On 2/15/22 10:34 AM, Eric Dumazet wrote:
>> diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
>> index af94a6d22a9d..e3811afd1756 100644
>> --- a/net/ipv4/tcp_input.c
>> +++ b/net/ipv4/tcp_input.c
>> @@ -4684,10 +4684,19 @@ static bool tcp_ooo_try_coalesce(struct sock *sk,
>> return res;
>> }
>>
>> -static void tcp_drop(struct sock *sk, struct sk_buff *skb)
>> +static void tcp_drop_reason(struct sock *sk, struct sk_buff *skb,
>> + enum skb_drop_reason reason)
>> {
>> sk_drops_add(sk, skb);
>> - __kfree_skb(skb);
>> + /* why __kfree_skb() used here before, other than kfree_skb()?
>> + * confusing......
>
> Do not add comments like that if you do not know the difference...
>
> __kfree_skb() is used by TCP stack because it owns skb in receive
> queues, and avoids touching skb->users
> because it must be one already.
and it bypasses kfree_skb tracepoint which seems by design.
