116 lines
2.7 KiB
C
116 lines
2.7 KiB
C
/* vi: set sw=4 ts=4: */
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/*
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* ionice implementation for busybox based on linux-utils-ng 2.14
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*
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* Copyright (C) 2008 by <u173034@informatik.uni-oldenburg.de>
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*
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* Licensed under GPLv2 or later, see file LICENSE in this source tree.
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*/
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//config:config IONICE
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//config: bool "ionice"
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//config: default y
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//config: select PLATFORM_LINUX
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//config: help
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//config: Set/set program io scheduling class and priority
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//config: Requires kernel >= 2.6.13
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//applet:IF_IONICE(APPLET(ionice, BB_DIR_BIN, BB_SUID_DROP))
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//kbuild:lib-$(CONFIG_IONICE) += ionice.o
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//usage:#define ionice_trivial_usage
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//usage: "[-c 1-3] [-n 0-7] [-p PID] [PROG]"
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//usage:#define ionice_full_usage "\n\n"
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//usage: "Change I/O priority and class\n"
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//usage: "\n -c Class. 1:realtime 2:best-effort 3:idle"
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//usage: "\n -n Priority"
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#include <sys/syscall.h>
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#include <asm/unistd.h>
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#include "libbb.h"
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static int ioprio_set(int which, int who, int ioprio)
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{
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return syscall(SYS_ioprio_set, which, who, ioprio);
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}
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static int ioprio_get(int which, int who)
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{
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return syscall(SYS_ioprio_get, which, who);
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}
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enum {
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IOPRIO_WHO_PROCESS = 1,
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IOPRIO_WHO_PGRP,
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IOPRIO_WHO_USER
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};
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enum {
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IOPRIO_CLASS_NONE,
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IOPRIO_CLASS_RT,
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IOPRIO_CLASS_BE,
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IOPRIO_CLASS_IDLE
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};
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static const char to_prio[] ALIGN1 = "none\0realtime\0best-effort\0idle";
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#define IOPRIO_CLASS_SHIFT 13
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int ionice_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
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int ionice_main(int argc UNUSED_PARAM, char **argv)
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{
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/* Defaults */
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int ioclass = 0;
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int pri = 0;
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int pid = 0; /* affect own porcess */
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int opt;
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enum {
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OPT_n = 1,
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OPT_c = 2,
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OPT_p = 4,
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};
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/* Numeric params */
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/* '+': stop at first non-option */
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opt = getopt32(argv, "+n:+c:+p:+", &pri, &ioclass, &pid);
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argv += optind;
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if (opt & OPT_c) {
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if (ioclass > 3)
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bb_error_msg_and_die("bad class %d", ioclass);
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// Do we need this (compat?)?
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// if (ioclass == IOPRIO_CLASS_NONE)
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// ioclass = IOPRIO_CLASS_BE;
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// if (ioclass == IOPRIO_CLASS_IDLE) {
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// //if (opt & OPT_n)
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// // bb_error_msg("ignoring priority for idle class");
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// pri = 7;
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// }
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}
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if (!(opt & (OPT_n|OPT_c))) {
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if (!(opt & OPT_p) && *argv)
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pid = xatoi_positive(*argv);
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pri = ioprio_get(IOPRIO_WHO_PROCESS, pid);
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if (pri == -1)
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bb_perror_msg_and_die("ioprio_%cet", 'g');
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ioclass = (pri >> IOPRIO_CLASS_SHIFT) & 0x3;
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pri &= 0xff;
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printf((ioclass == IOPRIO_CLASS_IDLE) ? "%s\n" : "%s: prio %d\n",
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nth_string(to_prio, ioclass), pri);
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} else {
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//printf("pri=%d class=%d val=%x\n",
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//pri, ioclass, pri | (ioclass << IOPRIO_CLASS_SHIFT));
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pri |= (ioclass << IOPRIO_CLASS_SHIFT);
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if (ioprio_set(IOPRIO_WHO_PROCESS, pid, pri) == -1)
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bb_perror_msg_and_die("ioprio_%cet", 's');
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if (argv[0]) {
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BB_EXECVP_or_die(argv);
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}
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}
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return EXIT_SUCCESS;
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}
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