Improve ctrlplane performance

The crlplane performance has been improved. This is necessary when
handling many IP in L3 mode (i.e. many ARP Requests/Replies).

Before this change, arp timer was updated as soon as an
arp request was tentativaly sent to the master. This means that,
if the request failed to be sent (e.g. ring full) we had to wait
arp_update_time (default 1sec) before trying again.

Now arp_update_time is only used when an arp reply is received.
If a request has been successfully sent, then the arp timer
is updated by 1 second (i.e. we will not send any arp reuest for this
IP within this second)
If we failed to send the request, then the timer is updated by 100 msec
which means we will wait 100 msec before trying again.
A too high value here would have meant that we have to wait a long time
before trying again. A too short value overload the master ring with
request to transmit ARP requests, so that master is unable to handle
arp replies.

arp_update_time is now also partly randomized to avoid all IPs to request
arp request at the beginning of the test. So if arp_update_time is 10 sec
then the configuration sets it to 5 to 15 sec.

As a final note the following parameter (already implemented before)
can be changed to improve ctrlplane performance (at the cost of dataplane)

ctrl path polling frequency=10000

Change-Id: I9660458a22e7442eaa0c83aaa0c9893a15069f98
Signed-off-by: Xavier Simonart <xavier.simonart@intel.com>

1 files changed, 13 insertions, 7 deletions

diff --git a/VNFs/DPPD-PROX/packet_utils.c b/VNFs/DPPD-PROX/packet_utils.c
index fb467555..e06529c4 100644
--- a/VNFs/DPPD-PROX/packet_utils.c
+++ b/VNFs/DPPD-PROX/packet_utils.c
@@ -24,6 +24,7 @@
 #include "defines.h"
 #include "handle_master.h"
 #include "prox_port_cfg.h"
+#include "packet_utils.h"
 
 static inline int find_ip(struct ether_hdr_arp *pkt, uint16_t len, uint32_t *ip_dst)
 {
@@ -76,7 +77,7 @@ static inline int find_ip(struct ether_hdr_arp *pkt, uint16_t len, uint32_t *ip_
    but this would require either thread safety, or the the exchange of information between master and generating core.
 */
 
-int write_dst_mac(struct task_base *tbase, struct rte_mbuf *mbuf, uint32_t *ip_dst)
+int write_dst_mac(struct task_base *tbase, struct rte_mbuf *mbuf, uint32_t *ip_dst, uint64_t **time)
 {
 	const uint64_t hz = rte_get_tsc_hz();
 	struct ether_hdr_arp *packet = rte_pktmbuf_mtod(mbuf, struct ether_hdr_arp *);
@@ -89,8 +90,9 @@ int write_dst_mac(struct task_base *tbase, struct rte_mbuf *mbuf, uint32_t *ip_d
 			memcpy(mac, &l3->gw.mac, sizeof(prox_rte_ether_addr));
 			return SEND_MBUF;
 		} else if (tsc > l3->gw.arp_update_time) {
-			// long time since we have sent an arp, send arp
-			l3->gw.arp_update_time = tsc + l3->arp_update_time * hz / 1000;
+			// long time since we have successfully sent an arp, send arp
+			// If sending ARP failed (ring full) then arp_update_time is not updated to avoid having to wait 1 sec to send ARP REQ again
+			*time = &l3->gw.arp_update_time;
 			*ip_dst = l3->gw.ip;
 			if ((l3->flags & FLAG_DST_MAC_KNOWN) && (tsc < l3->gw.arp_timeout)){
 				// MAC is valid in the table => send also the mbuf
@@ -121,7 +123,7 @@ int write_dst_mac(struct task_base *tbase, struct rte_mbuf *mbuf, uint32_t *ip_d
 					return SEND_MBUF;
 				} else if (tsc > l3->optimized_arp_table[idx].arp_update_time) {
 					// ARP not sent since a long time, send ARP
-					l3->optimized_arp_table[idx].arp_update_time = tsc + l3->arp_update_time * hz / 1000;
+						*time = &l3->optimized_arp_table[idx].arp_update_time;
 					if (tsc < l3->optimized_arp_table[idx].arp_timeout) {
 						// MAC still valid => also send mbuf
 						memcpy(mac, &l3->optimized_arp_table[idx].mac, sizeof(prox_rte_ether_addr));
@@ -138,7 +140,7 @@ int write_dst_mac(struct task_base *tbase, struct rte_mbuf *mbuf, uint32_t *ip_d
 		}
 		// IP address not found in table
 		l3->optimized_arp_table[l3->n_pkts].ip = *ip_dst;
-		l3->optimized_arp_table[l3->n_pkts].arp_update_time = tsc + l3->arp_update_time * hz / 1000;
+		*time = &l3->optimized_arp_table[l3->n_pkts].arp_update_time;
 		l3->n_pkts++;
 
 		if (l3->n_pkts < 4) {
@@ -172,7 +174,7 @@ int write_dst_mac(struct task_base *tbase, struct rte_mbuf *mbuf, uint32_t *ip_d
 				return DROP_MBUF;
 			} else {
 				l3->arp_table[ret].ip = *ip_dst;
-				l3->arp_table[ret].arp_update_time = tsc + l3->arp_update_time * hz / 1000;
+				*time = &l3->arp_table[ret].arp_update_time;
 			}
 			return SEND_ARP;
 		} else {
@@ -183,7 +185,7 @@ int write_dst_mac(struct task_base *tbase, struct rte_mbuf *mbuf, uint32_t *ip_d
 				return SEND_MBUF;
 			} else if (tsc > l3->arp_table[ret].arp_update_time) {
 				// ARP not sent since a long time, send ARP
-				l3->arp_table[ret].arp_update_time = tsc + l3->arp_update_time * hz / 1000;
+				*time = &l3->arp_table[ret].arp_update_time;
 				if (tsc < l3->arp_table[ret].arp_timeout) {
 					// MAC still valid => send also MBUF
 					memcpy(mac, &l3->arp_table[ret].mac, sizeof(prox_rte_ether_addr));
@@ -230,6 +232,7 @@ void task_init_l3(struct task_base *tbase, struct task_args *targ)
 	tbase->l3.core_id = targ->lconf->id;
 	tbase->l3.task_id = targ->id;
 	tbase->l3.tmaster = targ->tmaster;
+	tbase->l3.seed = (uint)rte_rdtsc();
 	if (targ->arp_timeout != 0)
 		tbase->l3.arp_timeout = targ->arp_timeout;
 	else
@@ -344,6 +347,7 @@ void handle_ctrl_plane_pkts(struct task_base *tbase, struct rte_mbuf **mbufs, ui
 				memcpy(&l3->gw.mac, &hdr->arp.data.sha, 6);
 				l3->flags |= FLAG_DST_MAC_KNOWN;
 				l3->gw.arp_timeout = tsc + update_time;
+				update_arp_update_time(l3, &l3->gw.arp_update_time, l3->arp_update_time);
 			} else if (l3->n_pkts < 4) {
 				// Few packets tracked - should be faster to loop through them thean using a hash table
 				for (idx = 0; idx < l3->n_pkts; idx++) {
@@ -354,6 +358,7 @@ void handle_ctrl_plane_pkts(struct task_base *tbase, struct rte_mbuf **mbufs, ui
 				if (idx < l3->n_pkts) {
 					memcpy(&l3->optimized_arp_table[idx].mac, &(hdr->arp.data.sha), sizeof(prox_rte_ether_addr));
 					l3->optimized_arp_table[idx].arp_timeout = tsc + update_time;
+					update_arp_update_time(l3, &l3->optimized_arp_table[idx].arp_update_time, l3->arp_update_time);
 				}
 			} else {
 				int ret = rte_hash_add_key(l3->ip_hash, (const void *)&ip);
@@ -362,6 +367,7 @@ void handle_ctrl_plane_pkts(struct task_base *tbase, struct rte_mbuf **mbufs, ui
 				} else {
 					memcpy(&l3->arp_table[ret].mac, &(hdr->arp.data.sha), sizeof(prox_rte_ether_addr));
 					l3->arp_table[ret].arp_timeout = tsc + update_time;
+					update_arp_update_time(l3, &l3->arp_table[ret].arp_update_time, l3->arp_update_time);
 				}
 			}
 			tx_drop(mbufs[j]);