per-zone and reclaim enhancements for memory controller: modifies vmscan.c for isolat...
[linux-2.6.git] / kernel / taskstats.c
index 4a0a502..07e86a8 100644 (file)
 
 #include <linux/kernel.h>
 #include <linux/taskstats_kern.h>
+#include <linux/tsacct_kern.h>
 #include <linux/delayacct.h>
+#include <linux/cpumask.h>
+#include <linux/percpu.h>
+#include <linux/cgroupstats.h>
+#include <linux/cgroup.h>
+#include <linux/fs.h>
+#include <linux/file.h>
 #include <net/genetlink.h>
 #include <asm/atomic.h>
 
+/*
+ * Maximum length of a cpumask that can be specified in
+ * the TASKSTATS_CMD_ATTR_REGISTER/DEREGISTER_CPUMASK attribute
+ */
+#define TASKSTATS_CPUMASK_MAXLEN       (100+6*NR_CPUS)
+
 static DEFINE_PER_CPU(__u32, taskstats_seqnum) = { 0 };
 static int family_registered;
-kmem_cache_t *taskstats_cache;
+struct kmem_cache *taskstats_cache;
 
 static struct genl_family family = {
        .id             = GENL_ID_GENERATE,
@@ -37,11 +50,34 @@ static struct nla_policy taskstats_cmd_get_policy[TASKSTATS_CMD_ATTR_MAX+1]
 __read_mostly = {
        [TASKSTATS_CMD_ATTR_PID]  = { .type = NLA_U32 },
        [TASKSTATS_CMD_ATTR_TGID] = { .type = NLA_U32 },
+       [TASKSTATS_CMD_ATTR_REGISTER_CPUMASK] = { .type = NLA_STRING },
+       [TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK] = { .type = NLA_STRING },};
+
+static struct nla_policy
+cgroupstats_cmd_get_policy[CGROUPSTATS_CMD_ATTR_MAX+1] __read_mostly = {
+       [CGROUPSTATS_CMD_ATTR_FD] = { .type = NLA_U32 },
+};
+
+struct listener {
+       struct list_head list;
+       pid_t pid;
+       char valid;
 };
 
+struct listener_list {
+       struct rw_semaphore sem;
+       struct list_head list;
+};
+static DEFINE_PER_CPU(struct listener_list, listener_array);
+
+enum actions {
+       REGISTER,
+       DEREGISTER,
+       CPU_DONT_CARE
+};
 
 static int prepare_reply(struct genl_info *info, u8 cmd, struct sk_buff **skbp,
-                       void **replyp, size_t size)
+                               size_t size)
 {
        struct sk_buff *skb;
        void *reply;
@@ -49,7 +85,7 @@ static int prepare_reply(struct genl_info *info, u8 cmd, struct sk_buff **skbp,
        /*
         * If new attributes are added, please revisit this allocation
         */
-       skb = nlmsg_new(size);
+       skb = genlmsg_new(size, GFP_KERNEL);
        if (!skb)
                return -ENOMEM;
 
@@ -57,71 +93,123 @@ static int prepare_reply(struct genl_info *info, u8 cmd, struct sk_buff **skbp,
                int seq = get_cpu_var(taskstats_seqnum)++;
                put_cpu_var(taskstats_seqnum);
 
-               reply = genlmsg_put(skb, 0, seq,
-                               family.id, 0, 0,
-                               cmd, family.version);
+               reply = genlmsg_put(skb, 0, seq, &family, 0, cmd);
        } else
-               reply = genlmsg_put(skb, info->snd_pid, info->snd_seq,
-                               family.id, 0, 0,
-                               cmd, family.version);
+               reply = genlmsg_put_reply(skb, info, &family, 0, cmd);
        if (reply == NULL) {
                nlmsg_free(skb);
                return -EINVAL;
        }
 
        *skbp = skb;
-       *replyp = reply;
        return 0;
 }
 
-static int send_reply(struct sk_buff *skb, pid_t pid, int event)
+/*
+ * Send taskstats data in @skb to listener with nl_pid @pid
+ */
+static int send_reply(struct sk_buff *skb, pid_t pid)
 {
-       struct genlmsghdr *genlhdr = nlmsg_data((struct nlmsghdr *)skb->data);
-       void *reply;
+       struct genlmsghdr *genlhdr = nlmsg_data(nlmsg_hdr(skb));
+       void *reply = genlmsg_data(genlhdr);
        int rc;
 
-       reply = genlmsg_data(genlhdr);
-
        rc = genlmsg_end(skb, reply);
        if (rc < 0) {
                nlmsg_free(skb);
                return rc;
        }
 
-       if (event == TASKSTATS_MSG_MULTICAST)
-               return genlmsg_multicast(skb, pid, TASKSTATS_LISTEN_GROUP);
        return genlmsg_unicast(skb, pid);
 }
 
-static int fill_pid(pid_t pid, struct task_struct *pidtsk,
+/*
+ * Send taskstats data in @skb to listeners registered for @cpu's exit data
+ */
+static void send_cpu_listeners(struct sk_buff *skb,
+                                       struct listener_list *listeners)
+{
+       struct genlmsghdr *genlhdr = nlmsg_data(nlmsg_hdr(skb));
+       struct listener *s, *tmp;
+       struct sk_buff *skb_next, *skb_cur = skb;
+       void *reply = genlmsg_data(genlhdr);
+       int rc, delcount = 0;
+
+       rc = genlmsg_end(skb, reply);
+       if (rc < 0) {
+               nlmsg_free(skb);
+               return;
+       }
+
+       rc = 0;
+       down_read(&listeners->sem);
+       list_for_each_entry(s, &listeners->list, list) {
+               skb_next = NULL;
+               if (!list_is_last(&s->list, &listeners->list)) {
+                       skb_next = skb_clone(skb_cur, GFP_KERNEL);
+                       if (!skb_next)
+                               break;
+               }
+               rc = genlmsg_unicast(skb_cur, s->pid);
+               if (rc == -ECONNREFUSED) {
+                       s->valid = 0;
+                       delcount++;
+               }
+               skb_cur = skb_next;
+       }
+       up_read(&listeners->sem);
+
+       if (skb_cur)
+               nlmsg_free(skb_cur);
+
+       if (!delcount)
+               return;
+
+       /* Delete invalidated entries */
+       down_write(&listeners->sem);
+       list_for_each_entry_safe(s, tmp, &listeners->list, list) {
+               if (!s->valid) {
+                       list_del(&s->list);
+                       kfree(s);
+               }
+       }
+       up_write(&listeners->sem);
+}
+
+static int fill_pid(pid_t pid, struct task_struct *tsk,
                struct taskstats *stats)
 {
-       int rc;
-       struct task_struct *tsk = pidtsk;
+       int rc = 0;
 
-       if (!pidtsk) {
-               read_lock(&tasklist_lock);
+       if (!tsk) {
+               rcu_read_lock();
                tsk = find_task_by_pid(pid);
-               if (!tsk) {
-                       read_unlock(&tasklist_lock);
+               if (tsk)
+                       get_task_struct(tsk);
+               rcu_read_unlock();
+               if (!tsk)
                        return -ESRCH;
-               }
-               get_task_struct(tsk);
-               read_unlock(&tasklist_lock);
        } else
                get_task_struct(tsk);
 
+       memset(stats, 0, sizeof(*stats));
        /*
         * Each accounting subsystem adds calls to its functions to
         * fill in relevant parts of struct taskstsats as follows
         *
-        *      rc = per-task-foo(stats, tsk);
-        *      if (rc)
-        *              goto err;
+        *      per-task-foo(stats, tsk);
         */
 
-       rc = delayacct_add_tsk(stats, tsk);
+       delayacct_add_tsk(stats, tsk);
+
+       /* fill in basic acct fields */
        stats->version = TASKSTATS_VERSION;
+       stats->nvcsw = tsk->nvcsw;
+       stats->nivcsw = tsk->nivcsw;
+       bacct_add_tsk(stats, tsk);
+
+       /* fill in extended acct fields */
+       xacct_add_tsk(stats, tsk);
 
        /* Define err: label here if needed */
        put_task_struct(tsk);
@@ -129,39 +217,32 @@ static int fill_pid(pid_t pid, struct task_struct *pidtsk,
 
 }
 
-static int fill_tgid(pid_t tgid, struct task_struct *tgidtsk,
+static int fill_tgid(pid_t tgid, struct task_struct *first,
                struct taskstats *stats)
 {
-       struct task_struct *tsk, *first;
+       struct task_struct *tsk;
        unsigned long flags;
+       int rc = -ESRCH;
 
        /*
         * Add additional stats from live tasks except zombie thread group
         * leaders who are already counted with the dead tasks
         */
-       first = tgidtsk;
-       if (!first) {
-               read_lock(&tasklist_lock);
+       rcu_read_lock();
+       if (!first)
                first = find_task_by_pid(tgid);
-               if (!first) {
-                       read_unlock(&tasklist_lock);
-                       return -ESRCH;
-               }
-               get_task_struct(first);
-               read_unlock(&tasklist_lock);
-       } else
-               get_task_struct(first);
 
-       /* Start with stats from dead tasks */
-       spin_lock_irqsave(&first->signal->stats_lock, flags);
+       if (!first || !lock_task_sighand(first, &flags))
+               goto out;
+
        if (first->signal->stats)
                memcpy(stats, first->signal->stats, sizeof(*stats));
-       spin_unlock_irqrestore(&first->signal->stats_lock, flags);
+       else
+               memset(stats, 0, sizeof(*stats));
 
        tsk = first;
-       read_lock(&tasklist_lock);
        do {
-               if (tsk->exit_state == EXIT_ZOMBIE && thread_group_leader(tsk))
+               if (tsk->exit_state)
                        continue;
                /*
                 * Accounting subsystem can call its functions here to
@@ -171,16 +252,21 @@ static int fill_tgid(pid_t tgid, struct task_struct *tgidtsk,
                 */
                delayacct_add_tsk(stats, tsk);
 
+               stats->nvcsw += tsk->nvcsw;
+               stats->nivcsw += tsk->nivcsw;
        } while_each_thread(first, tsk);
-       read_unlock(&tasklist_lock);
-       stats->version = TASKSTATS_VERSION;
 
+       unlock_task_sighand(first, &flags);
+       rc = 0;
+out:
+       rcu_read_unlock();
+
+       stats->version = TASKSTATS_VERSION;
        /*
-        * Accounting subsytems can also add calls here to modify
+        * Accounting subsystems can also add calls here to modify
         * fields of taskstats.
         */
-
-       return 0;
+       return rc;
 }
 
 
@@ -188,7 +274,7 @@ static void fill_tgid_exit(struct task_struct *tsk)
 {
        unsigned long flags;
 
-       spin_lock_irqsave(&tsk->signal->stats_lock, flags);
+       spin_lock_irqsave(&tsk->sighand->siglock, flags);
        if (!tsk->signal->stats)
                goto ret;
 
@@ -200,19 +286,165 @@ static void fill_tgid_exit(struct task_struct *tsk)
         */
        delayacct_add_tsk(tsk->signal->stats, tsk);
 ret:
-       spin_unlock_irqrestore(&tsk->signal->stats_lock, flags);
+       spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
        return;
 }
 
+static int add_del_listener(pid_t pid, cpumask_t *maskp, int isadd)
+{
+       struct listener_list *listeners;
+       struct listener *s, *tmp;
+       unsigned int cpu;
+       cpumask_t mask = *maskp;
+
+       if (!cpus_subset(mask, cpu_possible_map))
+               return -EINVAL;
+
+       if (isadd == REGISTER) {
+               for_each_cpu_mask(cpu, mask) {
+                       s = kmalloc_node(sizeof(struct listener), GFP_KERNEL,
+                                        cpu_to_node(cpu));
+                       if (!s)
+                               goto cleanup;
+                       s->pid = pid;
+                       INIT_LIST_HEAD(&s->list);
+                       s->valid = 1;
+
+                       listeners = &per_cpu(listener_array, cpu);
+                       down_write(&listeners->sem);
+                       list_add(&s->list, &listeners->list);
+                       up_write(&listeners->sem);
+               }
+               return 0;
+       }
+
+       /* Deregister or cleanup */
+cleanup:
+       for_each_cpu_mask(cpu, mask) {
+               listeners = &per_cpu(listener_array, cpu);
+               down_write(&listeners->sem);
+               list_for_each_entry_safe(s, tmp, &listeners->list, list) {
+                       if (s->pid == pid) {
+                               list_del(&s->list);
+                               kfree(s);
+                               break;
+                       }
+               }
+               up_write(&listeners->sem);
+       }
+       return 0;
+}
+
+static int parse(struct nlattr *na, cpumask_t *mask)
+{
+       char *data;
+       int len;
+       int ret;
+
+       if (na == NULL)
+               return 1;
+       len = nla_len(na);
+       if (len > TASKSTATS_CPUMASK_MAXLEN)
+               return -E2BIG;
+       if (len < 1)
+               return -EINVAL;
+       data = kmalloc(len, GFP_KERNEL);
+       if (!data)
+               return -ENOMEM;
+       nla_strlcpy(data, na, len);
+       ret = cpulist_parse(data, *mask);
+       kfree(data);
+       return ret;
+}
+
+static struct taskstats *mk_reply(struct sk_buff *skb, int type, u32 pid)
+{
+       struct nlattr *na, *ret;
+       int aggr;
+
+       aggr = (type == TASKSTATS_TYPE_PID)
+                       ? TASKSTATS_TYPE_AGGR_PID
+                       : TASKSTATS_TYPE_AGGR_TGID;
+
+       na = nla_nest_start(skb, aggr);
+       if (!na)
+               goto err;
+       if (nla_put(skb, type, sizeof(pid), &pid) < 0)
+               goto err;
+       ret = nla_reserve(skb, TASKSTATS_TYPE_STATS, sizeof(struct taskstats));
+       if (!ret)
+               goto err;
+       nla_nest_end(skb, na);
+
+       return nla_data(ret);
+err:
+       return NULL;
+}
+
+static int cgroupstats_user_cmd(struct sk_buff *skb, struct genl_info *info)
+{
+       int rc = 0;
+       struct sk_buff *rep_skb;
+       struct cgroupstats *stats;
+       struct nlattr *na;
+       size_t size;
+       u32 fd;
+       struct file *file;
+       int fput_needed;
+
+       na = info->attrs[CGROUPSTATS_CMD_ATTR_FD];
+       if (!na)
+               return -EINVAL;
+
+       fd = nla_get_u32(info->attrs[CGROUPSTATS_CMD_ATTR_FD]);
+       file = fget_light(fd, &fput_needed);
+       if (!file)
+               return 0;
+
+       size = nla_total_size(sizeof(struct cgroupstats));
 
-static int taskstats_send_stats(struct sk_buff *skb, struct genl_info *info)
+       rc = prepare_reply(info, CGROUPSTATS_CMD_NEW, &rep_skb,
+                               size);
+       if (rc < 0)
+               goto err;
+
+       na = nla_reserve(rep_skb, CGROUPSTATS_TYPE_CGROUP_STATS,
+                               sizeof(struct cgroupstats));
+       stats = nla_data(na);
+       memset(stats, 0, sizeof(*stats));
+
+       rc = cgroupstats_build(stats, file->f_dentry);
+       if (rc < 0) {
+               nlmsg_free(rep_skb);
+               goto err;
+       }
+
+       rc = send_reply(rep_skb, info->snd_pid);
+
+err:
+       fput_light(file, fput_needed);
+       return rc;
+}
+
+static int taskstats_user_cmd(struct sk_buff *skb, struct genl_info *info)
 {
        int rc = 0;
        struct sk_buff *rep_skb;
-       struct taskstats stats;
-       void *reply;
+       struct taskstats *stats;
        size_t size;
-       struct nlattr *na;
+       cpumask_t mask;
+
+       rc = parse(info->attrs[TASKSTATS_CMD_ATTR_REGISTER_CPUMASK], &mask);
+       if (rc < 0)
+               return rc;
+       if (rc == 0)
+               return add_del_listener(info->snd_pid, &mask, REGISTER);
+
+       rc = parse(info->attrs[TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK], &mask);
+       if (rc < 0)
+               return rc;
+       if (rc == 0)
+               return add_del_listener(info->snd_pid, &mask, DEREGISTER);
 
        /*
         * Size includes space for nested attributes
@@ -220,134 +452,146 @@ static int taskstats_send_stats(struct sk_buff *skb, struct genl_info *info)
        size = nla_total_size(sizeof(u32)) +
                nla_total_size(sizeof(struct taskstats)) + nla_total_size(0);
 
-       memset(&stats, 0, sizeof(stats));
-       rc = prepare_reply(info, TASKSTATS_CMD_NEW, &rep_skb, &reply, size);
+       rc = prepare_reply(info, TASKSTATS_CMD_NEW, &rep_skb, size);
        if (rc < 0)
                return rc;
 
+       rc = -EINVAL;
        if (info->attrs[TASKSTATS_CMD_ATTR_PID]) {
                u32 pid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_PID]);
-               rc = fill_pid(pid, NULL, &stats);
-               if (rc < 0)
+               stats = mk_reply(rep_skb, TASKSTATS_TYPE_PID, pid);
+               if (!stats)
                        goto err;
 
-               na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_PID);
-               NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_PID, pid);
-               NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS,
-                               stats);
+               rc = fill_pid(pid, NULL, stats);
+               if (rc < 0)
+                       goto err;
        } else if (info->attrs[TASKSTATS_CMD_ATTR_TGID]) {
                u32 tgid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_TGID]);
-               rc = fill_tgid(tgid, NULL, &stats);
-               if (rc < 0)
+               stats = mk_reply(rep_skb, TASKSTATS_TYPE_TGID, tgid);
+               if (!stats)
                        goto err;
 
-               na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_TGID);
-               NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_TGID, tgid);
-               NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS,
-                               stats);
-       } else {
-               rc = -EINVAL;
+               rc = fill_tgid(tgid, NULL, stats);
+               if (rc < 0)
+                       goto err;
+       } else
                goto err;
-       }
 
-       nla_nest_end(rep_skb, na);
-
-       return send_reply(rep_skb, info->snd_pid, TASKSTATS_MSG_UNICAST);
-
-nla_put_failure:
-       return genlmsg_cancel(rep_skb, reply);
+       return send_reply(rep_skb, info->snd_pid);
 err:
        nlmsg_free(rep_skb);
        return rc;
 }
 
+static struct taskstats *taskstats_tgid_alloc(struct task_struct *tsk)
+{
+       struct signal_struct *sig = tsk->signal;
+       struct taskstats *stats;
+
+       if (sig->stats || thread_group_empty(tsk))
+               goto ret;
+
+       /* No problem if kmem_cache_zalloc() fails */
+       stats = kmem_cache_zalloc(taskstats_cache, GFP_KERNEL);
+
+       spin_lock_irq(&tsk->sighand->siglock);
+       if (!sig->stats) {
+               sig->stats = stats;
+               stats = NULL;
+       }
+       spin_unlock_irq(&tsk->sighand->siglock);
+
+       if (stats)
+               kmem_cache_free(taskstats_cache, stats);
+ret:
+       return sig->stats;
+}
+
 /* Send pid data out on exit */
-void taskstats_exit_send(struct task_struct *tsk, struct taskstats *tidstats,
-                       int group_dead)
+void taskstats_exit(struct task_struct *tsk, int group_dead)
 {
        int rc;
+       struct listener_list *listeners;
+       struct taskstats *stats;
        struct sk_buff *rep_skb;
-       void *reply;
        size_t size;
        int is_thread_group;
-       struct nlattr *na;
-       unsigned long flags;
 
-       if (!family_registered || !tidstats)
+       if (!family_registered)
                return;
 
-       spin_lock_irqsave(&tsk->signal->stats_lock, flags);
-       is_thread_group = tsk->signal->stats ? 1 : 0;
-       spin_unlock_irqrestore(&tsk->signal->stats_lock, flags);
-
-       rc = 0;
        /*
         * Size includes space for nested attributes
         */
        size = nla_total_size(sizeof(u32)) +
                nla_total_size(sizeof(struct taskstats)) + nla_total_size(0);
 
-       if (is_thread_group)
-               size = 2 * size;        /* PID + STATS + TGID + STATS */
+       is_thread_group = !!taskstats_tgid_alloc(tsk);
+       if (is_thread_group) {
+               /* PID + STATS + TGID + STATS */
+               size = 2 * size;
+               /* fill the tsk->signal->stats structure */
+               fill_tgid_exit(tsk);
+       }
 
-       rc = prepare_reply(NULL, TASKSTATS_CMD_NEW, &rep_skb, &reply, size);
-       if (rc < 0)
-               goto ret;
+       listeners = &__raw_get_cpu_var(listener_array);
+       if (list_empty(&listeners->list))
+               return;
 
-       rc = fill_pid(tsk->pid, tsk, tidstats);
+       rc = prepare_reply(NULL, TASKSTATS_CMD_NEW, &rep_skb, size);
        if (rc < 0)
-               goto err_skb;
+               return;
 
-       na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_PID);
-       NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_PID, (u32)tsk->pid);
-       NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS,
-                       *tidstats);
-       nla_nest_end(rep_skb, na);
+       stats = mk_reply(rep_skb, TASKSTATS_TYPE_PID, tsk->pid);
+       if (!stats)
+               goto err;
 
-       if (!is_thread_group)
-               goto send;
+       rc = fill_pid(tsk->pid, tsk, stats);
+       if (rc < 0)
+               goto err;
 
        /*
-        * tsk has/had a thread group so fill the tsk->signal->stats structure
         * Doesn't matter if tsk is the leader or the last group member leaving
         */
-
-       fill_tgid_exit(tsk);
-       if (!group_dead)
+       if (!is_thread_group || !group_dead)
                goto send;
 
-       na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_TGID);
-       NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_TGID, (u32)tsk->tgid);
-       /* No locking needed for tsk->signal->stats since group is dead */
-       NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS,
-                       *tsk->signal->stats);
-       nla_nest_end(rep_skb, na);
+       stats = mk_reply(rep_skb, TASKSTATS_TYPE_TGID, tsk->tgid);
+       if (!stats)
+               goto err;
+
+       memcpy(stats, tsk->signal->stats, sizeof(*stats));
 
 send:
-       send_reply(rep_skb, 0, TASKSTATS_MSG_MULTICAST);
+       send_cpu_listeners(rep_skb, listeners);
        return;
-
-nla_put_failure:
-       genlmsg_cancel(rep_skb, reply);
-       goto ret;
-err_skb:
+err:
        nlmsg_free(rep_skb);
-ret:
-       return;
 }
 
 static struct genl_ops taskstats_ops = {
        .cmd            = TASKSTATS_CMD_GET,
-       .doit           = taskstats_send_stats,
+       .doit           = taskstats_user_cmd,
        .policy         = taskstats_cmd_get_policy,
 };
 
+static struct genl_ops cgroupstats_ops = {
+       .cmd            = CGROUPSTATS_CMD_GET,
+       .doit           = cgroupstats_user_cmd,
+       .policy         = cgroupstats_cmd_get_policy,
+};
+
 /* Needed early in initialization */
 void __init taskstats_init_early(void)
 {
-       taskstats_cache = kmem_cache_create("taskstats_cache",
-                                               sizeof(struct taskstats),
-                                               0, SLAB_PANIC, NULL, NULL);
+       unsigned int i;
+
+       taskstats_cache = KMEM_CACHE(taskstats, SLAB_PANIC);
+       for_each_possible_cpu(i) {
+               INIT_LIST_HEAD(&(per_cpu(listener_array, i).list));
+               init_rwsem(&(per_cpu(listener_array, i).sem));
+       }
 }
 
 static int __init taskstats_init(void)
@@ -362,8 +606,15 @@ static int __init taskstats_init(void)
        if (rc < 0)
                goto err;
 
+       rc = genl_register_ops(&family, &cgroupstats_ops);
+       if (rc < 0)
+               goto err_cgroup_ops;
+
        family_registered = 1;
+       printk("registered taskstats version %d\n", TASKSTATS_GENL_VERSION);
        return 0;
+err_cgroup_ops:
+       genl_unregister_ops(&family, &taskstats_ops);
 err:
        genl_unregister_family(&family);
        return rc;