| /* 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. |
| */ |
| |
| //usage:#define ionice_trivial_usage |
| //usage: "[-c 1-3] [-n 0-7] [-p PID] [PROG]" |
| //usage:#define ionice_full_usage "\n\n" |
| //usage: "Change I/O priority and class\n" |
| //usage: "\n -c Class. 1:realtime 2:best-effort 3:idle" |
| //usage: "\n -n Priority" |
| |
| #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[] = "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 porcess */ |
| int opt; |
| enum { |
| OPT_n = 1, |
| OPT_c = 2, |
| OPT_p = 4, |
| }; |
| |
| /* Numeric params */ |
| opt_complementary = "n+:c+:p+"; |
| /* '+': stop at first non-option */ |
| opt = getopt32(argv, "+n:c:p:", &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) |
| bb_perror_msg_and_die("ioprio_%cet", 's'); |
| if (argv[0]) { |
| BB_EXECVP_or_die(argv); |
| } |
| } |
| |
| return EXIT_SUCCESS; |
| } |