From dac27f4a09c274db048e80d2511102e540ac9e3a Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Tue, 28 Mar 2006 16:11:28 -0800 Subject: [PATCH] [PATCH] simplify do_signal_stop() do_signal_stop() considers 'thread_group_empty()' as a special case. This was needed to avoid taking tasklist_lock. Since this lock is unneeded any longer, we can remove this special case and simplify the code even more. Also, before this patch, finish_stop() was called with stop_count == -1 for 'thread_group_empty()' case. This is not strictly wrong, but confusing and unneeded. Signed-off-by: Oleg Nesterov Cc: john stultz Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/signal.c | 32 ++++++++------------------------ 1 file changed, 8 insertions(+), 24 deletions(-) diff --git a/kernel/signal.c b/kernel/signal.c index 2dfaa5076c31..efba39626e66 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -1685,8 +1685,7 @@ finish_stop(int stop_count) static int do_signal_stop(int signr) { struct signal_struct *sig = current->signal; - struct sighand_struct *sighand = current->sighand; - int stop_count = -1; + int stop_count; if (!likely(sig->flags & SIGNAL_STOP_DEQUEUED)) return 0; @@ -1696,30 +1695,14 @@ static int do_signal_stop(int signr) * There is a group stop in progress. We don't need to * start another one. */ - signr = sig->group_exit_code; stop_count = --sig->group_stop_count; - current->exit_code = signr; - set_current_state(TASK_STOPPED); - if (stop_count == 0) - sig->flags = SIGNAL_STOP_STOPPED; - } - else if (thread_group_empty(current)) { + } else { /* - * Lock must be held through transition to stopped state. - */ - current->exit_code = current->signal->group_exit_code = signr; - set_current_state(TASK_STOPPED); - sig->flags = SIGNAL_STOP_STOPPED; - } - else { - /* - * (sig->group_stop_count == 0) * There is no group stop already in progress. * We must initiate one now. */ struct task_struct *t; - current->exit_code = signr; sig->group_exit_code = signr; stop_count = 0; @@ -1735,13 +1718,14 @@ static int do_signal_stop(int signr) signal_wake_up(t, 0); } sig->group_stop_count = stop_count; - - set_current_state(TASK_STOPPED); - if (stop_count == 0) - sig->flags = SIGNAL_STOP_STOPPED; } - spin_unlock_irq(&sighand->siglock); + if (stop_count == 0) + sig->flags = SIGNAL_STOP_STOPPED; + current->exit_code = sig->group_exit_code; + __set_current_state(TASK_STOPPED); + + spin_unlock_irq(¤t->sighand->siglock); finish_stop(stop_count); return 1; }