Module: xenomai-3
Branch: next
Commit: 722da4411966267b8d3ae986d086736ae9579b4d
URL:
http://git.xenomai.org/?p=xenomai-3.git;a=commit;h=722da4411966267b8d3ae986d086736ae9579b4d
Author: Philippe Gerum <r...@xenomai.org>
Date: Tue Sep 30 17:09:40 2014 +0200
utils/autotune: update load generator
Create additional load with domain migrations.
---
doc/asciidoc/man1/autotune.adoc | 8 ++---
utils/autotune/autotune.c | 68 +++++++++++++++++++++++++--------------
2 files changed, 47 insertions(+), 29 deletions(-)
diff --git a/doc/asciidoc/man1/autotune.adoc b/doc/asciidoc/man1/autotune.adoc
index efea67e..b244c96 100644
--- a/doc/asciidoc/man1/autotune.adoc
+++ b/doc/asciidoc/man1/autotune.adoc
@@ -97,10 +97,10 @@ activity can slip in, treading over a larger address space).
Reset the gravity values to their factory defaults. These defaults
are statically defined by the Xenomai platform code.
-*--nohog*::
-Disable load generation while auto-tuning. *autotune* runs a simple
-load generator internally in parallel to estimating the latency, in
-order to eliminate irregular delays which tend to appear on fully idle
+*--noload*::
+Disable load generation while auto-tuning. *autotune* runs a load
+generator internally in parallel to estimating the latency, in order
+to eliminate irregular delays which tend to appear on fully idle
systems. Therefore, keeping the load generation enabled most often
leads to a more accurate estimation.
diff --git a/utils/autotune/autotune.c b/utils/autotune/autotune.c
index 1c13084..5a18310 100644
--- a/utils/autotune/autotune.c
+++ b/utils/autotune/autotune.c
@@ -24,11 +24,12 @@
#include <limits.h>
#include <time.h>
#include <error.h>
+#include <sys/cobalt.h>
#include <rtdm/autotune.h>
static int tune_irqlat, tune_kernlat, tune_userlat;
-static int reset, nohog, quiet;
+static int reset, noload, quiet;
static const struct option base_options[] = {
{
@@ -63,9 +64,9 @@ static const struct option base_options[] = {
.val = 1
},
{
-#define nohog_opt 5
- .name = "nohog",
- .flag = &nohog,
+#define noload_opt 5
+ .name = "noload",
+ .flag = &noload,
.val = 1
},
{
@@ -107,10 +108,11 @@ static void *sampler_thread(void *arg)
return NULL;
}
-static void *hog_thread(void *arg)
+static void *load_thread(void *arg)
{
- int fdi, fdo, count = 0;
+ int fdi, fdo, count = 0, wakelim;
ssize_t nbytes, ret;
+ struct timespec rqt;
char buf[512];
fdi = open("/dev/zero", O_RDONLY);
@@ -121,16 +123,25 @@ static void *hog_thread(void *arg)
if (fdi < 0)
error(1, errno, "/dev/null");
+ rqt.tv_sec = 0;
+ rqt.tv_nsec = CONFIG_XENO_DEFAULT_PERIOD * 2;
+ wakelim = 20000000 / rqt.tv_nsec;
+
for (;;) {
+ clock_nanosleep(CLOCK_MONOTONIC, 0, &rqt, NULL);
+
+ if (++count % wakelim) {
+ cobalt_thread_relax();
+ continue;
+ }
+
nbytes = read(fdi, buf, sizeof(buf));
if (nbytes <= 0)
- error(1, EIO, "hog streaming");
+ error(1, EIO, "load streaming");
if (nbytes > 0) {
ret = write(fdo, buf, nbytes);
(void)ret;
}
- if ((++count % 1024) == 0)
- usleep(10000);
}
return NULL;
@@ -157,7 +168,7 @@ static void create_sampler(pthread_t *tid, int fd)
pthread_setname_np(*tid, "sampler");
}
-static void create_hog(pthread_t *tid)
+static void create_load(pthread_t *tid)
{
struct sched_param param;
pthread_attr_t attr;
@@ -166,16 +177,16 @@ static void create_hog(pthread_t *tid)
pthread_attr_init(&attr);
pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
pthread_attr_setinheritsched(&attr, PTHREAD_EXPLICIT_SCHED);
- pthread_attr_setschedpolicy(&attr, SCHED_OTHER);
- param.sched_priority = 0;
+ pthread_attr_setschedpolicy(&attr, SCHED_FIFO);
+ param.sched_priority = 1;
pthread_attr_setschedparam(&attr, ¶m);
pthread_attr_setstacksize(&attr, PTHREAD_STACK_MIN * 8);
- ret = pthread_create(tid, &attr, hog_thread, NULL);
+ ret = pthread_create(tid, &attr, load_thread, NULL);
if (ret)
- error(1, ret, "hog thread");
+ error(1, ret, "load thread");
pthread_attr_destroy(&attr);
- pthread_setname_np(*tid, "hog");
+ pthread_setname_np(*tid, "loadgen");
}
static void usage(void)
@@ -186,7 +197,7 @@ static void usage(void)
fprintf(stderr, " --user user scheduling latency\n");
fprintf(stderr, " --period set the sampling period\n");
fprintf(stderr, " --reset reset core timer gravity to
factory defaults\n");
- fprintf(stderr, " --nohog disable load generation\n");
+ fprintf(stderr, " --noload disable load generation\n");
fprintf(stderr, " --quiet tame down verbosity\n");
fprintf(stderr, " --help print this help\n\n");
fprintf(stderr, "if no option is given, tune for all contexts using the
default period.\n");
@@ -227,7 +238,8 @@ static void run_tuner(int fd, int op, int period, const
char *type)
int main(int argc, char *const argv[])
{
int fd, period, ret, c, lindex, tuned = 0;
- pthread_t hog;
+ pthread_t load_pth;
+ time_t start;
period = CONFIG_XENO_DEFAULT_PERIOD;
@@ -252,7 +264,7 @@ int main(int argc, char *const argv[])
error(1, EINVAL, "invalid sampling period
(default %d)",
CONFIG_XENO_DEFAULT_PERIOD);
break;
- case nohog_opt:
+ case noload_opt:
case quiet_opt:
break;
case irq_opt:
@@ -280,13 +292,15 @@ int main(int argc, char *const argv[])
}
if (tune_irqlat || tune_kernlat || tune_userlat) {
- if (!nohog)
- create_hog(&hog);
+ if (!noload)
+ create_load(&load_pth);
if (!quiet)
- printf("Auto-tuning started, period=%d ns (may take a
while)\n",
- period);
+ printf("== auto-tuning started, period=%d ns (may take
a while)\n",
+ period);
} else
- nohog = 1;
+ noload = 1;
+
+ time(&start);
if (tune_irqlat)
run_tuner(fd, AUTOTUNE_RTIOC_IRQ, period, "irq");
@@ -297,8 +311,12 @@ int main(int argc, char *const argv[])
if (tune_userlat)
run_tuner(fd, AUTOTUNE_RTIOC_USER, period, "user");
- if (!nohog)
- pthread_cancel(hog);
+ if (!quiet && (tune_userlat || tune_kernlat || tune_userlat))
+ printf("== auto-tuning completed after %ds\n",
+ (int)(time(NULL) - start));
+
+ if (!noload)
+ pthread_cancel(load_pth);
close(fd);
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