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authorMikulas Patocka <mpatocka@redhat.com>2009-01-06 03:04:54 +0000
committerAlasdair G Kergon <agk@redhat.com>2009-01-06 03:04:54 +0000
commit90fa1527bddc7147dc0d590ee6184ca88bc50ecf (patch)
treea6b692b5a7ef777cbd8f2927783f593234b091d1
parenta1b51e98676932d031f5eec1325b2df4bbdc8f26 (diff)
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 <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
-rw-r--r--drivers/md/dm-snap.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index 6c96db26b87..4ceedd4f22a 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -9,6 +9,7 @@
#include <linux/blkdev.h>
#include <linux/ctype.h>
#include <linux/device-mapper.h>
+#include <linux/delay.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/kdev_t.h>
@@ -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