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Commit 34ec1234 authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Linus Torvalds
Browse files

[PATCH] taskstats: cleanup ->signal->stats allocation 



Allocate ->signal->stats on demand in taskstats_exit(), this allows us to
remove taskstats_tgid_alloc() (the last non-trivial inline) from taskstat's
public interface.

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 115085ea

include/linux/taskstats_kern.h

+0 −24
Original line number Diff line number Diff line
@@ -20,28 +20,6 @@ static inline void taskstats_tgid_init(struct signal_struct *sig) 
	sig->stats = NULL;

}



static inline void taskstats_tgid_alloc(struct task_struct *tsk)

{

	struct signal_struct *sig = tsk->signal;

	struct taskstats *stats;



	if (sig->stats != NULL)

		return;



	/* 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);

}



static inline void taskstats_tgid_free(struct signal_struct *sig)

{

	if (sig->stats)
@@ -55,8 +33,6 @@ static inline void taskstats_exit(struct task_struct *tsk, int group_dead) 
{}

static inline void taskstats_tgid_init(struct signal_struct *sig)

{}

static inline void taskstats_tgid_alloc(struct task_struct *tsk)

{}

static inline void taskstats_tgid_free(struct signal_struct *sig)

{}

static inline void taskstats_init_early(void)

kernel/fork.c

+0 −1
Original line number Diff line number Diff line
@@ -847,7 +847,6 @@ static inline int copy_signal(unsigned long clone_flags, struct task_struct * ts 
	if (clone_flags & CLONE_THREAD) {

		atomic_inc(&current->signal->count);

		atomic_inc(&current->signal->live);

		taskstats_tgid_alloc(current);

		return 0;

	}

	sig = kmem_cache_alloc(signal_cachep, GFP_KERNEL);

kernel/taskstats.c

+25 −1
Original line number Diff line number Diff line
@@ -412,6 +412,30 @@ static int taskstats_user_cmd(struct sk_buff *skb, struct genl_info *info) 
	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(struct task_struct *tsk, int group_dead)

{
@@ -433,7 +457,7 @@ void taskstats_exit(struct task_struct *tsk, int group_dead) 
	size = nla_total_size(sizeof(u32)) +

		nla_total_size(sizeof(struct taskstats)) + nla_total_size(0);



	is_thread_group = (tsk->signal->stats != NULL);

	is_thread_group = !!taskstats_tgid_alloc(tsk);

	if (is_thread_group) {

		/* PID + STATS + TGID + STATS */

		size = 2 * size;