[PATCH 1/2] app/testpmd: fwd engines report processed packets

[PATCH 1/2] app/testpmd: fwd engines report processed packets

[Anthony Harivel]

Change packet_fwd_t to return the number of processed packets instead of
a boolean.

This will be used in the next commit to determine the load ratio of an
lcore and adjust the sleep duration accordingly

Signed-off-by: Anthony Harivel <aharivel@redhat.com>
---
 .mailmap                      |  1 +
 app/test-pmd/5tswap.c         |  6 +++---
 app/test-pmd/csumonly.c       |  6 +++---
 app/test-pmd/flowgen.c        |  4 ++--
 app/test-pmd/icmpecho.c       |  6 +++---
 app/test-pmd/ieee1588fwd.c    | 18 +++++++++---------
 app/test-pmd/iofwd.c          |  6 +++---
 app/test-pmd/macfwd.c         |  6 +++---
 app/test-pmd/macswap.c        |  6 +++---
 app/test-pmd/noisy_vnf.c      |  4 ++--
 app/test-pmd/rxonly.c         |  6 +++---
 app/test-pmd/shared_rxq_fwd.c |  6 +++---
 app/test-pmd/testpmd.c        |  6 +++---
 app/test-pmd/testpmd.h        |  2 +-
 app/test-pmd/txonly.c         |  6 +++---
 15 files changed, 45 insertions(+), 44 deletions(-)

diff --git a/.mailmap b/.mailmap
index 156b2278ce84..97b5bdfe1cfd 100644
--- a/.mailmap
+++ b/.mailmap
@@ -111,6 +111,7 @@ Anna Lukin <annal@silicom.co.il>
 Anoob Joseph <anoobj@marvell.com> <anoob.joseph@caviumnetworks.com>
 Antara Ganesh Kolar <antara.ganesh.kolar@intel.com>
 Anthony Fee <anthonyx.fee@intel.com>
+Anthony Harivel <aharivel@redhat.com>
 Antonio Fischetti <antonio.fischetti@intel.com>
 Anupam Kapoor <anupam.kapoor@gmail.com>
 Apeksha Gupta <apeksha.gupta@nxp.com>
diff --git a/app/test-pmd/5tswap.c b/app/test-pmd/5tswap.c
index ff8c2dcde59e..f55d4547e3d6 100644
--- a/app/test-pmd/5tswap.c
+++ b/app/test-pmd/5tswap.c
@@ -81,7 +81,7 @@ swap_udp(struct rte_udp_hdr *udp_hdr)
  * 2,3,4. Swaps source and destination for MAC, IPv4/IPv6, UDP/TCP.
  * Parses each layer and swaps it. When the next layer doesn't match it stops.
  */
-static bool
+static size_t
 pkt_burst_5tuple_swap(struct fwd_stream *fs)
 {
 	struct rte_mbuf  *pkts_burst[MAX_PKT_BURST];
@@ -107,7 +107,7 @@ pkt_burst_5tuple_swap(struct fwd_stream *fs)
 	 */
 	nb_rx = common_fwd_stream_receive(fs, pkts_burst, nb_pkt_per_burst);
 	if (unlikely(nb_rx == 0))
-		return false;
+		return 0;
 
 	txp = &ports[fs->tx_port];
 	ol_flags = ol_flags_init(txp->dev_conf.txmode.offloads);
@@ -154,7 +154,7 @@ pkt_burst_5tuple_swap(struct fwd_stream *fs)
 	}
 	common_fwd_stream_transmit(fs, pkts_burst, nb_rx);
 
-	return true;
+	return nb_rx;
 }
 
 struct fwd_engine five_tuple_swap_fwd_engine = {
diff --git a/app/test-pmd/csumonly.c b/app/test-pmd/csumonly.c
index fc85c22a7757..2632894a29d1 100644
--- a/app/test-pmd/csumonly.c
+++ b/app/test-pmd/csumonly.c
@@ -828,7 +828,7 @@ pkts_ip_csum_recalc(struct rte_mbuf **pkts_burst, const uint16_t nb_pkts, uint64
  * IP, UDP, TCP and SCTP flags always concern the inner layer. The
  * OUTER_IP is only useful for tunnel packets.
  */
-static bool
+static size_t
 pkt_burst_checksum_forward(struct fwd_stream *fs)
 {
 	struct rte_mbuf *pkts_burst[MAX_PKT_BURST];
@@ -860,7 +860,7 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
 	/* receive a burst of packet */
 	nb_rx = common_fwd_stream_receive(fs, pkts_burst, nb_pkt_per_burst);
 	if (unlikely(nb_rx == 0))
-		return false;
+		return 0;
 
 	rx_bad_ip_csum = 0;
 	rx_bad_l4_csum = 0;
@@ -1174,7 +1174,7 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
 	fs->rx_bad_outer_l4_csum += rx_bad_outer_l4_csum;
 	fs->rx_bad_outer_ip_csum += rx_bad_outer_ip_csum;
 
-	return true;
+	return nb_rx;
 }
 
 struct fwd_engine csum_fwd_engine = {
diff --git a/app/test-pmd/flowgen.c b/app/test-pmd/flowgen.c
index 53b5f24f11e7..a89de81ce615 100644
--- a/app/test-pmd/flowgen.c
+++ b/app/test-pmd/flowgen.c
@@ -58,7 +58,7 @@ RTE_DEFINE_PER_LCORE(int, _next_flow);
  * terminate receive traffic.  Received traffic is simply discarded, but we
  * still do so in order to maintain traffic statistics.
  */
-static bool
+static size_t
 pkt_burst_flow_gen(struct fwd_stream *fs)
 {
 	unsigned pkt_size = tx_pkt_length - 4;	/* Adjust FCS */
@@ -168,7 +168,7 @@ pkt_burst_flow_gen(struct fwd_stream *fs)
 
 	RTE_PER_LCORE(_next_flow) = next_flow;
 
-	return true;
+	return nb_pkt;
 }
 
 static int
diff --git a/app/test-pmd/icmpecho.c b/app/test-pmd/icmpecho.c
index 68524484e305..3c08d3cb311e 100644
--- a/app/test-pmd/icmpecho.c
+++ b/app/test-pmd/icmpecho.c
@@ -269,7 +269,7 @@ ipv4_hdr_cksum(struct rte_ipv4_hdr *ip_h)
  * Receive a burst of packets, lookup for ICMP echo requests, and, if any,
  * send back ICMP echo replies.
  */
-static bool
+static size_t
 reply_to_icmp_echo_rqsts(struct fwd_stream *fs)
 {
 	struct rte_mbuf *pkts_burst[MAX_PKT_BURST];
@@ -296,7 +296,7 @@ reply_to_icmp_echo_rqsts(struct fwd_stream *fs)
 	 */
 	nb_rx = common_fwd_stream_receive(fs, pkts_burst, nb_pkt_per_burst);
 	if (unlikely(nb_rx == 0))
-		return false;
+		return 0;
 
 	nb_replies = 0;
 	for (i = 0; i < nb_rx; i++) {
@@ -477,7 +477,7 @@ reply_to_icmp_echo_rqsts(struct fwd_stream *fs)
 	if (nb_replies > 0)
 		common_fwd_stream_transmit(fs, pkts_burst, nb_replies);
 
-	return true;
+	return nb_rx;
 }
 
 struct fwd_engine icmp_echo_engine = {
diff --git a/app/test-pmd/ieee1588fwd.c b/app/test-pmd/ieee1588fwd.c
index 386d9f10e642..9f3f4b665f2f 100644
--- a/app/test-pmd/ieee1588fwd.c
+++ b/app/test-pmd/ieee1588fwd.c
@@ -89,7 +89,7 @@ port_ieee1588_tx_timestamp_check(portid_t pi)
 	       (wait_us == 1) ? "" : "s");
 }
 
-static bool
+static size_t
 ieee1588_packet_fwd(struct fwd_stream *fs)
 {
 	struct rte_mbuf  *mb;
@@ -103,7 +103,7 @@ ieee1588_packet_fwd(struct fwd_stream *fs)
 	 * Receive 1 packet at a time.
 	 */
 	if (common_fwd_stream_receive(fs, &mb, 1) == 0)
-		return false;
+		return 0;
 
 	/*
 	 * Check that the received packet is a PTP packet that was detected
@@ -124,14 +124,14 @@ ieee1588_packet_fwd(struct fwd_stream *fs)
 			       (unsigned) mb->pkt_len);
 		}
 		rte_pktmbuf_free(mb);
-		return false;
+		return 0;
 	}
 	if (eth_type != RTE_ETHER_TYPE_1588) {
 		printf("Port %u Received NON PTP packet incorrectly"
 		       " detected by hardware\n",
 		       fs->rx_port);
 		rte_pktmbuf_free(mb);
-		return false;
+		return 0;
 	}
 
 	/*
@@ -145,14 +145,14 @@ ieee1588_packet_fwd(struct fwd_stream *fs)
 		       " protocol version 0x%x (should be 0x02)\n",
 		       fs->rx_port, ptp_hdr->version);
 		rte_pktmbuf_free(mb);
-		return false;
+		return 0;
 	}
 	if (ptp_hdr->msg_id != PTP_SYNC_MESSAGE) {
 		printf("Port %u Received PTP V2 Ethernet frame with unexpected"
 		       " message ID 0x%x (expected 0x0 - PTP_SYNC_MESSAGE)\n",
 		       fs->rx_port, ptp_hdr->msg_id);
 		rte_pktmbuf_free(mb);
-		return false;
+		return 0;
 	}
 	printf("Port %u IEEE1588 PTP V2 SYNC Message filtered by hardware\n",
 	       fs->rx_port);
@@ -166,7 +166,7 @@ ieee1588_packet_fwd(struct fwd_stream *fs)
 		       " by hardware\n",
 		       fs->rx_port);
 		rte_pktmbuf_free(mb);
-		return false;
+		return 0;
 	}
 
 	/* For i40e we need the timesync register index. It is ignored for the
@@ -184,14 +184,14 @@ ieee1588_packet_fwd(struct fwd_stream *fs)
 	mb->ol_flags |= RTE_MBUF_F_TX_IEEE1588_TMST;
 	if (common_fwd_stream_transmit(fs, &mb, 1) == 0) {
 		printf("Port %u sent PTP packet dropped\n", fs->tx_port);
-		return false;
+		return 0;
 	}
 
 	/*
 	 * Check the TX timestamp.
 	 */
 	port_ieee1588_tx_timestamp_check(fs->tx_port);
-	return true;
+	return 1;
 }
 
 static int
diff --git a/app/test-pmd/iofwd.c b/app/test-pmd/iofwd.c
index ba06fae4a6b0..77814326291d 100644
--- a/app/test-pmd/iofwd.c
+++ b/app/test-pmd/iofwd.c
@@ -41,7 +41,7 @@
  * This is the fastest possible forwarding operation, as it does not access
  * to packets data.
  */
-static bool
+static size_t
 pkt_burst_io_forward(struct fwd_stream *fs)
 {
 	struct rte_mbuf *pkts_burst[MAX_PKT_BURST];
@@ -52,11 +52,11 @@ pkt_burst_io_forward(struct fwd_stream *fs)
 	 */
 	nb_rx = common_fwd_stream_receive(fs, pkts_burst, nb_pkt_per_burst);
 	if (unlikely(nb_rx == 0))
-		return false;
+		return 0;
 
 	common_fwd_stream_transmit(fs, pkts_burst, nb_rx);
 
-	return true;
+	return nb_rx;
 }
 
 struct fwd_engine io_fwd_engine = {
diff --git a/app/test-pmd/macfwd.c b/app/test-pmd/macfwd.c
index 7316d73315b1..c1c601c3cb83 100644
--- a/app/test-pmd/macfwd.c
+++ b/app/test-pmd/macfwd.c
@@ -41,7 +41,7 @@
  * Change the source and the destination Ethernet addressed of packets
  * before forwarding them.
  */
-static bool
+static size_t
 pkt_burst_mac_forward(struct fwd_stream *fs)
 {
 	struct rte_mbuf  *pkts_burst[MAX_PKT_BURST];
@@ -58,7 +58,7 @@ pkt_burst_mac_forward(struct fwd_stream *fs)
 	 */
 	nb_rx = common_fwd_stream_receive(fs, pkts_burst, nb_pkt_per_burst);
 	if (unlikely(nb_rx == 0))
-		return false;
+		return 0;
 
 	txp = &ports[fs->tx_port];
 	tx_offloads = txp->dev_conf.txmode.offloads;
@@ -88,7 +88,7 @@ pkt_burst_mac_forward(struct fwd_stream *fs)
 
 	common_fwd_stream_transmit(fs, pkts_burst, nb_rx);
 
-	return true;
+	return nb_rx;
 }
 
 struct fwd_engine mac_fwd_engine = {
diff --git a/app/test-pmd/macswap.c b/app/test-pmd/macswap.c
index 57f77003fe44..cad39b1a7369 100644
--- a/app/test-pmd/macswap.c
+++ b/app/test-pmd/macswap.c
@@ -47,7 +47,7 @@
  * MAC swap forwarding mode: Swap the source and the destination Ethernet
  * addresses of packets before forwarding them.
  */
-static bool
+static size_t
 pkt_burst_mac_swap(struct fwd_stream *fs)
 {
 	struct rte_mbuf  *pkts_burst[MAX_PKT_BURST];
@@ -58,12 +58,12 @@ pkt_burst_mac_swap(struct fwd_stream *fs)
 	 */
 	nb_rx = common_fwd_stream_receive(fs, pkts_burst, nb_pkt_per_burst);
 	if (unlikely(nb_rx == 0))
-		return false;
+		return 0;
 
 	do_macswap(pkts_burst, nb_rx, &ports[fs->tx_port]);
 	common_fwd_stream_transmit(fs, pkts_burst, nb_rx);
 
-	return true;
+	return nb_rx;
 }
 
 struct fwd_engine mac_swap_engine = {
diff --git a/app/test-pmd/noisy_vnf.c b/app/test-pmd/noisy_vnf.c
index 2bf90a983c7d..13660fbad338 100644
--- a/app/test-pmd/noisy_vnf.c
+++ b/app/test-pmd/noisy_vnf.c
@@ -110,7 +110,7 @@ sim_memory_lookups(struct noisy_config *ncf, uint16_t nb_pkts)
  *    out of the FIFO
  * 4. Cases 2 and 3 combined
  */
-static bool
+static size_t
 pkt_burst_noisy_vnf(struct fwd_stream *fs)
 {
 	const uint64_t freq_khz = rte_get_timer_hz() / 1000;
@@ -169,7 +169,7 @@ pkt_burst_noisy_vnf(struct fwd_stream *fs)
 		ncf->prev_time = rte_get_timer_cycles();
 	}
 end:
-	return nb_rx > 0 || nb_tx > 0;
+	return (nb_rx > nb_tx) ? nb_rx : nb_tx;
 }
 
 #define NOISY_STRSIZE 256
diff --git a/app/test-pmd/rxonly.c b/app/test-pmd/rxonly.c
index 315f9286cdbe..0583bbac87bb 100644
--- a/app/test-pmd/rxonly.c
+++ b/app/test-pmd/rxonly.c
@@ -41,7 +41,7 @@
 /*
  * Received a burst of packets.
  */
-static bool
+static size_t
 pkt_burst_receive(struct fwd_stream *fs)
 {
 	struct rte_mbuf  *pkts_burst[MAX_PKT_BURST];
@@ -52,11 +52,11 @@ pkt_burst_receive(struct fwd_stream *fs)
 	 */
 	nb_rx = common_fwd_stream_receive(fs, pkts_burst, nb_pkt_per_burst);
 	if (unlikely(nb_rx == 0))
-		return false;
+		return 0;
 
 	rte_pktmbuf_free_bulk(pkts_burst, nb_rx);
 
-	return true;
+	return nb_rx;
 }
 
 static void
diff --git a/app/test-pmd/shared_rxq_fwd.c b/app/test-pmd/shared_rxq_fwd.c
index 623d62da88cc..1ff846db48ca 100644
--- a/app/test-pmd/shared_rxq_fwd.c
+++ b/app/test-pmd/shared_rxq_fwd.c
@@ -89,7 +89,7 @@ forward_shared_rxq(struct fwd_stream *fs, uint16_t nb_rx,
 			  &pkts_burst[nb_rx - nb_sub_burst]);
 }
 
-static bool
+static size_t
 shared_rxq_fwd(struct fwd_stream *fs)
 {
 	struct rte_mbuf *pkts_burst[nb_pkt_per_burst];
@@ -97,10 +97,10 @@ shared_rxq_fwd(struct fwd_stream *fs)
 
 	nb_rx = common_fwd_stream_receive(fs, pkts_burst, nb_pkt_per_burst);
 	if (unlikely(nb_rx == 0))
-		return false;
+		return 0;
 	forward_shared_rxq(fs, nb_rx, pkts_burst);
 
-	return true;
+	return nb_rx;
 }
 
 static void
diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c
index 003269660801..e25c082387f5 100644
--- a/app/test-pmd/testpmd.c
+++ b/app/test-pmd/testpmd.c
@@ -2274,14 +2274,14 @@ run_pkt_fwd_on_lcore(struct fwd_lcore *fc, packet_fwd_t pkt_fwd)
 		for (sm_id = 0; sm_id < nb_fs; sm_id++) {
 			struct fwd_stream *fs = fsm[sm_id];
 			uint64_t start_fs_tsc = 0;
-			bool busy;
+			size_t pkts;
 
 			if (fs->disabled)
 				continue;
 			if (record_core_cycles)
 				start_fs_tsc = rte_rdtsc();
-			busy = (*pkt_fwd)(fs);
-			if (record_core_cycles && busy)
+			pkts = (*pkt_fwd)(fs);
+			if (record_core_cycles && pkts > 0)
 				fs->busy_cycles += rte_rdtsc() - start_fs_tsc;
 		}
 #ifdef RTE_LIB_BITRATESTATS
diff --git a/app/test-pmd/testpmd.h b/app/test-pmd/testpmd.h
index b9215720b615..b399a0dc7f84 100644
--- a/app/test-pmd/testpmd.h
+++ b/app/test-pmd/testpmd.h
@@ -382,7 +382,7 @@ struct fwd_lcore {
 typedef int (*port_fwd_begin_t)(portid_t pi);
 typedef void (*port_fwd_end_t)(portid_t pi);
 typedef void (*stream_init_t)(struct fwd_stream *fs);
-typedef bool (*packet_fwd_t)(struct fwd_stream *fs);
+typedef size_t (*packet_fwd_t)(struct fwd_stream *fs);
 
 struct fwd_engine {
 	const char       *fwd_mode_name; /**< Forwarding mode name. */
diff --git a/app/test-pmd/txonly.c b/app/test-pmd/txonly.c
index b3d68731047e..ecdf9c54d3ea 100644
--- a/app/test-pmd/txonly.c
+++ b/app/test-pmd/txonly.c
@@ -323,7 +323,7 @@ pkt_burst_prepare(struct rte_mbuf *pkt, struct rte_mempool *mbp,
 /*
  * Transmit a burst of multi-segments packets.
  */
-static bool
+static size_t
 pkt_burst_transmit(struct fwd_stream *fs)
 {
 	struct rte_mbuf *pkts_burst[MAX_PKT_BURST];
@@ -388,7 +388,7 @@ pkt_burst_transmit(struct fwd_stream *fs)
 	}
 
 	if (nb_pkt == 0)
-		return false;
+		return 0;
 
 	nb_tx = common_fwd_stream_transmit(fs, pkts_burst, nb_pkt);
 
@@ -404,7 +404,7 @@ pkt_burst_transmit(struct fwd_stream *fs)
 			       (unsigned) (nb_pkt - nb_tx));
 	}
 
-	return true;
+	return nb_tx;
 }
 
 static int
-- 
2.39.2

[PATCH 2/2] app/testpmd: add testpmd based sleeping

[Anthony Harivel]

Sleep for an incremental amount of time if the fwd engine has processed
less than at least half a burst of packets (i.e 16pkts with default
setting) on a polling iteration of testpmd.

Upon detecting the threshold of >= 16 pkts on an Rxq, reset the sleep
time to zero (i.e. no sleep).

Sleep time will be increased on each iteration where the low load
conditions remain up to a total of the max sleep time which is set by
the user with the "--max-sleep-us NUM" command line argument or when in
interactive "mode set max_sleep NUM".

The default max_sleep value is 0, which means that no sleeps will occur
and the default behaviour is unchanged from previously.

Testing has been performed on AMD EPYC 7702 server with --nb-cores 12.
The results were obtained via turbostat for each individual lcore:

max_sleep 0     ====== ======== ======== ========
                  idle    4Mpps   16Mpps   Bursts
=============== ====== ======== ======== ========
C1-state %           0        0        0        0
C2-state %           0        0        0        0
% usage            100      100      100      100
Watt / core       1.14     1.18     1.19     1.14
=============== ====== ======== ======== ========

max_sleep 500   ====== ======== ======== ========
                  idle    4Mpps   16Mpps   Bursts
=============== ====== ======== ======== ========
C1-state %          99       85       74     98.6
C2-state %           0        0        0        0
% usage              1       15       26        1
Watt / core       0.04     0.18     0.28     0 04
=============== ====== ======== ======== ========

max_sleep 1000  ====== ======== ======== ========
                  idle    4Mpps   16Mpps   Bursts
=============== ====== ======== ======== ========
C1-state %           0       85       74      0.3
C2-state %          99        0        0     97.6
% usage              1       15       25        1
Watt / core       0.02     0.18     0.28     0 02
=============== ====== ======== ======== ========

On most cases, the consumption of the cores is greatly improved while
still performing zero packet loss.

Latency test has been performed on each tests above. The CPU has a C1
latency of 1us and a C2 latency of 400us. On the worst case scenario, Tx
Burst of thousands packets every seconds, the following latency in us
(micro seconds) has been observed:

=========== ==== ===== ======
max_sleep      0   500   1000
----------- ---- ----- ------
max latency   14   560   1260
min latency    5     5      6
Avg latency    7   305    617
=========== ==== ===== ======

link: https://www.github.com/torvalds/linux/tree/master/tools/power/x86/turbostat
Signed-off-by: Anthony Harivel <aharivel@redhat.com>
---
 app/test-pmd/cmdline.c                      | 78 +++++++++++++++++++++
 app/test-pmd/parameters.c                   | 14 ++++
 app/test-pmd/testpmd.c                      | 24 ++++++-
 app/test-pmd/testpmd.h                      |  2 +
 doc/guides/testpmd_app_ug/run_app.rst       | 19 +++++
 doc/guides/testpmd_app_ug/testpmd_funcs.rst | 13 ++++
 6 files changed, 149 insertions(+), 1 deletion(-)

diff --git a/app/test-pmd/cmdline.c b/app/test-pmd/cmdline.c
index 02c72d06b768..b89aae1c3414 100644
--- a/app/test-pmd/cmdline.c
+++ b/app/test-pmd/cmdline.c
@@ -5522,6 +5522,82 @@ static cmdline_parse_inst_t cmd_set_link_check = {
 	},
 };
 
+/* *** SET MAX SLEEP *** */
+struct cmd_max_sleep_result {
+	cmdline_fixed_string_t set;
+	cmdline_fixed_string_t max_sleep;
+	uint64_t value;
+};
+
+static void
+cmd_max_sleep_set_parsed(void *parsed_result,
+		__rte_unused struct cmdline *cl,
+		__rte_unused void *data)
+{
+	struct cmd_max_sleep_result *res = parsed_result;
+	if ((!strcmp(res->set, "set"))
+		&& (!strcmp(res->max_sleep, "max_sleep")))
+		max_sleep_us = res->value;
+}
+
+static cmdline_parse_token_string_t cmd_max_sleep_set =
+	TOKEN_STRING_INITIALIZER(struct cmd_max_sleep_result,
+			set, "set");
+static cmdline_parse_token_string_t cmd_max_sleep =
+	TOKEN_STRING_INITIALIZER(struct cmd_max_sleep_result,
+			max_sleep, "max_sleep");
+static cmdline_parse_token_num_t cmd_max_sleep_value =
+	TOKEN_NUM_INITIALIZER(struct cmd_max_sleep_result,
+			value, RTE_UINT64);
+
+static cmdline_parse_inst_t cmd_set_max_sleep = {
+	.f = cmd_max_sleep_set_parsed,
+	.data = NULL,
+	.help_str = "set max_sleep <value>: Set the maximum sleep in micro seconds.",
+	.tokens = {
+		(void *)&cmd_max_sleep_set,
+		(void *)&cmd_max_sleep,
+		(void *)&cmd_max_sleep_value,
+		NULL,
+	},
+};
+
+/* *** SHOW MAX SLEEP *** */
+struct cmd_max_sleep_show_result {
+	cmdline_fixed_string_t show;
+	cmdline_fixed_string_t max_sleep;
+	uint64_t value;
+};
+
+static void
+cmd_max_sleep_show_parsed(void *parsed_result,
+		__rte_unused struct cmdline *cl,
+		__rte_unused void *data)
+{
+	struct cmd_max_sleep_show_result *res = parsed_result;
+	if ((!strcmp(res->show, "show"))
+		&& (!strcmp(res->max_sleep, "max_sleep")))
+		printf("max_sleep %"PRIu64" us\n", max_sleep_us);
+}
+
+static cmdline_parse_token_string_t cmd_show_max_sleep_show =
+	TOKEN_STRING_INITIALIZER(struct cmd_max_sleep_show_result,
+			show, "show");
+static cmdline_parse_token_string_t cmd_max_sleep_show =
+	TOKEN_STRING_INITIALIZER(struct cmd_max_sleep_show_result,
+			max_sleep, "max_sleep");
+
+static cmdline_parse_inst_t cmd_show_max_sleep = {
+	.f = cmd_max_sleep_show_parsed,
+	.data = NULL,
+	.help_str = "show max_sleep: Display the maximun sleep in micro seconds.",
+	.tokens = {
+		(void *)&cmd_show_max_sleep_show,
+		(void *)&cmd_max_sleep_show,
+		NULL,
+	},
+};
+
 /* *** SET FORWARDING MODE *** */
 struct cmd_set_fwd_mode_result {
 	cmdline_fixed_string_t set;
@@ -12770,6 +12846,8 @@ static cmdline_parse_ctx_t builtin_ctx[] = {
 	(cmdline_parse_inst_t *)&cmd_set_allmulti_mode_all,
 	(cmdline_parse_inst_t *)&cmd_set_flush_rx,
 	(cmdline_parse_inst_t *)&cmd_set_link_check,
+	(cmdline_parse_inst_t *)&cmd_set_max_sleep,
+	(cmdline_parse_inst_t *)&cmd_show_max_sleep,
 	(cmdline_parse_inst_t *)&cmd_vlan_offload,
 	(cmdline_parse_inst_t *)&cmd_vlan_tpid,
 	(cmdline_parse_inst_t *)&cmd_rx_vlan_filter_all,
diff --git a/app/test-pmd/parameters.c b/app/test-pmd/parameters.c
index 3b37809baf00..6cb4ce9edb0a 100644
--- a/app/test-pmd/parameters.c
+++ b/app/test-pmd/parameters.c
@@ -201,6 +201,9 @@ usage(char* progname)
 	printf("  --rx-mq-mode=0xX: hexadecimal bitmask of RX mq mode can be "
 	       "enabled\n");
 	printf("  --record-core-cycles: enable measurement of CPU cycles.\n");
+	printf("  --max-sleep-us: maximum sleep time that will be requested in\n"
+	       "    microseconds per iteration of packet processing which has received zero\n"
+	       "    or a small amount of packets from the Rx queues it is polling.\n");
 	printf("  --record-burst-stats: enable display of RX and TX bursts.\n");
 	printf("  --hairpin-mode=0xXX: bitmask set the hairpin port mode.\n"
 	       "    0x10 - explicit Tx rule, 0x02 - hairpin ports paired\n"
@@ -707,6 +710,7 @@ launch_args_parse(int argc, char** argv)
 		{ "no-iova-contig",             0, 0, 0 },
 		{ "rx-mq-mode",                 1, 0, 0 },
 		{ "record-core-cycles",         0, 0, 0 },
+		{ "max-sleep-us",               1, 0, 0 },
 		{ "record-burst-stats",         0, 0, 0 },
 		{ PARAM_NUM_PROCS,              1, 0, 0 },
 		{ PARAM_PROC_ID,                1, 0, 0 },
@@ -1459,6 +1463,16 @@ launch_args_parse(int argc, char** argv)
 			}
 			if (!strcmp(lgopts[opt_idx].name, "record-core-cycles"))
 				record_core_cycles = 1;
+			if (!strcmp(lgopts[opt_idx].name, "max-sleep-us")) {
+				char *end = NULL;
+				errno = 0;
+				unsigned long sleep = strtoul(optarg, &end, 10);
+
+				if (errno != 0 || *optarg == '\0' || *end != '\0' || sleep == 0)
+					rte_exit(EXIT_FAILURE, "max-sleep-us must be > 0\n");
+
+				max_sleep_us = sleep;
+			}
 			if (!strcmp(lgopts[opt_idx].name, "record-burst-stats"))
 				record_burst_stats = 1;
 			if (!strcmp(lgopts[opt_idx].name, PARAM_NUM_PROCS))
diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c
index e25c082387f5..ccd9be175c59 100644
--- a/app/test-pmd/testpmd.c
+++ b/app/test-pmd/testpmd.c
@@ -524,6 +524,11 @@ uint8_t gro_flush_cycles = GRO_DEFAULT_FLUSH_CYCLES;
  */
 enum rte_eth_rx_mq_mode rx_mq_mode = RTE_ETH_MQ_RX_VMDQ_DCB_RSS;
 
+/*
+ * Max sleep time requested in microseconds per iteration
+ */
+uint64_t max_sleep_us;
+
 /*
  * Used to set forced link speed
  */
@@ -2254,6 +2259,8 @@ static void
 run_pkt_fwd_on_lcore(struct fwd_lcore *fc, packet_fwd_t pkt_fwd)
 {
 	struct fwd_stream **fsm;
+	uint64_t sleep_us = 0;
+	uint64_t sleep_cycles;
 	uint64_t prev_tsc;
 	streamid_t nb_fs;
 	streamid_t sm_id;
@@ -2283,6 +2290,8 @@ run_pkt_fwd_on_lcore(struct fwd_lcore *fc, packet_fwd_t pkt_fwd)
 			pkts = (*pkt_fwd)(fs);
 			if (record_core_cycles && pkts > 0)
 				fs->busy_cycles += rte_rdtsc() - start_fs_tsc;
+			if (pkts > nb_pkt_per_burst / 2)
+				sleep_us = 0;
 		}
 #ifdef RTE_LIB_BITRATESTATS
 		if (bitrate_enabled != 0 &&
@@ -2302,10 +2311,23 @@ run_pkt_fwd_on_lcore(struct fwd_lcore *fc, packet_fwd_t pkt_fwd)
 				latencystats_lcore_id == rte_lcore_id())
 			rte_latencystats_update();
 #endif
+		sleep_cycles = 0;
+		if (max_sleep_us) {
+			/* Check if a sleep should happen on this iteration. */
+			if (sleep_us > 0) {
+				uint64_t tsc = rte_rdtsc();
+
+				rte_delay_us_sleep(sleep_us);
+				sleep_cycles = rte_rdtsc() - tsc;
+			}
+			if (sleep_us < max_sleep_us)
+				/* Increase sleep time for next iteration. */
+				sleep_us += 1;
+		}
 		if (record_core_cycles) {
 			uint64_t tsc = rte_rdtsc();
 
-			fc->total_cycles += tsc - prev_tsc;
+			fc->total_cycles += tsc - prev_tsc - sleep_cycles;
 			prev_tsc = tsc;
 		}
 	} while (! fc->stopped);
diff --git a/app/test-pmd/testpmd.h b/app/test-pmd/testpmd.h
index b399a0dc7f84..63758831d6c9 100644
--- a/app/test-pmd/testpmd.h
+++ b/app/test-pmd/testpmd.h
@@ -779,6 +779,8 @@ extern struct mplsoudp_decap_conf mplsoudp_decap_conf;
 
 extern enum rte_eth_rx_mq_mode rx_mq_mode;
 
+extern uint64_t max_sleep_us;
+
 extern struct rte_flow_action_conntrack conntrack_context;
 
 extern int proc_id;
diff --git a/doc/guides/testpmd_app_ug/run_app.rst b/doc/guides/testpmd_app_ug/run_app.rst
index 57b23241cf36..c5afe44e680f 100644
--- a/doc/guides/testpmd_app_ug/run_app.rst
+++ b/doc/guides/testpmd_app_ug/run_app.rst
@@ -555,6 +555,25 @@ The command line options are:
 
     The default value is 0. Hairpin will use single port mode and implicit Tx flow mode.
 
+*   ``--max-sleep-us=N``
+
+    Set the maximum sleep in micro seconds. The default value is 0.
+
+    When `max-sleep-us` is set, the lcores running the packet forwarding may stop active polling and
+    go to sleep for an incrementing amount of time. Each time the forwarding engine processes less
+    than half a burst of packets, the sleep time will be incremented by 1 micro second, up to the
+    maximum value set by the user.
+
+    At any point, if the forwarding engine returns more than half a burst of packets, the sleep time
+    will be reset to 0.
+
+    Sleeping in the packet processing path yields back control to the kernel scheduler. The actual
+    sleep/wakeup times are not guaranteed and may differ significantly depending on system
+    configuration, allowed C-states and scheduler timer resolution (on Linux, this is controlled by
+    ``prctl(PR_SET_TIMERSLACK, nanoseconds)`` and it defaults to 10 micro seconds).
+
+    In interactive mode, the maximum sleep time can be set with ``set max_sleep N`` and displayed
+    with ``show max_sleep``.
 
 Testpmd Multi-Process Command-line Options
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
diff --git a/doc/guides/testpmd_app_ug/testpmd_funcs.rst b/doc/guides/testpmd_app_ug/testpmd_funcs.rst
index 8f2384785930..53a67f02b702 100644
--- a/doc/guides/testpmd_app_ug/testpmd_funcs.rst
+++ b/doc/guides/testpmd_app_ug/testpmd_funcs.rst
@@ -637,6 +637,12 @@ Show fec mode of a port::
 
   testpmd> show port (port_id) fec_mode
 
+show max_sleep
+~~~~~~~~~~~~~~
+
+Show max_sleep in micro seconds::
+
+  testpmd> show max_sleep
 
 Configuration Functions
 -----------------------
@@ -1802,6 +1808,13 @@ Set fec mode for a specific port::
 
   testpmd> set port (port_id) fec_mode auto|off|rs|baser
 
+Set max_sleep
+~~~~~~~~~~~~
+
+Set max_sleep in micro seconds::
+
+  testpmd> set max_sleep <us>
+
 Config Sample actions list
 ~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-- 
2.39.2

Re: [PATCH 2/2] app/testpmd: add testpmd based sleeping

[Stephen Hemminger]

On Thu, 16 Mar 2023 16:14:38 +0100
Anthony Harivel <aharivel@redhat.com> wrote:

> Sleep for an incremental amount of time if the fwd engine has processed
> less than at least half a burst of packets (i.e 16pkts with default
> setting) on a polling iteration of testpmd.
> 
> Upon detecting the threshold of >= 16 pkts on an Rxq, reset the sleep
> time to zero (i.e. no sleep).
> 
> Sleep time will be increased on each iteration where the low load
> conditions remain up to a total of the max sleep time which is set by
> the user with the "--max-sleep-us NUM" command line argument or when in
> interactive "mode set max_sleep NUM".
> 
> The default max_sleep value is 0, which means that no sleeps will occur
> and the default behaviour is unchanged from previously.
> 
> Testing has been performed on AMD EPYC 7702 server with --nb-cores 12.
> The results were obtained via turbostat for each individual lcore:
> 
> max_sleep 0     ====== ======== ======== ========
>                   idle    4Mpps   16Mpps   Bursts
> =============== ====== ======== ======== ========
> C1-state %           0        0        0        0
> C2-state %           0        0        0        0
> % usage            100      100      100      100
> Watt / core       1.14     1.18     1.19     1.14
> =============== ====== ======== ======== ========
> 
> max_sleep 500   ====== ======== ======== ========
>                   idle    4Mpps   16Mpps   Bursts
> =============== ====== ======== ======== ========
> C1-state %          99       85       74     98.6
> C2-state %           0        0        0        0
> % usage              1       15       26        1
> Watt / core       0.04     0.18     0.28     0 04
> =============== ====== ======== ======== ========
> 
> max_sleep 1000  ====== ======== ======== ========
>                   idle    4Mpps   16Mpps   Bursts
> =============== ====== ======== ======== ========
> C1-state %           0       85       74      0.3
> C2-state %          99        0        0     97.6
> % usage              1       15       25        1
> Watt / core       0.02     0.18     0.28     0 02
> =============== ====== ======== ======== ========
> 
> On most cases, the consumption of the cores is greatly improved while
> still performing zero packet loss.
> 
> Latency test has been performed on each tests above. The CPU has a C1
> latency of 1us and a C2 latency of 400us. On the worst case scenario, Tx
> Burst of thousands packets every seconds, the following latency in us
> (micro seconds) has been observed:
> 
> =========== ==== ===== ======
> max_sleep      0   500   1000
> ----------- ---- ----- ------
> max latency   14   560   1260
> min latency    5     5      6
> Avg latency    7   305    617
> =========== ==== ===== ======
> 
> link: https://www.github.com/torvalds/linux/tree/master/tools/power/x86/turbostat
> Signed-off-by: Anthony Harivel <aharivel@redhat.com>

Testpmd is already grown beyond the original intended scope.
This seems like a feature which would be better added to forwarding example
apps. This is just feature creep here.

Re: [PATCH 2/2] app/testpmd: add testpmd based sleeping

[Ferruh Yigit]

On 3/16/2023 3:14 PM, Anthony Harivel wrote:
> Sleep for an incremental amount of time if the fwd engine has processed
> less than at least half a burst of packets (i.e 16pkts with default
> setting) on a polling iteration of testpmd.
> 
> Upon detecting the threshold of >= 16 pkts on an Rxq, reset the sleep
> time to zero (i.e. no sleep).
> 
> Sleep time will be increased on each iteration where the low load
> conditions remain up to a total of the max sleep time which is set by
> the user with the "--max-sleep-us NUM" command line argument or when in
> interactive "mode set max_sleep NUM".
> 
> The default max_sleep value is 0, which means that no sleeps will occur
> and the default behaviour is unchanged from previously.
> 
> Testing has been performed on AMD EPYC 7702 server with --nb-cores 12.
> The results were obtained via turbostat for each individual lcore:
> 
> max_sleep 0     ====== ======== ======== ========
>                   idle    4Mpps   16Mpps   Bursts
> =============== ====== ======== ======== ========
> C1-state %           0        0        0        0
> C2-state %           0        0        0        0
> % usage            100      100      100      100
> Watt / core       1.14     1.18     1.19     1.14
> =============== ====== ======== ======== ========
> 
> max_sleep 500   ====== ======== ======== ========
>                   idle    4Mpps   16Mpps   Bursts
> =============== ====== ======== ======== ========
> C1-state %          99       85       74     98.6
> C2-state %           0        0        0        0
> % usage              1       15       26        1
> Watt / core       0.04     0.18     0.28     0 04
> =============== ====== ======== ======== ========
> 
> max_sleep 1000  ====== ======== ======== ========
>                   idle    4Mpps   16Mpps   Bursts
> =============== ====== ======== ======== ========
> C1-state %           0       85       74      0.3
> C2-state %          99        0        0     97.6
> % usage              1       15       25        1
> Watt / core       0.02     0.18     0.28     0 02
> =============== ====== ======== ======== ========
> 
> On most cases, the consumption of the cores is greatly improved while
> still performing zero packet loss.
> 
> Latency test has been performed on each tests above. The CPU has a C1
> latency of 1us and a C2 latency of 400us. On the worst case scenario, Tx
> Burst of thousands packets every seconds, the following latency in us
> (micro seconds) has been observed:
> 
> =========== ==== ===== ======
> max_sleep      0   500   1000
> ----------- ---- ----- ------
> max latency   14   560   1260
> min latency    5     5      6
> Avg latency    7   305    617
> =========== ==== ===== ======
> 
> link: https://www.github.com/torvalds/linux/tree/master/tools/power/x86/turbostat
> Signed-off-by: Anthony Harivel <aharivel@redhat.com>

Hi Anthony,

What is the motivation here?

Re: [PATCH 2/2] app/testpmd: add testpmd based sleeping

[Anthony Harivel]

Ferruh Yigit, Mar 16, 2023 at 18:05:
> Hi Anthony,
>
> What is the motivation here?

Hi Ferruh,

AFAIK testpmd is the reference tool used for CI and tests whether it is
for functional or performance tests and I think it would be in
everyone's interest to consume less CPU during them. Moreover, all
patches coming to the ML are going through validation tests and this
could reduce the maintenance cost of the project.

Re: [PATCH 2/2] app/testpmd: add testpmd based sleeping

[Stephen Hemminger]

On Fri, 17 Mar 2023 12:09:04 +0100
"Anthony Harivel" <aharivel@redhat.com> wrote:

> Ferruh Yigit, Mar 16, 2023 at 18:05:
> > Hi Anthony,
> >
> > What is the motivation here?  
> 
> Hi Ferruh,
> 
> AFAIK testpmd is the reference tool used for CI and tests whether it is
> for functional or performance tests and I think it would be in
> everyone's interest to consume less CPU during them. Moreover, all
> patches coming to the ML are going through validation tests and this
> could reduce the maintenance cost of the project.

But it introduces another variable, and the performance would vary based on
sleeping and HW interaction. I think testpmd should just run with 100% CPU,
and leave the heuristics stuff to some of the example applications.

Re: [PATCH 2/2] app/testpmd: add testpmd based sleeping

[Robin Jarry]

Anthony Harivel, Mar 16, 2023 at 16:14:
> Sleep for an incremental amount of time if the fwd engine has processed
> less than at least half a burst of packets (i.e 16pkts with default
> setting) on a polling iteration of testpmd.
>
> Upon detecting the threshold of >= 16 pkts on an Rxq, reset the sleep
> time to zero (i.e. no sleep).
>
> Sleep time will be increased on each iteration where the low load
> conditions remain up to a total of the max sleep time which is set by
> the user with the "--max-sleep-us NUM" command line argument or when in
> interactive "mode set max_sleep NUM".
>
> The default max_sleep value is 0, which means that no sleeps will occur
> and the default behaviour is unchanged from previously.
>
> Testing has been performed on AMD EPYC 7702 server with --nb-cores 12.
> The results were obtained via turbostat for each individual lcore:
>
> max_sleep 0     ====== ======== ======== ========
>                   idle    4Mpps   16Mpps   Bursts
> =============== ====== ======== ======== ========
> C1-state %           0        0        0        0
> C2-state %           0        0        0        0
> % usage            100      100      100      100
> Watt / core       1.14     1.18     1.19     1.14
> =============== ====== ======== ======== ========
>
> max_sleep 500   ====== ======== ======== ========
>                   idle    4Mpps   16Mpps   Bursts
> =============== ====== ======== ======== ========
> C1-state %          99       85       74     98.6
> C2-state %           0        0        0        0
> % usage              1       15       26        1
> Watt / core       0.04     0.18     0.28     0 04
> =============== ====== ======== ======== ========
>
> max_sleep 1000  ====== ======== ======== ========
>                   idle    4Mpps   16Mpps   Bursts
> =============== ====== ======== ======== ========
> C1-state %           0       85       74      0.3
> C2-state %          99        0        0     97.6
> % usage              1       15       25        1
> Watt / core       0.02     0.18     0.28     0 02
> =============== ====== ======== ======== ========
>
> On most cases, the consumption of the cores is greatly improved while
> still performing zero packet loss.
>
> Latency test has been performed on each tests above. The CPU has a C1
> latency of 1us and a C2 latency of 400us. On the worst case scenario, Tx
> Burst of thousands packets every seconds, the following latency in us
> (micro seconds) has been observed:
>
> =========== ==== ===== ======
> max_sleep      0   500   1000
> ----------- ---- ----- ------
> max latency   14   560   1260
> min latency    5     5      6
> Avg latency    7   305    617
> =========== ==== ===== ======
>
> link: https://www.github.com/torvalds/linux/tree/master/tools/power/x86/turbostat
> Signed-off-by: Anthony Harivel <aharivel@redhat.com>

Given the amount of time testpmd is used in local development and
automated testing, adding such an option is a great addition to save CPU
power.

Thanks Anthony.

Reviewed-by: Robin Jarry <rjarry@redhat.com>

Re: [PATCH 2/2] app/testpmd: add testpmd based sleeping

[Ferruh Yigit]

On 3/17/2023 11:09 AM, Anthony Harivel wrote:
> Ferruh Yigit, Mar 16, 2023 at 18:05:
>> Hi Anthony,
>>
>> What is the motivation here?
> 
> Hi Ferruh,
> 
> AFAIK testpmd is the reference tool used for CI and tests whether it is
> for functional or performance tests and I think it would be in
> everyone's interest to consume less CPU during them. Moreover, all
> patches coming to the ML are going through validation tests and this
> could reduce the maintenance cost of the project.
> 

I don't think testpmd CPU usage is a real concern, it is only used by
limited number of people and only for a limited duration.
And optimizations like this may jeopardize its main task.


On the other hand, CPU/power consumption of a DPDK application in
production is a concern, and there may be many parties interested in to
reduce watt/core with a reasonable performance impact.

There is already a 'power' library for this purpose, to enable power
optimizations for all DPDK applications, instead of just implementing
them on a specific application (like testpmd).

In my experience heuristics approaches (as done in your patch) depends
on workload, while it helps for some usecases it may hurt in others.
Still there may be customers willing to test a specific one for a
specific workload.

What do you think to have these heuristics approaches implemented in the
power library, and add a new power sample application that selects one
of existing algorithm as a kind of plugin?
It can start with single algorithm, that is what you used in this patch.
But overall how to add them into power library needs to be designed.

cc'ed @Dave as power library/sample maintainer.