1 /* vi: set sw=4 ts=4: */
3 * ionice implementation for busybox based on linux-utils-ng 2.14
5 * Copyright (C) 2008 by <u173034@informatik.uni-oldenburg.de>
7 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
10 //usage:#define ionice_trivial_usage
11 //usage: "[-c 1-3] [-n 0-7] [-p PID] [PROG]"
12 //usage:#define ionice_full_usage "\n\n"
13 //usage: "Change I/O priority and class\n"
14 //usage: "\n -c Class. 1:realtime 2:best-effort 3:idle"
15 //usage: "\n -n Priority"
17 #include <sys/syscall.h>
18 #include <asm/unistd.h>
21 static int ioprio_set(int which, int who, int ioprio)
23 return syscall(SYS_ioprio_set, which, who, ioprio);
26 static int ioprio_get(int which, int who)
28 return syscall(SYS_ioprio_get, which, who);
32 IOPRIO_WHO_PROCESS = 1,
44 static const char to_prio[] = "none\0realtime\0best-effort\0idle";
46 #define IOPRIO_CLASS_SHIFT 13
48 int ionice_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
49 int ionice_main(int argc UNUSED_PARAM, char **argv)
54 int pid = 0; /* affect own porcess */
63 opt_complementary = "n+:c+:p+";
64 /* '+': stop at first non-option */
65 opt = getopt32(argv, "+n:c:p:", &pri, &ioclass, &pid);
70 bb_error_msg_and_die("bad class %d", ioclass);
71 // Do we need this (compat?)?
72 // if (ioclass == IOPRIO_CLASS_NONE)
73 // ioclass = IOPRIO_CLASS_BE;
74 // if (ioclass == IOPRIO_CLASS_IDLE) {
76 // // bb_error_msg("ignoring priority for idle class");
81 if (!(opt & (OPT_n|OPT_c))) {
82 if (!(opt & OPT_p) && *argv)
83 pid = xatoi_positive(*argv);
85 pri = ioprio_get(IOPRIO_WHO_PROCESS, pid);
87 bb_perror_msg_and_die("ioprio_%cet", 'g');
89 ioclass = (pri >> IOPRIO_CLASS_SHIFT) & 0x3;
91 printf((ioclass == IOPRIO_CLASS_IDLE) ? "%s\n" : "%s: prio %d\n",
92 nth_string(to_prio, ioclass), pri);
94 //printf("pri=%d class=%d val=%x\n",
95 //pri, ioclass, pri | (ioclass << IOPRIO_CLASS_SHIFT));
96 pri |= (ioclass << IOPRIO_CLASS_SHIFT);
97 if (ioprio_set(IOPRIO_WHO_PROCESS, pid, pri) == -1)
98 bb_perror_msg_and_die("ioprio_%cet", 's');
100 BB_EXECVP_or_die(argv);