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| author | Heiko Carstens <heiko.carstens@de.ibm.com> | 2009-01-23 16:40:26 +0100 |
|---|---|---|
| committer | Heiko Carstens <heiko.carstens@de.ibm.com> | 2009-01-23 16:40:29 +0100 |
| commit | 179cb81aa1e9dc5444f678a6dd4dbb90c60322e1 (patch) | |
| tree | b8f4c37049a357ba16fd94360ae3d4c2c8661810 /arch/s390 | |
| parent | f9a2f797fcde5a4aa818bd3ca8584fd1197e9c15 (diff) | |
| download | lwn-179cb81aa1e9dc5444f678a6dd4dbb90c60322e1.tar.gz lwn-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')
| -rw-r--r-- | arch/s390/kernel/time.c | 6 |
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(); } /* |