[PATCH 2/2] signals: document CLD_CONTINUED notification mechanics

[Oleg Nesterov]

A couple of small comments about how CLD_CONTINUED notification works.

Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>

--- 25/kernel/signal.c~2_DOC_NOTIFY	2008-03-12 13:29:42.000000000 +0300
+++ 25/kernel/signal.c	2008-03-12 15:16:52.000000000 +0300
@@ -630,6 +630,11 @@ static int prepare_signal(int sig, struc
 			why |= SIGNAL_CLD_STOPPED;
 
 		if (why) {
+			/*
+			 * The first thread which returns from finish_stop()
+			 * will take ->siglock, notice SIGNAL_CLD_MASK, and
+			 * notify its parent. See get_signal_to_deliver().
+			 */
 			signal->flags = why | SIGNAL_STOP_CONTINUED;
 			signal->group_stop_count = 0;
 			signal->group_exit_code = 0;
@@ -1652,7 +1657,7 @@ relock:
 	try_to_freeze();
 
 	spin_lock_irq(&sighand->siglock);
-
+	/* see prepare_signal(SIGCONT) */
 	if (unlikely(signal->flags & SIGNAL_CLD_MASK)) {
 		int why = (signal->flags & SIGNAL_STOP_CONTINUED)
 				? CLD_CONTINUED : CLD_STOPPED;

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