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

[Jason Wang]

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.

Thanks

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