Re: [RFC PATCH v1 1/3] vsock: use sk_skrcvlowat to set POLLIN,POLLRDNORM, bits.

[Stefano Garzarella]

On Mon, Jul 18, 2022 at 08:15:42AM +0000, Arseniy Krasnov wrote:
> Both bits indicate, that next data read call won't be blocked,
> but when sk_rcvlowat is not 1,these bits will be set by poll
> anyway,thus when user tries to dequeue data, it will wait until
> sk_rcvlowat bytes of data will be available.
>
> Signed-off-by: Arseniy Krasnov <AVKrasnov@xxxxxxxxxxxxxx>
> ---
> net/vmw_vsock/af_vsock.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
> index f04abf662ec6..0225f3558e30 100644
> --- a/net/vmw_vsock/af_vsock.c
> +++ b/net/vmw_vsock/af_vsock.c
> @@ -1067,7 +1067,7 @@ static __poll_t vsock_poll(struct file *file, struct socket *sock,
> 		    !(sk->sk_shutdown & RCV_SHUTDOWN)) {
> 			bool data_ready_now = false;
> 			int ret = transport->notify_poll_in(
> -					vsk, 1, &data_ready_now);
> +					vsk, sk->sk_rcvlowat, &data_ready_now);

In tcp_poll() we have the following:
    int target = sock_rcvlowat(sk, 0, INT_MAX);

Maybe we can do the same here.

Thanks,
Stefano

> 			if (ret < 0) {
> 				mask |= EPOLLERR;
> 			} else {
> --
> 2.25.1