virtio_balloon: export 'available' memory to balloon statistics
Add a new field, VIRTIO_BALLOON_S_AVAIL, to virtio_balloon memory
statistics protocol, corresponding to 'Available' in /proc/meminfo.
It indicates to the hypervisor how big the balloon can be inflated
without pushing the guest system to swap.
Signed-off-by: Igor Redko <redkoi@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/uapi/linux/virtio_balloon.h b/include/uapi/linux/virtio_balloon.h
index d7f1cbc..343d7dd 100644
--- a/include/uapi/linux/virtio_balloon.h
+++ b/include/uapi/linux/virtio_balloon.h
@@ -51,7 +51,8 @@
#define VIRTIO_BALLOON_S_MINFLT 3 /* Number of minor faults */
#define VIRTIO_BALLOON_S_MEMFREE 4 /* Total amount of free memory */
#define VIRTIO_BALLOON_S_MEMTOT 5 /* Total amount of memory */
-#define VIRTIO_BALLOON_S_NR 6
+#define VIRTIO_BALLOON_S_AVAIL 6 /* Available memory as in /proc */
+#define VIRTIO_BALLOON_S_NR 7
/*
* Memory statistics structure.