On 19.11.19 11:18, Michael S. Tsirkin wrote:

From: Wei Wang wei.w.wang@intel.com

Instead of multiplying by page order, virtio balloon divided by page order. The result is that it can often return 0 if there are a bit less than MAX_ORDER - 1 pages in use, and then shrinker scan won't be called.

Cc: stable@vger.kernel.org Fixes: 71994620bb25 ("virtio_balloon: replace oom notifier with shrinker") Signed-off-by: Wei Wang wei.w.wang@intel.com Signed-off-by: Michael S. Tsirkin mst@redhat.com

---

drivers/virtio/virtio_balloon.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index 7cee05cdf3fb..65df40f261ab 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -825,7 +825,7 @@ static unsigned long virtio_balloon_shrinker_count(struct shrinker *shrinker, unsigned long count; count = vb->num_pages / VIRTIO_BALLOON_PAGES_PER_PAGE;

• count += vb->num_free_page_blocks >> VIRTIO_BALLOON_FREE_PAGE_ORDER;

• count += vb->num_free_page_blocks << VIRTIO_BALLOON_FREE_PAGE_ORDER;

return count; }

Reviewed-by: David Hildenbrand david@redhat.com