Re: [RFC PATCH v2 1/9] vsock: use sk_rcvlowat to set POLLIN/POLLRDNORM

[Arseniy Krasnov]

On 27.07.2022 15:17, Stefano Garzarella wrote:
> On Mon, Jul 25, 2022 at 07:56:59AM +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.
>>
> 
> The patch LGTM, but I suggest you to rewrite the title and commit of the message to better explain what this patch does (pass sock_rcvlowat to notify_poll_in as target) and then explain why as you already did (to set POLLIN/POLLRDNORM only when target is reached).
Ok, i see. Ack
> 
> Thanks,
> Stefano
> 
>> Signed-off-by: Arseniy Krasnov <AVKrasnov@xxxxxxxxxxxxxx>
>> ---
>> net/vmw_vsock/af_vsock.c | 3 ++-
>> 1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
>> index f04abf662ec6..63a13fa2686a 100644
>> --- a/net/vmw_vsock/af_vsock.c
>> +++ b/net/vmw_vsock/af_vsock.c
>> @@ -1066,8 +1066,9 @@ static __poll_t vsock_poll(struct file *file, struct socket *sock,
>>         if (transport && transport->stream_is_active(vsk) &&
>>             !(sk->sk_shutdown & RCV_SHUTDOWN)) {
>>             bool data_ready_now = false;
>> +            int target = sock_rcvlowat(sk, 0, INT_MAX);
>>             int ret = transport->notify_poll_in(
>> -                    vsk, 1, &data_ready_now);
>> +                    vsk, target, &data_ready_now);
>>             if (ret < 0) {
>>                 mask |= EPOLLERR;
>>             } else {
>> -- 
>> 2.25.1
>