This patch has cyclictest work a bit better with ftrace. Some new options
have been added.
When -b is used:
-P : use the preemptoff tracer
-I : use the irqsoff tracer
-B : use preemptirqsoff tracer
If the above are not set, then it tries to use "events" tracer if it is
available (currently only available in the -rt kernel) and if that is not
set, it defaults to the sched-switch tracer.
-f will enabled the function tracer.
Signed-off-by: Steven Rostedt <srostedt@xxxxxxxxxx>
---
src/cyclictest/cyclictest.c | 109 +++++++++++++++++++++++++++++++++++++-------
1 file changed, 94 insertions(+), 15 deletions(-)
Index: rt-tests/src/cyclictest/cyclictest.c
===================================================================
--- rt-tests.orig/src/cyclictest/cyclictest.c 2008-06-02 22:51:55.000000000 -0400
+++ rt-tests/src/cyclictest/cyclictest.c 2008-06-03 11:20:46.000000000 -0400
@@ -85,6 +85,13 @@ extern int clock_nanosleep(clockid_t __c
#define KVARNAMELEN 32
#define KVALUELEN 32
+enum {
+ DEFAULTTRACE,
+ IRQSOFF,
+ PREEMPTOFF,
+ IRQPREEMPTOFF,
+};
+
/* Struct to transfer parameters to the thread */
struct thread_param {
int prio;
@@ -119,6 +126,7 @@ static int ftrace = 0;
static int kernelversion;
static int verbose = 0;
static int oscope_reduction = 1;
+static int tracetype;
/* Backup of kernel variables that we modify */
static struct kvars {
@@ -132,6 +140,7 @@ static struct kvars {
static char *procfileprefix = "/proc/sys/kernel/";
static char debugfileprefix[MAX_PATH];
+static char *fileprefix;
enum kernelversion {
KV_NOT_26,
@@ -172,25 +181,19 @@ static int set_debugfileprefix(void)
size = strlen(debugfileprefix);
size = MAX_PATH - size;
- strncat(debugfileprefix, "/tracing", size);
+ strncat(debugfileprefix, "/tracing/", size);
return 0;
}
-static int kernvar(int mode, char *name, char *value, size_t sizeofvalue)
+static int kernvar(int mode, const char *name, char *value, size_t sizeofvalue)
{
char filename[128];
- char *prefix;
int retval = 1;
int path;
- if (kernelversion == KV_26_CURR)
- prefix = debugfileprefix;
- else
- prefix = procfileprefix;
-
- strncpy(filename, prefix, sizeof(filename));
- strncat(filename, name, sizeof(filename) - sizeof(prefix));
+ strncpy(filename, fileprefix, sizeof(filename));
+ strncat(filename, name, sizeof(filename) - strlen(fileprefix));
path = open(filename, mode);
if (path >= 0) {
if (mode == O_RDONLY) {
@@ -208,7 +211,7 @@ static int kernvar(int mode, char *name,
return retval;
}
-static void setkernvar(char *name, char *value)
+static void setkernvar(const char *name, char *value)
{
int i;
char oldvalue[KVALUELEN];
@@ -287,6 +290,41 @@ void tracing(int on)
}
}
+static int settracer(char *tracer)
+{
+ char filename[MAX_PATH];
+ char name[100];
+ FILE *fp;
+ int ret;
+ int i;
+
+ /* Make sure tracer is available */
+ strncpy(filename, debugfileprefix, sizeof(filename));
+ strncat(filename, "available_tracers", sizeof(filename) - strlen(debugfileprefix));
+
+ fp = fopen(filename, "r");
+ if (!fp)
+ return -1;
+
+ for (i = 0; i < 10; i++) {
+ ret = fscanf(fp, "%99s", name);
+ if (!ret) {
+ ret = -1;
+ break;
+ }
+ if (strcmp(name, tracer) == 0) {
+ ret = 0;
+ break;
+ }
+ }
+ fclose(fp);
+
+ if (!ret)
+ setkernvar("current_tracer", tracer);
+
+ return ret;
+}
+
/*
* timer thread
*
@@ -330,12 +368,41 @@ void *timerthread(void *param)
if (tracelimit) {
if (kernelversion == KV_26_CURR) {
char buffer[32];
+ int ret;
+
sprintf(buffer, "%d", tracelimit);
setkernvar("tracing_thresh", buffer);
+
+ /* ftrace_enabled is a sysctl variable */
+ fileprefix = procfileprefix;
if (ftrace)
- setkernvar("current_tracer", "ftrace");
+ setkernvar("ftrace_enabled", "1");
else
- setkernvar("current_tracer", "sched_switch");
+ setkernvar("ftrace_enabled", "0");
+ fileprefix = debugfileprefix;
+
+ switch (tracetype) {
+ case IRQSOFF:
+ ret = settracer("irqsoff");
+ break;
+ case PREEMPTOFF:
+ ret = settracer("preemptoff");
+ break;
+ case IRQPREEMPTOFF:
+ ret = settracer("preemptirqsoff");
+ break;
+ default:
+ if ((ret = settracer("events"))) {
+ if (ftrace)
+ ret = settracer("ftrace");
+ else
+ ret = settracer("sched-switch");
+ }
+ }
+
+ if (ret)
+ fprintf(stderr, "Requested tracer not available\n");
+
setkernvar("iter_ctrl", "print-parent");
if (verbose) {
setkernvar("iter_ctrl", "sym-offset");
@@ -504,16 +571,19 @@ static void display_help(void)
"-a --affinity run thread #N on processor #N, if possible\n"
"-a PROC --affinity=PROC run all threads on processor #PROC\n"
"-b USEC --breaktrace=USEC send break trace command when latency > USEC\n"
+ "-B --preemptirqs both preempt and irqsoff tracing (used with -b)\n"
"-c CLOCK --clock=CLOCK select clock\n"
" 0 = CLOCK_MONOTONIC (default)\n"
" 1 = CLOCK_REALTIME\n"
"-d DIST --distance=DIST distance of thread intervals in us default=500\n"
"-f function trace (when -b is active)\n"
"-i INTV --interval=INTV base interval of thread in us default=1000\n"
+ "-I --irqsoff Irqsoff tracing (used with -b)\n"
"-l LOOPS --loops=LOOPS number of loops: default=0(endless)\n"
"-n --nanosleep use clock_nanosleep\n"
"-o RED --oscope=RED oscilloscope mode, reduce verbose output by RED\n"
"-p PRIO --prio=PRIO priority of highest prio thread\n"
+ "-P --preemptoff Preempt off tracing (used with -b)\n"
"-q --quiet print only a summary on exit\n"
"-r --relative use relative timer instead of absolute\n"
"-s --system use sys_nanosleep and sys_setitimer\n"
@@ -560,14 +630,17 @@ static void process_options (int argc, c
static struct option long_options[] = {
{"affinity", optional_argument, NULL, 'a'},
{"breaktrace", required_argument, NULL, 'b'},
+ {"preemptirqs", no_argument, NULL, 'B'},
{"clock", required_argument, NULL, 'c'},
{"distance", required_argument, NULL, 'd'},
{"ftrace", no_argument, NULL, 'f'},
{"interval", required_argument, NULL, 'i'},
+ {"irqsoff", no_argument, NULL, 'I'},
{"loops", required_argument, NULL, 'l'},
{"nanosleep", no_argument, NULL, 'n'},
{"oscope", required_argument, NULL, 'o'},
{"priority", required_argument, NULL, 'p'},
+ {"preemptoff", no_argument, NULL, 'P'},
{"quiet", no_argument, NULL, 'q'},
{"relative", no_argument, NULL, 'r'},
{"system", no_argument, NULL, 's'},
@@ -576,7 +649,7 @@ static void process_options (int argc, c
{"help", no_argument, NULL, '?'},
{NULL, 0, NULL, 0}
};
- int c = getopt_long (argc, argv, "a::b:c:d:fi:l:no:p:qrst::v",
+ int c = getopt_long (argc, argv, "a::b:Bc:d:fi:Il:no:p:Pqrst::v",
long_options, &option_index);
if (c == -1)
break;
@@ -589,14 +662,17 @@ static void process_options (int argc, c
setaffinity = AFFINITY_USEALL;
break;
case 'b': tracelimit = atoi(optarg); break;
+ case 'B': tracetype = IRQPREEMPTOFF; break;
case 'c': clocksel = atoi(optarg); break;
case 'd': distance = atoi(optarg); break;
case 'f': ftrace = 1; break;
case 'i': interval = atoi(optarg); break;
+ case 'I': tracetype = IRQSOFF; break;
case 'l': max_cycles = atoi(optarg); break;
case 'n': use_nanosleep = MODE_CLOCK_NANOSLEEP; break;
case 'o': oscope_reduction = atoi(optarg); break;
case 'p': priority = atoi(optarg); break;
+ case 'P': tracetype = PREEMPTOFF; break;
case 'q': quiet = 1; break;
case 'r': timermode = TIMER_RELTIME; break;
case 's': use_system = MODE_SYS_OFFSET; break;
@@ -746,6 +822,8 @@ int main(int argc, char **argv)
char testname[MAX_PATH];
set_debugfileprefix();
+ fileprefix = debugfileprefix;
+
strcpy(testname, debugfileprefix);
strcat(testname, "tracing_enabled");
if (access(testname, R_OK)) {
@@ -753,7 +831,8 @@ int main(int argc, char **argv)
"debug fs not mounted, "
"TRACERs not configured?\n", testname);
}
- }
+ } else if (tracelimit)
+ fileprefix = procfileprefix;
if (check_timer())
fprintf(stderr, "WARNING: High resolution timers not available\n");
--
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