The default value of send and receive buffer area for host DMA
is much larger than it needs to be. Experimentation shows that
a much smaller buffer still keeps same performance; change
from 16M buffer to 4M receive and 1M send.
Make the size a module parameter so that it can be adjusted
as needed for testing or special needs. It would have been
better to use ethtool to control this but ethtool rx/tx parameters
are in number of descriptors not bytes.
Signed-off-by: Stephen Hemminger <sthem...@microsoft.com>
---
drivers/net/hyperv/hyperv_net.h | 2 ++
drivers/net/hyperv/netvsc.c | 18 ++++++++++--------
drivers/net/hyperv/netvsc_drv.c | 40 +++++++++++++++++++++++++++++++++++-----
3 files changed, 47 insertions(+), 13 deletions(-)
diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
index 2b4a9b058f6d..21666df4cd35 100644
--- a/drivers/net/hyperv/hyperv_net.h
+++ b/drivers/net/hyperv/hyperv_net.h
@@ -148,6 +148,8 @@ struct netvsc_device_info {
unsigned char mac_adr[ETH_ALEN];
bool link_state; /* 0 - link up, 1 - link down */
u32 ring_size;
+ u32 recv_buf_size;
+ u32 send_buf_size;
u32 max_num_vrss_chns;
u32 num_chn;
};
diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index 480bd7704b68..59ca5fd6797d 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -488,16 +488,16 @@ static int negotiate_nvsp_ver(struct hv_device *device,
return ret;
}
-static int netvsc_connect_vsp(struct hv_device *device)
+static int netvsc_connect_vsp(struct hv_device *device,
+ const struct netvsc_device_info *device_info)
{
- int ret;
struct netvsc_device *net_device;
struct nvsp_message *init_packet;
- int ndis_version;
const u32 ver_list[] = {
NVSP_PROTOCOL_VERSION_1, NVSP_PROTOCOL_VERSION_2,
NVSP_PROTOCOL_VERSION_4, NVSP_PROTOCOL_VERSION_5 };
- int i;
+ u32 max_recv_buf_size, ndis_version;
+ int i, ret;
net_device = get_outbound_net_device(device);
if (!net_device)
@@ -546,10 +546,12 @@ static int netvsc_connect_vsp(struct hv_device *device)
/* Post the big receive buffer to NetVSP */
if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_2)
- net_device->recv_buf_size = NETVSC_RECEIVE_BUFFER_SIZE_LEGACY;
+ max_recv_buf_size = NETVSC_RECEIVE_BUFFER_SIZE_LEGACY;
else
- net_device->recv_buf_size = NETVSC_RECEIVE_BUFFER_SIZE;
- net_device->send_buf_size = NETVSC_SEND_BUFFER_SIZE;
+ max_recv_buf_size = NETVSC_RECEIVE_BUFFER_SIZE;
+
+ net_device->recv_buf_size = min(max_recv_buf_size,
device_info->recv_buf_size);
+ net_device->send_buf_size = min_t(u32, NETVSC_SEND_BUFFER_SIZE,
device_info->send_buf_size);
ret = netvsc_init_buf(device);
@@ -1360,7 +1362,7 @@ int netvsc_device_add(struct hv_device *device,
rcu_assign_pointer(net_device_ctx->nvdev, net_device);
/* Connect with the NetVsp */
- ret = netvsc_connect_vsp(device);
+ ret = netvsc_connect_vsp(device, device_info);
if (ret != 0) {
netdev_err(ndev,
"unable to connect to NetVSP - %d\n", ret);
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index fb743c78f3dc..ef3a3a46790f 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -40,13 +40,23 @@
#include "hyperv_net.h"
-#define RING_SIZE_MIN 64
+#define RING_SIZE_MIN 64
+#define RECV_BUFFER_MIN 16
+#define SEND_BUFFER_MIN 4
#define LINKCHANGE_INT (2 * HZ)
static unsigned int ring_size = 128;
module_param(ring_size, uint, 0444);
MODULE_PARM_DESC(ring_size, "Ring buffer size (# of pages)");
+static unsigned int recv_buffer_size = (4 * 1024 * 1024) / PAGE_SIZE;
+module_param(recv_buffer_size, uint, 0444);
+MODULE_PARM_DESC(recv_buffer_size, "Receive buffer size (# of pages)");
+
+static unsigned int send_buffer_size = (1024 * 1024) / PAGE_SIZE;
+module_param(send_buffer_size, uint, 0444);
+MODULE_PARM_DESC(send_buffer_size, "Send buffer size (# of pages)");
+
static const u32 default_msg = NETIF_MSG_DRV | NETIF_MSG_PROBE |
NETIF_MSG_LINK | NETIF_MSG_IFUP |
NETIF_MSG_IFDOWN | NETIF_MSG_RX_ERR |
@@ -764,8 +774,8 @@ static void netvsc_get_channels(struct net_device *net,
}
}
-static int netvsc_set_queues(struct net_device *net, struct hv_device *dev,
- u32 num_chn)
+static int netvsc_set_queues(struct net_device *net, struct netvsc_device
*nvdev,
+ struct hv_device *dev, u32 num_chn)
{
struct netvsc_device_info device_info;
int ret;
@@ -774,6 +784,8 @@ static int netvsc_set_queues(struct net_device *net, struct
hv_device *dev,
device_info.num_chn = num_chn;
device_info.ring_size = ring_size;
device_info.max_num_vrss_chns = num_chn;
+ device_info.send_buf_size = nvdev->send_buf_size;
+ device_info.recv_buf_size = nvdev->recv_buf_size;
ret = rndis_filter_device_add(dev, &device_info);
if (ret)
@@ -824,11 +836,11 @@ static int netvsc_set_channels(struct net_device *net,
rndis_filter_device_remove(dev, nvdev);
- ret = netvsc_set_queues(net, dev, count);
+ ret = netvsc_set_queues(net, nvdev, dev, count);
if (ret == 0)
nvdev->num_chn = count;
else
- netvsc_set_queues(net, dev, nvdev->num_chn);
+ netvsc_set_queues(net, nvdev, dev, nvdev->num_chn);
if (was_running)
ret = netvsc_open(net);
@@ -917,6 +929,8 @@ static int netvsc_change_mtu(struct net_device *ndev, int
mtu)
device_info.ring_size = ring_size;
device_info.num_chn = nvdev->num_chn;
device_info.max_num_vrss_chns = nvdev->num_chn;
+ device_info.send_buf_size = nvdev->send_buf_size;
+ device_info.recv_buf_size = nvdev->recv_buf_size;
rndis_filter_device_remove(hdev, nvdev);
@@ -1568,6 +1582,9 @@ static int netvsc_probe(struct hv_device *dev,
memset(&device_info, 0, sizeof(device_info));
device_info.ring_size = ring_size;
device_info.num_chn = VRSS_CHANNEL_DEFAULT;
+ device_info.send_buf_size = send_buffer_size * PAGE_SIZE;
+ device_info.recv_buf_size = recv_buffer_size * PAGE_SIZE;
+
ret = rndis_filter_device_add(dev, &device_info);
if (ret != 0) {
netdev_err(net, "unable to add netvsc device (ret %d)\n", ret);
@@ -1716,6 +1733,19 @@ static int __init netvsc_drv_init(void)
pr_notice("Increased ring_size to %u (min allowed)\n",
ring_size);
}
+
+ if (recv_buffer_size < RECV_BUFFER_MIN) {
+ recv_buffer_size = RECV_BUFFER_MIN;
+ pr_notice("Increased receive buffer size to %u (min allowed)\n",
+ recv_buffer_size);
+ }
+
+ if (send_buffer_size < SEND_BUFFER_MIN) {
+ send_buffer_size = SEND_BUFFER_MIN;
+ pr_notice("Increased receive buffer size to %u (min allowed)\n",
+ send_buffer_size);
+ }
+
ret = vmbus_driver_register(&netvsc_drv);
if (ret)
--
2.11.0
