From: Amerigo Wang <amwang@redhat.com>
Date: Wed, 23 Dec 2009 10:04:49 -0500
Subject: [misc] khungtaskd: set PF_NOFREEZE flag to fix suspend
Message-id: <20091223100756.4643.29619.sendpatchset@localhost.localdomain>
Patchwork-id: 22269
O-Subject: [PATCH RHEL5] khungtaskd: set PF_NOFREEZE flag by itself
Bugzilla: 550014
RH-Acked-by: Matthew Garrett <mjg@redhat.com>
RH-Acked-by: Jarod Wilson <jarod@redhat.com>

BZ:
https://bugzilla.redhat.com/show_bug.cgi?id=550014

Description:
In RHEL5 kernel, kthread_run() will not set PF_NOFREEZE
for us, we have to set this flag by our own.

Fixes a suspend hang witnessed on some systems.

Upstream status:
Upstream doesn't need this.

Signed-off-by: WANG Cong <amwang@redhat.com>


diff --git a/kernel/hung_task.c b/kernel/hung_task.c
index 0d5a150..0fc6038 100644
--- a/kernel/hung_task.c
+++ b/kernel/hung_task.c
@@ -189,6 +189,10 @@ int proc_dohung_task_timeout_secs(struct ctl_table *table, int write,
 static int watchdog(void *dummy)
 {
 	set_user_nice(current, 0);
+	/*
+	 * kthread_run() doesn't help us here.
+	 */
+	current->flags |= PF_NOFREEZE;
 
 	for ( ; ; ) {
 		unsigned long timeout = sysctl_hung_task_timeout_secs;