> -----Original Message-----
> From: Intel-wired-lan <[email protected]> On Behalf
> Of David Yang
> Sent: Monday, January 19, 2026 5:27 PM
> To: [email protected]
> Cc: David Yang <[email protected]>; Nguyen, Anthony L
> <[email protected]>; Kitszel, Przemyslaw
> <[email protected]>; Andrew Lunn <[email protected]>;
> David S. Miller <[email protected]>; Eric Dumazet
> <[email protected]>; Jakub Kicinski <[email protected]>; Paolo Abeni
> <[email protected]>; Pavan Kumar Linga <[email protected]>;
> Burra, Phani R <[email protected]>; Willem de Bruijn
> <[email protected]>; Alan Brady <[email protected]>; Samudrala,
> Sridhar <[email protected]>; Hay, Joshua A
> <[email protected]>; [email protected]; linux-
> [email protected]
> Subject: [Intel-wired-lan] [PATCH net] idpf: Fix data race in
> idpf_net_dim
>
> In idpf_net_dim(), some statistics protected by u64_stats_sync, are
> read and accumulated in ignorance of possible u64_stats_fetch_retry()
> events.
> The correct way to copy statistics is already illustrated by
> idpf_add_queue_stats(). Fix this by reading them into temporary
> variables first.
>
> Fixes: c2d548cad150 ("idpf: add TX splitq napi poll support")
> Fixes: 3a8845af66ed ("idpf: add RX splitq napi poll support")
> Signed-off-by: David Yang <[email protected]>
> ---
> drivers/net/ethernet/intel/idpf/idpf_txrx.c | 16 +++++++++++-----
> 1 file changed, 11 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/net/ethernet/intel/idpf/idpf_txrx.c
> b/drivers/net/ethernet/intel/idpf/idpf_txrx.c
> index 97a5fe766b6b..66ba645e8b90 100644
> --- a/drivers/net/ethernet/intel/idpf/idpf_txrx.c
> +++ b/drivers/net/ethernet/intel/idpf/idpf_txrx.c
> @@ -3956,7 +3956,7 @@ static void idpf_update_dim_sample(struct
> idpf_q_vector *q_vector, static void idpf_net_dim(struct
> idpf_q_vector *q_vector) {
> struct dim_sample dim_sample = { };
> - u64 packets, bytes;
> + u64 packets, bytes, pkts, bts;
> u32 i;
>
> if (!IDPF_ITR_IS_DYNAMIC(q_vector->tx_intr_mode))
> @@ -3968,9 +3968,12 @@ static void idpf_net_dim(struct idpf_q_vector
> *q_vector)
>
> do {
> start = u64_stats_fetch_begin(&txq->stats_sync);
> - packets += u64_stats_read(&txq->q_stats.packets);
> - bytes += u64_stats_read(&txq->q_stats.bytes);
> + pkts = u64_stats_read(&txq->q_stats.packets);
> + bts = u64_stats_read(&txq->q_stats.bytes);
> } while (u64_stats_fetch_retry(&txq->stats_sync,
> start));
> +
> + packets += pkts;
> + bytes += bts;
> }
>
> idpf_update_dim_sample(q_vector, &dim_sample, &q_vector-
> >tx_dim, @@ -3987,9 +3990,12 @@ static void idpf_net_dim(struct
> idpf_q_vector *q_vector)
>
> do {
> start = u64_stats_fetch_begin(&rxq->stats_sync);
> - packets += u64_stats_read(&rxq->q_stats.packets);
> - bytes += u64_stats_read(&rxq->q_stats.bytes);
> + pkts = u64_stats_read(&rxq->q_stats.packets);
> + bts = u64_stats_read(&rxq->q_stats.bytes);
> } while (u64_stats_fetch_retry(&rxq->stats_sync,
> start));
> +
> + packets += pkts;
> + bytes += bts;
> }
>
> idpf_update_dim_sample(q_vector, &dim_sample, &q_vector-
> >rx_dim,
> --
> 2.51.0
Reviewed-by: Aleksandr Loktionov <[email protected]>
