The request-based DM support for checking queue congestion doesn't
require access to the live DM table.
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
---
drivers/md/dm.c | 17 ++++++++---------
1 file changed, 8 insertions(+), 9 deletions(-)
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 873512d..c92e356 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -2135,19 +2135,18 @@ static int dm_any_congested(void *congested_data, int bdi_bits)
struct dm_table *map;
if (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) {
- map = dm_get_live_table_fast(md);
- if (map) {
+ if (dm_request_based(md)) {
/*
- * Request-based dm cares about only own queue for
- * the query about congestion status of request_queue
+ * With request-based DM we only need to check the
+ * top-level queue for congestion.
*/
- if (dm_request_based(md))
- r = md->queue->backing_dev_info.wb.state &
- bdi_bits;
- else
+ r = md->queue->backing_dev_info.wb.state & bdi_bits;
+ } else {
+ map = dm_get_live_table_fast(md);
+ if (map)
r = dm_table_any_congested(map, bdi_bits);
+ dm_put_live_table_fast(md);
}
- dm_put_live_table_fast(md);
}
return r;
--
2.5.4 (Apple Git-61)
--
dm-devel mailing list
dm-devel@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/dm-devel
