Linux Virtualization - Nov 2017 - [PATCH v3] virtio_balloon: include disk/file caches memory statistics

Add a new field VIRTIO_BALLOON_S_CACHES to virtio_balloon memory
statistics protocol. The value represents all disk/file caches.

In this case it corresponds to the sum of values
Buffers+Cached+SwapCached from /proc/meminfo.

Signed-off-by: Tom?? Golembiovsk? <tgolembi at redhat.com>
---
 drivers/virtio/virtio_balloon.c     | 4 ++++
 include/uapi/linux/virtio_balloon.h | 3 ++-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index f0b3a0b9d42f..d2bd13bbaf9f 100644
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -244,11 +244,13 @@ static unsigned int update_balloon_stats(struct
virtio_balloon *vb)
 	struct sysinfo i;
 	unsigned int idx = 0;
 	long available;
+	unsigned long caches;
 
 	all_vm_events(events);
 	si_meminfo(&i);
 
 	available = si_mem_available();
+	caches = global_node_page_state(NR_FILE_PAGES);
 
 #ifdef CONFIG_VM_EVENT_COUNTERS
 	update_stat(vb, idx++, VIRTIO_BALLOON_S_SWAP_IN,
@@ -264,6 +266,8 @@ static unsigned int update_balloon_stats(struct
virtio_balloon *vb)
 				pages_to_bytes(i.totalram));
 	update_stat(vb, idx++, VIRTIO_BALLOON_S_AVAIL,
 				pages_to_bytes(available));
+	update_stat(vb, idx++, VIRTIO_BALLOON_S_CACHES,
+				pages_to_bytes(caches));
 
 	return idx;
 }
diff --git a/include/uapi/linux/virtio_balloon.h
b/include/uapi/linux/virtio_balloon.h
index 343d7ddefe04..4e8b8304b793 100644
--- a/include/uapi/linux/virtio_balloon.h
+++ b/include/uapi/linux/virtio_balloon.h
@@ -52,7 +52,8 @@ struct virtio_balloon_config {
 #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_AVAIL    6   /* Available memory as in /proc */
-#define VIRTIO_BALLOON_S_NR       7
+#define VIRTIO_BALLOON_S_CACHES   7   /* Disk caches */
+#define VIRTIO_BALLOON_S_NR       8
 
 /*
  * Memory statistics structure.
-- 
2.15.0

On Sun, 12 Nov 2017 13:05:38 +0100
Tom?? Golembiovsk? <tgolembi at redhat.com> wrote:
> Add a new field VIRTIO_BALLOON_S_CACHES to virtio_balloon memory
> statistics protocol. The value represents all disk/file caches.
> 
> In this case it corresponds to the sum of values
> Buffers+Cached+SwapCached from /proc/meminfo.
> 
> Signed-off-by: Tom?? Golembiovsk? <tgolembi at redhat.com>
> ---
>  drivers/virtio/virtio_balloon.c     | 4 ++++
>  include/uapi/linux/virtio_balloon.h | 3 ++-
>  2 files changed, 6 insertions(+), 1 deletion(-)
> 
 
ping


-- 
Tom?? Golembiovsk? <tgolembi at redhat.com>

On Sun, Nov 12, 2017 at 01:05:38PM +0100, Tom?? Golembiovsk?
wrote:
> Add a new field VIRTIO_BALLOON_S_CACHES to virtio_balloon memory
> statistics protocol. The value represents all disk/file caches.
> 
> In this case it corresponds to the sum of values
> Buffers+Cached+SwapCached from /proc/meminfo.
> 
> Signed-off-by: Tom?? Golembiovsk? <tgolembi at redhat.com>

I parked this on vhost branch, part of linux next.
> ---
>  drivers/virtio/virtio_balloon.c     | 4 ++++
>  include/uapi/linux/virtio_balloon.h | 3 ++-
>  2 files changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/virtio/virtio_balloon.c
b/drivers/virtio/virtio_balloon.c
> index f0b3a0b9d42f..d2bd13bbaf9f 100644
> --- a/drivers/virtio/virtio_balloon.c
> +++ b/drivers/virtio/virtio_balloon.c
> @@ -244,11 +244,13 @@ static unsigned int update_balloon_stats(struct
virtio_balloon *vb)
>  	struct sysinfo i;
>  	unsigned int idx = 0;
>  	long available;
> +	unsigned long caches;
>  
>  	all_vm_events(events);
>  	si_meminfo(&i);
>  
>  	available = si_mem_available();
> +	caches = global_node_page_state(NR_FILE_PAGES);
>  
>  #ifdef CONFIG_VM_EVENT_COUNTERS
>  	update_stat(vb, idx++, VIRTIO_BALLOON_S_SWAP_IN,
> @@ -264,6 +266,8 @@ static unsigned int update_balloon_stats(struct
virtio_balloon *vb)
>  				pages_to_bytes(i.totalram));
>  	update_stat(vb, idx++, VIRTIO_BALLOON_S_AVAIL,
>  				pages_to_bytes(available));
> +	update_stat(vb, idx++, VIRTIO_BALLOON_S_CACHES,
> +				pages_to_bytes(caches));
>  
>  	return idx;
>  }
> diff --git a/include/uapi/linux/virtio_balloon.h
b/include/uapi/linux/virtio_balloon.h
> index 343d7ddefe04..4e8b8304b793 100644
> --- a/include/uapi/linux/virtio_balloon.h
> +++ b/include/uapi/linux/virtio_balloon.h
> @@ -52,7 +52,8 @@ struct virtio_balloon_config {
>  #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_AVAIL    6   /* Available memory as in /proc */
> -#define VIRTIO_BALLOON_S_NR       7
> +#define VIRTIO_BALLOON_S_CACHES   7   /* Disk caches */
> +#define VIRTIO_BALLOON_S_NR       8
>  
>  /*
>   * Memory statistics structure.
> -- 
> 2.15.0