1/*
2 * Copyright (c) 2008, The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *  * Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 *  * Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in
12 *    the documentation and/or other materials provided with the
13 *    distribution.
14 *  * Neither the name of Google, Inc. nor the names of its contributors
15 *    may be used to endorse or promote products derived from this
16 *    software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
21 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
22 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
24 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
25 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
26 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
27 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
28 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include <stdio.h>
33#include <unistd.h>
34#include <stdlib.h>
35#include <sys/time.h>
36#include <sys/resource.h>
37#include <sched.h>
38#include <getopt.h>
39
40static void
41usage(const char *s)
42{
43    fprintf(stderr, "USAGE: %s [[-r] [-t TYPE] priority pids ...] [-g pid]\n", s);
44    exit(EXIT_FAILURE);
45}
46
47void print_prio(pid_t pid)
48{
49    int sched;
50    struct sched_param sp;
51
52    printf("pid %d's priority: %d\n", pid, getpriority(PRIO_PROCESS, pid));
53
54    printf("scheduling class: ");
55    sched = sched_getscheduler(pid);
56    switch (sched) {
57    case SCHED_FIFO:
58        printf("FIFO\n");
59        break;
60    case SCHED_RR:
61        printf("RR\n");
62        break;
63    case SCHED_OTHER:
64        printf("Normal\n");
65        break;
66    case -1:
67        perror("sched_getscheduler");
68        break;
69    default:
70        printf("Unknown\n");
71    }
72
73    sched_getparam(pid, &sp);
74    printf("RT prio: %d (of %d to %d)\n", sp.sched_priority,
75           sched_get_priority_min(sched), sched_get_priority_max(sched));
76}
77
78int get_sched(char *str)
79{
80    if (strcasecmp(str, "RR") == 0)
81        return SCHED_RR;
82    else if (strcasecmp(str, "FIFO") == 0)
83        return SCHED_FIFO;
84    else if (strcasecmp(str, "NORMAL") == 0)
85        return SCHED_OTHER;
86    else if (strcasecmp(str, "OTHER") == 0)
87        return SCHED_OTHER;
88    return SCHED_RR;
89}
90
91int renice_main(int argc, char *argv[])
92{
93    int prio;
94    int realtime = 0;
95    int opt;
96    int sched = SCHED_RR;
97    char *cmd = argv[0];
98
99    do {
100        opt = getopt(argc, argv, "rt:g:");
101        if (opt == -1)
102            break;
103        switch (opt) {
104        case 'r':
105            // do realtime priority adjustment
106            realtime = 1;
107            break;
108        case 't':
109            sched = get_sched(optarg);
110            break;
111        case 'g':
112            print_prio(atoi(optarg));
113            return 0;
114        default:
115            usage(cmd);
116        }
117    } while (1);
118
119    argc -= optind;
120    argv += optind;
121
122    if (argc < 1)
123        usage(cmd);
124
125    prio = atoi(argv[0]);
126    argc--;
127    argv++;
128
129    if (argc < 1)
130        usage(cmd);
131
132    while(argc) {
133        pid_t pid;
134
135        pid = atoi(argv[0]);
136        argc--;
137        argv++;
138
139        if (realtime) {
140            struct sched_param sp = { .sched_priority = prio };
141            int ret;
142
143            ret = sched_setscheduler(pid, sched, &sp);
144            if (ret) {
145                perror("sched_set_scheduler");
146                exit(EXIT_FAILURE);
147            }
148        } else {
149            int ret;
150
151            ret = setpriority(PRIO_PROCESS, pid, prio);
152            if (ret) {
153                perror("setpriority");
154                exit(EXIT_FAILURE);
155            }
156        }
157    }
158
159    return 0;
160}
161