[RFC 1/4] net/af_packet: remove volatile from statistics

[Scott Mitchell]

Can you clarify why removal of volatile is safe (visibility, ordering)
when the producer thread and consumer thread can be different?

On Wed, Jan 28, 2026 at 9:39 AM Stephen Hemminger
<stephen at networkplumber.org> wrote:
>
> Statistics are only updated from a single thread at a time and
> the compiler should not have to worry about optimizing them.
> The statistics returned are 64 bit so use uint64_t instead
> of arch specific unsigned long.
>
> Signed-off-by: Stephen Hemminger <stephen at networkplumber.org>
> ---
>  drivers/net/af_packet/rte_eth_af_packet.c | 14 +++++++-------
>  1 file changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/net/af_packet/rte_eth_af_packet.c b/drivers/net/af_packet/rte_eth_af_packet.c
> index ef11b8fb6b..158393dd70 100644
> --- a/drivers/net/af_packet/rte_eth_af_packet.c
> +++ b/drivers/net/af_packet/rte_eth_af_packet.c
> @@ -57,10 +57,10 @@ struct __rte_cache_aligned pkt_rx_queue {
>         uint8_t vlan_strip;
>         uint8_t timestamp_offloading;
>
> -       volatile unsigned long rx_pkts;
> -       volatile unsigned long rx_bytes;
> -       volatile unsigned long rx_nombuf;
> -       volatile unsigned long rx_dropped_pkts;
> +       uint64_t rx_pkts;
> +       uint64_t rx_bytes;
> +       uint64_t rx_nombuf;
> +       uint64_t rx_dropped_pkts;
>  };
>
>  struct __rte_cache_aligned pkt_tx_queue {
> @@ -72,9 +72,9 @@ struct __rte_cache_aligned pkt_tx_queue {
>         unsigned int framecount;
>         unsigned int framenum;
>
> -       volatile unsigned long tx_pkts;
> -       volatile unsigned long err_pkts;
> -       volatile unsigned long tx_bytes;
> +       uint64_t tx_pkts;
> +       uint64_t tx_bytes;
> +       uint64_t err_pkts;
>  };
>
>  struct pmd_internals {
> --
> 2.51.0
>