[PATCH] Make suspend possible with a traced process at a breakpoint

It should be possible to suspend, either to RAM or to disk, if there's a
traced process that has just reached a breakpoint.  However, this is a
special case, because its parent process might have been frozen already and
then we are unable to deliver the "freeze" signal to the traced process.
If this happens, it's better to cancel the freezing of the traced process.

Ref. http://bugzilla.kernel.org/show_bug.cgi?id=6787

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 6afa72e..6674fc1 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1558,6 +1558,14 @@
 }
 
 /*
+ * Sometimes we may need to cancel the previous 'freeze' request
+ */
+static inline void do_not_freeze(struct task_struct *p)
+{
+	p->flags &= ~PF_FREEZE;
+}
+
+/*
  * Wake up a frozen process
  */
 static inline int thaw_process(struct task_struct *p)