blob: c54b3a6e14371ea56ea46edb633e10f0a3b701d8
| 1 | /* vi: set sw=4 ts=4: */ |
| 2 | /* |
| 3 | * ionice implementation for busybox based on linux-utils-ng 2.14 |
| 4 | * |
| 5 | * Copyright (C) 2008 by <u173034@informatik.uni-oldenburg.de> |
| 6 | * |
| 7 | * Licensed under GPLv2 or later, see file LICENSE in this source tree. |
| 8 | */ |
| 9 | //config:config IONICE |
| 10 | //config: bool "ionice" |
| 11 | //config: default y |
| 12 | //config: select PLATFORM_LINUX |
| 13 | //config: help |
| 14 | //config: Set/set program io scheduling class and priority |
| 15 | //config: Requires kernel >= 2.6.13 |
| 16 | |
| 17 | //applet:IF_IONICE(APPLET(ionice, BB_DIR_BIN, BB_SUID_DROP)) |
| 18 | |
| 19 | //kbuild:lib-$(CONFIG_IONICE) += ionice.o |
| 20 | |
| 21 | //usage:#define ionice_trivial_usage |
| 22 | //usage: "[-c 1-3] [-n 0-7] [-p PID] [PROG]" |
| 23 | //usage:#define ionice_full_usage "\n\n" |
| 24 | //usage: "Change I/O priority and class\n" |
| 25 | //usage: "\n -c Class. 1:realtime 2:best-effort 3:idle" |
| 26 | //usage: "\n -n Priority" |
| 27 | |
| 28 | #include <sys/syscall.h> |
| 29 | #include <asm/unistd.h> |
| 30 | #include "libbb.h" |
| 31 | |
| 32 | static int ioprio_set(int which, int who, int ioprio) |
| 33 | { |
| 34 | return syscall(SYS_ioprio_set, which, who, ioprio); |
| 35 | } |
| 36 | |
| 37 | static int ioprio_get(int which, int who) |
| 38 | { |
| 39 | return syscall(SYS_ioprio_get, which, who); |
| 40 | } |
| 41 | |
| 42 | enum { |
| 43 | IOPRIO_WHO_PROCESS = 1, |
| 44 | IOPRIO_WHO_PGRP, |
| 45 | IOPRIO_WHO_USER |
| 46 | }; |
| 47 | |
| 48 | enum { |
| 49 | IOPRIO_CLASS_NONE, |
| 50 | IOPRIO_CLASS_RT, |
| 51 | IOPRIO_CLASS_BE, |
| 52 | IOPRIO_CLASS_IDLE |
| 53 | }; |
| 54 | |
| 55 | static const char to_prio[] ALIGN1 = "none\0realtime\0best-effort\0idle"; |
| 56 | |
| 57 | #define IOPRIO_CLASS_SHIFT 13 |
| 58 | |
| 59 | int ionice_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
| 60 | int ionice_main(int argc UNUSED_PARAM, char **argv) |
| 61 | { |
| 62 | /* Defaults */ |
| 63 | int ioclass = 0; |
| 64 | int pri = 0; |
| 65 | int pid = 0; /* affect own porcess */ |
| 66 | int opt; |
| 67 | enum { |
| 68 | OPT_n = 1, |
| 69 | OPT_c = 2, |
| 70 | OPT_p = 4, |
| 71 | }; |
| 72 | |
| 73 | /* Numeric params */ |
| 74 | /* '+': stop at first non-option */ |
| 75 | opt = getopt32(argv, "+n:+c:+p:+", &pri, &ioclass, &pid); |
| 76 | argv += optind; |
| 77 | |
| 78 | if (opt & OPT_c) { |
| 79 | if (ioclass > 3) |
| 80 | bb_error_msg_and_die("bad class %d", ioclass); |
| 81 | // Do we need this (compat?)? |
| 82 | // if (ioclass == IOPRIO_CLASS_NONE) |
| 83 | // ioclass = IOPRIO_CLASS_BE; |
| 84 | // if (ioclass == IOPRIO_CLASS_IDLE) { |
| 85 | // //if (opt & OPT_n) |
| 86 | // // bb_error_msg("ignoring priority for idle class"); |
| 87 | // pri = 7; |
| 88 | // } |
| 89 | } |
| 90 | |
| 91 | if (!(opt & (OPT_n|OPT_c))) { |
| 92 | if (!(opt & OPT_p) && *argv) |
| 93 | pid = xatoi_positive(*argv); |
| 94 | |
| 95 | pri = ioprio_get(IOPRIO_WHO_PROCESS, pid); |
| 96 | if (pri == -1) |
| 97 | bb_perror_msg_and_die("ioprio_%cet", 'g'); |
| 98 | |
| 99 | ioclass = (pri >> IOPRIO_CLASS_SHIFT) & 0x3; |
| 100 | pri &= 0xff; |
| 101 | printf((ioclass == IOPRIO_CLASS_IDLE) ? "%s\n" : "%s: prio %d\n", |
| 102 | nth_string(to_prio, ioclass), pri); |
| 103 | } else { |
| 104 | //printf("pri=%d class=%d val=%x\n", |
| 105 | //pri, ioclass, pri | (ioclass << IOPRIO_CLASS_SHIFT)); |
| 106 | pri |= (ioclass << IOPRIO_CLASS_SHIFT); |
| 107 | if (ioprio_set(IOPRIO_WHO_PROCESS, pid, pri) == -1) |
| 108 | bb_perror_msg_and_die("ioprio_%cet", 's'); |
| 109 | if (argv[0]) { |
| 110 | BB_EXECVP_or_die(argv); |
| 111 | } |
| 112 | } |
| 113 | |
| 114 | return EXIT_SUCCESS; |
| 115 | } |
| 116 |