From: Christoph Hellwig <hch@lst.de>
Date: Thu, 11 Jun 2020 08:44:45 +0200
Subject: [PATCH] blk-mq: short cut the IPI path in blk_mq_force_complete_rq
 for !SMP
References: bsc#1175995,jsc#SLE-15608
Git-commit: d6cc464cc58424e137eca5e0a53226291044f5d2
Patch-mainline: v5.9-rc1

Let the compile optimize out the entire IPI path, given that we are
obviously not going to use it.

Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 block/blk-mq.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index d3634458ec31..08ab65e14884 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -701,7 +701,8 @@ void blk_mq_force_complete_rq(struct request *rq)
 		return;
 	}
 
-	if (!test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags)) {
+	if (!IS_ENABLED(CONFIG_SMP) ||
+	    !test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags)) {
 		q->mq_ops->complete(rq);
 		return;
 	}
-- 
2.16.4