[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	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	23	static inline void taskstats_tgid_free(struct signal_struct *sig)
46	24	{
47	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	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	36	static inline void taskstats_tgid_free(struct signal_struct *sig)
61	37	{}
62	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	847	if (clone_flags & CLONE_THREAD) {
848	848	atomic_inc(&current->signal->count);
849	849	atomic_inc(&current->signal->live);
850		− taskstats_tgid_alloc(current);
851	850	return 0;
852	851	}
853	852	sig = kmem_cache_alloc(signal_cachep, GFP_KERNEL);

kernel/taskstats.c+25−1

@@ -412,6 +412,30 @@ err: · 411 unmodified lines
412	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	439	/* Send pid data out on exit */
416	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	457	size = nla_total_size(sizeof(u32)) +
434	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	461	if (is_thread_group) {
438	462	/* PID + STATS + TGID + STATS */
439	463	size = 2 * size;