From 34ec12349c8a9505adc59d72f92b4595bc2483ff Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Wed, 6 Dec 2006 20:36:52 -0800 Subject: [PATCH] [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 Cc: Balbir Singh Cc: Shailabh Nagar Cc: Jay Lan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/taskstats_kern.h | 24 ------------------------ kernel/fork.c | 1 - kernel/taskstats.c | 26 +++++++++++++++++++++++++- 3 files changed, 25 insertions(+), 26 deletions(-) diff --git a/include/linux/taskstats_kern.h b/include/linux/taskstats_kern.h index f1261a532496..7e9680f4afdd 100644 --- a/include/linux/taskstats_kern.h +++ b/include/linux/taskstats_kern.h @@ -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) diff --git a/kernel/fork.c b/kernel/fork.c index f37980df1d58..658838148647 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -847,7 +847,6 @@ static inline int copy_signal(unsigned long clone_flags, struct task_struct * ts if (clone_flags & CLONE_THREAD) { atomic_inc(¤t->signal->count); atomic_inc(¤t->signal->live); - taskstats_tgid_alloc(current); return 0; } sig = kmem_cache_alloc(signal_cachep, GFP_KERNEL); diff --git a/kernel/taskstats.c b/kernel/taskstats.c index 2654886fe058..7d793d6b1e90 100644 --- a/kernel/taskstats.c +++ b/kernel/taskstats.c @@ -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; -- GitLab