| Message ID | 1430951345-7767-1-git-send-email-kys@microsoft.com |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
From: "K. Y. Srinivasan" <kys@microsoft.com> Date: Wed, 6 May 2015 15:29:05 -0700 > - ret = vmbus_sendpacket_pagebuffer(out_channel, > - pgbuf, > - packet->page_buf_cnt, > - &nvmsg, > - sizeof(struct nvsp_message), > - req_id); > + ret = vmbus_sendpacket_pagebuffer_ctl(out_channel, > + pgbuf, > + packet->page_buf_cnt, > + &nvmsg, > + sizeof(struct > + nvsp_message), > + req_id, > + vmbus_flags, > + !packet->xmit_more); > } else { > - ret = vmbus_sendpacket( > + ret = vmbus_sendpacket_ctl( > out_channel, &nvmsg, > sizeof(struct nvsp_message), > req_id, > VM_PKT_DATA_INBAND, > - VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED); > + vmbus_flags, !packet->xmit_more); Just as you did for the vmbus_sendpacket_pagebuffer_ctl() call above, you'll need to reindent the arguments for the vmbus_sendpacket_ctl() call since the openning parenthesis is now at a different column. Thanks. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
> -----Original Message----- > From: David Miller [mailto:davem@davemloft.net] > Sent: Sunday, May 10, 2015 2:51 PM > To: KY Srinivasan > Cc: netdev@vger.kernel.org; linux-kernel@vger.kernel.org; > devel@linuxdriverproject.org; olaf@aepfle.de; apw@canonical.com; > jasowang@redhat.com > Subject: Re: [PATCH V4 net-next 1/1] hv_netvsc: Use the xmit_more skb flag > to optimize signaling the host > > From: "K. Y. Srinivasan" <kys@microsoft.com> > Date: Wed, 6 May 2015 15:29:05 -0700 > > > - ret = vmbus_sendpacket_pagebuffer(out_channel, > > - pgbuf, > > - packet->page_buf_cnt, > > - &nvmsg, > > - sizeof(struct > nvsp_message), > > - req_id); > > + ret = vmbus_sendpacket_pagebuffer_ctl(out_channel, > > + pgbuf, > > + packet->page_buf_cnt, > > + &nvmsg, > > + sizeof(struct > > + nvsp_message), > > + req_id, > > + vmbus_flags, > > + !packet->xmit_more); > > } else { > > - ret = vmbus_sendpacket( > > + ret = vmbus_sendpacket_ctl( > > out_channel, &nvmsg, > > sizeof(struct nvsp_message), > > req_id, > > VM_PKT_DATA_INBAND, > > - > VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED); > > + vmbus_flags, !packet->xmit_more); > > Just as you did for the vmbus_sendpacket_pagebuffer_ctl() call above, > you'll need to reindent the arguments for the vmbus_sendpacket_ctl() > call since the openning parenthesis is now at a different column. Done. Regards, K. Y > > Thanks. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c index ea091bc..1ab4f9e 100644 --- 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); nvmsg.hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT; if (packet->is_data_pkt) { @@ -769,30 +771,42 @@ static inline int netvsc_send_pkt( if (out_channel->rescind) return -ENODEV; + /* + * It is possible that once we successfully place this packet + * on the ringbuffer, we may stop the queue. In that case, we want + * to notify the host independent of the xmit_more flag. We don't + * need to be precise here; in the worst case we may signal the host + * unnecessarily. + */ + if (ring_avail < (RING_AVAIL_PERCENT_LOWATER + 1)) + packet->xmit_more = false; + if (packet->page_buf_cnt) { pgbuf = packet->cp_partial ? packet->page_buf + packet->rmsg_pgcnt : packet->page_buf; - ret = vmbus_sendpacket_pagebuffer(out_channel, - pgbuf, - packet->page_buf_cnt, - &nvmsg, - sizeof(struct nvsp_message), - req_id); + ret = vmbus_sendpacket_pagebuffer_ctl(out_channel, + pgbuf, + packet->page_buf_cnt, + &nvmsg, + sizeof(struct + nvsp_message), + req_id, + vmbus_flags, + !packet->xmit_more); } else { - ret = vmbus_sendpacket( + ret = vmbus_sendpacket_ctl( out_channel, &nvmsg, sizeof(struct nvsp_message), req_id, VM_PKT_DATA_INBAND, - VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED); + vmbus_flags, !packet->xmit_more); } if (ret == 0) { atomic_inc(&net_device->num_outstanding_sends); atomic_inc(&net_device->queue_sends[q_idx]); - if (hv_ringbuf_avail_percent(&out_channel->outbound) < - RING_AVAIL_PERCENT_LOWATER) { + if (ring_avail < RING_AVAIL_PERCENT_LOWATER) { netif_tx_stop_queue(netdev_get_tx_queue( ndev, q_idx));
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. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> --- v2: Fixed up indentation based on feedback from David Miller. v3,v4: If the queue could be stopped, deal with that condition: Eric Dumazet <eric.dumazet@gmail.com> drivers/net/hyperv/netvsc.c | 34 ++++++++++++++++++++++++---------- 1 files changed, 24 insertions(+), 10 deletions(-)