RE: [PATCH V4 net-next 1/1] hv_netvsc: Use the xmit_more skb flag to optimize signaling the host

2015-05-10 Thread KY Srinivasan 


> -Original Message-
> From: David Miller [mailto:da...@davemloft.net]
> Sent: Sunday, May 10, 2015 2:51 PM
> To: KY Srinivasan
> Cc: net...@vger.kernel.org; linux-kernel@vger.kernel.org;
> de...@linuxdriverproject.org; o...@aepfle.de; a...@canonical.com;
> jasow...@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" 
> Date: Wed,  6 May 2015 15:29:05 -0700
> 
> > -   ret = vmbus_sendpacket_pagebuffer(out_channel,
> > - pgbuf,
> > - packet->page_buf_cnt,
> > - ,
> > - sizeof(struct
> nvsp_message),
> > - req_id);
> > +   ret = vmbus_sendpacket_pagebuffer_ctl(out_channel,
> > + pgbuf,
> > + packet->page_buf_cnt,
> > + ,
> > + sizeof(struct
> > +nvsp_message),
> > + req_id,
> > + vmbus_flags,
> > + !packet->xmit_more);
> > } else {
> > -   ret = vmbus_sendpacket(
> > +   ret = vmbus_sendpacket_ctl(
> > out_channel, ,
> > 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.
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Re: [PATCH V4 net-next 1/1] hv_netvsc: Use the xmit_more skb flag to optimize signaling the host

2015-05-10 Thread David Miller 
From: "K. Y. Srinivasan" 
Date: Wed,  6 May 2015 15:29:05 -0700

> - ret = vmbus_sendpacket_pagebuffer(out_channel,
> -   pgbuf,
> -   packet->page_buf_cnt,
> -   ,
> -   sizeof(struct nvsp_message),
> -   req_id);
> + ret = vmbus_sendpacket_pagebuffer_ctl(out_channel,
> +   pgbuf,
> +   packet->page_buf_cnt,
> +   ,
> +   sizeof(struct
> +  nvsp_message),
> +   req_id,
> +   vmbus_flags,
> +   !packet->xmit_more);
>   } else {
> - ret = vmbus_sendpacket(
> + ret = vmbus_sendpacket_ctl(
>   out_channel, ,
>   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.
--
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Re: [PATCH V4 net-next 1/1] hv_netvsc: Use the xmit_more skb flag to optimize signaling the host

2015-05-10 Thread David Miller 
From: K. Y. Srinivasan k...@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 linux-kernel in
the body of a message to majord...@vger.kernel.org
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RE: [PATCH V4 net-next 1/1] hv_netvsc: Use the xmit_more skb flag to optimize signaling the host

2015-05-10 Thread KY Srinivasan 


 -Original Message-
 From: David Miller [mailto:da...@davemloft.net]
 Sent: Sunday, May 10, 2015 2:51 PM
 To: KY Srinivasan
 Cc: net...@vger.kernel.org; linux-kernel@vger.kernel.org;
 de...@linuxdriverproject.org; o...@aepfle.de; a...@canonical.com;
 jasow...@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 k...@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.
--
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[PATCH V4 net-next 1/1] hv_netvsc: Use the xmit_more skb flag to optimize signaling the host

2015-05-06 Thread K. Y. Srinivasan 
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 
---
v2: Fixed up indentation based on feedback from David Miller.
v3,v4: If the queue could be stopped, deal with that condition: Eric 
Dumazet 

 drivers/net/hyperv/netvsc.c |   34 --
 1 files changed, 24 insertions(+), 10 deletions(-)

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(_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,
- ,
- sizeof(struct nvsp_message),
- req_id);
+   ret = vmbus_sendpacket_pagebuffer_ctl(out_channel,
+ pgbuf,
+ packet->page_buf_cnt,
+ ,
+ sizeof(struct
+nvsp_message),
+ req_id,
+ vmbus_flags,
+ !packet->xmit_more);
} else {
-   ret = vmbus_sendpacket(
+   ret = vmbus_sendpacket_ctl(
out_channel, ,
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(_device->num_outstanding_sends);
atomic_inc(_device->queue_sends[q_idx]);
 
-   if (hv_ringbuf_avail_percent(_channel->outbound) <
-   RING_AVAIL_PERCENT_LOWATER) {
+   if (ring_avail < RING_AVAIL_PERCENT_LOWATER) {
netif_tx_stop_queue(netdev_get_tx_queue(
ndev, q_idx));
 
-- 
1.7.4.1

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[PATCH V4 net-next 1/1] hv_netvsc: Use the xmit_more skb flag to optimize signaling the host

2015-05-06 Thread K. Y. Srinivasan 
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 k...@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.duma...@gmail.com

 drivers/net/hyperv/netvsc.c |   34 --
 1 files changed, 24 insertions(+), 10 deletions(-)

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));
 
-- 
1.7.4.1

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