[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.

Oleg Nesterov committed 19 years ago

Commit 34ec1231 parent 115085e3 files · +25 −26Browse files

Unified · Split

3 files

include/linux/taskstats_kern.h +0 −24
kernel/fork.c +0 −1
kernel/taskstats.c +25 −1

include/linux/taskstats_kern.h+0−24

@@ -20,28 +20,6 @@ static inline void taskstats_tgid_init(struct signal_struct *sig) · 19 unmodified lines
20	sig->stats = NULL;	20	sig->stats = NULL;
21	}	21	}
22		22
23	static inline void taskstats_tgid_alloc(struct task_struct *tsk)
24	{
25	struct signal_struct *sig = tsk->signal;
26	struct taskstats *stats;
27
28	if (sig->stats != NULL)
29	return;
30
31	/* No problem if kmem_cache_zalloc() fails */
32	stats = kmem_cache_zalloc(taskstats_cache, GFP_KERNEL);
33
34	spin_lock_irq(&tsk->sighand->siglock);
35	if (!sig->stats) {
36	sig->stats = stats;
37	stats = NULL;
38	}
39	spin_unlock_irq(&tsk->sighand->siglock);
40
41	if (stats)
42	kmem_cache_free(taskstats_cache, stats);
43	}
44
45	static inline void taskstats_tgid_free(struct signal_struct *sig)	23	static inline void taskstats_tgid_free(struct signal_struct *sig)
46	{	24	{
47	if (sig->stats)	25	if (sig->stats)
@@ -55,8 +33,6 @@ static inline void taskstats_exit(struct task_struct *tsk, int group_dead) · 7 unmodified lines
55	{}	33	{}
56	static inline void taskstats_tgid_init(struct signal_struct *sig)	34	static inline void taskstats_tgid_init(struct signal_struct *sig)
57	{}	35	{}
58	static inline void taskstats_tgid_alloc(struct task_struct *tsk)
59	{}
60	static inline void taskstats_tgid_free(struct signal_struct *sig)	36	static inline void taskstats_tgid_free(struct signal_struct *sig)
61	{}	37	{}
62	static inline void taskstats_init_early(void)	38	static inline void taskstats_init_early(void)

kernel/fork.c+0−1

@@ -847,7 +847,6 @@ static inline int copy_signal(unsigned long clone_flags, struct task_struct * ts · 846 unmodified lines
847	if (clone_flags & CLONE_THREAD) {	847	if (clone_flags & CLONE_THREAD) {
848	atomic_inc(&current->signal->count);	848	atomic_inc(&current->signal->count);
849	atomic_inc(&current->signal->live);	849	atomic_inc(&current->signal->live);
850	taskstats_tgid_alloc(current);
851	return 0;	850	return 0;
852	}	851	}
853	sig = kmem_cache_alloc(signal_cachep, GFP_KERNEL);	852	sig = kmem_cache_alloc(signal_cachep, GFP_KERNEL);

kernel/taskstats.c+25−1

@@ -412,6 +412,30 @@ err: · 411 unmodified lines
412	return rc;	412	return rc;
413	}	413	}
414		414
		415	static struct taskstats taskstats_tgid_alloc(struct task_struct tsk)
		416	{
		417	struct signal_struct *sig = tsk->signal;
		418	struct taskstats *stats;
		419
		420	if (sig->stats \|\| thread_group_empty(tsk))
		421	goto ret;
		422
		423	/* No problem if kmem_cache_zalloc() fails */
		424	stats = kmem_cache_zalloc(taskstats_cache, GFP_KERNEL);
		425
		426	spin_lock_irq(&tsk->sighand->siglock);
		427	if (!sig->stats) {
		428	sig->stats = stats;
		429	stats = NULL;
		430	}
		431	spin_unlock_irq(&tsk->sighand->siglock);
		432
		433	if (stats)
		434	kmem_cache_free(taskstats_cache, stats);
		435	ret:
		436	return sig->stats;
		437	}
		438
415	/* Send pid data out on exit */	439	/* Send pid data out on exit */
416	void taskstats_exit(struct task_struct *tsk, int group_dead)	440	void taskstats_exit(struct task_struct *tsk, int group_dead)
417	{	441	{
@@ -433,7 +457,7 @@ void taskstats_exit(struct task_struct *tsk, int group_dead) · 15 unmodified lines
433	size = nla_total_size(sizeof(u32)) +	457	size = nla_total_size(sizeof(u32)) +
434	nla_total_size(sizeof(struct taskstats)) + nla_total_size(0);	458	nla_total_size(sizeof(struct taskstats)) + nla_total_size(0);
435		459
436	is_thread_group = (tsk->signal->stats != NULL);	460	is_thread_group = !!taskstats_tgid_alloc(tsk);
437	if (is_thread_group) {	461	if (is_thread_group) {
438	/* PID + STATS + TGID + STATS */	462	/* PID + STATS + TGID + STATS */
439	size = 2 * size;	463	size = 2 * size;