Commit 115085ea authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Linus Torvalds
Browse files

[PATCH] taskstats: cleanup do_exit() path 



do_exit:
	taskstats_exit_alloc()
	...
	taskstats_exit_send()
	taskstats_exit_free()

I think this is not good, let it be a single function exported to the core
kernel, taskstats_exit(), which does alloc + send + free itself.

Signed-off-by: default avatarOleg Nesterov <oleg@tv-sign.ru>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Shailabh Nagar <nagar@watson.ibm.com>
Cc: Jay Lan <jlan@engr.sgi.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 128fb956

include/linux/taskstats_kern.h

+2 −15
Original line number Diff line number Diff line
@@ -15,12 +15,6 @@ 
extern struct kmem_cache *taskstats_cache;

extern struct mutex taskstats_exit_mutex;



static inline void taskstats_exit_free(struct taskstats *tidstats)

{

	if (tidstats)

		kmem_cache_free(taskstats_cache, tidstats);

}



static inline void taskstats_tgid_init(struct signal_struct *sig)

{

	sig->stats = NULL;
@@ -54,17 +48,10 @@ static inline void taskstats_tgid_free(struct signal_struct *sig) 
		kmem_cache_free(taskstats_cache, sig->stats);

}



extern void taskstats_exit_alloc(struct taskstats **, unsigned int *);

extern void taskstats_exit_send(struct task_struct *, struct taskstats *, int, unsigned int);

extern void taskstats_exit(struct task_struct *, int group_dead);

extern void taskstats_init_early(void);

#else

static inline void taskstats_exit_alloc(struct taskstats **ptidstats, unsigned int *mycpu)

{}

static inline void taskstats_exit_free(struct taskstats *ptidstats)

{}

static inline void taskstats_exit_send(struct task_struct *tsk,

				       struct taskstats *tidstats,

				       int group_dead, unsigned int cpu)

static inline void taskstats_exit(struct task_struct *tsk, int group_dead)

{}

static inline void taskstats_tgid_init(struct signal_struct *sig)

{}

kernel/exit.c

+2 −6
Original line number Diff line number Diff line
@@ -850,9 +850,7 @@ static void exit_notify(struct task_struct *tsk) 
fastcall NORET_TYPE void do_exit(long code)

{

	struct task_struct *tsk = current;

	struct taskstats *tidstats;

	int group_dead;

	unsigned int mycpu;



	profile_task_exit(tsk);
@@ -890,8 +888,6 @@ fastcall NORET_TYPE void do_exit(long code) 
				current->comm, current->pid,

				preempt_count());



	taskstats_exit_alloc(&tidstats, &mycpu);



	acct_update_integrals(tsk);

	if (tsk->mm) {

		update_hiwater_rss(tsk->mm);
@@ -911,8 +907,8 @@ fastcall NORET_TYPE void do_exit(long code) 
#endif

	if (unlikely(tsk->audit_context))

		audit_free(tsk);

	taskstats_exit_send(tsk, tidstats, group_dead, mycpu);

	taskstats_exit_free(tidstats);



	taskstats_exit(tsk, group_dead);



	exit_mm(tsk);

kernel/taskstats.c

+15 −26
Original line number Diff line number Diff line
@@ -119,10 +119,10 @@ static int send_reply(struct sk_buff *skb, pid_t pid) 
/*

 * Send taskstats data in @skb to listeners registered for @cpu's exit data

 */

static void send_cpu_listeners(struct sk_buff *skb, unsigned int cpu)

static void send_cpu_listeners(struct sk_buff *skb,

					struct listener_list *listeners)

{

	struct genlmsghdr *genlhdr = nlmsg_data((struct nlmsghdr *)skb->data);

	struct listener_list *listeners;

	struct listener *s, *tmp;

	struct sk_buff *skb_next, *skb_cur = skb;

	void *reply = genlmsg_data(genlhdr);
@@ -135,7 +135,6 @@ static void send_cpu_listeners(struct sk_buff *skb, unsigned int cpu) 
	}



	rc = 0;

	listeners = &per_cpu(listener_array, cpu);

	down_read(&listeners->sem);

	list_for_each_entry(s, &listeners->list, list) {

		skb_next = NULL;
@@ -413,28 +412,12 @@ err: 
	return rc;

}



void taskstats_exit_alloc(struct taskstats **ptidstats, unsigned int *mycpu)

{

	struct listener_list *listeners;

	/*

	 * This is the cpu on which the task is exiting currently and will

	 * be the one for which the exit event is sent, even if the cpu

	 * on which this function is running changes later.

	 */

	*mycpu = raw_smp_processor_id();



	listeners = &per_cpu(listener_array, *mycpu);



	*ptidstats = NULL;

	if (!list_empty(&listeners->list))

		*ptidstats = kmem_cache_zalloc(taskstats_cache, GFP_KERNEL);

}



/* Send pid data out on exit */

void taskstats_exit_send(struct task_struct *tsk, struct taskstats *tidstats,

			int group_dead, unsigned int mycpu)

void taskstats_exit(struct task_struct *tsk, int group_dead)

{

	int rc;

	struct listener_list *listeners;

	struct taskstats *tidstats;

	struct sk_buff *rep_skb;

	void *reply;

	size_t size;
@@ -458,12 +441,17 @@ void taskstats_exit_send(struct task_struct *tsk, struct taskstats *tidstats, 
		fill_tgid_exit(tsk);

	}



	listeners = &__raw_get_cpu_var(listener_array);

	if (list_empty(&listeners->list))

		return;



	tidstats = kmem_cache_zalloc(taskstats_cache, GFP_KERNEL);

	if (!tidstats)

		return;



	rc = prepare_reply(NULL, TASKSTATS_CMD_NEW, &rep_skb, &reply, size);

	if (rc < 0)

		goto ret;

		goto free_stats;



	rc = fill_pid(tsk->pid, tsk, tidstats);

	if (rc < 0)
@@ -492,15 +480,16 @@ void taskstats_exit_send(struct task_struct *tsk, struct taskstats *tidstats, 
	nla_nest_end(rep_skb, na);



send:

	send_cpu_listeners(rep_skb, mycpu);

	send_cpu_listeners(rep_skb, listeners);

free_stats:

	kmem_cache_free(taskstats_cache, tidstats);

	return;



nla_put_failure:

	genlmsg_cancel(rep_skb, reply);

err_skb:

	nlmsg_free(rep_skb);

ret:

	return;

	goto free_stats;

}



static struct genl_ops taskstats_ops = {

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