[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>
This commit is contained in:
Heiko Carstens 2009-01-23 16:40:26 +01:00
parent f9a2f797fc
commit 179cb81aa1

View File

@ -399,8 +399,10 @@ static struct workqueue_struct *time_sync_wq;
static void __init time_init_wq(void)
{
if (!time_sync_wq)
time_sync_wq = create_singlethread_workqueue("timesync");
if (time_sync_wq)
return;
time_sync_wq = create_singlethread_workqueue("timesync");
stop_machine_create();
}
/*