[RFC PATCH v2 09/11] bfq: disallow merge CLASS_RT with other class

[brookxu]

From: Chunguang Xu <brookxu@xxxxxxxxxxx>

In EMQ, perhaps we should not merge the CLASS_RT queue
with other class queues. Otherwise, the delay of
CLASS_RT IO will increase.

Signed-off-by: Chunguang Xu <brookxu@xxxxxxxxxxx>
---
 block/bfq-iosched.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index 9330043cdd53..bb6cc8c9ddf5 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -2623,6 +2623,9 @@ static bool bfq_may_be_close_cooperator(struct bfq_queue *bfqq,
 	if (!bfq_bfqq_sync(bfqq) || !bfq_bfqq_sync(new_bfqq))
 		return false;
 
+	if (bfq_class_rt(bfqq) && !bfq_class_rt(new_bfqq))
+		return false;
+
 	return true;
 }
 
-- 
2.30.0