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| author | Oleg Nesterov <oleg@redhat.com> | 2010-05-26 14:43:24 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-05-27 09:12:47 -0700 |
| commit | b3ac022cb9dc5883505a88b159d1b240ad1ef405 (patch) | |
| tree | bffa035303cbe3c5bde048ac3d3154fb57059e2d /kernel/exit.c | |
| parent | dd98acf74762764fbc4382a1d9a244f11a2658cc (diff) | |
| download | lwn-b3ac022cb9dc5883505a88b159d1b240ad1ef405.tar.gz lwn-b3ac022cb9dc5883505a88b159d1b240ad1ef405.zip | |
proc: turn signal_struct->count into "int nr_threads"
No functional changes, just s/atomic_t count/int nr_threads/.
With the recent changes this counter has a single user, get_nr_threads()
And, none of its callers need the really accurate number of threads, not
to mention each caller obviously races with fork/exit. It is only used to
report this value to the user-space, except first_tid() uses it to avoid
the unnecessary while_each_thread() loop in the unlikely case.
It is a bit sad we need a word in struct signal_struct for this, perhaps
we can change get_nr_threads() to approximate the number of threads using
signal->live and kill ->nr_threads later.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.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>
Diffstat (limited to 'kernel/exit.c')
| -rw-r--r-- | kernel/exit.c | 5 |
1 files changed, 1 insertions, 4 deletions
diff --git a/kernel/exit.c b/kernel/exit.c index 357d443d5a00..ceffc67b564a 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -83,14 +83,10 @@ static void __exit_signal(struct task_struct *tsk) struct sighand_struct *sighand; struct tty_struct *uninitialized_var(tty); - BUG_ON(!sig); - BUG_ON(!atomic_read(&sig->count)); - sighand = rcu_dereference_check(tsk->sighand, rcu_read_lock_held() || lockdep_tasklist_lock_is_held()); spin_lock(&sighand->siglock); - atomic_dec(&sig->count); posix_cpu_timers_exit(tsk); if (group_dead) { @@ -130,6 +126,7 @@ static void __exit_signal(struct task_struct *tsk) sig->sum_sched_runtime += tsk->se.sum_exec_runtime; } + sig->nr_threads--; __unhash_process(tsk, group_dead); /* |