Shailabh Nagar | c757249 | 2006-07-14 00:24:40 -0700 | [diff] [blame] | 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> |
Shailabh Nagar | 6f44993 | 2006-07-14 00:24:41 -0700 | [diff] [blame] | 21 | #include <linux/delayacct.h> |
Shailabh Nagar | c757249 | 2006-07-14 00:24:40 -0700 | [diff] [blame] | 22 | #include <net/genetlink.h> |
| 23 | #include <asm/atomic.h> |
| 24 | |
| 25 | static DEFINE_PER_CPU(__u32, taskstats_seqnum) = { 0 }; |
| 26 | static int family_registered; |
| 27 | kmem_cache_t *taskstats_cache; |
Shailabh Nagar | c757249 | 2006-07-14 00:24:40 -0700 | [diff] [blame] | 28 | |
| 29 | static struct genl_family family = { |
| 30 | .id = GENL_ID_GENERATE, |
| 31 | .name = TASKSTATS_GENL_NAME, |
| 32 | .version = TASKSTATS_GENL_VERSION, |
| 33 | .maxattr = TASKSTATS_CMD_ATTR_MAX, |
| 34 | }; |
| 35 | |
| 36 | static struct nla_policy taskstats_cmd_get_policy[TASKSTATS_CMD_ATTR_MAX+1] |
| 37 | __read_mostly = { |
| 38 | [TASKSTATS_CMD_ATTR_PID] = { .type = NLA_U32 }, |
| 39 | [TASKSTATS_CMD_ATTR_TGID] = { .type = NLA_U32 }, |
| 40 | }; |
| 41 | |
| 42 | |
| 43 | static int prepare_reply(struct genl_info *info, u8 cmd, struct sk_buff **skbp, |
| 44 | void **replyp, size_t size) |
| 45 | { |
| 46 | struct sk_buff *skb; |
| 47 | void *reply; |
| 48 | |
| 49 | /* |
| 50 | * If new attributes are added, please revisit this allocation |
| 51 | */ |
| 52 | skb = nlmsg_new(size); |
| 53 | if (!skb) |
| 54 | return -ENOMEM; |
| 55 | |
| 56 | if (!info) { |
| 57 | int seq = get_cpu_var(taskstats_seqnum)++; |
| 58 | put_cpu_var(taskstats_seqnum); |
| 59 | |
| 60 | reply = genlmsg_put(skb, 0, seq, |
| 61 | family.id, 0, 0, |
| 62 | cmd, family.version); |
| 63 | } else |
| 64 | reply = genlmsg_put(skb, info->snd_pid, info->snd_seq, |
| 65 | family.id, 0, 0, |
| 66 | cmd, family.version); |
| 67 | if (reply == NULL) { |
| 68 | nlmsg_free(skb); |
| 69 | return -EINVAL; |
| 70 | } |
| 71 | |
| 72 | *skbp = skb; |
| 73 | *replyp = reply; |
| 74 | return 0; |
| 75 | } |
| 76 | |
| 77 | static int send_reply(struct sk_buff *skb, pid_t pid, int event) |
| 78 | { |
| 79 | struct genlmsghdr *genlhdr = nlmsg_data((struct nlmsghdr *)skb->data); |
| 80 | void *reply; |
| 81 | int rc; |
| 82 | |
| 83 | reply = genlmsg_data(genlhdr); |
| 84 | |
| 85 | rc = genlmsg_end(skb, reply); |
| 86 | if (rc < 0) { |
| 87 | nlmsg_free(skb); |
| 88 | return rc; |
| 89 | } |
| 90 | |
| 91 | if (event == TASKSTATS_MSG_MULTICAST) |
| 92 | return genlmsg_multicast(skb, pid, TASKSTATS_LISTEN_GROUP); |
| 93 | return genlmsg_unicast(skb, pid); |
| 94 | } |
| 95 | |
| 96 | static int fill_pid(pid_t pid, struct task_struct *pidtsk, |
| 97 | struct taskstats *stats) |
| 98 | { |
| 99 | int rc; |
| 100 | struct task_struct *tsk = pidtsk; |
| 101 | |
| 102 | if (!pidtsk) { |
| 103 | read_lock(&tasklist_lock); |
| 104 | tsk = find_task_by_pid(pid); |
| 105 | if (!tsk) { |
| 106 | read_unlock(&tasklist_lock); |
| 107 | return -ESRCH; |
| 108 | } |
| 109 | get_task_struct(tsk); |
| 110 | read_unlock(&tasklist_lock); |
| 111 | } else |
| 112 | get_task_struct(tsk); |
| 113 | |
| 114 | /* |
| 115 | * Each accounting subsystem adds calls to its functions to |
| 116 | * fill in relevant parts of struct taskstsats as follows |
| 117 | * |
| 118 | * rc = per-task-foo(stats, tsk); |
| 119 | * if (rc) |
| 120 | * goto err; |
| 121 | */ |
| 122 | |
Shailabh Nagar | 6f44993 | 2006-07-14 00:24:41 -0700 | [diff] [blame] | 123 | rc = delayacct_add_tsk(stats, tsk); |
| 124 | stats->version = TASKSTATS_VERSION; |
| 125 | |
| 126 | /* Define err: label here if needed */ |
Shailabh Nagar | c757249 | 2006-07-14 00:24:40 -0700 | [diff] [blame] | 127 | put_task_struct(tsk); |
| 128 | return rc; |
| 129 | |
| 130 | } |
| 131 | |
| 132 | static int fill_tgid(pid_t tgid, struct task_struct *tgidtsk, |
| 133 | struct taskstats *stats) |
| 134 | { |
Shailabh Nagar | c757249 | 2006-07-14 00:24:40 -0700 | [diff] [blame] | 135 | struct task_struct *tsk, *first; |
Shailabh Nagar | ad4ecbc | 2006-07-14 00:24:44 -0700 | [diff] [blame^] | 136 | unsigned long flags; |
Shailabh Nagar | c757249 | 2006-07-14 00:24:40 -0700 | [diff] [blame] | 137 | |
Shailabh Nagar | ad4ecbc | 2006-07-14 00:24:44 -0700 | [diff] [blame^] | 138 | /* |
| 139 | * Add additional stats from live tasks except zombie thread group |
| 140 | * leaders who are already counted with the dead tasks |
| 141 | */ |
Shailabh Nagar | c757249 | 2006-07-14 00:24:40 -0700 | [diff] [blame] | 142 | first = tgidtsk; |
Shailabh Nagar | c757249 | 2006-07-14 00:24:40 -0700 | [diff] [blame] | 143 | if (!first) { |
Shailabh Nagar | ad4ecbc | 2006-07-14 00:24:44 -0700 | [diff] [blame^] | 144 | read_lock(&tasklist_lock); |
Shailabh Nagar | c757249 | 2006-07-14 00:24:40 -0700 | [diff] [blame] | 145 | first = find_task_by_pid(tgid); |
| 146 | if (!first) { |
| 147 | read_unlock(&tasklist_lock); |
| 148 | return -ESRCH; |
| 149 | } |
Shailabh Nagar | ad4ecbc | 2006-07-14 00:24:44 -0700 | [diff] [blame^] | 150 | get_task_struct(first); |
| 151 | read_unlock(&tasklist_lock); |
| 152 | } else |
| 153 | get_task_struct(first); |
| 154 | |
| 155 | /* Start with stats from dead tasks */ |
| 156 | spin_lock_irqsave(&first->signal->stats_lock, flags); |
| 157 | if (first->signal->stats) |
| 158 | memcpy(stats, first->signal->stats, sizeof(*stats)); |
| 159 | spin_unlock_irqrestore(&first->signal->stats_lock, flags); |
| 160 | |
Shailabh Nagar | c757249 | 2006-07-14 00:24:40 -0700 | [diff] [blame] | 161 | tsk = first; |
Shailabh Nagar | ad4ecbc | 2006-07-14 00:24:44 -0700 | [diff] [blame^] | 162 | read_lock(&tasklist_lock); |
Shailabh Nagar | c757249 | 2006-07-14 00:24:40 -0700 | [diff] [blame] | 163 | do { |
Shailabh Nagar | ad4ecbc | 2006-07-14 00:24:44 -0700 | [diff] [blame^] | 164 | if (tsk->exit_state == EXIT_ZOMBIE && thread_group_leader(tsk)) |
| 165 | continue; |
Shailabh Nagar | c757249 | 2006-07-14 00:24:40 -0700 | [diff] [blame] | 166 | /* |
Shailabh Nagar | ad4ecbc | 2006-07-14 00:24:44 -0700 | [diff] [blame^] | 167 | * Accounting subsystem can call its functions here to |
Shailabh Nagar | c757249 | 2006-07-14 00:24:40 -0700 | [diff] [blame] | 168 | * fill in relevant parts of struct taskstsats as follows |
| 169 | * |
Shailabh Nagar | ad4ecbc | 2006-07-14 00:24:44 -0700 | [diff] [blame^] | 170 | * per-task-foo(stats, tsk); |
Shailabh Nagar | c757249 | 2006-07-14 00:24:40 -0700 | [diff] [blame] | 171 | */ |
Shailabh Nagar | ad4ecbc | 2006-07-14 00:24:44 -0700 | [diff] [blame^] | 172 | delayacct_add_tsk(stats, tsk); |
Shailabh Nagar | 6f44993 | 2006-07-14 00:24:41 -0700 | [diff] [blame] | 173 | |
Shailabh Nagar | c757249 | 2006-07-14 00:24:40 -0700 | [diff] [blame] | 174 | } while_each_thread(first, tsk); |
| 175 | read_unlock(&tasklist_lock); |
Shailabh Nagar | 6f44993 | 2006-07-14 00:24:41 -0700 | [diff] [blame] | 176 | stats->version = TASKSTATS_VERSION; |
| 177 | |
Shailabh Nagar | c757249 | 2006-07-14 00:24:40 -0700 | [diff] [blame] | 178 | /* |
Shailabh Nagar | ad4ecbc | 2006-07-14 00:24:44 -0700 | [diff] [blame^] | 179 | * Accounting subsytems can also add calls here to modify |
| 180 | * fields of taskstats. |
Shailabh Nagar | c757249 | 2006-07-14 00:24:40 -0700 | [diff] [blame] | 181 | */ |
| 182 | |
Shailabh Nagar | ad4ecbc | 2006-07-14 00:24:44 -0700 | [diff] [blame^] | 183 | return 0; |
Shailabh Nagar | c757249 | 2006-07-14 00:24:40 -0700 | [diff] [blame] | 184 | } |
| 185 | |
Shailabh Nagar | ad4ecbc | 2006-07-14 00:24:44 -0700 | [diff] [blame^] | 186 | |
| 187 | static void fill_tgid_exit(struct task_struct *tsk) |
| 188 | { |
| 189 | unsigned long flags; |
| 190 | |
| 191 | spin_lock_irqsave(&tsk->signal->stats_lock, flags); |
| 192 | if (!tsk->signal->stats) |
| 193 | goto ret; |
| 194 | |
| 195 | /* |
| 196 | * Each accounting subsystem calls its functions here to |
| 197 | * accumalate its per-task stats for tsk, into the per-tgid structure |
| 198 | * |
| 199 | * per-task-foo(tsk->signal->stats, tsk); |
| 200 | */ |
| 201 | delayacct_add_tsk(tsk->signal->stats, tsk); |
| 202 | ret: |
| 203 | spin_unlock_irqrestore(&tsk->signal->stats_lock, flags); |
| 204 | return; |
| 205 | } |
| 206 | |
| 207 | |
Shailabh Nagar | c757249 | 2006-07-14 00:24:40 -0700 | [diff] [blame] | 208 | static int taskstats_send_stats(struct sk_buff *skb, struct genl_info *info) |
| 209 | { |
| 210 | int rc = 0; |
| 211 | struct sk_buff *rep_skb; |
| 212 | struct taskstats stats; |
| 213 | void *reply; |
| 214 | size_t size; |
| 215 | struct nlattr *na; |
| 216 | |
| 217 | /* |
| 218 | * Size includes space for nested attributes |
| 219 | */ |
| 220 | size = nla_total_size(sizeof(u32)) + |
| 221 | nla_total_size(sizeof(struct taskstats)) + nla_total_size(0); |
| 222 | |
| 223 | memset(&stats, 0, sizeof(stats)); |
| 224 | rc = prepare_reply(info, TASKSTATS_CMD_NEW, &rep_skb, &reply, size); |
| 225 | if (rc < 0) |
| 226 | return rc; |
| 227 | |
| 228 | if (info->attrs[TASKSTATS_CMD_ATTR_PID]) { |
| 229 | u32 pid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_PID]); |
| 230 | rc = fill_pid(pid, NULL, &stats); |
| 231 | if (rc < 0) |
| 232 | goto err; |
| 233 | |
| 234 | na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_PID); |
| 235 | NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_PID, pid); |
| 236 | NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS, |
| 237 | stats); |
| 238 | } else if (info->attrs[TASKSTATS_CMD_ATTR_TGID]) { |
| 239 | u32 tgid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_TGID]); |
| 240 | rc = fill_tgid(tgid, NULL, &stats); |
| 241 | if (rc < 0) |
| 242 | goto err; |
| 243 | |
| 244 | na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_TGID); |
| 245 | NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_TGID, tgid); |
| 246 | NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS, |
| 247 | stats); |
| 248 | } else { |
| 249 | rc = -EINVAL; |
| 250 | goto err; |
| 251 | } |
| 252 | |
| 253 | nla_nest_end(rep_skb, na); |
| 254 | |
| 255 | return send_reply(rep_skb, info->snd_pid, TASKSTATS_MSG_UNICAST); |
| 256 | |
| 257 | nla_put_failure: |
| 258 | return genlmsg_cancel(rep_skb, reply); |
| 259 | err: |
| 260 | nlmsg_free(rep_skb); |
| 261 | return rc; |
| 262 | } |
| 263 | |
| 264 | /* Send pid data out on exit */ |
| 265 | void taskstats_exit_send(struct task_struct *tsk, struct taskstats *tidstats, |
Shailabh Nagar | ad4ecbc | 2006-07-14 00:24:44 -0700 | [diff] [blame^] | 266 | int group_dead) |
Shailabh Nagar | c757249 | 2006-07-14 00:24:40 -0700 | [diff] [blame] | 267 | { |
| 268 | int rc; |
| 269 | struct sk_buff *rep_skb; |
| 270 | void *reply; |
| 271 | size_t size; |
| 272 | int is_thread_group; |
| 273 | struct nlattr *na; |
Shailabh Nagar | ad4ecbc | 2006-07-14 00:24:44 -0700 | [diff] [blame^] | 274 | unsigned long flags; |
Shailabh Nagar | c757249 | 2006-07-14 00:24:40 -0700 | [diff] [blame] | 275 | |
| 276 | if (!family_registered || !tidstats) |
| 277 | return; |
| 278 | |
Shailabh Nagar | ad4ecbc | 2006-07-14 00:24:44 -0700 | [diff] [blame^] | 279 | spin_lock_irqsave(&tsk->signal->stats_lock, flags); |
| 280 | is_thread_group = tsk->signal->stats ? 1 : 0; |
| 281 | spin_unlock_irqrestore(&tsk->signal->stats_lock, flags); |
Shailabh Nagar | c757249 | 2006-07-14 00:24:40 -0700 | [diff] [blame] | 282 | |
Shailabh Nagar | ad4ecbc | 2006-07-14 00:24:44 -0700 | [diff] [blame^] | 283 | rc = 0; |
Shailabh Nagar | c757249 | 2006-07-14 00:24:40 -0700 | [diff] [blame] | 284 | /* |
| 285 | * Size includes space for nested attributes |
| 286 | */ |
| 287 | size = nla_total_size(sizeof(u32)) + |
| 288 | nla_total_size(sizeof(struct taskstats)) + nla_total_size(0); |
| 289 | |
| 290 | if (is_thread_group) |
| 291 | size = 2 * size; /* PID + STATS + TGID + STATS */ |
| 292 | |
| 293 | rc = prepare_reply(NULL, TASKSTATS_CMD_NEW, &rep_skb, &reply, size); |
| 294 | if (rc < 0) |
| 295 | goto ret; |
| 296 | |
| 297 | rc = fill_pid(tsk->pid, tsk, tidstats); |
| 298 | if (rc < 0) |
| 299 | goto err_skb; |
| 300 | |
| 301 | na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_PID); |
| 302 | NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_PID, (u32)tsk->pid); |
| 303 | NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS, |
| 304 | *tidstats); |
| 305 | nla_nest_end(rep_skb, na); |
| 306 | |
Shailabh Nagar | ad4ecbc | 2006-07-14 00:24:44 -0700 | [diff] [blame^] | 307 | if (!is_thread_group) |
| 308 | goto send; |
Shailabh Nagar | c757249 | 2006-07-14 00:24:40 -0700 | [diff] [blame] | 309 | |
Shailabh Nagar | c757249 | 2006-07-14 00:24:40 -0700 | [diff] [blame] | 310 | /* |
Shailabh Nagar | ad4ecbc | 2006-07-14 00:24:44 -0700 | [diff] [blame^] | 311 | * tsk has/had a thread group so fill the tsk->signal->stats structure |
| 312 | * Doesn't matter if tsk is the leader or the last group member leaving |
Shailabh Nagar | c757249 | 2006-07-14 00:24:40 -0700 | [diff] [blame] | 313 | */ |
Shailabh Nagar | ad4ecbc | 2006-07-14 00:24:44 -0700 | [diff] [blame^] | 314 | |
| 315 | fill_tgid_exit(tsk); |
| 316 | if (!group_dead) |
| 317 | goto send; |
Shailabh Nagar | c757249 | 2006-07-14 00:24:40 -0700 | [diff] [blame] | 318 | |
| 319 | na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_TGID); |
| 320 | NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_TGID, (u32)tsk->tgid); |
Shailabh Nagar | ad4ecbc | 2006-07-14 00:24:44 -0700 | [diff] [blame^] | 321 | /* No locking needed for tsk->signal->stats since group is dead */ |
Shailabh Nagar | c757249 | 2006-07-14 00:24:40 -0700 | [diff] [blame] | 322 | NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS, |
Shailabh Nagar | ad4ecbc | 2006-07-14 00:24:44 -0700 | [diff] [blame^] | 323 | *tsk->signal->stats); |
Shailabh Nagar | c757249 | 2006-07-14 00:24:40 -0700 | [diff] [blame] | 324 | nla_nest_end(rep_skb, na); |
| 325 | |
Shailabh Nagar | ad4ecbc | 2006-07-14 00:24:44 -0700 | [diff] [blame^] | 326 | send: |
Shailabh Nagar | c757249 | 2006-07-14 00:24:40 -0700 | [diff] [blame] | 327 | send_reply(rep_skb, 0, TASKSTATS_MSG_MULTICAST); |
Shailabh Nagar | ad4ecbc | 2006-07-14 00:24:44 -0700 | [diff] [blame^] | 328 | return; |
Shailabh Nagar | c757249 | 2006-07-14 00:24:40 -0700 | [diff] [blame] | 329 | |
| 330 | nla_put_failure: |
| 331 | genlmsg_cancel(rep_skb, reply); |
| 332 | goto ret; |
| 333 | err_skb: |
| 334 | nlmsg_free(rep_skb); |
| 335 | ret: |
Shailabh Nagar | c757249 | 2006-07-14 00:24:40 -0700 | [diff] [blame] | 336 | return; |
| 337 | } |
| 338 | |
| 339 | static struct genl_ops taskstats_ops = { |
| 340 | .cmd = TASKSTATS_CMD_GET, |
| 341 | .doit = taskstats_send_stats, |
| 342 | .policy = taskstats_cmd_get_policy, |
| 343 | }; |
| 344 | |
| 345 | /* Needed early in initialization */ |
| 346 | void __init taskstats_init_early(void) |
| 347 | { |
| 348 | taskstats_cache = kmem_cache_create("taskstats_cache", |
| 349 | sizeof(struct taskstats), |
| 350 | 0, SLAB_PANIC, NULL, NULL); |
| 351 | } |
| 352 | |
| 353 | static int __init taskstats_init(void) |
| 354 | { |
| 355 | int rc; |
| 356 | |
| 357 | rc = genl_register_family(&family); |
| 358 | if (rc) |
| 359 | return rc; |
| 360 | |
| 361 | rc = genl_register_ops(&family, &taskstats_ops); |
| 362 | if (rc < 0) |
| 363 | goto err; |
| 364 | |
| 365 | family_registered = 1; |
| 366 | return 0; |
| 367 | err: |
| 368 | genl_unregister_family(&family); |
| 369 | return rc; |
| 370 | } |
| 371 | |
| 372 | /* |
| 373 | * late initcall ensures initialization of statistics collection |
| 374 | * mechanisms precedes initialization of the taskstats interface |
| 375 | */ |
| 376 | late_initcall(taskstats_init); |