Commit 179cb81a authored Jan 23, 2009 by Heiko Carstens

[S390] etr/stp: fix possible deadlock



Precreate stop_machine threads in case the machine supports ETR/STP.
Otherwise we might deadlock if a time sync operation gets scheduled
and the creation of stop_machine threads would cause disk I/O.
This is just the minimal fix.
The real fix would be to only precreate stop_machine threads if
ETR/STP is actually used. But that would be a rather large and
complicated patch.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

parent f9a2f797

arch/s390/kernel/time.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -399,8 +399,10 @@ static struct workqueue_struct *time_sync_wq;

		static void __init time_init_wq(void)
		{
		if (!time_sync_wq)
		if (time_sync_wq)
		return;
		time_sync_wq = create_singlethread_workqueue("timesync");
		stop_machine_create();
		}

		/*