Re: [PATCH net-next1/2] net: core: use listified Rx for GRO_NORMAL in napi_gro_receive()

[Alexander Lobakin <alobakin@dlink.ru>]

Edward Cree wrote 10.10.2019 21:23:
> On 10/10/2019 15:42, Alexander Lobakin wrote:
>> Commit 323ebb61e32b4 ("net: use listified RX for handling GRO_NORMAL
>> skbs") made use of listified skb processing for the users of
>> napi_gro_frags().
>> The same technique can be used in a way more common napi_gro_receive()
>> to speed up non-merged (GRO_NORMAL) skbs for a wide range of drivers,
>> including gro_cells and mac80211 users.
>> 
>> Signed-off-by: Alexander Lobakin <alobakin@dlink.ru>
>> ---
>>  net/core/dev.c | 49 +++++++++++++++++++++++++------------------------
>>  1 file changed, 25 insertions(+), 24 deletions(-)
>> 
>> diff --git a/net/core/dev.c b/net/core/dev.c
>> index 8bc3dce71fc0..a33f56b439ce 100644
>> --- a/net/core/dev.c
>> +++ b/net/core/dev.c
>> @@ -5884,6 +5884,26 @@ struct packet_offload 
>> *gro_find_complete_by_type(__be16 type)
>>  }
>>  EXPORT_SYMBOL(gro_find_complete_by_type);
>> 
>> +/* Pass the currently batched GRO_NORMAL SKBs up to the stack. */
>> +static void gro_normal_list(struct napi_struct *napi)
>> +{
>> +	if (!napi->rx_count)
>> +		return;
>> +	netif_receive_skb_list_internal(&napi->rx_list);
>> +	INIT_LIST_HEAD(&napi->rx_list);
>> +	napi->rx_count = 0;
>> +}
>> +
>> +/* Queue one GRO_NORMAL SKB up for list processing.  If batch size 
>> exceeded,
>> + * pass the whole batch up to the stack.
>> + */
>> +static void gro_normal_one(struct napi_struct *napi, struct sk_buff 
>> *skb)
>> +{
>> +	list_add_tail(&skb->list, &napi->rx_list);
>> +	if (++napi->rx_count >= gro_normal_batch)
>> +		gro_normal_list(napi);
>> +}
>> +
>>  static void napi_skb_free_stolen_head(struct sk_buff *skb)
>>  {
>>  	skb_dst_drop(skb);
>> @@ -5891,12 +5911,13 @@ static void napi_skb_free_stolen_head(struct 
>> sk_buff *skb)
>>  	kmem_cache_free(skbuff_head_cache, skb);
>>  }
>> 
>> -static gro_result_t napi_skb_finish(gro_result_t ret, struct sk_buff 
>> *skb)
>> +static gro_result_t napi_skb_finish(struct napi_struct *napi,
>> +				    struct sk_buff *skb,
>> +				    gro_result_t ret)
> Any reason why the argument order here is changed around?

Actually yes: to match napi_skb_finish() and napi_frags_finish()
prototypes, as gro_normal one() required an addition of napi
argument anyway.

> 
> -Ed
>>  {
>>  	switch (ret) {
>>  	case GRO_NORMAL:
>> -		if (netif_receive_skb_internal(skb))
>> -			ret = GRO_DROP;
>> +		gro_normal_one(napi, skb);
>>  		break;
>> 
>>  	case GRO_DROP:
>> @@ -5928,7 +5949,7 @@ gro_result_t napi_gro_receive(struct napi_struct 
>> *napi, struct sk_buff *skb)
>> 
>>  	skb_gro_reset_offset(skb);
>> 
>> -	ret = napi_skb_finish(dev_gro_receive(napi, skb), skb);
>> +	ret = napi_skb_finish(napi, skb, dev_gro_receive(napi, skb));
>>  	trace_napi_gro_receive_exit(ret);
>> 
>>  	return ret;
>> @@ -5974,26 +5995,6 @@ struct sk_buff *napi_get_frags(struct 
>> napi_struct *napi)
>>  }
>>  EXPORT_SYMBOL(napi_get_frags);
>> 
>> -/* Pass the currently batched GRO_NORMAL SKBs up to the stack. */
>> -static void gro_normal_list(struct napi_struct *napi)
>> -{
>> -	if (!napi->rx_count)
>> -		return;
>> -	netif_receive_skb_list_internal(&napi->rx_list);
>> -	INIT_LIST_HEAD(&napi->rx_list);
>> -	napi->rx_count = 0;
>> -}
>> -
>> -/* Queue one GRO_NORMAL SKB up for list processing.  If batch size 
>> exceeded,
>> - * pass the whole batch up to the stack.
>> - */
>> -static void gro_normal_one(struct napi_struct *napi, struct sk_buff 
>> *skb)
>> -{
>> -	list_add_tail(&skb->list, &napi->rx_list);
>> -	if (++napi->rx_count >= gro_normal_batch)
>> -		gro_normal_list(napi);
>> -}
>> -
>>  static gro_result_t napi_frags_finish(struct napi_struct *napi,
>>  				      struct sk_buff *skb,
>>  				      gro_result_t ret)

Regards,
ᚷ ᛖ ᚢ ᚦ ᚠ ᚱ