From 4a9209bf1db1fc02a00f683aeb3c2754fe8ef99b Mon Sep 17 00:00:00 2001
From: Xinrui Mao <xinrui.mao@intel.com>
Date: Fri, 16 Sep 2022 05:47:56 +0000
Subject: [PATCH] lib/nbd: return nbd_poll idle or busy accordingly

The previous version missed the case of return value of _nbd_poll
equals to 0,and thus,when using nbd with no io,spdk_top shows high
cpu utilization.Return idle when _nbd_poll return 0.

Fixes #2697

Signed-off-by: Xinrui Mao <xinrui.mao@intel.com>
Change-Id: Ifa2ca3010e10250b5320a8282dfed3d97bea5105
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/14615
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Community-CI: Mellanox Build Bot
---
 lib/nbd/nbd.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/nbd/nbd.c b/lib/nbd/nbd.c
index bac4f8fa3..3b33c309c 100644
--- a/lib/nbd/nbd.c
+++ b/lib/nbd/nbd.c
@@ -835,7 +835,7 @@ nbd_poll(void *arg)
 		spdk_nbd_stop(nbd);
 	}
 
-	return SPDK_POLLER_BUSY;
+	return rc == 0 ? SPDK_POLLER_IDLE : SPDK_POLLER_BUSY;
 }
 
 static void *