/*
* ionice: set or get process io scheduling class and priority
*
* Copyright (C) 2005 Jens Axboe <axboe@suse.de> SUSE Labs
*
* Released under the terms of the GNU General Public License version 2
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <getopt.h>
#include <unistd.h>
#include <sys/ptrace.h>
#include <sys/syscall.h>
#include <asm/unistd.h>
#if defined(__i386__)
#define __NR_ioprio_set 289
#define __NR_ioprio_get 290
#elif defined(__powerpc__) || defined(__powerpc64__)
#define __NR_ioprio_set 273
#define __NR_ioprio_get 274
#elif defined(__x86_64__)
#define __NR_ioprio_set 251
#define __NR_ioprio_get 252
#elif defined(__ia64__)
#define __NR_ioprio_set 1274
#define __NR_ioprio_get 1275
#elif defined(__alpha__)
#define __NR_ioprio_set 442
#define __NR_ioprio_get 443
#elif defined(__s390x__) || defined(__s390__)
#define __NR_ioprio_set 282
#define __NR_ioprio_get 283
#elif defined(__sparc__)
#define __NR_ioprio_set 196
#define __NR_ioprio_get 218
#else
#error "Unsupported arch"
#endif
static inline int ioprio_set(int which, int who, int ioprio)
{
return syscall(__NR_ioprio_set, which, who, ioprio);
}
static inline int ioprio_get(int which, int who)
{
return syscall(__NR_ioprio_get, which, who);
}
enum {
IOPRIO_CLASS_NONE,
IOPRIO_CLASS_RT,
IOPRIO_CLASS_BE,
IOPRIO_CLASS_IDLE,
};
enum {
IOPRIO_WHO_PROCESS = 1,
IOPRIO_WHO_PGRP,
IOPRIO_WHO_USER,
};
#define IOPRIO_CLASS_SHIFT 13
const char *to_prio[] = { "none", "realtime", "best-effort", "idle", };
static void usage(void)
{
printf("Usage: ionice [OPTIONS] [COMMAND [ARG]...]\n");
printf("Sets or gets process io scheduling class and priority.\n");
printf("\n\t-n\tClass data (typically 0-7, lower being higher prio)\n");
printf("\t-c\tScheduling class\n");
printf("\t\t\t1: realtime, 2: best-effort, 3: idle\n");
printf("\t-p\tProcess pid\n");
printf("\t-h\tThis help page\n");
printf("\nJens Axboe <axboe@suse.de> (C) 2005\n");
}
int main(int argc, char *argv[])
{
int ioprio = 4, set = 0, ioprio_class = IOPRIO_CLASS_BE;
int c, pid = 0;
while ((c = getopt(argc, argv, "+n:c:p:h")) != EOF) {
switch (c) {
case 'n':
ioprio = strtol(optarg, NULL, 10);
set = 1;
break;
case 'c':
ioprio_class = strtol(optarg, NULL, 10);
set = 1;
break;
case 'p':
pid = strtol(optarg, NULL, 10);
break;
case 'h':
default:
usage();
exit(0);
}
}
switch (ioprio_class) {
case IOPRIO_CLASS_NONE:
ioprio_class = IOPRIO_CLASS_BE;
break;
case IOPRIO_CLASS_RT:
case IOPRIO_CLASS_BE:
break;
case IOPRIO_CLASS_IDLE:
ioprio = 7;
break;
default:
printf("bad prio class %d\n", ioprio_class);
return 1;
}
if (!set) {
if (!pid && argv[optind])
pid = strtol(argv[optind], NULL, 10);
ioprio = ioprio_get(IOPRIO_WHO_PROCESS, pid);
if (ioprio == -1)
perror("ioprio_get");
else {
ioprio_class = ioprio >> IOPRIO_CLASS_SHIFT;
ioprio = ioprio & 0xff;
printf("%s: prio %d\n", to_prio[ioprio_class], ioprio);
}
} else {
if (ioprio_set(IOPRIO_WHO_PROCESS, pid, ioprio | ioprio_class << IOPRIO_CLASS_SHIFT) == -1) {
perror("ioprio_set");
return 1;
}
if (argv[optind])
execvp(argv[optind], &argv[optind]);
}
return 0;
}
