Re: [RFC PATCH v3 4/9] vmci/vsock: use 'target' in notify_poll_in callback

From: Vishnu Dasa <vdasa@vmware.com>
To: Stefano Garzarella <sgarzare@redhat.com>
Cc: Arseniy Krasnov <AVKrasnov@sberdevices.ru>,
	Bryan Tan <bryantan@vmware.com>,
	Pv-drivers <Pv-drivers@vmware.com>,
	"David S. Miller" <davem@davemloft.net>,
	"edumazet@google.com" <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	"kys@microsoft.com" <kys@microsoft.com>,
	"haiyangz@microsoft.com" <haiyangz@microsoft.com>,
	"sthemmin@microsoft.com" <sthemmin@microsoft.com>,
	"wei.liu@kernel.org" <wei.liu@kernel.org>,
	Dexuan Cui <decui@microsoft.com>,
	Stefan Hajnoczi <stefanha@redhat.com>,
	Krasnov Arseniy <oxffffaa@gmail.com>,
	"virtualization@lists.linux-foundation.org" 
	<virtualization@lists.linux-foundation.org>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-hyperv@vger.kernel.org" <linux-hyperv@vger.kernel.org>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	kernel <kernel@sberdevices.ru>
Subject: Re: [RFC PATCH v3 4/9] vmci/vsock: use 'target' in notify_poll_in callback
Date: Fri, 19 Aug 2022 04:49:56 +0000	[thread overview]
Message-ID: <0783F6F8-901A-4186-B4E7-01FE099F1939@vmware.com> (raw)
In-Reply-To: <20220808103611.4ma4c5fpszrmstvx@sgarzare-redhat>

> On Aug 8, 2022, at 3:36 AM, Stefano Garzarella <sgarzare@redhat.com> wrote:
> 
> On Wed, Aug 03, 2022 at 01:57:54PM +0000, Arseniy Krasnov wrote:
>> This callback controls setting of POLLIN,POLLRDNORM output bits of poll()
>> syscall,but in some cases,it is incorrectly to set it, when socket has
>> at least 1 bytes of available data. Use 'target' which is already exists
>> and equal to sk_rcvlowat in this case.
> 
> Ditto as the previous patch.
> With that fixed:
> 
> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
> 
> @Bryan, @Vishnu, if you're happy with this change, can you ack/review?

This patch looks good to me.

Thank you, Arseniy for running the test with VMCI.  I also ran some of
our internal tests successfully with this patch series.

> Thanks,
> Stefano
> 
>> 
>> Signed-off-by: Arseniy Krasnov <AVKrasnov@sberdevices.ru>

Reviewed-by: Vishnu Dasa <vdasa@vmware.com>

>> ---
>> net/vmw_vsock/vmci_transport_notify.c        | 8 ++++----
>> net/vmw_vsock/vmci_transport_notify_qstate.c | 8 ++++----
>> 2 files changed, 8 insertions(+), 8 deletions(-)
>> 
>> diff --git a/net/vmw_vsock/vmci_transport_notify.c b/net/vmw_vsock/vmci_transport_notify.c
>> index d69fc4b595ad..852097e2b9e6 100644
>> --- a/net/vmw_vsock/vmci_transport_notify.c
>> +++ b/net/vmw_vsock/vmci_transport_notify.c
>> @@ -340,12 +340,12 @@ vmci_transport_notify_pkt_poll_in(struct sock *sk,
>> {
>>      struct vsock_sock *vsk = vsock_sk(sk);
>> 
>> -      if (vsock_stream_has_data(vsk)) {
>> +      if (vsock_stream_has_data(vsk) >= target) {
>>              *data_ready_now = true;
>>      } else {
>> -              /* We can't read right now because there is nothing in the
>> -               * queue. Ask for notifications when there is something to
>> -               * read.
>> +              /* We can't read right now because there is not enough data
>> +               * in the queue. Ask for notifications when there is something
>> +               * to read.
>>               */
>>              if (sk->sk_state == TCP_ESTABLISHED) {
>>                      if (!send_waiting_read(sk, 1))
>> diff --git a/net/vmw_vsock/vmci_transport_notify_qstate.c b/net/vmw_vsock/vmci_transport_notify_qstate.c
>> index 0f36d7c45db3..12f0cb8fe998 100644
>> --- a/net/vmw_vsock/vmci_transport_notify_qstate.c
>> +++ b/net/vmw_vsock/vmci_transport_notify_qstate.c
>> @@ -161,12 +161,12 @@ vmci_transport_notify_pkt_poll_in(struct sock *sk,
>> {
>>      struct vsock_sock *vsk = vsock_sk(sk);
>> 
>> -      if (vsock_stream_has_data(vsk)) {
>> +      if (vsock_stream_has_data(vsk) >= target) {
>>              *data_ready_now = true;
>>      } else {
>> -              /* We can't read right now because there is nothing in the
>> -               * queue. Ask for notifications when there is something to
>> -               * read.
>> +              /* We can't read right now because there is not enough data
>> +               * in the queue. Ask for notifications when there is something
>> +               * to read.
>>               */
>>              if (sk->sk_state == TCP_ESTABLISHED)
>>                      vsock_block_update_write_window(sk);
>> --
>> 2.25.1