[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: Oleg 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: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Oleg Nesterov 2006-12-06 20:36:52 -08:00 committed by Linus Torvalds
parent 115085ea07
commit 34ec12349c
3 changed files with 25 additions and 26 deletions

View File

@ -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)

View File

@ -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);

View File

@ -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;