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