From 5057dcd0f1aaad57e07e728ba20a99e205c6b9de Mon Sep 17 00:00:00 2001 From: Igor Redko Date: Thu, 17 Mar 2016 14:19:08 -0700 Subject: [PATCH] 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 Signed-off-by: Denis V. Lunev Reviewed-by: Roman Kagan Cc: Michael S. Tsirkin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/virtio/virtio_balloon.c | 6 ++++++ include/uapi/linux/virtio_balloon.h | 3 ++- 2 files changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index 0c3691f46575..f2b77dea8d3c 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -30,6 +30,7 @@ #include #include #include +#include /* * Balloon device works in 4K page units. So each page is pointed to by @@ -229,10 +230,13 @@ static void update_balloon_stats(struct virtio_balloon *vb) unsigned long events[NR_VM_EVENT_ITEMS]; struct sysinfo i; int idx = 0; + long available; all_vm_events(events); si_meminfo(&i); + available = si_mem_available(); + update_stat(vb, idx++, VIRTIO_BALLOON_S_SWAP_IN, pages_to_bytes(events[PSWPIN])); update_stat(vb, idx++, VIRTIO_BALLOON_S_SWAP_OUT, @@ -243,6 +247,8 @@ static void update_balloon_stats(struct virtio_balloon *vb) pages_to_bytes(i.freeram)); update_stat(vb, idx++, VIRTIO_BALLOON_S_MEMTOT, pages_to_bytes(i.totalram)); + update_stat(vb, idx++, VIRTIO_BALLOON_S_AVAIL, + pages_to_bytes(available)); } /* diff --git a/include/uapi/linux/virtio_balloon.h b/include/uapi/linux/virtio_balloon.h index d7f1cbc3766c..343d7ddefe04 100644 --- a/include/uapi/linux/virtio_balloon.h +++ b/include/uapi/linux/virtio_balloon.h @@ -51,7 +51,8 @@ struct virtio_balloon_config { #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. -- 2.20.1