From 9564e138b1f6eb137f7149772438d3f3fb3277dd Mon Sep 17 00:00:00 2001 From: Adam Litke Date: Mon, 30 Nov 2009 10:14:15 -0600 Subject: virtio: Add memory statistics reporting to the balloon driver (V4) Changes since V3: - Do not do endian conversions as they will be done in the host - Report stats that reference a quantity of memory in bytes - Minor coding style updates Changes since V2: - Increase stat field size to 64 bits - Report all sizes in kb (not pages) - Drop anon_pages stat and fix endianness conversion Changes since V1: - Use a virtqueue instead of the device config space When using ballooning to manage overcommitted memory on a host, a system for guests to communicate their memory usage to the host can provide information that will minimize the impact of ballooning on the guests. The current method employs a daemon running in each guest that communicates memory statistics to a host daemon at a specified time interval. The host daemon aggregates this information and inflates and/or deflates balloons according to the level of host memory pressure. This approach is effective but overly complex since a daemon must be installed inside each guest and coordinated to communicate with the host. A simpler approach is to collect memory statistics in the virtio balloon driver and communicate them directly to the hypervisor. This patch enables the guest-side support by adding stats collection and reporting to the virtio balloon driver. Signed-off-by: Adam Litke Cc: Anthony Liguori Cc: virtualization@lists.linux-foundation.org Signed-off-by: Rusty Russell (minor fixes) --- include/linux/virtio_balloon.h | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'include') diff --git a/include/linux/virtio_balloon.h b/include/linux/virtio_balloon.h index 1418f048cb34..a50ecd1b81a2 100644 --- a/include/linux/virtio_balloon.h +++ b/include/linux/virtio_balloon.h @@ -7,6 +7,7 @@ /* The feature bitmap for virtio balloon */ #define VIRTIO_BALLOON_F_MUST_TELL_HOST 0 /* Tell before reclaiming pages */ +#define VIRTIO_BALLOON_F_STATS_VQ 1 /* Memory Stats virtqueue */ /* Size of a PFN in the balloon interface. */ #define VIRTIO_BALLOON_PFN_SHIFT 12 @@ -18,4 +19,18 @@ struct virtio_balloon_config /* Number of pages we've actually got in balloon. */ __le32 actual; }; + +#define VIRTIO_BALLOON_S_SWAP_IN 0 /* Amount of memory swapped in */ +#define VIRTIO_BALLOON_S_SWAP_OUT 1 /* Amount of memory swapped out */ +#define VIRTIO_BALLOON_S_MAJFLT 2 /* Number of major faults */ +#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 + +struct virtio_balloon_stat { + u16 tag; + u64 val; +} __attribute__((packed)); + #endif /* _LINUX_VIRTIO_BALLOON_H */ -- cgit