-----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