Module: xenomai-2.5
Branch: master
Commit: d8dcd83dda2cc38a2dbbb93dfc7d495e1e03b002
URL:
http://git.xenomai.org/?p=xenomai-2.5.git;a=commit;h=d8dcd83dda2cc38a2dbbb93dfc7d495e1e03b002
Author: Gilles Chanteperdrix <gilles.chanteperd...@xenomai.org>
Date: Sat Jan 16 19:10:17 2010 +0100
latency: account for and signal involuntary mode switches.
---
src/testsuite/latency/latency.c | 109 ++++++++++++++++++++++++++++-----------
1 files changed, 78 insertions(+), 31 deletions(-)
diff --git a/src/testsuite/latency/latency.c b/src/testsuite/latency/latency.c
index f82a072..ca5f1bf 100644
--- a/src/testsuite/latency/latency.c
+++ b/src/testsuite/latency/latency.c
@@ -1,13 +1,16 @@
-#include <sys/mman.h>
-#include <sys/time.h>
-#include <unistd.h>
#include <stdlib.h>
#include <math.h>
#include <stdio.h>
#include <string.h>
#include <signal.h>
-#include <getopt.h>
#include <time.h>
+
+#include <sys/mman.h>
+#include <sys/time.h>
+#include <unistd.h>
+
+#include <execinfo.h>
+
#include <native/task.h>
#include <native/timer.h>
#include <native/sem.h>
@@ -20,6 +23,7 @@ RT_SEM display_sem;
#define ONE_BILLION 1000000000
#define TEN_MILLION 10000000
+unsigned max_relaxed;
long minjitter, maxjitter, avgjitter;
long gminjitter = TEN_MILLION, gmaxjitter = -TEN_MILLION, goverrun = 0;
long long gavgjitter = 0;
@@ -32,6 +36,8 @@ int benchdev_no = 0;
int benchdev = -1;
int freeze_max = 0;
int priority = T_HIPRIO;
+int stop_upon_switch = 0;
+sig_atomic_t sampling_relaxed = 0;
#define USER_TASK 0
#define KERNEL_TASK 1
@@ -70,8 +76,9 @@ static inline void add_histogram(long *histogram, long addval)
void latency(void *cookie)
{
int err, count, nsamples, warmup = 1;
- RTIME expected_tsc, period_tsc, start_ticks;
+ RTIME expected_tsc, period_tsc, start_ticks, fault_threshold;
RT_TIMER_INFO timer_info;
+ unsigned old_relaxed = 0;
err = rt_timer_inquire(&timer_info);
@@ -80,6 +87,7 @@ void latency(void *cookie)
return;
}
+ fault_threshold = rt_timer_ns2tsc(CONFIG_XENO_DEFAULT_PERIOD);
nsamples = ONE_BILLION / period_ns;
period_tsc = rt_timer_ns2tsc(period_ns);
/* start time: one millisecond from now. */
@@ -103,14 +111,22 @@ void latency(void *cookie)
test_loops++;
for (count = sumj = 0; count < nsamples; count++) {
+ unsigned new_relaxed;
unsigned long ov;
expected_tsc += period_tsc;
err = rt_task_wait_period(&ov);
dt = (long)(rt_timer_tsc() - expected_tsc);
- if (dt > maxj)
+ new_relaxed = sampling_relaxed;
+ if (dt > maxj) {
+ if (new_relaxed != old_relaxed
+ && dt > fault_threshold)
+ max_relaxed +=
+ new_relaxed - old_relaxed;
maxj = dt;
+ }
+ old_relaxed = new_relaxed;
if (dt < minj)
minj = dt;
sumj += dt;
@@ -274,17 +290,17 @@ void display(void *cookie)
(dt / 60) % 60, dt % 60,
test_mode_names[test_mode],
period_ns / 1000, priority);
- printf("RTH|%12s|%12s|%12s|%8s|%12s|%12s\n",
- "-----lat min", "-----lat avg",
- "-----lat max", "-overrun",
- "----lat best", "---lat worst");
+ printf("RTH|%11s|%11s|%11s|%8s|%6s|%11s|%11s\n",
+ "----lat min", "----lat avg",
+ "----lat max", "-overrun", "---msw",
+ "---lat best", "--lat worst");
}
-
- printf("RTD|%12.3f|%12.3f|%12.3f|%8ld|%12.3f|%12.3f\n",
+
printf("RTD|%11.3f|%11.3f|%11.3f|%8ld|%6u|%11.3f|%11.3f\n",
(double)minj / 1000,
(double)avgj / 1000,
(double)maxj / 1000,
goverrun,
+ max_relaxed,
(double)gminj / 1000, (double)gmaxj / 1000);
}
}
@@ -396,12 +412,16 @@ void cleanup(void)
test_duration = actual_duration;
printf
-
("---|------------|------------|------------|--------|-------------------------\n"
- "RTS|%12.3f|%12.3f|%12.3f|%8ld|
%.2ld:%.2ld:%.2ld/%.2d:%.2d:%.2d\n",
+
("---|-----------|-----------|-----------|--------|------|-------------------------\n"
+ "RTS|%11.3f|%11.3f|%11.3f|%8ld|%6u|
%.2ld:%.2ld:%.2ld/%.2d:%.2d:%.2d\n",
(double)gminj / 1000, (double)gavgj / 1000, (double)gmaxj / 1000,
- goverrun, actual_duration / 3600, (actual_duration / 60) % 60,
+ goverrun, max_relaxed, actual_duration / 3600, (actual_duration /
60) % 60,
actual_duration % 60, test_duration / 3600,
(test_duration / 60) % 60, test_duration % 60);
+ if (max_relaxed > 0)
+ printf(
+"Warning! some latency maxima may have been due to involuntary mode
switches.\n"
+"Please contact xenomai-h...@gna.org\n");
if (histogram_avg)
free(histogram_avg);
@@ -425,13 +445,32 @@ void faulthand(int sig)
kill(getpid(), sig);
}
+void mode_sw(int sig)
+{
+ const char buffer[] = "Mode switch, aborting. Backtrace:\n";
+ static void *bt[200];
+ unsigned n;
+
+ if (!stop_upon_switch) {
+ ++sampling_relaxed;
+ return;
+ }
+
+ write(STDERR_FILENO, buffer, sizeof(buffer));
+ n = backtrace(bt, sizeof(bt)/sizeof(bt[0]));
+ backtrace_symbols_fd(bt, n, STDERR_FILENO);
+
+ signal(sig, SIG_DFL);
+ kill(getpid(), sig);
+}
+
int main(int argc, char **argv)
{
int c, err;
char task_name[16];
int cpu = 0;
- while ((c = getopt(argc, argv, "hp:l:T:qH:B:sD:t:fc:P:")) != EOF)
+ while ((c = getopt(argc, argv, "hp:l:T:qH:B:sD:t:fc:P:b")) != EOF)
switch (c) {
case 'h':
@@ -497,22 +536,29 @@ int main(int argc, char **argv)
priority = atoi(optarg);
break;
+ case 'b':
+ stop_upon_switch = 1;
+ break;
+
default:
- fprintf(stderr, "usage: latency [options]\n"
- " [-h] # print
histograms of min, avg, max latencies\n"
- " [-s] # print
statistics of min, avg, max latencies\n"
- " [-H <histogram-size>] # default =
200, increase if your last bucket is full\n"
- " [-B <bucket-size>] # default =
1000ns, decrease for more resolution\n"
- " [-p <period_us>] # sampling
period\n"
- " [-l <data-lines per header>] # default=21, 0
to supress headers\n"
- " [-T <test_duration_seconds>] # default=0, so
^C to end\n"
- " [-q] # supresses
RTD, RTH lines if -T is used\n"
- " [-D <testing_device_no>] # number of
testing device, default=0\n"
- " [-t <test_mode>] # 0=user task
(default), 1=kernel task, 2=timer IRQ\n"
- " [-f] # freeze trace
for each new max latency\n"
- " [-c <cpu>] # pin measuring
task down to given CPU\n"
- " [-P <priority>] # task priority
(test mode 0 and 1 only)\n");
+ fprintf(stderr,
+"usage: latency [options]\n"
+" [-h] # print histograms of min, avg, max
latencies\n"
+" [-s] # print statistics of min, avg, max
latencies\n"
+" [-H <histogram-size>] # default = 200, increase if your last bucket
is full\n"
+" [-B <bucket-size>] # default = 1000ns, decrease for more
resolution\n"
+" [-p <period_us>] # sampling period\n"
+" [-l <data-lines per header>] # default=21, 0 to supress headers\n"
+" [-T <test_duration_seconds>] # default=0, so ^C to end\n"
+" [-q] # supresses RTD, RTH lines if -T is used\n"
+" [-D <testing_device_no>] # number of testing device, default=0\n"
+" [-t <test_mode>] # 0=user task (default), 1=kernel task,
2=timer IRQ\n"
+" [-f] # freeze trace for each new max latency\n"
+" [-c <cpu>] # pin measuring task down to given CPU\n"
+" [-P <priority>] # task priority (test mode 0 and 1 only)\n"
+" [-b] # break upon mode switch\n"
+);
exit(2);
}
@@ -548,6 +594,7 @@ int main(int argc, char **argv)
signal(SIGTERM, sighand);
signal(SIGHUP, sighand);
signal(SIGALRM, sighand);
+ signal(SIGXCPU, mode_sw);
if (freeze_max) {
/* If something goes wrong, we want to freeze the current
@@ -605,7 +652,7 @@ int main(int argc, char **argv)
snprintf(task_name, sizeof(task_name), "sampling-%d", getpid());
err =
rt_task_create(&latency_task, task_name, 0, priority,
- T_FPU | cpu);
+ T_FPU | cpu | T_WARNSW);
if (err) {
fprintf(stderr,
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