From: Zi Yan <ziy@xxxxxxxxxx> virtio_balloon used MAX_ORDER to report free page blocks to host, as MAX_ORDER becomes modifiable in later commits, the reported free size might be too big. pageblock_order is either 1/2 of or the same as MAX_ORDER currently. Use pageblock_order instead to make virtio_balloon have a constant free page block report size when MAX_ORDER is changed in the later commits. Signed-off-by: Zi Yan <ziy@xxxxxxxxxx> Cc: "Michael S. Tsirkin" <mst@xxxxxxxxxx> Cc: David Hildenbrand <david@xxxxxxxxxx> Cc: Jason Wang <jasowang@xxxxxxxxxx> Cc: virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx Cc: linux-mm@xxxxxxxxx Cc: linux-kernel@xxxxxxxxxxxxxxx --- 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 5b15936a5214..51447737538b 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -33,7 +33,7 @@ #define VIRTIO_BALLOON_FREE_PAGE_ALLOC_FLAG (__GFP_NORETRY | __GFP_NOWARN | \ __GFP_NOMEMALLOC) /* The order of free page blocks to report to host */ -#define VIRTIO_BALLOON_HINT_BLOCK_ORDER MAX_ORDER +#define VIRTIO_BALLOON_HINT_BLOCK_ORDER pageblock_order /* The size of a free page block in bytes */ #define VIRTIO_BALLOON_HINT_BLOCK_BYTES \ (1 << (VIRTIO_BALLOON_HINT_BLOCK_ORDER + PAGE_SHIFT)) -- 2.35.1