Re: [PATCH v2 net-next] net: core: use listified Rx for GRO_NORMAL in napi_gro_receive()

From: Edward Cree <ecree@solarflare.com>
To: Alexander Lobakin <alobakin@dlink.ru>, Paolo Abeni <pabeni@redhat.com>
Cc: Johannes Berg <johannes@sipsolutions.net>,
	Nicholas Johnson <nicholas.johnson-opensource@outlook.com.au>,
	David Miller <davem@davemloft.net>, <jiri@mellanox.com>,
	<edumazet@google.com>, <idosch@mellanox.com>,
	<petrm@mellanox.com>, <sd@queasysnail.net>,
	<f.fainelli@gmail.com>, <jaswinder.singh@linaro.org>,
	<ilias.apalodimas@linaro.org>, <linux-kernel@vger.kernel.org>,
	<emmanuel.grumbach@intel.com>, <luciano.coelho@intel.com>,
	<linuxwifi@intel.com>, <kvalo@codeaurora.org>,
	<netdev@vger.kernel.org>, <linux-wireless@vger.kernel.org>
Subject: Re: [PATCH v2 net-next] net: core: use listified Rx for GRO_NORMAL in napi_gro_receive()
Date: Mon, 25 Nov 2019 13:21:49 +0000	[thread overview]
Message-ID: <e437dc2d-aff3-2893-8d80-6abae4fcb84a@solarflare.com> (raw)
In-Reply-To: <d535d5142e42b8c550f0220200e3779d@dlink.ru>

On 25/11/2019 12:02, Alexander Lobakin wrote:
> I'm not very familiar with iwlwifi, but as a work around manual
> napi_gro_flush() you can also manually flush napi->rx_list to
> prevent packets from stalling:
>
> diff -Naur a/drivers/net/wireless/intel/iwlwifi/pcie/rx.c b/drivers/net/wireless/intel/iwlwifi/pcie/rx.c
> --- a/drivers/net/wireless/intel/iwlwifi/pcie/rx.c    2019-11-25 14:55:03.610355230 +0300
> +++ b/drivers/net/wireless/intel/iwlwifi/pcie/rx.c    2019-11-25 14:57:29.399556868 +0300
> @@ -1526,8 +1526,16 @@
>      if (unlikely(emergency && count))
>          iwl_pcie_rxq_alloc_rbs(trans, GFP_ATOMIC, rxq);
>
> -    if (rxq->napi.poll)
> +    if (rxq->napi.poll) {
> +        if (rxq->napi.rx_count) {
> +            netif_receive_skb_list(&rxq->napi.rx_list);
> +
> +            INIT_LIST_HEAD(&rxq->napi.rx_list);
> +            rxq->napi.rx_count = 0;
> +        }
> +
>          napi_gro_flush(&rxq->napi, false);
> +    }
>
>      iwl_pcie_rxq_restock(trans, rxq);
>  }
... or we could export gro_normal_list(), instead of open-coding it
 in the driver?

-Ed