Re: [PATCH net-next v3 3/3] mptcp: refine memory scheduling

[Mat Martineau <mathew.j.martineau@linux.intel.com>]

On Mon, 20 Jun 2022, Paolo Abeni wrote:

> Similar to commit 7c80b038d23e ("net: fix sk_wmem_schedule() and
> sk_rmem_schedule() errors"), let the MPTCP receive path schedule
> exactly the required amount of memory.
>
> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
> ---
> net/mptcp/protocol.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
> index b31bac33f87a..0e295b3bce54 100644
> --- a/net/mptcp/protocol.c
> +++ b/net/mptcp/protocol.c
> @@ -326,6 +326,7 @@ static bool mptcp_rmem_schedule(struct sock *sk, struct sock *ssk, int size)
> 	if (size < msk->rmem_fwd_alloc)

With the change below, also would be good to change the above line to:

 	if (size <= msk->rmem_fwd_alloc)

so there's no attempt to allocate 0 new pages.

> 		return true;
>
> +	size -= msk->rmem_fwd_alloc;
> 	amt = sk_mem_pages(size);
> 	amount = amt << PAGE_SHIFT;
> 	if (!__sk_mem_raise_allocated(sk, size, amt, SK_MEM_RECV))
> -- 
> 2.35.3
>
>
>

--
Mat Martineau
Intel