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@xxxxxxxxx> Reviewed-by: Cornelia Huck <cohuck@xxxxxxxxxx> Reviewed-by: Halil Pasic <pasic@xxxxxxxxxxxxx> Tested-by: Christian Borntraeger <borntraeger@xxxxxxxxxx> --- drivers/virtio/virtio_balloon.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index 45d32f5..d48c12c 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); -- 2.7.4