From 90fa1527bddc7147dc0d590ee6184ca88bc50ecf Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Tue, 6 Jan 2009 03:04:54 +0000 Subject: [PATCH] dm snapshot: change yield to msleep Change yield() to msleep(1). If the thread had realtime priority, yield() doesn't really yield, so the yielding process would loop indefinitely and cause machine lockup. Signed-off-by: Mikulas Patocka Signed-off-by: Alasdair G Kergon --- drivers/md/dm-snap.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c index 6c96db26b87c..4ceedd4f22af 100644 --- a/drivers/md/dm-snap.c +++ b/drivers/md/dm-snap.c @@ -9,6 +9,7 @@ #include #include #include +#include #include #include #include @@ -735,7 +736,7 @@ static void snapshot_dtr(struct dm_target *ti) unregister_snapshot(s); while (atomic_read(&s->pending_exceptions_count)) - yield(); + msleep(1); /* * Ensure instructions in mempool_destroy aren't reordered * before atomic_read. @@ -888,10 +889,10 @@ static void pending_complete(struct dm_snap_pending_exception *pe, int success) /* * Check for conflicting reads. This is extremely improbable, - * so yield() is sufficient and there is no need for a wait queue. + * so msleep(1) is sufficient and there is no need for a wait queue. */ while (__chunk_is_tracked(s, pe->e.old_chunk)) - yield(); + msleep(1); /* * Add a proper exception, and remove the