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/*
* Copyright (C) 2009 Carsten Emde <carsten.emde@osadl.org>
* Copyright (C) 2010 Clark Williams <williams@redhat.com>
*
* based on functions from cyclictest that has
* (C) 2008-2009 Clark Williams <williams@redhat.com>
* (C) 2005-2007 Thomas Gleixner <tglx@linutronix.de>
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sched.h>
#include <stdarg.h>
#include "rt-utils.h"
static char debugfileprefix[MAX_PATH];
/*
* Finds the tracing directory in a mounted debugfs
*/
char *get_debugfileprefix(void)
{
char type[100];
FILE *fp;
int size;
if (debugfileprefix[0] != '\0')
return debugfileprefix;
if ((fp = fopen("/proc/mounts","r")) == NULL)
return debugfileprefix;
while (fscanf(fp, "%*s %"
STR(MAX_PATH)
"s %99s %*s %*d %*d\n",
debugfileprefix, type) == 2) {
if (strcmp(type, "debugfs") == 0)
break;
}
fclose(fp);
if (strcmp(type, "debugfs") != 0) {
debugfileprefix[0] = '\0';
return debugfileprefix;
}
size = sizeof(debugfileprefix) - strlen(debugfileprefix);
strncat(debugfileprefix, "/tracing/", size);
return debugfileprefix;
}
int check_privs(void)
{
int policy = sched_getscheduler(0);
struct sched_param param;
/* if we're already running a realtime scheduler
* then we *should* be able to change things later
*/
if (policy == SCHED_FIFO || policy == SCHED_RR)
return 0;
/* try to change to SCHED_FIFO */
param.sched_priority = 1;
if (sched_setscheduler(0, SCHED_FIFO, ¶m)) {
fprintf(stderr, "Unable to change scheduling policy!\n");
fprintf(stderr, "either run as root or join realtime group\n");
return 1;
}
/* we're good; change back and return success */
param.sched_priority = 0;
sched_setscheduler(0, policy, NULL);
return 0;
}
void warn(char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
fputs("WARNING: ", stderr);
vfprintf(stderr, fmt, ap);
va_end(ap);
}
void fatal(char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
fputs("FATAL: ", stderr);
vfprintf(stderr, fmt, ap);
va_end(ap);
exit(EXIT_FAILURE);
}
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