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authorHeiko Carstens <heiko.carstens@de.ibm.com>2009-01-23 16:40:26 +0100
committerHeiko Carstens <heiko.carstens@de.ibm.com>2009-01-23 16:40:29 +0100
commit179cb81aa1e9dc5444f678a6dd4dbb90c60322e1 (patch)
treeb8f4c37049a357ba16fd94360ae3d4c2c8661810 /arch/s390/kernel/time.c
parentf9a2f797fcde5a4aa818bd3ca8584fd1197e9c15 (diff)
downloadblackbird-op-linux-179cb81aa1e9dc5444f678a6dd4dbb90c60322e1.tar.gz
blackbird-op-linux-179cb81aa1e9dc5444f678a6dd4dbb90c60322e1.zip
[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>
Diffstat (limited to 'arch/s390/kernel/time.c')
-rw-r--r--arch/s390/kernel/time.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c
index d649600df5b9..fc468cae4460 100644
--- a/arch/s390/kernel/time.c
+++ b/arch/s390/kernel/time.c
@@ -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();
}
/*
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