busybox/util-linux/ionice.c
Denys Vlasenko 5353df91cb Update applet size estimates
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2023-07-10 17:25:21 +02:00

119 lines
2.9 KiB
C

/* vi: set sw=4 ts=4: */
/*
* ionice implementation for busybox based on linux-utils-ng 2.14
*
* Copyright (C) 2008 by <u173034@informatik.uni-oldenburg.de>
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
//config:config IONICE
//config: bool "ionice (4 kb)"
//config: default y
//config: help
//config: Set/set program io scheduling class and priority
//config: Requires kernel >= 2.6.13
//applet:IF_IONICE(APPLET_NOEXEC(ionice, ionice, BB_DIR_BIN, BB_SUID_DROP, ionice))
//kbuild:lib-$(CONFIG_IONICE) += ionice.o
//usage:#define ionice_trivial_usage
//usage: "[-c 1-3] [-n 0-7] [-t] { -p PID | PROG ARGS }"
//TODO: | -P PGID | -u UID; also -pPu can take _list of_ IDs
//usage:#define ionice_full_usage "\n\n"
//usage: "Change I/O priority and class\n"
//usage: "\n -c N Class. 1:realtime 2:best-effort 3:idle"
//usage: "\n -n N Priority"
//usage: "\n -t Ignore errors"
#include <sys/syscall.h>
#include <asm/unistd.h>
#include "libbb.h"
static int ioprio_set(int which, int who, int ioprio)
{
return syscall(SYS_ioprio_set, which, who, ioprio);
}
static int ioprio_get(int which, int who)
{
return syscall(SYS_ioprio_get, which, who);
}
enum {
IOPRIO_WHO_PROCESS = 1,
IOPRIO_WHO_PGRP,
IOPRIO_WHO_USER
};
enum {
IOPRIO_CLASS_NONE,
IOPRIO_CLASS_RT,
IOPRIO_CLASS_BE,
IOPRIO_CLASS_IDLE
};
static const char to_prio[] ALIGN1 = "none\0realtime\0best-effort\0idle";
#define IOPRIO_CLASS_SHIFT 13
int ionice_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int ionice_main(int argc UNUSED_PARAM, char **argv)
{
/* Defaults */
int ioclass = 0;
int pri = 0;
int pid = 0; /* affect own process */
int opt;
enum {
OPT_n = 1 << 0,
OPT_c = 1 << 1,
OPT_p = 1 << 2,
OPT_t = 1 << 3,
};
/* '+': stop at first non-option */
/* numeric params for -n -c -p */
opt = getopt32(argv, "+""n:+c:+p:+t", &pri, &ioclass, &pid);
argv += optind;
if (opt & OPT_c) {
if (ioclass > 3)
bb_error_msg_and_die("bad class %d", ioclass);
// Do we need this (compat?)?
// if (ioclass == IOPRIO_CLASS_NONE)
// ioclass = IOPRIO_CLASS_BE;
// if (ioclass == IOPRIO_CLASS_IDLE) {
// //if (opt & OPT_n)
// // bb_error_msg("ignoring priority for idle class");
// pri = 7;
// }
}
if (!(opt & (OPT_n|OPT_c))) {
if (!(opt & OPT_p) && *argv)
pid = xatoi_positive(*argv);
pri = ioprio_get(IOPRIO_WHO_PROCESS, pid);
if (pri == -1)
bb_perror_msg_and_die("ioprio_%cet", 'g');
ioclass = (pri >> IOPRIO_CLASS_SHIFT) & 0x3;
pri &= 0xff;
printf((ioclass == IOPRIO_CLASS_IDLE) ? "%s\n" : "%s: prio %d\n",
nth_string(to_prio, ioclass), pri);
} else {
//printf("pri=%d class=%d val=%x\n",
//pri, ioclass, pri | (ioclass << IOPRIO_CLASS_SHIFT));
pri |= (ioclass << IOPRIO_CLASS_SHIFT);
if (ioprio_set(IOPRIO_WHO_PROCESS, pid, pri) == -1)
if (!(opt & OPT_t))
bb_perror_msg_and_die("ioprio_%cet", 's');
if (argv[0]) {
BB_EXECVP_or_die(argv);
}
}
return EXIT_SUCCESS;
}