bitrate: add bitrate statistics library

This patch adds a library that calculates peak and average data-rate
statistics. For ethernet devices. These statistics are reported using
the metrics library.

Signed-off-by: Remy Horton <remy.horton@intel.com>

MAINTAINERS

@@ -679,6 +679,10 @@ Metrics
 M: Remy Horton <remy.horton@intel.com>
 F: lib/librte_metrics/
 
+Bit-rate statistics
+M: Remy Horton <remy.horton@intel.com>
+F: lib/librte_bitratestats/
+
 
 Test Applications
 -----------------

config/common_base

@@ -557,6 +557,11 @@ CONFIG_RTE_LIBRTE_JOBSTATS=y
 #
 CONFIG_RTE_LIBRTE_METRICS=y
 
+#
+# Compile the bitrate statistics library
+#
+CONFIG_RTE_LIBRTE_BITRATE=y
+
 #
 # Compile librte_lpm
 #

doc/api/doxy-api-index.md

@@ -158,4 +158,5 @@ There are many libraries, so their headers may be grouped by topics:
   [ABI compat]         (@ref rte_compat.h),
   [keepalive]          (@ref rte_keepalive.h),
   [device metrics]     (@ref rte_metrics.h),
+  [bitrate statistics] (@ref rte_bitrate.h),
   [version]            (@ref rte_version.h)

doc/api/doxy-api.conf

@@ -36,6 +36,7 @@ INPUT                   = doc/api/doxy-api-index.md \
                           lib/librte_eal/common/include \
                           lib/librte_eal/common/include/generic \
                           lib/librte_acl \
+                          lib/librte_bitratestats \
                           lib/librte_cfgfile \
                           lib/librte_cmdline \
                           lib/librte_compat \

doc/guides/prog_guide/metrics_lib.rst

@@ -178,3 +178,68 @@ print out all metrics for a given port:
         free(metrics);
         free(names);
     }
+
+
+Bit-rate statistics library
+---------------------------
+
+The bit-rate library calculates the exponentially-weighted moving
+average and peak bit-rates for each active port (i.e. network device).
+These statistics are reported via the metrics library using the
+following names:
+
+    - ``mean_bits_in``: Average inbound bit-rate
+    - ``mean_bits_out``:  Average outbound bit-rate
+    - ``ewma_bits_in``: Average inbound bit-rate (EWMA smoothed)
+    - ``ewma_bits_out``:  Average outbound bit-rate (EWMA smoothed)
+    - ``peak_bits_in``:  Peak inbound bit-rate
+    - ``peak_bits_out``:  Peak outbound bit-rate
+
+Once initialised and clocked at the appropriate frequency, these
+statistics can be obtained by querying the metrics library.
+
+Initialization
+~~~~~~~~~~~~~~
+
+Before the library can be used, it has to be initialised by calling
+``rte_stats_bitrate_create()``, which will return a bit-rate
+calculation object. Since the bit-rate library uses the metrics library
+to report the calculated statistics, the bit-rate library then needs to
+register the calculated statistics with the metrics library. This is
+done using the helper function ``rte_stats_bitrate_reg()``.
+
+.. code-block:: c
+
+    struct rte_stats_bitrates *bitrate_data;
+
+    bitrate_data = rte_stats_bitrate_create();
+    if (bitrate_data == NULL)
+        rte_exit(EXIT_FAILURE, "Could not allocate bit-rate data.\n");
+    rte_stats_bitrate_reg(bitrate_data);
+
+Controlling the sampling rate
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Since the library works by periodic sampling but does not use an
+internal thread, the application has to periodically call
+``rte_stats_bitrate_calc()``. The frequency at which this function
+is called should be the intended sampling rate required for the
+calculated statistics. For instance if per-second statistics are
+desired, this function should be called once a second.
+
+.. code-block:: c
+
+    tics_datum = rte_rdtsc();
+    tics_per_1sec = rte_get_timer_hz();
+
+    while( 1 ) {
+        /* ... */
+        tics_current = rte_rdtsc();
+	if (tics_current - tics_datum >= tics_per_1sec) {
+	    /* Periodic bitrate calculation */
+	    for (idx_port = 0; idx_port < cnt_ports; idx_port++)
+	            rte_stats_bitrate_calc(bitrate_data, idx_port);
+		tics_datum = tics_current;
+	    }
+        /* ... */
+    }

doc/guides/rel_notes/release_17_05.rst

@@ -227,6 +227,11 @@ New Features
   reporting mechanism that is independent of other libraries such
   as ethdev.
 
+* **Added bit-rate calculation library.**
+
+  A library that can be used to calculate device bit-rates. Calculated
+  bitrates are reported using the metrics library.
+
 
 Resolved Issues
 ---------------
@@ -433,6 +438,7 @@ The libraries prepended with a plus sign were incremented in this version.
 .. code-block:: diff
 
      librte_acl.so.2
+   + librte_bitratestats.so.1
      librte_cfgfile.so.2
      librte_cmdline.so.2
      librte_cryptodev.so.2

lib/Makefile

@@ -72,6 +72,8 @@ DIRS-$(CONFIG_RTE_LIBRTE_JOBSTATS) += librte_jobstats
 DEPDIRS-librte_jobstats := librte_eal
 DIRS-$(CONFIG_RTE_LIBRTE_METRICS) += librte_metrics
 DEPDIRS-librte_metrics := librte_eal
+DIRS-$(CONFIG_RTE_LIBRTE_BITRATE) += librte_bitratestats
+DEPDIRS-librte_bitratestats := librte_eal librte_metrics librte_ether
 DIRS-$(CONFIG_RTE_LIBRTE_POWER) += librte_power
 DEPDIRS-librte_power := librte_eal
 DIRS-$(CONFIG_RTE_LIBRTE_METER) += librte_meter

lib/librte_bitratestats/Makefile

@@ -0,0 +1,49 @@
+#   BSD LICENSE
+#
+#   Copyright(c) 2017 Intel Corporation. All rights reserved.
+#   All rights reserved.
+#
+#   Redistribution and use in source and binary forms, with or without
+#   modification, are permitted provided that the following conditions
+#   are met:
+#
+#     * Redistributions of source code must retain the above copyright
+#       notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above copyright
+#       notice, this list of conditions and the following disclaimer in
+#       the documentation and/or other materials provided with the
+#       distribution.
+#     * Neither the name of Intel Corporation nor the names of its
+#       contributors may be used to endorse or promote products derived
+#       from this software without specific prior written permission.
+#
+#   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+#   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+#   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+#   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+#   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+#   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+#   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+#   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+#   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+#   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+#   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+include $(RTE_SDK)/mk/rte.vars.mk
+
+# library name
+LIB = librte_bitratestats.a
+
+CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR) -O3
+
+EXPORT_MAP := rte_bitratestats_version.map
+
+LIBABIVER := 1
+
+# all source are stored in SRCS-y
+SRCS-$(CONFIG_RTE_LIBRTE_BITRATE) := rte_bitrate.c
+
+# Install header file
+SYMLINK-$(CONFIG_RTE_LIBRTE_BITRATE)-include += rte_bitrate.h
+
+include $(RTE_SDK)/mk/rte.lib.mk

lib/librte_bitratestats/rte_bitrate.c

@@ -0,0 +1,146 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2017 Intel Corporation. All rights reserved.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <rte_common.h>
+#include <rte_ethdev.h>
+#include <rte_malloc.h>
+#include <rte_metrics.h>
+#include <rte_bitrate.h>
+
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+
+/*
+ * Persistent bit-rate data.
+ * @internal
+ */
+struct rte_stats_bitrate {
+	uint64_t last_ibytes;
+	uint64_t last_obytes;
+	uint64_t peak_ibits;
+	uint64_t peak_obits;
+	uint64_t mean_ibits;
+	uint64_t mean_obits;
+	uint64_t ewma_ibits;
+	uint64_t ewma_obits;
+};
+
+struct rte_stats_bitrates {
+	struct rte_stats_bitrate port_stats[RTE_MAX_ETHPORTS];
+	uint16_t id_stats_set;
+};
+
+struct rte_stats_bitrates *
+rte_stats_bitrate_create(void)
+{
+	return rte_zmalloc(NULL, sizeof(struct rte_stats_bitrates),
+		RTE_CACHE_LINE_SIZE);
+}
+
+int
+rte_stats_bitrate_reg(struct rte_stats_bitrates *bitrate_data)
+{
+	const char * const names[] = {
+		"ewma_bits_in", "ewma_bits_out",
+		"mean_bits_in", "mean_bits_out",
+		"peak_bits_in", "peak_bits_out",
+	};
+	int return_value;
+
+	return_value = rte_metrics_reg_names(&names[0], ARRAY_SIZE(names));
+	if (return_value >= 0)
+		bitrate_data->id_stats_set = return_value;
+	return return_value;
+}
+
+int
+rte_stats_bitrate_calc(struct rte_stats_bitrates *bitrate_data,
+	uint8_t port_id)
+{
+	struct rte_stats_bitrate *port_data;
+	struct rte_eth_stats eth_stats;
+	int ret_code;
+	uint64_t cnt_bits;
+	int64_t delta;
+	const int64_t alpha_percent = 20;
+	uint64_t values[6];
+
+	ret_code = rte_eth_stats_get(port_id, &eth_stats);
+	if (ret_code != 0)
+		return ret_code;
+
+	port_data = &bitrate_data->port_stats[port_id];
+
+	/* Incoming bitrate. This is an iteratively calculated EWMA
+	 * (Exponentially Weighted Moving Average) that uses a
+	 * weighting factor of alpha_percent. An unsmoothed mean
+	 * for just the current time delta is also calculated for the
+	 * benefit of people who don't understand signal processing.
+	 */
+	cnt_bits = (eth_stats.ibytes - port_data->last_ibytes) << 3;
+	port_data->last_ibytes = eth_stats.ibytes;
+	if (cnt_bits > port_data->peak_ibits)
+		port_data->peak_ibits = cnt_bits;
+	delta = cnt_bits;
+	delta -= port_data->ewma_ibits;
+	/* The +-50 fixes integer rounding during divison */
+	if (delta > 0)
+		delta = (delta * alpha_percent + 50) / 100;
+	else
+		delta = (delta * alpha_percent - 50) / 100;
+	port_data->ewma_ibits += delta;
+	port_data->mean_ibits = cnt_bits;
+
+	/* Outgoing bitrate (also EWMA) */
+	cnt_bits = (eth_stats.obytes - port_data->last_obytes) << 3;
+	port_data->last_obytes = eth_stats.obytes;
+	if (cnt_bits > port_data->peak_obits)
+		port_data->peak_obits = cnt_bits;
+	delta = cnt_bits;
+	delta -= port_data->ewma_obits;
+	if (delta > 0)
+		delta = (delta * alpha_percent + 50) / 100;
+	else
+		delta = (delta * alpha_percent - 50) / 100;
+	port_data->ewma_obits += delta;
+	port_data->mean_obits = cnt_bits;
+
+	values[0] = port_data->ewma_ibits;
+	values[1] = port_data->ewma_obits;
+	values[2] = port_data->mean_ibits;
+	values[3] = port_data->mean_obits;
+	values[4] = port_data->peak_ibits;
+	values[5] = port_data->peak_obits;
+	rte_metrics_update_values(port_id, bitrate_data->id_stats_set,
+		values, ARRAY_SIZE(values));
+	return 0;
+}

lib/librte_bitratestats/rte_bitrate.h

@@ -0,0 +1,84 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2017 Intel Corporation. All rights reserved.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _RTE_BITRATE_H_
+#define _RTE_BITRATE_H_
+
+/**
+ *  Bitrate statistics data structure.
+ *  This data structure is intentionally opaque.
+ */
+struct rte_stats_bitrates;
+
+
+/**
+ * Allocate a bitrate statistics structure
+ *
+ * @return
+ *   - Pointer to structure on success
+ *   - NULL on error (zmalloc failure)
+ */
+struct rte_stats_bitrates *rte_stats_bitrate_create(void);
+
+
+/**
+ * Register bitrate statistics with the metric library.
+ *
+ * @param bitrate_data
+ *   Pointer allocated by rte_stats_create()
+ *
+ * @return
+ *   Zero on success
+ *   Negative on error
+ */
+int rte_stats_bitrate_reg(struct rte_stats_bitrates *bitrate_data);
+
+
+/**
+ * Calculate statistics for current time window. The period with which
+ * this function is called should be the intended sampling window width.
+ *
+ * @param bitrate_data
+ *   Bitrate statistics data pointer
+ *
+ * @param port_id
+ *   Port id to calculate statistics for
+ *
+ * @return
+ *  - Zero on success
+ *  - Negative value on error
+ */
+int rte_stats_bitrate_calc(struct rte_stats_bitrates *bitrate_data,
+	uint8_t port_id);
+
+#endif /* _RTE_BITRATE_H_ */

lib/librte_bitratestats/rte_bitratestats_version.map

@@ -0,0 +1,9 @@
+DPDK_17.05 {
+	global:
+
+	rte_stats_bitrate_calc;
+	rte_stats_bitrate_create;
+	rte_stats_bitrate_reg;
+
+	local: *;
+};

mk/rte.app.mk

@@ -74,6 +74,7 @@ _LDLIBS-$(CONFIG_RTE_LIBRTE_ACL)            += -lrte_acl
 _LDLIBS-$(CONFIG_RTE_LIBRTE_ACL)            += --no-whole-archive
 _LDLIBS-$(CONFIG_RTE_LIBRTE_JOBSTATS)       += -lrte_jobstats
 _LDLIBS-$(CONFIG_RTE_LIBRTE_METRICS)        += -lrte_metrics
+_LDLIBS-$(CONFIG_RTE_LIBRTE_BITRATE)        += -lrte_bitratestats
 _LDLIBS-$(CONFIG_RTE_LIBRTE_POWER)          += -lrte_power
 
 _LDLIBS-$(CONFIG_RTE_LIBRTE_TIMER)          += -lrte_timer