Denis Vlasenko | 4acdb46 | 2009-01-31 21:45:57 +0000 | [diff] [blame] | 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 tarball for details. |
| 8 | */ |
| 9 | |
| 10 | #include <sys/syscall.h> |
| 11 | #include <asm/unistd.h> |
| 12 | #include "libbb.h" |
| 13 | |
| 14 | static int ioprio_set(int which, int who, int ioprio) |
| 15 | { |
| 16 | return syscall(SYS_ioprio_set, which, who, ioprio); |
| 17 | } |
| 18 | |
| 19 | static int ioprio_get(int which, int who) |
| 20 | { |
| 21 | return syscall(SYS_ioprio_get, which, who); |
| 22 | } |
| 23 | |
| 24 | enum { |
| 25 | IOPRIO_WHO_PROCESS = 1, |
| 26 | IOPRIO_WHO_PGRP, |
| 27 | IOPRIO_WHO_USER |
| 28 | }; |
| 29 | |
| 30 | enum { |
| 31 | IOPRIO_CLASS_NONE, |
| 32 | IOPRIO_CLASS_RT, |
| 33 | IOPRIO_CLASS_BE, |
| 34 | IOPRIO_CLASS_IDLE |
| 35 | }; |
| 36 | |
| 37 | static const char to_prio[] = "none\0realtime\0best-effort\0idle"; |
| 38 | |
| 39 | #define IOPRIO_CLASS_SHIFT 13 |
| 40 | |
| 41 | int ionice_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
| 42 | int ionice_main(int argc UNUSED_PARAM, char **argv) |
| 43 | { |
| 44 | /* Defaults */ |
| 45 | int ioclass = 0; |
| 46 | int pri = 0; |
| 47 | int pid = 0; /* affect own porcess */ |
| 48 | int opt; |
| 49 | enum { |
| 50 | OPT_n = 1, |
| 51 | OPT_c = 2, |
| 52 | OPT_p = 4, |
| 53 | }; |
| 54 | |
| 55 | /* Numeric params */ |
| 56 | opt_complementary = "n+:c+:p+"; |
| 57 | /* '+': stop at first non-option */ |
| 58 | opt = getopt32(argv, "+n:c:p:", &pri, &ioclass, &pid); |
| 59 | argv += optind; |
| 60 | |
| 61 | if (opt & OPT_c) { |
| 62 | if (ioclass > 3) |
| 63 | bb_error_msg_and_die("bad class %d", ioclass); |
| 64 | // Do we need this (compat?)? |
| 65 | // if (ioclass == IOPRIO_CLASS_NONE) |
| 66 | // ioclass = IOPRIO_CLASS_BE; |
| 67 | // if (ioclass == IOPRIO_CLASS_IDLE) { |
| 68 | // //if (opt & OPT_n) |
| 69 | // // bb_error_msg("ignoring priority for idle class"); |
| 70 | // pri = 7; |
| 71 | // } |
| 72 | } |
| 73 | |
| 74 | if (!(opt & (OPT_n|OPT_c))) { |
| 75 | if (!(opt & OPT_p) && *argv) |
| 76 | pid = xatoi_u(*argv); |
| 77 | |
| 78 | pri = ioprio_get(IOPRIO_WHO_PROCESS, pid); |
| 79 | if (pri == -1) |
| 80 | bb_perror_msg_and_die("ioprio_%cet", 'g'); |
| 81 | |
| 82 | ioclass = (pri >> IOPRIO_CLASS_SHIFT) & 0x3; |
| 83 | pri &= 0xff; |
| 84 | printf((ioclass == IOPRIO_CLASS_IDLE) ? "%s\n" : "%s: prio %d\n", |
| 85 | nth_string(to_prio, ioclass), pri); |
| 86 | } else { |
| 87 | //printf("pri=%d class=%d val=%x\n", |
| 88 | //pri, ioclass, pri | (ioclass << IOPRIO_CLASS_SHIFT)); |
| 89 | pri |= (ioclass << IOPRIO_CLASS_SHIFT); |
| 90 | if (ioprio_set(IOPRIO_WHO_PROCESS, pid, pri) == -1) |
| 91 | bb_perror_msg_and_die("ioprio_%cet", 's'); |
| 92 | if (*argv) { |
| 93 | BB_EXECVP(*argv, argv); |
| 94 | bb_simple_perror_msg_and_die(*argv); |
| 95 | } |
| 96 | } |
| 97 | |
| 98 | return EXIT_SUCCESS; |
| 99 | } |