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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> | |
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 | */ | |
0ae64684 | 80 | skb = nlmsg_new(genlmsg_total_size(size), GFP_KERNEL); |
c757249a SN |
81 | if (!skb) |
82 | return -ENOMEM; | |
83 | ||
84 | if (!info) { | |
85 | int seq = get_cpu_var(taskstats_seqnum)++; | |
86 | put_cpu_var(taskstats_seqnum); | |
87 | ||
88 | reply = genlmsg_put(skb, 0, seq, | |
89 | family.id, 0, 0, | |
90 | cmd, family.version); | |
91 | } else | |
92 | reply = genlmsg_put(skb, info->snd_pid, info->snd_seq, | |
93 | family.id, 0, 0, | |
94 | cmd, family.version); | |
95 | if (reply == NULL) { | |
96 | nlmsg_free(skb); | |
97 | return -EINVAL; | |
98 | } | |
99 | ||
100 | *skbp = skb; | |
101 | *replyp = reply; | |
102 | return 0; | |
103 | } | |
104 | ||
f9fd8914 SN |
105 | /* |
106 | * Send taskstats data in @skb to listener with nl_pid @pid | |
107 | */ | |
108 | static int send_reply(struct sk_buff *skb, pid_t pid) | |
c757249a SN |
109 | { |
110 | struct genlmsghdr *genlhdr = nlmsg_data((struct nlmsghdr *)skb->data); | |
f9fd8914 | 111 | void *reply = genlmsg_data(genlhdr); |
c757249a SN |
112 | int rc; |
113 | ||
c757249a SN |
114 | rc = genlmsg_end(skb, reply); |
115 | if (rc < 0) { | |
116 | nlmsg_free(skb); | |
117 | return rc; | |
118 | } | |
119 | ||
c757249a SN |
120 | return genlmsg_unicast(skb, pid); |
121 | } | |
122 | ||
f9fd8914 SN |
123 | /* |
124 | * Send taskstats data in @skb to listeners registered for @cpu's exit data | |
125 | */ | |
d94a0415 | 126 | static void send_cpu_listeners(struct sk_buff *skb, unsigned int cpu) |
f9fd8914 SN |
127 | { |
128 | struct genlmsghdr *genlhdr = nlmsg_data((struct nlmsghdr *)skb->data); | |
129 | struct listener_list *listeners; | |
130 | struct listener *s, *tmp; | |
131 | struct sk_buff *skb_next, *skb_cur = skb; | |
132 | void *reply = genlmsg_data(genlhdr); | |
d94a0415 | 133 | int rc, delcount = 0; |
f9fd8914 SN |
134 | |
135 | rc = genlmsg_end(skb, reply); | |
136 | if (rc < 0) { | |
137 | nlmsg_free(skb); | |
d94a0415 | 138 | return; |
f9fd8914 SN |
139 | } |
140 | ||
141 | rc = 0; | |
142 | listeners = &per_cpu(listener_array, cpu); | |
bb129994 | 143 | down_read(&listeners->sem); |
d94a0415 | 144 | list_for_each_entry(s, &listeners->list, list) { |
f9fd8914 SN |
145 | skb_next = NULL; |
146 | if (!list_is_last(&s->list, &listeners->list)) { | |
147 | skb_next = skb_clone(skb_cur, GFP_KERNEL); | |
d94a0415 | 148 | if (!skb_next) |
f9fd8914 | 149 | break; |
f9fd8914 | 150 | } |
d94a0415 SN |
151 | rc = genlmsg_unicast(skb_cur, s->pid); |
152 | if (rc == -ECONNREFUSED) { | |
bb129994 SN |
153 | s->valid = 0; |
154 | delcount++; | |
f9fd8914 SN |
155 | } |
156 | skb_cur = skb_next; | |
157 | } | |
bb129994 | 158 | up_read(&listeners->sem); |
f9fd8914 | 159 | |
d94a0415 SN |
160 | if (skb_cur) |
161 | nlmsg_free(skb_cur); | |
162 | ||
bb129994 | 163 | if (!delcount) |
d94a0415 | 164 | return; |
bb129994 SN |
165 | |
166 | /* Delete invalidated entries */ | |
167 | down_write(&listeners->sem); | |
168 | list_for_each_entry_safe(s, tmp, &listeners->list, list) { | |
169 | if (!s->valid) { | |
170 | list_del(&s->list); | |
171 | kfree(s); | |
172 | } | |
173 | } | |
174 | up_write(&listeners->sem); | |
f9fd8914 SN |
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); |
f3cef7a9 JL |
203 | |
204 | /* fill in basic acct fields */ | |
6f44993f | 205 | stats->version = TASKSTATS_VERSION; |
f3cef7a9 | 206 | bacct_add_tsk(stats, tsk); |
6f44993f | 207 | |
9acc1853 JL |
208 | /* fill in extended acct fields */ |
209 | xacct_add_tsk(stats, tsk); | |
210 | ||
6f44993f | 211 | /* Define err: label here if needed */ |
c757249a SN |
212 | put_task_struct(tsk); |
213 | return rc; | |
214 | ||
215 | } | |
216 | ||
217 | static int fill_tgid(pid_t tgid, struct task_struct *tgidtsk, | |
218 | struct taskstats *stats) | |
219 | { | |
c757249a | 220 | struct task_struct *tsk, *first; |
ad4ecbcb | 221 | unsigned long flags; |
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 | */ | |
c757249a | 227 | first = tgidtsk; |
c757249a | 228 | if (!first) { |
ad4ecbcb | 229 | read_lock(&tasklist_lock); |
c757249a SN |
230 | first = find_task_by_pid(tgid); |
231 | if (!first) { | |
232 | read_unlock(&tasklist_lock); | |
233 | return -ESRCH; | |
234 | } | |
ad4ecbcb SN |
235 | get_task_struct(first); |
236 | read_unlock(&tasklist_lock); | |
237 | } else | |
238 | get_task_struct(first); | |
239 | ||
ad4ecbcb | 240 | |
c757249a | 241 | tsk = first; |
ad4ecbcb | 242 | read_lock(&tasklist_lock); |
fca178c0 ON |
243 | /* Start with stats from dead tasks */ |
244 | if (first->signal) { | |
245 | spin_lock_irqsave(&first->signal->stats_lock, flags); | |
246 | if (first->signal->stats) | |
247 | memcpy(stats, first->signal->stats, sizeof(*stats)); | |
248 | spin_unlock_irqrestore(&first->signal->stats_lock, flags); | |
249 | } | |
250 | ||
c757249a | 251 | do { |
ad4ecbcb SN |
252 | if (tsk->exit_state == EXIT_ZOMBIE && thread_group_leader(tsk)) |
253 | continue; | |
c757249a | 254 | /* |
ad4ecbcb | 255 | * Accounting subsystem can call its functions here to |
c757249a SN |
256 | * fill in relevant parts of struct taskstsats as follows |
257 | * | |
ad4ecbcb | 258 | * per-task-foo(stats, tsk); |
c757249a | 259 | */ |
ad4ecbcb | 260 | delayacct_add_tsk(stats, tsk); |
6f44993f | 261 | |
c757249a SN |
262 | } while_each_thread(first, tsk); |
263 | read_unlock(&tasklist_lock); | |
6f44993f SN |
264 | stats->version = TASKSTATS_VERSION; |
265 | ||
c757249a | 266 | /* |
ad4ecbcb SN |
267 | * Accounting subsytems can also add calls here to modify |
268 | * fields of taskstats. | |
c757249a | 269 | */ |
fca178c0 | 270 | put_task_struct(first); |
ad4ecbcb SN |
271 | return 0; |
272 | } | |
273 | ||
274 | ||
275 | static void fill_tgid_exit(struct task_struct *tsk) | |
276 | { | |
277 | unsigned long flags; | |
278 | ||
279 | spin_lock_irqsave(&tsk->signal->stats_lock, flags); | |
280 | if (!tsk->signal->stats) | |
281 | goto ret; | |
282 | ||
283 | /* | |
284 | * Each accounting subsystem calls its functions here to | |
285 | * accumalate its per-task stats for tsk, into the per-tgid structure | |
286 | * | |
287 | * per-task-foo(tsk->signal->stats, tsk); | |
288 | */ | |
289 | delayacct_add_tsk(tsk->signal->stats, tsk); | |
290 | ret: | |
291 | spin_unlock_irqrestore(&tsk->signal->stats_lock, flags); | |
292 | return; | |
c757249a SN |
293 | } |
294 | ||
f9fd8914 SN |
295 | static int add_del_listener(pid_t pid, cpumask_t *maskp, int isadd) |
296 | { | |
297 | struct listener_list *listeners; | |
298 | struct listener *s, *tmp; | |
299 | unsigned int cpu; | |
300 | cpumask_t mask = *maskp; | |
ad4ecbcb | 301 | |
f9fd8914 SN |
302 | if (!cpus_subset(mask, cpu_possible_map)) |
303 | return -EINVAL; | |
304 | ||
305 | if (isadd == REGISTER) { | |
306 | for_each_cpu_mask(cpu, mask) { | |
307 | s = kmalloc_node(sizeof(struct listener), GFP_KERNEL, | |
308 | cpu_to_node(cpu)); | |
309 | if (!s) | |
310 | goto cleanup; | |
311 | s->pid = pid; | |
312 | INIT_LIST_HEAD(&s->list); | |
bb129994 | 313 | s->valid = 1; |
f9fd8914 SN |
314 | |
315 | listeners = &per_cpu(listener_array, cpu); | |
316 | down_write(&listeners->sem); | |
317 | list_add(&s->list, &listeners->list); | |
318 | up_write(&listeners->sem); | |
319 | } | |
320 | return 0; | |
321 | } | |
322 | ||
323 | /* Deregister or cleanup */ | |
324 | cleanup: | |
325 | for_each_cpu_mask(cpu, mask) { | |
326 | listeners = &per_cpu(listener_array, cpu); | |
327 | down_write(&listeners->sem); | |
328 | list_for_each_entry_safe(s, tmp, &listeners->list, list) { | |
329 | if (s->pid == pid) { | |
330 | list_del(&s->list); | |
331 | kfree(s); | |
332 | break; | |
333 | } | |
334 | } | |
335 | up_write(&listeners->sem); | |
336 | } | |
337 | return 0; | |
338 | } | |
339 | ||
340 | static int parse(struct nlattr *na, cpumask_t *mask) | |
341 | { | |
342 | char *data; | |
343 | int len; | |
344 | int ret; | |
345 | ||
346 | if (na == NULL) | |
347 | return 1; | |
348 | len = nla_len(na); | |
349 | if (len > TASKSTATS_CPUMASK_MAXLEN) | |
350 | return -E2BIG; | |
351 | if (len < 1) | |
352 | return -EINVAL; | |
353 | data = kmalloc(len, GFP_KERNEL); | |
354 | if (!data) | |
355 | return -ENOMEM; | |
356 | nla_strlcpy(data, na, len); | |
357 | ret = cpulist_parse(data, *mask); | |
358 | kfree(data); | |
359 | return ret; | |
360 | } | |
361 | ||
362 | static int taskstats_user_cmd(struct sk_buff *skb, struct genl_info *info) | |
c757249a SN |
363 | { |
364 | int rc = 0; | |
365 | struct sk_buff *rep_skb; | |
366 | struct taskstats stats; | |
367 | void *reply; | |
368 | size_t size; | |
369 | struct nlattr *na; | |
f9fd8914 SN |
370 | cpumask_t mask; |
371 | ||
372 | rc = parse(info->attrs[TASKSTATS_CMD_ATTR_REGISTER_CPUMASK], &mask); | |
373 | if (rc < 0) | |
374 | return rc; | |
375 | if (rc == 0) | |
376 | return add_del_listener(info->snd_pid, &mask, REGISTER); | |
377 | ||
378 | rc = parse(info->attrs[TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK], &mask); | |
379 | if (rc < 0) | |
380 | return rc; | |
381 | if (rc == 0) | |
382 | return add_del_listener(info->snd_pid, &mask, DEREGISTER); | |
c757249a SN |
383 | |
384 | /* | |
385 | * Size includes space for nested attributes | |
386 | */ | |
387 | size = nla_total_size(sizeof(u32)) + | |
388 | nla_total_size(sizeof(struct taskstats)) + nla_total_size(0); | |
389 | ||
390 | memset(&stats, 0, sizeof(stats)); | |
391 | rc = prepare_reply(info, TASKSTATS_CMD_NEW, &rep_skb, &reply, size); | |
392 | if (rc < 0) | |
393 | return rc; | |
394 | ||
395 | if (info->attrs[TASKSTATS_CMD_ATTR_PID]) { | |
396 | u32 pid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_PID]); | |
397 | rc = fill_pid(pid, NULL, &stats); | |
398 | if (rc < 0) | |
399 | goto err; | |
400 | ||
401 | na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_PID); | |
402 | NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_PID, pid); | |
403 | NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS, | |
404 | stats); | |
405 | } else if (info->attrs[TASKSTATS_CMD_ATTR_TGID]) { | |
406 | u32 tgid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_TGID]); | |
407 | rc = fill_tgid(tgid, NULL, &stats); | |
408 | if (rc < 0) | |
409 | goto err; | |
410 | ||
411 | na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_TGID); | |
412 | NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_TGID, tgid); | |
413 | NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS, | |
414 | stats); | |
415 | } else { | |
416 | rc = -EINVAL; | |
417 | goto err; | |
418 | } | |
419 | ||
420 | nla_nest_end(rep_skb, na); | |
421 | ||
f9fd8914 | 422 | return send_reply(rep_skb, info->snd_pid); |
c757249a SN |
423 | |
424 | nla_put_failure: | |
425 | return genlmsg_cancel(rep_skb, reply); | |
426 | err: | |
427 | nlmsg_free(rep_skb); | |
428 | return rc; | |
429 | } | |
430 | ||
f9fd8914 SN |
431 | void taskstats_exit_alloc(struct taskstats **ptidstats, unsigned int *mycpu) |
432 | { | |
433 | struct listener_list *listeners; | |
434 | struct taskstats *tmp; | |
435 | /* | |
436 | * This is the cpu on which the task is exiting currently and will | |
437 | * be the one for which the exit event is sent, even if the cpu | |
438 | * on which this function is running changes later. | |
439 | */ | |
440 | *mycpu = raw_smp_processor_id(); | |
441 | ||
442 | *ptidstats = NULL; | |
443 | tmp = kmem_cache_zalloc(taskstats_cache, SLAB_KERNEL); | |
444 | if (!tmp) | |
445 | return; | |
446 | ||
447 | listeners = &per_cpu(listener_array, *mycpu); | |
448 | down_read(&listeners->sem); | |
449 | if (!list_empty(&listeners->list)) { | |
450 | *ptidstats = tmp; | |
451 | tmp = NULL; | |
452 | } | |
453 | up_read(&listeners->sem); | |
454 | kfree(tmp); | |
455 | } | |
456 | ||
c757249a SN |
457 | /* Send pid data out on exit */ |
458 | void taskstats_exit_send(struct task_struct *tsk, struct taskstats *tidstats, | |
f9fd8914 | 459 | int group_dead, unsigned int mycpu) |
c757249a SN |
460 | { |
461 | int rc; | |
462 | struct sk_buff *rep_skb; | |
463 | void *reply; | |
464 | size_t size; | |
465 | int is_thread_group; | |
466 | struct nlattr *na; | |
ad4ecbcb | 467 | unsigned long flags; |
c757249a SN |
468 | |
469 | if (!family_registered || !tidstats) | |
470 | return; | |
471 | ||
ad4ecbcb SN |
472 | spin_lock_irqsave(&tsk->signal->stats_lock, flags); |
473 | is_thread_group = tsk->signal->stats ? 1 : 0; | |
474 | spin_unlock_irqrestore(&tsk->signal->stats_lock, flags); | |
c757249a | 475 | |
ad4ecbcb | 476 | rc = 0; |
c757249a SN |
477 | /* |
478 | * Size includes space for nested attributes | |
479 | */ | |
480 | size = nla_total_size(sizeof(u32)) + | |
481 | nla_total_size(sizeof(struct taskstats)) + nla_total_size(0); | |
482 | ||
483 | if (is_thread_group) | |
484 | size = 2 * size; /* PID + STATS + TGID + STATS */ | |
485 | ||
486 | rc = prepare_reply(NULL, TASKSTATS_CMD_NEW, &rep_skb, &reply, size); | |
487 | if (rc < 0) | |
488 | goto ret; | |
489 | ||
490 | rc = fill_pid(tsk->pid, tsk, tidstats); | |
491 | if (rc < 0) | |
492 | goto err_skb; | |
493 | ||
494 | na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_PID); | |
495 | NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_PID, (u32)tsk->pid); | |
496 | NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS, | |
497 | *tidstats); | |
498 | nla_nest_end(rep_skb, na); | |
499 | ||
ad4ecbcb SN |
500 | if (!is_thread_group) |
501 | goto send; | |
c757249a | 502 | |
c757249a | 503 | /* |
ad4ecbcb SN |
504 | * tsk has/had a thread group so fill the tsk->signal->stats structure |
505 | * Doesn't matter if tsk is the leader or the last group member leaving | |
c757249a | 506 | */ |
ad4ecbcb SN |
507 | |
508 | fill_tgid_exit(tsk); | |
509 | if (!group_dead) | |
510 | goto send; | |
c757249a SN |
511 | |
512 | na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_TGID); | |
513 | NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_TGID, (u32)tsk->tgid); | |
ad4ecbcb | 514 | /* No locking needed for tsk->signal->stats since group is dead */ |
c757249a | 515 | NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS, |
ad4ecbcb | 516 | *tsk->signal->stats); |
c757249a SN |
517 | nla_nest_end(rep_skb, na); |
518 | ||
ad4ecbcb | 519 | send: |
f9fd8914 | 520 | send_cpu_listeners(rep_skb, mycpu); |
ad4ecbcb | 521 | return; |
c757249a SN |
522 | |
523 | nla_put_failure: | |
524 | genlmsg_cancel(rep_skb, reply); | |
525 | goto ret; | |
526 | err_skb: | |
527 | nlmsg_free(rep_skb); | |
528 | ret: | |
c757249a SN |
529 | return; |
530 | } | |
531 | ||
532 | static struct genl_ops taskstats_ops = { | |
533 | .cmd = TASKSTATS_CMD_GET, | |
f9fd8914 | 534 | .doit = taskstats_user_cmd, |
c757249a SN |
535 | .policy = taskstats_cmd_get_policy, |
536 | }; | |
537 | ||
538 | /* Needed early in initialization */ | |
539 | void __init taskstats_init_early(void) | |
540 | { | |
f9fd8914 SN |
541 | unsigned int i; |
542 | ||
c757249a SN |
543 | taskstats_cache = kmem_cache_create("taskstats_cache", |
544 | sizeof(struct taskstats), | |
545 | 0, SLAB_PANIC, NULL, NULL); | |
f9fd8914 SN |
546 | for_each_possible_cpu(i) { |
547 | INIT_LIST_HEAD(&(per_cpu(listener_array, i).list)); | |
548 | init_rwsem(&(per_cpu(listener_array, i).sem)); | |
549 | } | |
c757249a SN |
550 | } |
551 | ||
552 | static int __init taskstats_init(void) | |
553 | { | |
554 | int rc; | |
555 | ||
556 | rc = genl_register_family(&family); | |
557 | if (rc) | |
558 | return rc; | |
559 | ||
560 | rc = genl_register_ops(&family, &taskstats_ops); | |
561 | if (rc < 0) | |
562 | goto err; | |
563 | ||
564 | family_registered = 1; | |
565 | return 0; | |
566 | err: | |
567 | genl_unregister_family(&family); | |
568 | return rc; | |
569 | } | |
570 | ||
571 | /* | |
572 | * late initcall ensures initialization of statistics collection | |
573 | * mechanisms precedes initialization of the taskstats interface | |
574 | */ | |
575 | late_initcall(taskstats_init); |