From: Joseph Matan <joseph.matan...@gmail.com>
The percentile filter can be very useful when running in a non-ptp-aware
environment.
For example, if we set a low percentile value (and the filter length is large
enough),
we can still get a good estimation of the real delay,
even if our setup is running under heavy network traffic.
(when setting the percentile value to 0.50, the median filter is a private
use-case of the percentile filter)
Signed-off-by: Joseph Matan <joseph.matan...@gmail.com>
---
clock.c | 3 ++-
config.c | 6 ++++--
configs/default.cfg | 1 +
filter.c | 8 +++++---
filter.h | 8 +++++---
makefile | 2 +-
mmedian.c => mpercentile.c | 42 +++++++++++++++++++++-----------------
mmedian.h => mpercentile.h | 10 ++++-----
nsm.c | 2 +-
port.c | 3 ++-
ptp4l.8 | 6 +++++-
tsproc.c | 4 ++--
tsproc.h | 3 ++-
13 files changed, 58 insertions(+), 40 deletions(-)
rename mmedian.c => mpercentile.c (64%)
rename mmedian.h => mpercentile.h (81%)
diff --git a/clock.c b/clock.c
index ec70f91..9c4b6cc 100644
--- a/clock.c
+++ b/clock.c
@@ -1171,7 +1171,8 @@ struct clock *clock_create(enum clock_type type, struct
config *config,
}
c->tsproc = tsproc_create(config_get_int(config, NULL, "tsproc_mode"),
config_get_int(config, NULL, "delay_filter"),
- config_get_int(config, NULL,
"delay_filter_length"));
+ config_get_int(config, NULL,
"delay_filter_length"),
+ config_get_double(config, NULL,
"delay_filter_percentile"));
if (!c->tsproc) {
pr_err("Failed to create time stamp processor");
return NULL;
diff --git a/config.c b/config.c
index eb8b988..31351f4 100644
--- a/config.c
+++ b/config.c
@@ -158,8 +158,9 @@ static struct config_enum dataset_comp_enu[] = {
};
static struct config_enum delay_filter_enu[] = {
- { "moving_average", FILTER_MOVING_AVERAGE },
- { "moving_median", FILTER_MOVING_MEDIAN },
+ { "moving_average", FILTER_MOVING_AVERAGE },
+ { "moving_median", FILTER_MOVING_MEDIAN },
+ { "moving_percentile", FILTER_MOVING_PERCENTILE },
{ NULL, 0 },
};
@@ -238,6 +239,7 @@ struct config_item config_tab[] = {
PORT_ITEM_INT("delayAsymmetry", 0, INT_MIN, INT_MAX),
PORT_ITEM_ENU("delay_filter", FILTER_MOVING_MEDIAN, delay_filter_enu),
PORT_ITEM_INT("delay_filter_length", 10, 1, INT_MAX),
+ PORT_ITEM_DBL("delay_filter_percentile", 0.5, 0.0, 1.0),
PORT_ITEM_ENU("delay_mechanism", DM_E2E, delay_mech_enu),
GLOB_ITEM_INT("dscp_event", 0, 0, 63),
GLOB_ITEM_INT("dscp_general", 0, 0, 63),
diff --git a/configs/default.cfg b/configs/default.cfg
index d615610..29cba1a 100644
--- a/configs/default.cfg
+++ b/configs/default.cfg
@@ -102,6 +102,7 @@ time_stamping hardware
tsproc_mode filter
delay_filter moving_median
delay_filter_length 10
+delay_filter_percentile 0.5
egressLatency 0
ingressLatency 0
boundary_clock_jbod 0
diff --git a/filter.c b/filter.c
index fceb29a..f779280 100644
--- a/filter.c
+++ b/filter.c
@@ -19,15 +19,17 @@
#include "filter_private.h"
#include "mave.h"
-#include "mmedian.h"
+#include "mpercentile.h"
-struct filter *filter_create(enum filter_type type, int length)
+struct filter *filter_create(enum filter_type type, int length, double
percentile)
{
switch (type) {
case FILTER_MOVING_AVERAGE:
return mave_create(length);
case FILTER_MOVING_MEDIAN:
- return mmedian_create(length);
+ return mpercentile_create(length, 0.5);
+ case FILTER_MOVING_PERCENTILE:
+ return mpercentile_create(length, percentile);
default:
return NULL;
}
diff --git a/filter.h b/filter.h
index 5a196bc..78be629 100644
--- a/filter.h
+++ b/filter.h
@@ -31,15 +31,17 @@ struct filter;
enum filter_type {
FILTER_MOVING_AVERAGE,
FILTER_MOVING_MEDIAN,
+ FILTER_MOVING_PERCENTILE,
};
/**
* Create a new instance of a filter.
- * @param type The type of the filter to create.
- * @param length The filter's length.
+ * @param type The type of the filter to create.
+ * @param length The filter's length.
+ * @param percentile The percentile of the delay filter samples (valid only
for FILTER_MOVING_PERCENTILE filter type).
* @return A pointer to a new filter on success, NULL otherwise.
*/
-struct filter *filter_create(enum filter_type type, int length);
+struct filter *filter_create(enum filter_type type, int length, double
percentile);
/**
* Destroy an instance of a filter.
diff --git a/makefile b/makefile
index 33e7ca0..7de5eab 100644
--- a/makefile
+++ b/makefile
@@ -23,7 +23,7 @@ VER = -DVER=$(version)
CFLAGS = -Wall $(VER) $(incdefs) $(DEBUG) $(EXTRA_CFLAGS)
LDLIBS = -lm -lrt -pthread $(EXTRA_LDFLAGS)
PRG = ptp4l hwstamp_ctl nsm phc2sys phc_ctl pmc timemaster ts2phc
-FILTERS = filter.o mave.o mmedian.o
+FILTERS = filter.o mave.o mpercentile.o
SERVOS = linreg.o ntpshm.o nullf.o pi.o servo.o
TRANSP = raw.o transport.o udp.o udp6.o uds.o
TS2PHC = ts2phc.o lstab.o nmea.o serial.o sock.o ts2phc_generic_master.o \
diff --git a/mmedian.c b/mpercentile.c
similarity index 64%
rename from mmedian.c
rename to mpercentile.c
index 2383467..cb4010b 100644
--- a/mmedian.c
+++ b/mpercentile.c
@@ -1,5 +1,5 @@
/**
- * @file mmedian.c
+ * @file mpercentile.c
* @note Copyright (C) 2013 Miroslav Lichvar <mlich...@redhat.com>
*
* This program is free software; you can redistribute it and/or modify
@@ -19,36 +19,41 @@
#include <stdlib.h>
#include <string.h>
-#include "mmedian.h"
+#include "mpercentile.h"
#include "filter_private.h"
+#include "print.h"
+#include "math.h"
-struct mmedian {
+struct mpercentile {
struct filter filter;
int cnt;
int len;
int index;
+ double percentile;
+ int percentile_index;
/* Indices sorted by value. */
int *order;
/* Values stored in circular buffer. */
tmv_t *samples;
};
-static void mmedian_destroy(struct filter *filter)
+static void mpercentile_destroy(struct filter *filter)
{
- struct mmedian *m = container_of(filter, struct mmedian, filter);
+ struct mpercentile *m = container_of(filter, struct mpercentile,
filter);
free(m->order);
free(m->samples);
free(m);
}
-static tmv_t mmedian_sample(struct filter *filter, tmv_t sample)
+static tmv_t mpercentile_sample(struct filter *filter, tmv_t sample)
{
- struct mmedian *m = container_of(filter, struct mmedian, filter);
+ struct mpercentile *m = container_of(filter, struct mpercentile,
filter);
int i;
m->samples[m->index] = sample;
if (m->cnt < m->len) {
m->cnt++;
+ m->percentile_index = (int)round(m->percentile * (m->cnt - 1));
} else {
/* Remove index of the replaced value from order. */
for (i = 0; i < m->cnt; i++)
@@ -69,32 +74,30 @@ static tmv_t mmedian_sample(struct filter *filter, tmv_t
sample)
m->index = (1 + m->index) % m->len;
- if (m->cnt % 2)
- return m->samples[m->order[m->cnt / 2]];
- else
- return tmv_div(tmv_add(m->samples[m->order[m->cnt / 2 - 1]],
- m->samples[m->order[m->cnt / 2]]), 2);
+ /*TODO: deleteMe*/ pr_info("lenght(%d) percentile(%0.2f)
percentile_index(%d), filtered_delay(%lld)",
+ m->cnt, m->percentile, m->percentile_index,
tmv_to_nanoseconds(m->samples[m->order[m->percentile_index]]));
+ return m->samples[m->order[m->percentile_index]];
}
-static void mmedian_reset(struct filter *filter)
+static void mpercentile_reset(struct filter *filter)
{
- struct mmedian *m = container_of(filter, struct mmedian, filter);
+ struct mpercentile *m = container_of(filter, struct mpercentile,
filter);
m->cnt = 0;
m->index = 0;
}
-struct filter *mmedian_create(int length)
+struct filter *mpercentile_create(int length, double percentile)
{
- struct mmedian *m;
+ struct mpercentile *m;
if (length < 1)
return NULL;
m = calloc(1, sizeof(*m));
if (!m)
return NULL;
- m->filter.destroy = mmedian_destroy;
- m->filter.sample = mmedian_sample;
- m->filter.reset = mmedian_reset;
+ m->filter.destroy = mpercentile_destroy;
+ m->filter.sample = mpercentile_sample;
+ m->filter.reset = mpercentile_reset;
m->order = calloc(1, length * sizeof(*m->order));
if (!m->order) {
free(m);
@@ -107,5 +110,6 @@ struct filter *mmedian_create(int length)
return NULL;
}
m->len = length;
+ m->percentile = percentile;
return &m->filter;
}
diff --git a/mmedian.h b/mpercentile.h
similarity index 81%
rename from mmedian.h
rename to mpercentile.h
index 8fee0dc..193a333 100644
--- a/mmedian.h
+++ b/mpercentile.h
@@ -1,6 +1,6 @@
/**
- * @file mmedian.h
- * @brief Implements a moving median.
+ * @file mpercentile.h
+ * @brief Implements a moving percentile.
* @note Copyright (C) 2013 Miroslav Lichvar <mlich...@redhat.com>
*
* This program is free software; you can redistribute it and/or modify
@@ -17,11 +17,11 @@
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
-#ifndef HAVE_MMEDIAN_H
-#define HAVE_MMEDIAN_H
+#ifndef HAVE_MPERCENTILE_H
+#define HAVE_MPERCENTILE_H
#include "filter.h"
-struct filter *mmedian_create(int length);
+struct filter *mpercentile_create(int length, double percentile);
#endif
diff --git a/nsm.c b/nsm.c
index 5aa925b..3ede6a0 100644
--- a/nsm.c
+++ b/nsm.c
@@ -295,7 +295,7 @@ static int nsm_open(struct nsm *nsm, struct config *cfg)
}
nsm->port_identity.portNumber = 1;
- nsm->tsproc = tsproc_create(TSPROC_RAW, FILTER_MOVING_AVERAGE, 10);
+ nsm->tsproc = tsproc_create(TSPROC_RAW, FILTER_MOVING_AVERAGE, 10, 0);
if (!nsm->tsproc) {
pr_err("failed to create time stamp processor");
goto no_tsproc;
diff --git a/port.c b/port.c
index c82bdaf..6dae97b 100644
--- a/port.c
+++ b/port.c
@@ -3200,7 +3200,8 @@ struct port *port_open(const char *phc_device,
p->tsproc = tsproc_create(config_get_int(cfg, p->name, "tsproc_mode"),
config_get_int(cfg, p->name, "delay_filter"),
- config_get_int(cfg, p->name,
"delay_filter_length"));
+ config_get_int(cfg, p->name,
"delay_filter_length"),
+ config_get_double(cfg, p->name,
"delay_filter_percentile"));
if (!p->tsproc) {
pr_err("Failed to create time stamp processor");
goto err_uc_service;
diff --git a/ptp4l.8 b/ptp4l.8
index a0779ef..3a3fc13 100644
--- a/ptp4l.8
+++ b/ptp4l.8
@@ -340,13 +340,17 @@ The default is filter.
.TP
.B delay_filter
Select the algorithm used to filter the measured delay and peer delay. Possible
-values are moving_average and moving_median.
+values are moving_average, moving_median and moving_percentile.
The default is moving_median.
.TP
.B delay_filter_length
The length of the delay filter in samples.
The default is 10.
.TP
+.B delay_filter_percentile
+The percentile of the delay filter samples (relevant only when choosing the
delay_filter as moving_percentile).
+The default is 0.5 (50%).
+.TP
.B egressLatency
Specifies the difference in nanoseconds between the actual transmission
time at the reference plane and the reported transmit time stamp. This
diff --git a/tsproc.c b/tsproc.c
index a871049..8ace4a6 100644
--- a/tsproc.c
+++ b/tsproc.c
@@ -61,7 +61,7 @@ static int weighting(struct tsproc *tsp)
}
struct tsproc *tsproc_create(enum tsproc_mode mode,
- enum filter_type delay_filter, int filter_length)
+ enum filter_type delay_filter, int filter_length,
double percentile)
{
struct tsproc *tsp;
@@ -81,7 +81,7 @@ struct tsproc *tsproc_create(enum tsproc_mode mode,
return NULL;
}
- tsp->delay_filter = filter_create(delay_filter, filter_length);
+ tsp->delay_filter = filter_create(delay_filter, filter_length,
percentile);
if (!tsp->delay_filter) {
free(tsp);
return NULL;
diff --git a/tsproc.h b/tsproc.h
index fdb35a8..5970705 100644
--- a/tsproc.h
+++ b/tsproc.h
@@ -40,10 +40,11 @@ enum tsproc_mode {
* @param mode Time stamp processing mode.
* @param delay_filter Type of the filter that will be applied to delay.
* @param filter_length Length of the filter.
+ * @param percentile The percentile of the delay filter samples (valid
only for FILTER_MOVING_PERCENTILE filter type).
* @return A pointer to a new tsproc on success, NULL otherwise.
*/
struct tsproc *tsproc_create(enum tsproc_mode mode,
- enum filter_type delay_filter, int filter_length);
+ enum filter_type delay_filter, int filter_length,
double percentile);
/**
* Destroy a time stamp processor.
--
2.17.1
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