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Message-ID: <c1b2a6583245560952db0cde3e3d6ff9db4cbd5a.camel@sipsolutions.net>
Subject: Re: [RFC] mac80211: add a function for running rx without passing
 skbs to the stack
From:   Johannes Berg <johannes@sipsolutions.net>
To:     Felix Fietkau <nbd@nbd.name>, linux-wireless@vger.kernel.org
Date:   Sat, 25 Jul 2020 21:14:19 +0200
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References: <20200725185554.17346-1-nbd@nbd.name>
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> +void ieee80211_rx_napi(struct ieee80211_hw *hw, struct ieee80211_sta *pubsta,
> +		       struct sk_buff *skb, struct napi_struct *napi)
> +{
> +	struct sk_buff_head list;
> +
> +	__skb_queue_head_init(&list);
> +
> +	/*
> +	 * key references and virtual interfaces are protected using RCU
> +	 * and this requires that we are in a read-side RCU section during
> +	 * receive processing
> +	 */
> +	rcu_read_lock();
> +	ieee80211_rx_list(hw, pubsta, skb, &list);
> +	rcu_read_unlock();
> +
> +	while ((skb = __skb_dequeue(&list)) != NULL)

I'd drop the != NULL, but no strong feelings :)

> +		if (napi)
> +			napi_gro_receive(napi, skb);
> +		else
> +			netif_receive_skb(skb);

Nit: I'd prefer braces on the loop, just makes it nicer to read IMHO.

OTOH, the !napi case should use netif_receive_skb_list(), no?

Given the discussion, it also seems a bit odd to add more work for NAPI
poll where we process one by one ... But I see why you did that, and I
guess it's not actually that much more work.

johannes