[RFC PATCH v2 08/11] bfq: disallow idle if CLASS_RT waiting for service

[brookxu]

From: Chunguang Xu <brookxu@xxxxxxxxxxx>

if CLASS_RT is waiting for service，queues belong
to other class disallow idle, so that a schedule
can be invoked in time.

Signed-off-by: Chunguang Xu <brookxu@xxxxxxxxxxx>
---
 block/bfq-iosched.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index a5f13589df79..9330043cdd53 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -4263,6 +4263,11 @@ static bool bfq_better_to_idle(struct bfq_queue *bfqq)
 	if (unlikely(bfqd->strict_guarantees))
 		return true;
 
+#ifdef CONFIG_BFQ_GROUP_IOSCHED
+	if (!bfq_class_rt(bfqq) && bfqd->busy_groups[0])
+		return false;
+#endif
+
 	/*
 	 * Idling is performed only if slice_idle > 0. In addition, we
 	 * do not idle if
-- 
2.30.0