Re: [PATCH] tcp_input: move out condition check from tcp_data_queue()
On Sun, 2017-08-06 at 21:57 +0400, Ilya Matveychikov wrote: > > On Aug 6, 2017, at 9:07 PM, Eric Dumazet wrote: > > > > On Sun, 2017-08-06 at 13:51 +0400, Ilya Matveychikov wrote: > >> As tcp_data_queue() function is used just only twice it's better > >> to move out the first check and wrap it with inline. It saves a > >> single call in case the condition evaluated as true. > >> ... > > We wont accept such a change, because this code does not need to be > > inlined in the callers, ( and btw inline in .c files are discouraged > > these days ) > > Not sure that I understand you point. What’s the reason for that code > not need to be inlined in the callers? You sent a patch, you have to explain why it is needed. Your changelog is absolutely not giving a compelling reason. TCP stack is already complex, no need to add yet another obfuscation unless there is a strong reason.
Re: [PATCH] tcp_input: move out condition check from tcp_data_queue()
> On Aug 6, 2017, at 9:07 PM, Eric Dumazet wrote:
>
> On Sun, 2017-08-06 at 13:51 +0400, Ilya Matveychikov wrote:
>> As tcp_data_queue() function is used just only twice it's better
>> to move out the first check and wrap it with inline. It saves a
>> single call in case the condition evaluated as true.
>>
>> Signed-off-by: Ilya V. Matveychikov
>> ---
>> net/ipv4/tcp_input.c | 14 +-
>> 1 file changed, 9 insertions(+), 5 deletions(-)
>>
>> diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
>> index 2920e0c..141a722 100644
>> --- a/net/ipv4/tcp_input.c
>> +++ b/net/ipv4/tcp_input.c
>> @@ -4585,16 +4585,12 @@ int tcp_send_rcvq(struct sock *sk, struct msghdr
>> *msg, size_t size)
>>
>> }
>>
>> -static void tcp_data_queue(struct sock *sk, struct sk_buff *skb)
>> +static void __tcp_data_queue(struct sock *sk, struct sk_buff *skb)
>> {
>> struct tcp_sock *tp = tcp_sk(sk);
>> bool fragstolen = false;
>> int eaten = -1;
>>
>> -if (TCP_SKB_CB(skb)->seq == TCP_SKB_CB(skb)->end_seq) {
>> -__kfree_skb(skb);
>> -return;
>> -}
>> skb_dst_drop(skb);
>> __skb_pull(skb, tcp_hdr(skb)->doff * 4);
>>
>> @@ -4703,6 +4699,14 @@ static void tcp_data_queue(struct sock *sk, struct
>> sk_buff *skb)
>> tcp_data_queue_ofo(sk, skb);
>> }
>>
>> +static inline void tcp_data_queue(struct sock *sk, struct sk_buff *skb)
>> +{
>> +if (TCP_SKB_CB(skb)->seq == TCP_SKB_CB(skb)->end_seq)
>> +__kfree_skb(skb);
>> +else
>> +__tcp_data_queue(sk, skb);
>> +}
>> +
>
> We wont accept such a change, because this code does not need to be
> inlined in the callers, ( and btw inline in .c files are discouraged
> these days )
Not sure that I understand you point. What’s the reason for that code
not need to be inlined in the callers?
Re: [PATCH] tcp_input: move out condition check from tcp_data_queue()
On Sun, 2017-08-06 at 13:51 +0400, Ilya Matveychikov wrote:
> As tcp_data_queue() function is used just only twice it's better
> to move out the first check and wrap it with inline. It saves a
> single call in case the condition evaluated as true.
>
> Signed-off-by: Ilya V. Matveychikov
> ---
> net/ipv4/tcp_input.c | 14 +-
> 1 file changed, 9 insertions(+), 5 deletions(-)
>
> diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
> index 2920e0c..141a722 100644
> --- a/net/ipv4/tcp_input.c
> +++ b/net/ipv4/tcp_input.c
> @@ -4585,16 +4585,12 @@ int tcp_send_rcvq(struct sock *sk, struct msghdr
> *msg, size_t size)
>
> }
>
> -static void tcp_data_queue(struct sock *sk, struct sk_buff *skb)
> +static void __tcp_data_queue(struct sock *sk, struct sk_buff *skb)
> {
> struct tcp_sock *tp = tcp_sk(sk);
> bool fragstolen = false;
> int eaten = -1;
>
> - if (TCP_SKB_CB(skb)->seq == TCP_SKB_CB(skb)->end_seq) {
> - __kfree_skb(skb);
> - return;
> - }
> skb_dst_drop(skb);
> __skb_pull(skb, tcp_hdr(skb)->doff * 4);
>
> @@ -4703,6 +4699,14 @@ static void tcp_data_queue(struct sock *sk, struct
> sk_buff *skb)
> tcp_data_queue_ofo(sk, skb);
> }
>
> +static inline void tcp_data_queue(struct sock *sk, struct sk_buff *skb)
> +{
> + if (TCP_SKB_CB(skb)->seq == TCP_SKB_CB(skb)->end_seq)
> + __kfree_skb(skb);
> + else
> + __tcp_data_queue(sk, skb);
> +}
> +
We wont accept such a change, because this code does not need to be
inlined in the callers, ( and btw inline in .c files are discouraged
these days )
