Subject: Re: [PATCH net-next,V4, 3/3] net: mana: Add ethtool counters for RX CQEs in coalesced type

From: Simon Horman <[email-masked]>
Date: Wed, 11 Mar 2026 17:58:35 +0000

On Mon, Mar 09, 2026 at 02:20:45PM -0700, Haiyang Zhang wrote:
> From: Haiyang Zhang <[email-masked]>
> 
> For RX CQEs with type CQE_RX_COALESCED_4, to measure the coalescing
> efficiency, add counters to count how many contains 2, 3, 4 packets
> respectively.
> Also, add a counter for the error case of first packet with length == 0.
> 
> Reviewed-by: Long Li <[email-masked]>
> Signed-off-by: Haiyang Zhang <[email-masked]>
> ---
>  drivers/net/ethernet/microsoft/mana/mana_en.c | 21 ++++++++++++++++++-
>  .../ethernet/microsoft/mana/mana_ethtool.c    | 15 +++++++++++--
>  include/net/mana/mana.h                       |  9 +++++---
>  3 files changed, 39 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
> index fa30046dcd3d..85f7a56d0d90 100644
> --- a/drivers/net/ethernet/microsoft/mana/mana_en.c
> +++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
> @@ -2148,11 +2148,23 @@ static void mana_process_rx_cqe(struct mana_rxq *rxq, struct mana_cq *cq,
>  		old_buf = NULL;
>  		pktlen = oob->ppi[i].pkt_len;
>  		if (pktlen == 0) {
> -			if (i == 0)
> +			/* Collect coalesced CQE count based on packets processed.
> +			 * Coalesced CQEs have at least 2 packets, so index is i - 2.
> +			 */
> +			if (i > 1) {
> +				u64_stats_update_begin(&rxq->stats.syncp);
> +				rxq->stats.coalesced_cqe[i - 2]++;
> +				u64_stats_update_end(&rxq->stats.syncp);
> +			} else if (i == 0) {
> +				/* Error case stat */
> +				u64_stats_update_begin(&rxq->stats.syncp);
> +				rxq->stats.pkt_len0_err++;
> +				u64_stats_update_end(&rxq->stats.syncp);
>  				netdev_err_once(
>  					ndev,
>  					"RX pkt len=0, rq=%u, cq=%u, rxobj=0x%llx\n",
>  					rxq->gdma_id, cq->gdma_id, rxq->rxobj);
> +			}
>  			break;

Hi Haiyang Zhang,

As there is a break here, can the accounting logic above be move out of the
loop, and merged with the "Coalesced CQE with all 4 packets" accounting
logic that is already there?

As is, accounting seems split between and slightly duplicated in two locations.

>  		}
>  
> @@ -2175,6 +2187,13 @@ static void mana_process_rx_cqe(struct mana_rxq *rxq, struct mana_cq *cq,
>  		if (!coalesced)
>  			break;
>  	}
> +
> +	/* Coalesced CQE with all 4 packets */
> +	if (coalesced && i == MANA_RXCOMP_OOB_NUM_PPI) {
> +		u64_stats_update_begin(&rxq->stats.syncp);
> +		rxq->stats.coalesced_cqe[MANA_RXCOMP_OOB_NUM_PPI - 2]++;
> +		u64_stats_update_end(&rxq->stats.syncp);
> +	}
>  }
>  
>  static void mana_poll_rx_cq(struct mana_cq *cq)

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