
358 | nla_strlcpy(data, na, len); |
359 | ret = cpulist_parse(data, mask); |
360 | kfree(data); |
361 | return ret; |
362 | } |
363 | |
364 | static struct taskstats *mk_reply(struct sk_buff *skb, int type, u32 pid) |
365 | { |
366 | struct nlattr *na, *ret; |
367 | int aggr; |
368 | |
369 | aggr = (type == TASKSTATS_TYPE_PID) |
370 | ? TASKSTATS_TYPE_AGGR_PID |
371 | : TASKSTATS_TYPE_AGGR_TGID; |
372 | |
373 | na = nla_nest_start(skb, aggr); |
374 | if (!na) |
375 | goto err; |
376 | |
377 | if (nla_put(skb, type, sizeof(pid), &pid) < 0) { |
378 | nla_nest_cancel(skb, na); |
379 | goto err; |
380 | } |
381 | ret = nla_reserve_64bit(skb, TASKSTATS_TYPE_STATS, |
382 | sizeof(struct taskstats), TASKSTATS_TYPE_NULL); |
383 | if (!ret) { |
384 | nla_nest_cancel(skb, na); |
385 | goto err; |
386 | } |
387 | nla_nest_end(skb, na); |
388 | |
389 | return nla_data(ret); |
390 | err: |
391 | return NULL; |
392 | } |
393 | |
394 | static int cgroupstats_user_cmd(struct sk_buff *skb, struct genl_info *info) |
395 | { |
396 | int rc = 0; |
397 | struct sk_buff *rep_skb; |
398 | struct cgroupstats *stats; |
399 | struct nlattr *na; |
400 | size_t size; |
401 | u32 fd; |
402 | struct fd f; |
403 | |
404 | na = info->attrs[CGROUPSTATS_CMD_ATTR_FD]; |
405 | if (!na) |
406 | return -EINVAL; |
407 | |
408 | fd = nla_get_u32(info->attrs[CGROUPSTATS_CMD_ATTR_FD]); |
409 | f = fdget(fd); |
410 | if (!f.file) |
411 | return 0; |
412 | |
413 | size = nla_total_size(sizeof(struct cgroupstats)); |
414 | |
415 | rc = prepare_reply(info, CGROUPSTATS_CMD_NEW, &rep_skb, |
416 | size); |
417 | if (rc < 0) |
418 | goto err; |
419 | |
420 | na = nla_reserve(rep_skb, CGROUPSTATS_TYPE_CGROUP_STATS, |
421 | sizeof(struct cgroupstats)); |
422 | if (na == NULL) { |
423 | nlmsg_free(rep_skb); |
424 | rc = -EMSGSIZE; |
425 | goto err; |
426 | } |
427 | |
428 | stats = nla_data(na); |
429 | memset(stats, 0, sizeof(*stats)); |
430 | |
431 | rc = cgroupstats_build(stats, f.file->f_path.dentry); |
432 | if (rc < 0) { |
433 | nlmsg_free(rep_skb); |
434 | goto err; |
435 | } |
436 | |
437 | rc = send_reply(rep_skb, info); |
438 | |
439 | err: |
440 | fdput(f); |
441 | return rc; |
442 | } |
443 | |
444 | static int cmd_attr_register_cpumask(struct genl_info *info) |
445 | { |
446 | cpumask_var_t mask; |
447 | int rc; |
448 | |
449 | if (!alloc_cpumask_var(&mask, GFP_KERNEL)) |
450 | return -ENOMEM; |
451 | rc = parse(info->attrs[TASKSTATS_CMD_ATTR_REGISTER_CPUMASK], mask); |
452 | if (rc < 0) |
453 | goto out; |
454 | rc = add_del_listener(info->snd_portid, mask, REGISTER); |
455 | out: |
456 | free_cpumask_var(mask); |
457 | return rc; |
458 | } |
459 | |
460 | static int cmd_attr_deregister_cpumask(struct genl_info *info) |
461 | { |
462 | cpumask_var_t mask; |
463 | int rc; |
464 | |
465 | if (!alloc_cpumask_var(&mask, GFP_KERNEL)) |
466 | return -ENOMEM; |
467 | rc = parse(info->attrs[TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK], mask); |
468 | if (rc < 0) |
469 | goto out; |
470 | rc = add_del_listener(info->snd_portid, mask, DEREGISTER); |
471 | out: |
472 | free_cpumask_var(mask); |
473 | return rc; |
474 | } |
475 | |
476 | static size_t taskstats_packet_size(void) |
477 | { |
478 | size_t size; |
479 | |
480 | size = nla_total_size(sizeof(u32)) + |
481 | nla_total_size_64bit(sizeof(struct taskstats)) + |
482 | nla_total_size(0); |
483 | |
484 | return size; |
485 | } |
486 | |
487 | static int cmd_attr_pid(struct genl_info *info) |
488 | { |
489 | struct taskstats *stats; |
490 | struct sk_buff *rep_skb; |
491 | size_t size; |
492 | u32 pid; |
493 | int rc; |
494 | |
495 | size = taskstats_packet_size(); |
496 | |
497 | rc = prepare_reply(info, TASKSTATS_CMD_NEW, &rep_skb, size); |
498 | if (rc < 0) |
499 | return rc; |
500 | |
501 | rc = -EINVAL; |
502 | pid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_PID]); |
503 | stats = mk_reply(rep_skb, TASKSTATS_TYPE_PID, pid); |
504 | if (!stats) |
505 | goto err; |
506 | |
507 | rc = fill_stats_for_pid(pid, stats); |
508 | if (rc < 0) |
509 | goto err; |
510 | return send_reply(rep_skb, info); |
511 | err: |
512 | nlmsg_free(rep_skb); |
513 | return rc; |
514 | } |
515 | |
516 | static int cmd_attr_tgid(struct genl_info *info) |
517 | { |
518 | struct taskstats *stats; |
519 | struct sk_buff *rep_skb; |
520 | size_t size; |
521 | u32 tgid; |
522 | int rc; |
523 | |
524 | size = taskstats_packet_size(); |
525 | |
526 | rc = prepare_reply(info, TASKSTATS_CMD_NEW, &rep_skb, size); |
527 | if (rc < 0) |
528 | return rc; |
529 | |
530 | rc = -EINVAL; |
531 | tgid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_TGID]); |
532 | stats = mk_reply(rep_skb, TASKSTATS_TYPE_TGID, tgid); |
533 | if (!stats) |
534 | goto err; |
535 | |
536 | rc = fill_stats_for_tgid(tgid, stats); |
537 | if (rc < 0) |
538 | goto err; |
539 | return send_reply(rep_skb, info); |
540 | err: |
541 | nlmsg_free(rep_skb); |
542 | return rc; |
543 | } |
544 | |
545 | static int taskstats_user_cmd(struct sk_buff *skb, struct genl_info *info) |
546 | { |
547 | if (info->attrs[TASKSTATS_CMD_ATTR_REGISTER_CPUMASK]) |
548 | return cmd_attr_register_cpumask(info); |
549 | else if (info->attrs[TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK]) |
550 | return cmd_attr_deregister_cpumask(info); |
551 | else if (info->attrs[TASKSTATS_CMD_ATTR_PID]) |
552 | return cmd_attr_pid(info); |
553 | else if (info->attrs[TASKSTATS_CMD_ATTR_TGID]) |
554 | return cmd_attr_tgid(info); |
555 | else |
556 | return -EINVAL; |
557 | } |
558 | |
559 | static struct taskstats *taskstats_tgid_alloc(struct task_struct *tsk) |
560 | { |
561 | struct signal_struct *sig = tsk->signal; |
562 | struct taskstats *stats; |
563 | |
564 | if (sig->stats || thread_group_empty(tsk)) |
565 | goto ret; |
566 | |
567 | /* No problem if kmem_cache_zalloc() fails */ |
568 | stats = kmem_cache_zalloc(taskstats_cache, GFP_KERNEL); |
569 | |
570 | spin_lock_irq(&tsk->sighand->siglock); |
571 | if (!sig->stats) { |
572 | sig->stats = stats; |
573 | stats = NULL; |
574 | } |
575 | spin_unlock_irq(&tsk->sighand->siglock); |
576 | |
577 | if (stats) |
578 | kmem_cache_free(taskstats_cache, stats); |
579 | ret: |
580 | return sig->stats; |
581 | } |
582 | |
583 | /* Send pid data out on exit */ |
584 | void taskstats_exit(struct task_struct *tsk, int group_dead) |
585 | { |
586 | int rc; |
587 | struct listener_list *listeners; |
588 | struct taskstats *stats; |
589 | struct sk_buff *rep_skb; |
590 | size_t size; |
591 | int is_thread_group; |
592 | |
593 | if (!family_registered) |
594 | return; |
595 | |
596 | /* |
597 | * Size includes space for nested attributes |
598 | */ |
599 | size = taskstats_packet_size(); |
600 | |
601 | is_thread_group = !!taskstats_tgid_alloc(tsk); |
602 | if (is_thread_group) { |
603 | /* PID + STATS + TGID + STATS */ |
604 | size = 2 * size; |
605 | /* fill the tsk->signal->stats structure */ |
606 | fill_tgid_exit(tsk); |
607 | } |
608 | |
609 | listeners = raw_cpu_ptr(&listener_array); |
610 | if (list_empty(&listeners->list)) |
611 | return; |
612 | |
613 | rc = prepare_reply(NULL, TASKSTATS_CMD_NEW, &rep_skb, size); |
614 | if (rc < 0) |
615 | return; |
616 | |
617 | stats = mk_reply(rep_skb, TASKSTATS_TYPE_PID, |
618 | task_pid_nr_ns(tsk, &init_pid_ns)); |
619 | if (!stats) |
620 | goto err; |
621 | |
622 | fill_stats(&init_user_ns, &init_pid_ns, tsk, stats); |
623 | |
624 | /* |
625 | * Doesn't matter if tsk is the leader or the last group member leaving |
626 | */ |
627 | if (!is_thread_group || !group_dead) |
628 | goto send; |
629 | |
630 | stats = mk_reply(rep_skb, TASKSTATS_TYPE_TGID, |
631 | task_tgid_nr_ns(tsk, &init_pid_ns)); |
632 | if (!stats) |
633 | goto err; |
634 | |
635 | memcpy(stats, tsk->signal->stats, sizeof(*stats)); |
636 | |
637 | send: |
638 | send_cpu_listeners(rep_skb, listeners); |
639 | return; |
640 | err: |
641 | nlmsg_free(rep_skb); |
642 | } |
643 | |
644 | static const struct genl_ops taskstats_ops[] = { |
645 | { |
646 | .cmd = TASKSTATS_CMD_GET, |
647 | .doit = taskstats_user_cmd, |
648 | .policy = taskstats_cmd_get_policy, |
649 | .flags = GENL_ADMIN_PERM, |
650 | }, |
651 | { |
652 | .cmd = CGROUPSTATS_CMD_GET, |
653 | .doit = cgroupstats_user_cmd, |
654 | .policy = cgroupstats_cmd_get_policy, |
655 | }, |
656 | }; |
657 | |
658 | /* Needed early in initialization */ |
659 | void __init taskstats_init_early(void) |
660 | { |
661 | unsigned int i; |
662 | |
663 | taskstats_cache = KMEM_CACHE(taskstats, SLAB_PANIC); |
664 | for_each_possible_cpu(i) { |
665 | INIT_LIST_HEAD(&(per_cpu(listener_array, i).list)); |
666 | init_rwsem(&(per_cpu(listener_array, i).sem)); |
667 | } |
668 | } |
669 | |
670 | static int __init taskstats_init(void) |
671 | { |
672 | int rc; |
673 | |
674 | rc = genl_register_family_with_ops(&family, taskstats_ops); |
675 | if (rc) |
676 | return rc; |
677 | |
678 | family_registered = 1; |
679 | pr_info("registered taskstats version %d\n", TASKSTATS_GENL_VERSION); |
680 | return 0; |
681 | } |
682 | |
683 | /* |
684 | * late initcall ensures initialization of statistics collection |
685 | * mechanisms precedes initialization of the taskstats interface |
686 | */ |
687 | late_initcall(taskstats_init); |
688 |