Re: [PATCH V5 1/1] hv_netvsc: Use the xmit_more skb flag to optimize signaling the host

From: Joe Perches
Date: Mon May 11 2015 - 01:58:23 EST


On Sun, 2015-05-10 at 21:08 -0700, K. Y. Srinivasan wrote:
> Based on the information given to this driver (via the xmit_more skb flag),
> we can defer signaling the host if more packets are on the way. This will help
> make the host more efficient since it can potentially process a larger batch of
> packets. Implement this optimization.

trivia:

I think that indirecting VMBUS_DATA_PACKET_FLAG_COMPLETTION_REQUESTED
into a non-const temporary isn't very useful.

Whenever overly long identifiers like VMBUS_<FOO> is used,
I think that it'd be better to use it directly and ignore
80 column warnings.

Same with the "sizeof(struct nvsp_message)" on two lines.

> diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
[]
> @@ -743,6 +743,8 @@ static inline int netvsc_send_pkt(
> u64 req_id;
> int ret;
> struct hv_page_buffer *pgbuf;
> + u32 vmbus_flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
> + u32 ring_avail = hv_ringbuf_avail_percent(&out_channel->outbound);
[]
> @@ -769,30 +771,41 @@ static inline int netvsc_send_pkt(
[]
> + ret = vmbus_sendpacket_pagebuffer_ctl(out_channel,
> + pgbuf,
> + packet->page_buf_cnt,
> + &nvmsg,
> + sizeof(struct
> + nvsp_message),
> + req_id,
> + vmbus_flags,
> + !packet->xmit_more);

[]

> netif_tx_stop_queue(netdev_get_tx_queue(
> ndev, q_idx));

This could be on one line too.


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