RE: [PATCH V3 2/2 net-next] hyperv: Support batched notification

[KY Srinivasan]

> -----Original Message-----
> From: Jason Wang [mailto:jasowang@xxxxxxxxxx]
> Sent: Thursday, March 19, 2015 10:58 PM
> To: KY Srinivasan
> Cc: davem@xxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; devel@xxxxxxxxxxxxxxxxxxxxxx; olaf@xxxxxxxxx;
> apw@xxxxxxxxxxxxx
> Subject: RE: [PATCH V3 2/2 net-next] hyperv: Support batched notification
> 
> 
> 
> On Fri, Mar 20, 2015 at 12:53 AM, KY Srinivasan <kys@xxxxxxxxxxxxx>
> wrote:
> >
> >
> >>  -----Original Message-----
> >>  From: Jason Wang [mailto:jasowang@xxxxxxxxxx]
> >>  Sent: Tuesday, March 17, 2015 8:09 PM
> >>  To: KY Srinivasan
> >>  Cc: davem@xxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx; linux-
> >>  kernel@xxxxxxxxxxxxxxx; devel@xxxxxxxxxxxxxxxxxxxxxx;
> >> olaf@xxxxxxxxx;
> >>  apw@xxxxxxxxxxxxx; KY Srinivasan
> >>  Subject: Re: [PATCH V3 2/2 net-next] hyperv: Support batched
> >> notification
> >>
> >>
> >>
> >>  On Wed, Mar 18, 2015 at 12:02 AM, K. Y. Srinivasan
> >> <kys@xxxxxxxxxxxxx>
> >>  wrote:
> >>  > Optimize notifying the host by deferring notification until there
> >>  > are no more packets to be sent. This will help in batching the
> >>  > requests
> >>  > on the host.
> >>  >
> >>  > Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
> >>  > ---
> >>  >  drivers/net/hyperv/hyperv_net.h   |    2 +-
> >>  >  drivers/net/hyperv/netvsc.c       |   14 +++++++++-----
> >>  >  drivers/net/hyperv/netvsc_drv.c   |    2 +-
> >>  >  drivers/net/hyperv/rndis_filter.c |    2 +-
> >>  >  4 files changed, 12 insertions(+), 8 deletions(-)
> >>  >
> >>  > diff --git a/drivers/net/hyperv/hyperv_net.h
> >>  > b/drivers/net/hyperv/hyperv_net.h
> >>  > index 4815843..3fd9896 100644
> >>  > --- a/drivers/net/hyperv/hyperv_net.h
> >>  > +++ b/drivers/net/hyperv/hyperv_net.h
> >>  > @@ -184,7 +184,7 @@ struct rndis_device {
> >>  >  int netvsc_device_add(struct hv_device *device, void
> >>  > *additional_info);
> >>  >  int netvsc_device_remove(struct hv_device *device);
> >>  >  int netvsc_send(struct hv_device *device,
> >>  > -		struct hv_netvsc_packet *packet);
> >>  > +		struct hv_netvsc_packet *packet, bool kick_q);
> >>  >  void netvsc_linkstatus_callback(struct hv_device *device_obj,
> >>  >  				struct rndis_message *resp);
> >>  >  int netvsc_recv_callback(struct hv_device *device_obj,
> >>  > diff --git a/drivers/net/hyperv/netvsc.c
> >> b/drivers/net/hyperv/netvsc.c
> >>  > index 208eb05..9003b94 100644
> >>  > --- a/drivers/net/hyperv/netvsc.c
> >>  > +++ b/drivers/net/hyperv/netvsc.c
> >>  > @@ -707,7 +707,7 @@ static u32 netvsc_copy_to_send_buf(struct
> >>  > netvsc_device *net_device,
> >>  >  }
> >>  >
> >>  >  int netvsc_send(struct hv_device *device,
> >>  > -			struct hv_netvsc_packet *packet)
> >>  > +			struct hv_netvsc_packet *packet, bool kick_q)
> >>  >  {
> >>  >  	struct netvsc_device *net_device;
> >>  >  	int ret = 0;
> >>  > @@ -719,6 +719,7 @@ int netvsc_send(struct hv_device *device,
> >>  >  	u32 msg_size = 0;
> >>  >  	struct sk_buff *skb = NULL;
> >>  >  	u16 q_idx = packet->q_idx;
> >>  > +	u32 vmbus_flags =
> >>  VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
> >>  >
> >>  >
> >>  >  	net_device = get_outbound_net_device(device);
> >>  > @@ -768,18 +769,21 @@ int netvsc_send(struct hv_device *device,
> >>  >  		return -ENODEV;
> >>  >
> >>  >  	if (packet->page_buf_cnt) {
> >>  > -		ret = vmbus_sendpacket_pagebuffer(out_channel,
> >>  > +		ret = vmbus_sendpacket_pagebuffer_ctl(out_channel,
> >>  >  						  packet->page_buf,
> >>  >  						  packet->page_buf_cnt,
> >>  >  						  &sendMessage,
> >>  >  						  sizeof(struct
> >>  nvsp_message),
> >>  > -						  req_id);
> >>  > +						  req_id,
> >>  > +						  vmbus_flags,
> >>  > +						  kick_q);
> >>  >  	} else {
> >>  > -		ret = vmbus_sendpacket(out_channel, &sendMessage,
> >>  > +		ret = vmbus_sendpacket_ctl(out_channel, &sendMessage,
> >>  >  				sizeof(struct nvsp_message),
> >>  >  				req_id,
> >>  >  				VM_PKT_DATA_INBAND,
> >>  > -
> >>  	VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
> >>  > +				vmbus_flags,
> >>  > +				kick_q);
> >>  >  	}
> >>  >
> >>  >  	if (ret == 0) {
> >>  > diff --git a/drivers/net/hyperv/netvsc_drv.c
> >>  > b/drivers/net/hyperv/netvsc_drv.c
> >>  > index a06bd66..eae58db 100644
> >>  > --- a/drivers/net/hyperv/netvsc_drv.c
> >>  > +++ b/drivers/net/hyperv/netvsc_drv.c
> >>  > @@ -556,7 +556,7 @@ do_send:
> >>  >  	packet->page_buf_cnt = init_page_array(rndis_msg,
> >>  rndis_msg_size,
> >>  >  					skb, &packet->page_buf[0]);
> >>  >
> >>  > -	ret = netvsc_send(net_device_ctx->device_ctx, packet);
> >>  > +	ret = netvsc_send(net_device_ctx->device_ctx, packet,
> >>  > !skb->xmit_more);
> >>  >
> >>
> >>  Looks like the issue of V2 still there (E.g we need to kick when
> >>  hv_ringbuffer_write() returns -EAGAIN?
> >
> > Jason, this issue will be handled in the lower layer. I have already
> > submitted a patch to the vmbus
> > Driver that correctly signals the host when EAGAIN is encountered.
> >
> > Regards,
> >
> > K. Y
> 
> Okay, find the mail but looks like I was not cced.
> 
> Please keep me in the cc list for hyperv patches.

Sorry about that; will do.

K. Y
> 
> Thanks