From: Wei Wang <wei.w.wang@intel.com>
Date: Mon, 7 Jan 2019 07:01:05 +0000 (+0800)
Subject: virtio-balloon: improve update_balloon_size_func
X-Git-Tag: v5.15~6818^2~6
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=53e946cb347e8993cee1d091c97a38be73d34bdd;p=platform%2Fkernel%2Flinux-starfive.git

virtio-balloon: improve update_balloon_size_func

There is no need to update the balloon actual register when there is no
ballooning request. This patch avoids update_balloon_size when diff is 0.

Signed-off-by: Wei Wang <wei.w.wang@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---

diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index fb12fe2..e33dc8e 100644
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -457,9 +457,12 @@ static void update_balloon_size_func(struct work_struct *work)
 			  update_balloon_size_work);
 	diff = towards_target(vb);
 
+	if (!diff)
+		return;
+
 	if (diff > 0)
 		diff -= fill_balloon(vb, diff);
-	else if (diff < 0)
+	else
 		diff += leak_balloon(vb, -diff);
 	update_balloon_size(vb);