Re: [PATCH mptcp-next-next 2/3] mptcp: move the whole rx path under msk socket lock protection

[Matthieu Baerts <matttbe@kernel.org>]

Hi Paolo,

On 29/11/2024 18:45, Paolo Abeni wrote:
> After commit c2e6048fa1cf ("mptcp: fix race in release_cb") it's
> pretty straight forward move the whole MPTCP rx path under the socket
> lock leveraging the release_cb.
> 
> We can drop a bunch of spin_lock pairs in the receive functions, use
> a single receive queue and invoke __mptcp_move_skbs only when subflows
> ask for it.
> 
> This will allow more cleanup in the next patch

(...)

> diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
> index f768aa4473fb..159add48f6d9 100644
> --- a/net/mptcp/protocol.c
> +++ b/net/mptcp/protocol.c

(...)

> @@ -2290,9 +2283,8 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
>  		}
>  	}
>  
> -	pr_debug("msk=%p rx queue empty=%d:%d copied=%d\n",
> -		 msk, skb_queue_empty_lockless(&sk->sk_receive_queue),
> -		 skb_queue_empty(&msk->receive_queue), copied);
> +	pr_debug("msk=%p rx queue empty=%d copied=%d",

A small detail: the '\n' at the end is missing: no need to delay the
output if it is not supposed to be used with a pr_cont().

(Something we can fix when applying the patches.)

Cheers,
Matt
-- 
Sponsored by the NGI0 Core fund.