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authorOleg Nesterov <oleg@redhat.com>2010-05-26 14:43:22 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-05-27 09:12:47 -0700
commit7e49827cc937a742ae02078b483e3eb78f791a2a (patch)
tree0f3e0a8483a41b2221c74b8286b2349af03dab04
parent6e1be45aa6ba6a36c0312f65ecf311135c73001d (diff)
downloadop-kernel-dev-7e49827cc937a742ae02078b483e3eb78f791a2a.zip
op-kernel-dev-7e49827cc937a742ae02078b483e3eb78f791a2a.tar.gz
proc: get_nr_threads() doesn't need ->siglock any longer
Now that task->signal can't go away get_nr_threads() doesn't need ->siglock to read signal->count. Also, make it inline, move into sched.h, and convert 2 other proc users of signal->count to use this (now trivial) helper. Henceforth get_nr_threads() is the only valid user of signal->count, we are ready to turn it into "int nr_threads" or, perhaps, kill it. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--fs/proc/array.c4
-rw-r--r--fs/proc/base.c12
-rw-r--r--include/linux/sched.h5
3 files changed, 7 insertions, 14 deletions
diff --git a/fs/proc/array.c b/fs/proc/array.c
index 885ab55..9b58d38 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -267,7 +267,7 @@ static inline void task_sig(struct seq_file *m, struct task_struct *p)
shpending = p->signal->shared_pending.signal;
blocked = p->blocked;
collect_sigign_sigcatch(p, &ignored, &caught);
- num_threads = atomic_read(&p->signal->count);
+ num_threads = get_nr_threads(p);
rcu_read_lock(); /* FIXME: is this correct? */
qsize = atomic_read(&__task_cred(p)->user->sigpending);
rcu_read_unlock();
@@ -410,7 +410,7 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
tty_nr = new_encode_dev(tty_devnum(sig->tty));
}
- num_threads = atomic_read(&sig->count);
+ num_threads = get_nr_threads(task);
collect_sigign_sigcatch(task, &sigign, &sigcatch);
cmin_flt = sig->cmin_flt;
diff --git a/fs/proc/base.c b/fs/proc/base.c
index c7f9f23..c384e8b 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -166,18 +166,6 @@ static int get_fs_path(struct task_struct *task, struct path *path, bool root)
return result;
}
-static int get_nr_threads(struct task_struct *tsk)
-{
- unsigned long flags;
- int count = 0;
-
- if (lock_task_sighand(tsk, &flags)) {
- count = atomic_read(&tsk->signal->count);
- unlock_task_sighand(tsk, &flags);
- }
- return count;
-}
-
static int proc_cwd_link(struct inode *inode, struct path *path)
{
struct task_struct *task = get_proc_task(inode);
diff --git a/include/linux/sched.h b/include/linux/sched.h
index dd597d8..ccd2d15 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2147,6 +2147,11 @@ extern bool current_is_single_threaded(void);
#define while_each_thread(g, t) \
while ((t = next_thread(t)) != g)
+static inline int get_nr_threads(struct task_struct *tsk)
+{
+ return atomic_read(&tsk->signal->count);
+}
+
/* de_thread depends on thread_group_leader not being a pid based check */
#define thread_group_leader(p) (p == p->group_leader)
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