Re: [RFC 2/3] virtio_balloon: introduce memory allocation stall counter

[David Hildenbrand <david@xxxxxxxxxx>]

On 15.04.24 10:41, zhenwei pi wrote:
> Memory allocation stall counter represents the performance/latency of
> memory allocation, expose this counter to the host side by virtio
> balloon device via out-of-bound way.
>
> Signed-off-by: zhenwei pi <pizhenwei@xxxxxxxxxxxxx>
> ---
>   drivers/virtio/virtio_balloon.c     | 19 ++++++++++++++++++-
>   include/uapi/linux/virtio_balloon.h |  6 ++++--
>   2 files changed, 22 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
> index fd8daa742734..4b9c9569f6e5 100644
> --- a/drivers/virtio/virtio_balloon.c
> +++ b/drivers/virtio/virtio_balloon.c
> @@ -321,7 +321,7 @@ static unsigned int update_balloon_stats(struct virtio_balloon *vb)
>   	unsigned long events[NR_VM_EVENT_ITEMS];
>   	struct sysinfo i;
>   	unsigned int idx = 0;
> -	long available;
> +	long available, stall = 0;
>   	unsigned long caches;
>   
>   	all_vm_events(events);
> @@ -355,6 +355,23 @@ static unsigned int update_balloon_stats(struct virtio_balloon *vb)
>   	update_stat(vb, idx++, VIRTIO_BALLOON_S_OOM_KILL,
>   				events[OOM_KILL]);
>   
> +	/* sum all the stall event */
> +#ifdef CONFIG_ZONE_DMA
> +	stall += events[ALLOCSTALL_DMA];
> +#endif
> +#ifdef CONFIG_ZONE_DMA32
> +	stall += events[ALLOCSTALL_DMA32];
> +#endif
> +#ifdef CONFIG_HIGHMEM
> +	stall += events[ALLOCSTALL_HIGH];
> +#endif
> +#ifdef CONFIG_ZONE_DEVICE
> +	stall += events[ALLOCSTALL_DEVICE];
> +#endif
> +	stall += events[ALLOCSTALL_NORMAL];
> +	stall += events[ALLOCSTALL_MOVABLE];
> +	update_stat(vb, idx++, VIRTIO_BALLOON_S_ALLOC_STALL, stall);
> +
>   	return idx;
>   }
>   
> diff --git a/include/uapi/linux/virtio_balloon.h b/include/uapi/linux/virtio_balloon.h
> index cde5547e64a7..13d0c32ba27c 100644
> --- a/include/uapi/linux/virtio_balloon.h
> +++ b/include/uapi/linux/virtio_balloon.h
> @@ -72,7 +72,8 @@ struct virtio_balloon_config {
>   #define VIRTIO_BALLOON_S_HTLB_PGALLOC  8  /* Hugetlb page allocations */
>   #define VIRTIO_BALLOON_S_HTLB_PGFAIL   9  /* Hugetlb page allocation failures */
>   #define VIRTIO_BALLOON_S_OOM_KILL      10 /* OOM killer invocations */
> -#define VIRTIO_BALLOON_S_NR       11
> +#define VIRTIO_BALLOON_S_ALLOC_STALL   11 /* Stall count of memory allocatoin */
> +#define VIRTIO_BALLOON_S_NR       12
>   
>   #define VIRTIO_BALLOON_S_NAMES_WITH_PREFIX(VIRTIO_BALLOON_S_NAMES_prefix) { \
>   	VIRTIO_BALLOON_S_NAMES_prefix "swap-in", \
> @@ -85,7 +86,8 @@ struct virtio_balloon_config {
>   	VIRTIO_BALLOON_S_NAMES_prefix "disk-caches", \
>   	VIRTIO_BALLOON_S_NAMES_prefix "hugetlb-allocations", \
>   	VIRTIO_BALLOON_S_NAMES_prefix "hugetlb-failures", \
> -	VIRTIO_BALLOON_S_NAMES_prefix "oom-kill" \
> +	VIRTIO_BALLOON_S_NAMES_prefix "oom-kill", \
> +	VIRTIO_BALLOON_S_NAMES_prefix "alloc-stall" \

"alloc-stalls"

--
Cheers,

David / dhildenb