commit WIP for rostedt

Signed-off-by: Clark Williams <williams@redhat.com>

3 files changed, 200 insertions, 45 deletions

diff --git a/src/cyclictest/cyclictest.c b/src/cyclictest/cyclictest.c
index 6be5521..0f3e981 100644
--- a/src/cyclictest/cyclictest.c
+++ b/src/cyclictest/cyclictest.c
@@ -114,6 +114,7 @@ enum {
 	IRQPREEMPTOFF,
 	WAKEUP,
 	WAKEUPRT,
+	LATENCY,
 	CUSTOM,
 };
 
@@ -154,7 +155,7 @@ struct thread_stat {
 
 static int shutdown;
 static int tracelimit = 0;
-static int ftrace = 1;
+static int ftrace = 0;
 static int kernelversion;
 static int verbose = 0;
 static int oscope_reduction = 1;
@@ -172,6 +173,7 @@ static pthread_mutex_t refresh_on_max_lock = PTHREAD_MUTEX_INITIALIZER;
 
 static pthread_mutex_t break_thread_id_lock = PTHREAD_MUTEX_INITIALIZER;
 static pid_t break_thread_id = 0;
+static uint64_t break_thread_value = 0;
 
 /* Backup of kernel variables that we modify */
 static struct kvars {
@@ -369,44 +371,11 @@ void tracing(int on)
 
 static int settracer(char *tracer)
 {
-	char filename[MAX_PATH];
-	char tracers[MAX_PATH];
-	char *name;
-	FILE *fp;
-	int ret = -1;
-	int len;
-	const char *delim = " \t\n";
-	char *prefix = get_debugfileprefix();
-
-	/* Make sure tracer is available */
-	strncpy(filename, prefix, sizeof(filename));
-	strncat(filename, "available_tracers", 
-		sizeof(filename) - strlen(prefix));
-
-	fp = fopen(filename, "r");
-	if (!fp)
-		return -1;
-
-	if (!(len = fread(tracers, 1, sizeof(tracers), fp))) {
-		fclose(fp);
-		return -1;
-	}
-	tracers[len] = '\0';
-	fclose(fp);
-
-	name = strtok(tracers, delim);
-	while (name) {
-		if (strcmp(name, tracer) == 0) {
-			ret = 0;
-			break;
-		}
-		name = strtok(NULL, delim);
-	}
-
-	if (!ret)
+	if (valid_tracer(tracer)) {
 		setkernvar("current_tracer", tracer);
-
-	return ret;
+		return 0;
+	}
+	return -1;
 }
 
 static void setup_tracer(void)
@@ -414,6 +383,9 @@ static void setup_tracer(void)
 	if (!tracelimit)
 		return;
 
+	if (mount_debugfs(NULL))
+		fatal("could not mount debugfs");
+
 	if (kernelversion >= KV_26_33) {
 		char testname[MAX_PATH];
 
@@ -447,10 +419,8 @@ static void setup_tracer(void)
 
 		switch (tracetype) {
 		case NOTRACE:
-			if (ftrace)
-				ret = settracer(functiontracer);
-			else
-				ret = 0;
+			setkernvar("events/enable", "1");
+			ret = settracer("nop");
 			break;
 		case IRQSOFF:
 			ret = settracer("irqsoff");
@@ -463,11 +433,20 @@ static void setup_tracer(void)
 			break;
 		case EVENTS:
 			/* per rostedt: use nop tracer with event tracing */
-			setkernvar("events/enable", "1");
 			ret = settracer("nop");
+			/* turn on all events */
+			event_enable_all();
 			break;
 		case CTXTSWITCH:
-			ret = settracer("sched_switch");
+			if (valid_tracer("sched_switch"))
+			    ret = settracer("sched_switch");
+			else {
+				if ((ret = settracer("nop")))
+					break;
+				if ((ret = event_enable("sched/sched_wakeup")))
+					break;
+				ret = event_enable("sched/sched_switch");
+			}
 			break;
                case WAKEUP:
                        ret = settracer("wakeup");
@@ -745,6 +724,7 @@ void *timerthread(void *param)
 			pthread_mutex_lock(&break_thread_id_lock);
 			if (break_thread_id == 0)
 				break_thread_id = stat->tid;
+			break_thread_value = diff;
 			pthread_mutex_unlock(&break_thread_id_lock);
 		}
 		stat->act = diff;
@@ -1533,8 +1513,10 @@ int main(int argc, char **argv)
 
 	if (tracelimit) {
 		print_tids(parameters, num_threads);
-		if (break_thread_id)
+		if (break_thread_id) {
 			printf("# Break thread: %d\n", break_thread_id);
+			printf("# Break value: %lu\n", break_thread_value);
+		}
 	}
 	
 
@@ -1561,6 +1543,9 @@ int main(int argc, char **argv)
 	if (trace_fd >= 0)
 		close(trace_fd);
 
+	/* turn off all events */
+	event_disable_all();
+
 	/* unlock everything */
 	if (lockall)
 		munlockall();
diff --git a/src/include/rt-utils.h b/src/include/rt-utils.h
index 68857f3..730344e 100644
--- a/src/include/rt-utils.h
+++ b/src/include/rt-utils.h
@@ -8,6 +8,15 @@
 
 int check_privs(void);
 char *get_debugfileprefix(void);
+int mount_debugfs(char *);
+int get_tracers(char ***);
+int valid_tracer(char *);
+
+int setevent(char *event, char *val);
+int event_enable(char *event);
+int event_disable(char *event);
+int event_enable_all(void);
+int event_disable_all(void);
 
 void warn(char *fmt, ...);
 void fatal(char *fmt, ...);
diff --git a/src/lib/rt-utils.c b/src/lib/rt-utils.c
index da27a3a..952ad7f 100644
--- a/src/lib/rt-utils.c
+++ b/src/lib/rt-utils.c
@@ -11,6 +11,8 @@
 #include <string.h>
 #include <sched.h>
 #include <stdarg.h>
+#include <errno.h>
+#include <fcntl.h>
 #include "rt-utils.h"
 
 static char debugfileprefix[MAX_PATH];
@@ -50,6 +52,165 @@ char *get_debugfileprefix(void)
 	return debugfileprefix;
 }
 
+int mount_debugfs(char *path)
+{
+	char *mountpoint = path;
+	char cmd[MAX_PATH];
+	int ret;
+
+	if (get_debugfileprefix())
+		return 0;
+	
+	if (!mountpoint)
+		mountpoint = "/sys/kernel/debug";
+	
+	sprintf(cmd, "mount -t debugfs debugfs %s", mountpoint);
+	ret = system(cmd);
+	if (ret != 0) {
+		fprintf(stderr, "Error mounting debugfs at %s: %s\n", mountpoint, strerror(errno));
+		return -1;
+	}
+	return 0;
+		
+}
+
+static char **tracer_list;
+static char *tracer_buffer;
+static int num_tracers;
+#define CHUNKSZ   1024
+
+/*
+ * return a list of the tracers configured into the running kernel
+ */
+
+int get_tracers(char ***list)
+{
+	int ret;
+	FILE *fp;
+	char buffer[CHUNKSZ];
+	char *prefix = get_debugfileprefix();
+	char *tmpbuf = NULL;
+	char *ptr;
+	int tmpsz = 0;
+
+	/* if we've already parse it, return what we have */
+	if (tracer_list) {
+		*list = tracer_list;
+		return num_tracers;
+	}
+
+	/* open the tracing file available_tracers */
+	sprintf(buffer, "%savailable_tracers", prefix);
+	if ((fp = fopen(buffer, "r")) == NULL)
+		fatal ("Can't open %s for reading\n", buffer);
+
+	/* allocate initial buffer */
+	ptr = tmpbuf = malloc(CHUNKSZ);
+	if (ptr == NULL)
+		fatal("error allocating initial space for tracer list\n");
+
+	/* read in the list of available tracers */
+	while((ret = fread(buffer, sizeof(char), CHUNKSZ, fp))) {
+		if ((ptr+ret+1) > (tmpbuf+tmpsz)) {
+			tmpbuf = realloc(tmpbuf, tmpsz + CHUNKSZ);
+			if (tmpbuf == NULL)
+				fatal("error allocating space for list of valid tracers\n");
+			tmpsz += CHUNKSZ;
+		}
+		strncpy(ptr, buffer, ret);
+		ptr += ret;
+	}
+	fclose(fp);
+	if (tmpsz == 0)
+		fatal("error reading available tracers\n");
+	
+	tracer_buffer = tmpbuf;
+
+	/* get a buffer for the pointers to tracers */
+	if (!(tracer_list = malloc(sizeof(char *))))
+		fatal ("error allocatinging tracer list buffer\n");
+
+	/* parse the buffer */
+	ptr = strtok(tmpbuf, " \t\n\r");
+	do {
+		tracer_list[num_tracers++] = ptr;
+		tracer_list = realloc(tracer_list, sizeof(char*)*(num_tracers+1));
+		tracer_list[num_tracers] = NULL;
+	} while ((ptr = strtok(NULL, " \t\n\r")) != NULL);
+
+	/* return the list and number of tracers */
+	*list = tracer_list;
+	return num_tracers;
+}
+
+
+/* 
+ * return zero if tracername is not a valid tracer, non-zero if it is 
+ */
+
+int valid_tracer(char *tracername)
+{
+	char **list;
+	int ntracers;
+	int i;
+
+	ntracers = get_tracers(&list);
+	if (ntracers == 0 || tracername == NULL)
+		return 0;
+	for (i = 0; i < ntracers; i++)
+		if (strncmp(list[i], tracername, strlen(list[i])) == 0)
+			return 1;
+	return 0;
+}
+
+/*
+ * enable event tracepoint
+ */
+int setevent(char *event, char *val)
+{
+	char *prefix = get_debugfileprefix();
+	char buffer[MAX_PATH];
+	int fd;
+	int ret;
+
+	sprintf(buffer, "%s%s", prefix, event);
+	if ((fd = open(buffer, O_WRONLY)) < 0) {
+		warn("unable to open %s\n", buffer);
+		return -1;
+	}
+	if ((ret = write(fd, val, strlen(val))) < 0) {
+		warn("unable to write %s to %s\n", val, buffer);
+		close(fd);
+		return -1;
+	}
+	close(fd);
+	return 0;
+}
+
+int event_enable_all(void)
+{
+	return setevent("events/enable", "1");
+}
+
+int event_disable_all(void)
+{
+	return setevent("events/enable", "0");
+}
+
+int event_enable(char *event) 
+{
+	char path[MAX_PATH];
+	sprintf(path, "events/%s/enable", event);
+	return setevent(path, "1");
+}
+
+int event_disable(char *event)
+{
+	char path[MAX_PATH];
+	sprintf(path, "events/%s/enable", event);
+	return setevent(path, "0");
+}
+	
 int check_privs(void)
 {
 	int policy = sched_getscheduler(0);