Re: [PATCH] virtio_balloon: export huge page allocation statistics

["Michael S. Tsirkin" <mst@redhat.com>]

On Fri, Feb 16, 2018 at 09:44:32PM -0800, Jonathan Helman wrote:
> Export statistics for successful and failed huge page allocations
> from the virtio balloon driver. These 2 stats come directly from
> the vm_events HTLB_BUDDY_PGALLOC and HTLB_BUDDY_PGALLOC_FAIL.
> Signed-off-by: Jonathan Helman <jonathan.helman@oracle.com>

Any host/guest intergace changes need to be copied to
the virtio TC mailing list (subscriber-only, sorry about that):
virtio-dev@lists.oasis-open.org

> ---
>  drivers/virtio/virtio_balloon.c     | 6 ++++++
>  include/uapi/linux/virtio_balloon.h | 4 +++-
>  2 files changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
> index dfe5684..6b237e3 100644
> --- a/drivers/virtio/virtio_balloon.c
> +++ b/drivers/virtio/virtio_balloon.c
> @@ -272,6 +272,12 @@ static unsigned int update_balloon_stats(struct virtio_balloon *vb)
>  				pages_to_bytes(events[PSWPOUT]));
>  	update_stat(vb, idx++, VIRTIO_BALLOON_S_MAJFLT, events[PGMAJFAULT]);
>  	update_stat(vb, idx++, VIRTIO_BALLOON_S_MINFLT, events[PGFAULT]);
> +#ifdef CONFIG_HUGETLB_PAGE
> +	update_stat(vb, idx++, VIRTIO_BALLOON_S_HTLB_PGALLOC,
> +		    events[HTLB_BUDDY_PGALLOC]);
> +	update_stat(vb, idx++, VIRTIO_BALLOON_S_HTLB_PGFAIL,
> +		    events[HTLB_BUDDY_PGALLOC_FAIL]);
> +#endif
>  #endif
>  	update_stat(vb, idx++, VIRTIO_BALLOON_S_MEMFREE,
>  				pages_to_bytes(i.freeram));
> diff --git a/include/uapi/linux/virtio_balloon.h b/include/uapi/linux/virtio_balloon.h
> index 4e8b830..e3e8071 100644
> --- a/include/uapi/linux/virtio_balloon.h
> +++ b/include/uapi/linux/virtio_balloon.h
> @@ -53,7 +53,9 @@ struct virtio_balloon_config {
>  #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_CACHES   7   /* Disk caches */
> -#define VIRTIO_BALLOON_S_NR       8
> +#define VIRTIO_BALLOON_S_HTLB_PGALLOC  8  /* Number of htlb pgalloc successes */
> +#define VIRTIO_BALLOON_S_HTLB_PGFAIL   9  /* Number of htlb pgalloc failures */
> +#define VIRTIO_BALLOON_S_NR       10

Can you clarify the comments pls? Eschew abbreviation.

>  
>  /*
>   * Memory statistics structure.
> -- 
> 1.8.3.1