hv_netvsc: minor optimizations
Subsystems (3)
cover hv_netvsc: minor optimizations
These are a set of local optimizations the Hyper-V networking driver. Also include a vmbus patch in this set, because it depends on the netvsc that last used that function.
Stephen Hemminger (6):
hv_netvsc: drop unused macros
hv_netvsc: don't need local xmit_more
hv_netvsc: replace divide with mask when computing padding
hv_netvsc: use reciprocal divide to speed up percent calculation
hv_netvsc: optimize initialization of RNDIS header
vmbus: make hv_get_ringbuffer_availbytes local
drivers/hv/ring_buffer.c | 23 ++++++++++++ drivers/net/hyperv/hyperv_net.h | 32 ++--------------- drivers/net/hyperv/netvsc.c | 26 ++++++-------- drivers/net/hyperv/netvsc_drv.c | 74 ++++++++++++++++++--------------------- drivers/net/hyperv/rndis_filter.c | 4 +-- include/linux/hyperv.h | 22 ------------ 6 files changed, 73 insertions(+), 108 deletions(-)
Signature · 1 line
2.11.0
PATCH 1/6 hv_netvsc: drop unused macros
Signed-off-by Stephen Hemminger <[email protected]>
--- drivers/net/hyperv/hyperv_net.h | 26 -------------------------- 1 file changed, 26 deletions(-)
drivers/net/hyperv/hyperv_net.h +0 -26
@@ -1425,32 +1425,6 @@ struct rndis_message { (sizeof (msg) + (sizeof (struct rndis_message ) - \ sizeof(union rndis_message_container))) -/* get pointer to info buffer with message pointer */ -#define MESSAGE_TO_INFO_BUFFER (msg) \ - (((unsigned char *)(msg)) + msg->info_buf_offset) - -/* get pointer to status buffer with message pointer */ -#define MESSAGE_TO_STATUS_BUFFER (msg) \ - (((unsigned char *)(msg)) + msg->status_buf_offset) - -/* get pointer to OOBD buffer with message pointer */ -#define MESSAGE_TO_OOBD_BUFFER (msg) \ - (((unsigned char *)(msg)) + msg->oob_data_offset) - -/* get pointer to data buffer with message pointer */ -#define MESSAGE_TO_DATA_BUFFER (msg) \ - (((unsigned char *)(msg)) + msg->per_pkt_info_offset) - -/* get pointer to contained message from NDIS_MESSAGE pointer */ -#define RNDIS_MESSAGE_PTR_TO_MESSAGE_PTR (rndis_msg) \ - ((void *) &rndis_msg->msg) - -/* get pointer to contained message from NDIS_MESSAGE pointer */ -#define RNDIS_MESSAGE_RAW_PTR_TO_MESSAGE_PTR (rndis_msg) \ - ((void *) rndis_msg) - - -#define RNDIS_HEADER_SIZE (sizeof(struct rndis_message) - \ sizeof(union rndis_message_container))
Signature · 1 line
2.11.0
PATCH 2/6 hv_netvsc: don't need local xmit_more
In reply to Stephen HemmingerSince skb is always non-NULL in the copy portion of netvsc_send do not need local variable.
Signed-off-by Stephen Hemminger <[email protected]>
--- drivers/net/hyperv/netvsc.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
drivers/net/hyperv/netvsc.c +1 -2
@@ -848,7 +848,6 @@ int netvsc_send(struct net_device_context *ndev_ctx,struct hv_netvsc_packet *msd_send =NULL , *cur_send =NULL ;struct sk_buff *msd_skb =NULL ;bool try_batch; -bool xmit_more = (skb !=NULL ) ? skb->xmit_more : false;/* If device is rescinded, return error and packet will get dropped. */ if (unlikely (!net_device || net_device->destroy))
@@ -922,7 +921,7 @@ int netvsc_send(struct net_device_context *ndev_ctx,if (msdp->skb)dev_consume_skb_any (msdp->skb); -if (xmit_more && !packet->cp_partial) { +if (skb->xmit_more && !packet->cp_partial) { msdp->skb = skb; msdp->pkt = packet; msdp->count++;
Signature · 1 line
2.11.0
PATCH 3/6 hv_netvsc: replace divide with mask when computing padding
In reply to Stephen HemmingerPacket alignment is always a power of 2 therefore modulus can be replaced with a faster and operation
Signed-off-by Stephen Hemminger <[email protected]>
--- drivers/net/hyperv/netvsc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
drivers/net/hyperv/netvsc.c +2 -1
@@ -712,11 +712,12 @@ static u32 netvsc_copy_to_send_buf(struct netvsc_device *net_device,int i;u32 msg_size =0 ;u32 padding =0 ; -u32 remain = packet->total_data_buflen % net_device->pkt_align;u32 page_count = packet->cp_partial ? packet->rmsg_pgcnt : packet->page_buf_cnt; +u32 remain;/* Add padding */ + remain = packet->total_data_buflen & (net_device->pkt_align -1 );if (skb->xmit_more && remain && !packet->cp_partial) { padding = net_device->pkt_align - remain; rndis_msg->msg_len += padding;
Signature · 1 line
2.11.0
PATCH 4/6 hv_netvsc: use reciprocal divide to speed up percent calculation
In reply to Stephen HemmingerEvery packet sent checks the available ring space. The calculation can be sped up by using reciprocal divide which is multiplication.
Since ring_size can only be configured by module parameter, so it doesn't have to be passed around everywhere. Also it should be unsigned since it is number of pages.
Signed-off-by Stephen Hemminger <[email protected]>
--- drivers/net/hyperv/hyperv_net.h | 6 +++--- drivers/net/hyperv/netvsc.c | 20 +++++++------------- drivers/net/hyperv/netvsc_drv.c | 17 +++++++++-------- drivers/net/hyperv/rndis_filter.c | 4 ++-- 4 files changed, 21 insertions(+), 26 deletions(-)
drivers/net/hyperv/hyperv_net.h +3 -3
@@ -146,7 +146,6 @@ struct hv_netvsc_packet {struct netvsc_device_info {unsigned char mac_adr[ETH_ALEN ]; -int ring_size;u32 num_chn;u32 send_sections;u32 recv_sections;
@@ -188,6 +187,9 @@ struct rndis_message;struct netvsc_device ;struct net_device_context ; +extern u32 netvsc_ring_bytes; +extern struct reciprocal_value netvsc_ring_reciprocal; +struct netvsc_device *netvsc_device_add (struct hv_device *device,const struct netvsc_device_info *info);int netvsc_alloc_recv_comp_ring (struct netvsc_device *net_device,u32 q_idx);
@@ -804,8 +806,6 @@ struct netvsc_device {struct rndis_device *extension; -int ring_size; -u32 max_pkt;/* max number of pkt in one send, e.g. 8 */ u32 pkt_align;/* alignment bytes, e.g. 8 */
drivers/net/hyperv/netvsc.c +7 -13
@@ -31,6 +31,7 @@#include <linux/vmalloc.h> #include <linux/rtnetlink.h> #include <linux/prefetch.h> +#include <linux/reciprocal_div.h> #include <asm/sync_bitops.h>
@@ -588,14 +589,11 @@ void netvsc_device_remove(struct hv_device *device)* Get the percentage of available bytes to write in the ring. * The return value is in range from 0 to 100. */ -static inline u32 hv_ringbuf_avail_percent ( -struct hv_ring_buffer_info *ring_info) +static u32 hv_ringbuf_avail_percent (const struct hv_ring_buffer_info *ring_info) { -u32 avail_read, avail_write; +u32 avail_write =hv_get_bytes_to_write (ring_info); -hv_get_ringbuffer_availbytes (ring_info, &avail_read, &avail_write); - -return avail_write *100 / ring_info->ring_datasize; +return reciprocal_divide (avail_write *100 , netvsc_ring_reciprocal); } static inline void netvsc_free_send_slot(struct netvsc_device *net_device,
@@ -1249,7 +1247,6 @@ struct netvsc_device *netvsc_device_add(struct hv_device *device, const struct netvsc_device_info *device_info) {int i, ret =0 ; -int ring_size = device_info->ring_size;struct netvsc_device *net_device;struct net_device *ndev =hv_get_drvdata (device);struct net_device_context *net_device_ctx =netdev_priv (ndev);
@@ -1261,8 +1258,6 @@ struct netvsc_device *netvsc_device_add(struct hv_device *device,for (i =0 ; i <VRSS_SEND_TAB_SIZE ; i++) net_device_ctx->tx_table[i] =0 ; - net_device->ring_size = ring_size; -/* Because the device uses NAPI, all the interrupt batching and * control is done via Net softirq, not the channel handling */
@@ -1289,10 +1284,9 @@ struct netvsc_device *netvsc_device_add(struct hv_device *device, netvsc_poll, NAPI_POLL_WEIGHT);/* Open the channel */ - ret =vmbus_open (device->channel, ring_size *PAGE_SIZE , - ring_size *PAGE_SIZE ,NULL ,0 , - netvsc_channel_cb, - net_device->chan_table); + ret =vmbus_open (device->channel, netvsc_ring_bytes, + netvsc_ring_bytes,NULL ,0 , + netvsc_channel_cb, net_device->chan_table);if (ret !=0 ) {netif_napi_del (&net_device->chan_table[0 ].napi);
drivers/net/hyperv/netvsc_drv.c +9 -8
@@ -35,6 +35,7 @@#include <linux/slab.h> #include <linux/rtnetlink.h> #include <linux/netpoll.h> +#include <linux/reciprocal_div.h> #include <net/arp.h> #include <net/route.h>
@@ -54,9 +55,11 @@#define LINKCHANGE_INT (2 * HZ)#define VF_TAKEOVER_INT (HZ / 10) -static int ring_size =128 ; -module_param (ring_size, int,S_IRUGO ); +static unsigned int ring_size__ro_after_init =128 ; +module_param (ring_size, uint,S_IRUGO );MODULE_PARM_DESC (ring_size,"Ring buffer size (# of pages)" ); +unsigned int netvsc_ring_bytes__ro_after_init ; +struct reciprocal_value netvsc_ring_reciprocal__ro_after_init ;static const u32 default_msg =NETIF_MSG_DRV |NETIF_MSG_PROBE | NETIF_MSG_LINK | NETIF_MSG_IFUP |
@@ -860,7 +863,6 @@ static int netvsc_set_channels(struct net_device *net,memset (&device_info,0 ,sizeof (device_info)); device_info.num_chn = count; - device_info.ring_size = ring_size; device_info.send_sections = nvdev->send_section_cnt; device_info.send_section_size = nvdev->send_section_size; device_info.recv_sections = nvdev->recv_section_cnt;
@@ -975,7 +977,6 @@ static int netvsc_change_mtu(struct net_device *ndev, int mtu)rndis_filter_close (nvdev);memset (&device_info,0 ,sizeof (device_info)); - device_info.ring_size = ring_size; device_info.num_chn = nvdev->num_chn; device_info.send_sections = nvdev->send_section_cnt; device_info.send_section_size = nvdev->send_section_size;
@@ -1539,7 +1540,6 @@ static int netvsc_set_ringparam(struct net_device *ndev,memset (&device_info,0 ,sizeof (device_info)); device_info.num_chn = nvdev->num_chn; - device_info.ring_size = ring_size; device_info.send_sections = new_tx; device_info.send_section_size = nvdev->send_section_size; device_info.recv_sections = new_rx;
@@ -1995,7 +1995,6 @@ static int netvsc_probe(struct hv_device *dev,/* Notify the netvsc driver of the new device */ memset (&device_info,0 ,sizeof (device_info)); - device_info.ring_size = ring_size; device_info.num_chn =VRSS_CHANNEL_DEFAULT ; device_info.send_sections =NETVSC_DEFAULT_TX ; device_info.send_section_size =NETVSC_SEND_SECTION_SIZE ;
@@ -2158,11 +2157,13 @@ static int __init netvsc_drv_init(void)if (ring_size <RING_SIZE_MIN ) { ring_size =RING_SIZE_MIN ; -pr_info ("Increased ring_size to %d (min allowed)\n" , +pr_info ("Increased ring_size to %u (min allowed)\n" , ring_size); } - ret =vmbus_driver_register (&netvsc_drv); + netvsc_ring_bytes = ring_size *PAGE_SIZE ; + netvsc_ring_reciprocal =reciprocal_value (netvsc_ring_bytes); + ret =vmbus_driver_register (&netvsc_drv);if (ret)return ret;
drivers/net/hyperv/rndis_filter.c +2 -2
@@ -1040,8 +1040,8 @@ static void netvsc_sc_open(struct vmbus_channel *new_sc)/* Set the channel before opening.*/ nvchan->channel = new_sc; - ret =vmbus_open (new_sc, nvscdev->ring_size *PAGE_SIZE , - nvscdev->ring_size *PAGE_SIZE ,NULL ,0 , + ret =vmbus_open (new_sc, netvsc_ring_bytes, + netvsc_ring_bytes,NULL ,0 , netvsc_channel_cb, nvchan);if (ret ==0 )napi_enable (&nvchan->napi);
Signature · 1 line
2.11.0
PATCH 5/6 hv_netvsc: optimize initialization of RNDIS header
In reply to Stephen HemmingerThe memset of the whole maximum possible RNDIS header is unnecessary. For the main part of the header use a structure assignment.
No need to memset the whole per packet info. Instead rely on caller to set what it wants. Also get rid of cast to void and signed/unsigned conversion. Now return pointer to per packet data (rather than the header) which simplifies use by code setting up the packet data.
Signed-off-by Stephen Hemminger <[email protected]>
--- drivers/net/hyperv/netvsc_drv.c | 57 +++++++++++++++++++---------------------- 1 file changed, 26 insertions(+), 31 deletions(-)
drivers/net/hyperv/netvsc_drv.c +26 -31
@@ -177,17 +177,15 @@ static int netvsc_close(struct net_device *net)return ret; } -static void *init_ppi_data (struct rndis_message *msg,u32 ppi_size, -int pkt_type) +static inline void *init_ppi_data (struct rndis_message *msg, +u32 ppi_size,u32 pkt_type) { -struct rndis_packet *rndis_pkt; +struct rndis_packet *rndis_pkt = &msg->msg.pkt;struct rndis_per_packet_info *ppi; - rndis_pkt = &msg->msg.pkt; rndis_pkt->data_offset += ppi_size; - - ppi = (struct rndis_per_packet_info *)((void *)rndis_pkt + - rndis_pkt->per_pkt_info_offset + rndis_pkt->per_pkt_info_len); + ppi = (void *)rndis_pkt + rndis_pkt->per_pkt_info_offset + + rndis_pkt->per_pkt_info_len; ppi->size = ppi_size; ppi->type = pkt_type;
@@ -195,7 +193,7 @@ static void *init_ppi_data(struct rndis_message *msg, u32 ppi_size, rndis_pkt->per_pkt_info_len += ppi_size; -return ppi; +return ppi +1 ; }/* Azure hosts don't support non-TCP port numbers in hashing for fragmented
@@ -472,10 +470,8 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)int ret;unsigned int num_data_pgs;struct rndis_message *rndis_msg; -struct rndis_packet *rndis_pkt;struct net_device *vf_netdev;u32 rndis_msg_size; -struct rndis_per_packet_info *ppi;u32 hash;struct hv_page_buffer pb[MAX_PAGE_BUFFER_COUNT ];
@@ -530,34 +526,36 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net) rndis_msg = (struct rndis_message *)skb->head; -memset (rndis_msg,0 ,RNDIS_AND_PPI_SIZE ); -/* Add the rndis header */ rndis_msg->ndis_msg_type =RNDIS_MSG_PACKET ; rndis_msg->msg_len = packet->total_data_buflen; - rndis_pkt = &rndis_msg->msg.pkt; - rndis_pkt->data_offset =sizeof (struct rndis_packet ); - rndis_pkt->data_len = packet->total_data_buflen; - rndis_pkt->per_pkt_info_offset =sizeof (struct rndis_packet ); + + rndis_msg->msg.pkt = (struct rndis_packet ) { + .data_offset =sizeof (struct rndis_packet ), + .data_len = packet->total_data_buflen, + .per_pkt_info_offset =sizeof (struct rndis_packet ), + }; rndis_msg_size = RNDIS_MESSAGE_SIZE(struct rndis_packet); hash =skb_get_hash_raw (skb);if (hash !=0 && net->real_num_tx_queues >1 ) { +u32 *hash_info; + rndis_msg_size +=NDIS_HASH_PPI_SIZE ; - ppi =init_ppi_data (rndis_msg,NDIS_HASH_PPI_SIZE , -NBL_HASH_VALUE ); - *(u32 *)((void *)ppi + ppi->ppi_offset) = hash; + hash_info =init_ppi_data (rndis_msg,NDIS_HASH_PPI_SIZE , +NBL_HASH_VALUE ); + *hash_info = hash; }if (skb_vlan_tag_present (skb)) {struct ndis_pkt_8021q_info *vlan; rndis_msg_size +=NDIS_VLAN_PPI_SIZE ; - ppi =init_ppi_data (rndis_msg,NDIS_VLAN_PPI_SIZE , -IEEE_8021Q_INFO ); + vlan =init_ppi_data (rndis_msg,NDIS_VLAN_PPI_SIZE , +IEEE_8021Q_INFO ); - vlan = (void *)ppi + ppi->ppi_offset; + vlan->value =0 ; vlan->vlanid = skb->vlan_tci &VLAN_VID_MASK ; vlan->pri = (skb->vlan_tci &VLAN_PRIO_MASK ) >>VLAN_PRIO_SHIFT ;
@@ -567,11 +565,10 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)struct ndis_tcp_lso_info *lso_info; rndis_msg_size +=NDIS_LSO_PPI_SIZE ; - ppi =init_ppi_data (rndis_msg,NDIS_LSO_PPI_SIZE , -TCP_LARGESEND_PKTINFO ); - - lso_info = (void *)ppi + ppi->ppi_offset; + lso_info =init_ppi_data (rndis_msg,NDIS_LSO_PPI_SIZE , +TCP_LARGESEND_PKTINFO ); + lso_info->value =0 ; lso_info->lso_v2_transmit.type =NDIS_TCP_LARGE_SEND_OFFLOAD_V2_TYPE ;if (skb->protocol ==htons (ETH_P_IP )) { lso_info->lso_v2_transmit.ip_version =
@@ -596,12 +593,10 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)struct ndis_tcp_ip_checksum_info *csum_info; rndis_msg_size +=NDIS_CSUM_PPI_SIZE ; - ppi =init_ppi_data (rndis_msg,NDIS_CSUM_PPI_SIZE , -TCPIP_CHKSUM_PKTINFO ); - - csum_info = (struct ndis_tcp_ip_checksum_info *)((void *)ppi + - ppi->ppi_offset); + csum_info =init_ppi_data (rndis_msg,NDIS_CSUM_PPI_SIZE , +TCPIP_CHKSUM_PKTINFO ); + csum_info->value =0 ; csum_info->transmit.tcp_header_offset =skb_transport_offset (skb);if (skb->protocol ==htons (ETH_P_IP )) {
Signature · 1 line
2.11.0
PATCH 6/6 vmbus: make hv_get_ringbuffer_availbytes local
In reply to Stephen HemmingerThe last use of hv_get_ringbuffer_availbytes in drivers is now gone. Only used by the debug info routine so make it static. Also, add READ_ONCE() to avoid any possible issues with potentially volatile index values.
Signed-off-by Stephen Hemminger <[email protected]>
--- drivers/hv/ring_buffer.c | 23 +++++++++++++++++++++++ include/linux/hyperv.h | 22 ---------------------- 2 files changed, 23 insertions(+), 22 deletions(-)
drivers/hv/ring_buffer.c +23 -0
@@ -140,6 +140,29 @@ static u32 hv_copyto_ringbuffer(return start_write_offset; } +/* +* +* hv_get_ringbuffer_availbytes() +* +* Get number of bytes available to read and to write to +* for the specified ring buffer +*/ +static void +hv_get_ringbuffer_availbytes (const struct hv_ring_buffer_info *rbi, +u32 *read,u32 *write) +{ +u32 read_loc, write_loc, dsize; + +/* Capture the read/write indices before they changed */ + read_loc =READ_ONCE (rbi->ring_buffer->read_index); + write_loc =READ_ONCE (rbi->ring_buffer->write_index); + dsize = rbi->ring_datasize; + + *write = write_loc >= read_loc ? dsize - (write_loc - read_loc) : + read_loc - write_loc; + *read = dsize - *write; +} +/* Get various debug metrics for the specified ring buffer. */ void hv_ringbuffer_get_debuginfo (const struct hv_ring_buffer_info *ring_info,struct hv_ring_buffer_debug_info *debug_info)
include/linux/hyperv.h +0 -22
@@ -127,28 +127,6 @@ struct hv_ring_buffer_info {u32 priv_read_index; }; -/* -* -* hv_get_ringbuffer_availbytes() -* -* Get number of bytes available to read and to write to -* for the specified ring buffer -*/ -static inline void -hv_get_ringbuffer_availbytes (const struct hv_ring_buffer_info *rbi, -u32 *read,u32 *write) -{ -u32 read_loc, write_loc, dsize; - -/* Capture the read/write indices before they changed */ - read_loc = rbi->ring_buffer->read_index; - write_loc = rbi->ring_buffer->write_index; - dsize = rbi->ring_datasize; - - *write = write_loc >= read_loc ? dsize - (write_loc - read_loc) : - read_loc - write_loc; - *read = dsize - *write; -}static inline u32 hv_get_bytes_to_read (const struct hv_ring_buffer_info *rbi) {
Signature · 1 line
2.11.0
David Miller
maintainerFrom: Stephen Hemminger <[email protected]>
Date: Fri, 1 Dec 2017 11:01:43 -0800
Quoted 3 lines
These are a set of local optimizations the Hyper-V networking driver. Also include a vmbus patch in this set, because it depends on the netvsc that last used that function.
Series applied.
For the ring percentage stuff, I would suggest sticking to power of 2 arithmetic (and thus approximations) even when the ring size is not a power of 2. That way you won't even need multiplies.