/* 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. */ //config:config IONICE //config: bool "ionice (3.6 kb)" //config: default y //config: select PLATFORM_LINUX //config: help //config: Set/set program io scheduling class and priority //config: Requires kernel >= 2.6.13 //applet:IF_IONICE(APPLET_NOEXEC(ionice, ionice, BB_DIR_BIN, BB_SUID_DROP, ionice)) //kbuild:lib-$(CONFIG_IONICE) += ionice.o //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[] ALIGN1 = "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 */ /* '+': 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; }