1 /* This file is part of the KDE Project
2 SPDX-FileCopyrightText: 2008 Sebastian Trueg <trueg@kde.org>
3
4 Parts of this file are based on code from Strigi
5 SPDX-FileCopyrightText: 2006-2007 Jos van den Oever <jos@vandenoever.info>
6
7 SPDX-License-Identifier: LGPL-2.0-or-later
8 */
9
10 #include "priority.h"
11
12 #ifndef _GNU_SOURCE
13 #define _GNU_SOURCE
14 #endif
15
16 #include <QDebug>
17
18 #ifndef _WIN32
19 #include <cerrno>
20 #include <sys/resource.h>
21 #include <sys/syscall.h>
22 #include <unistd.h>
23
24 #include <sched.h>
25 #endif
26
27 #ifdef SYS_ioprio_set
28 namespace
29 {
30 #ifndef IOPRIO_CLASS_IDLE
31 enum { IOPRIO_CLASS_NONE, IOPRIO_CLASS_RT, IOPRIO_CLASS_BE, IOPRIO_CLASS_IDLE };
32 #endif
33
34 #ifndef IOPRIO_WHO_PROCESS
35 enum { IOPRIO_WHO_PROCESS = 1, IOPRIO_WHO_PGRP, IOPRIO_WHO_USER };
36 #endif
37
38 #ifndef IOPRIO_CLASS_SHIFT
39 const int IOPRIO_CLASS_SHIFT = 13;
40 #endif
41 }
42 #endif
43
lowerIOPriority()44 bool lowerIOPriority()
45 {
46 #ifdef SYS_ioprio_set
47 if (syscall(SYS_ioprio_set, IOPRIO_WHO_PROCESS, 0, IOPRIO_CLASS_IDLE << IOPRIO_CLASS_SHIFT) < 0) {
48 qDebug("cannot set io scheduling to idle (%s). Trying best effort.\n", strerror(errno));
49 if (syscall(SYS_ioprio_set, IOPRIO_WHO_PROCESS, 0, 7 | IOPRIO_CLASS_BE << IOPRIO_CLASS_SHIFT) < 0) {
50 qDebug("cannot set io scheduling to best effort.\n");
51 return false;
52 }
53 }
54 return true;
55 #else
56 return false;
57 #endif
58 }
59
lowerPriority()60 bool lowerPriority()
61 {
62 #ifndef Q_OS_WIN
63 return !setpriority(PRIO_PROCESS, 0, 19);
64 #else
65 return false;
66 #endif
67 }
68
lowerSchedulingPriority()69 bool lowerSchedulingPriority()
70 {
71 #ifdef SCHED_BATCH
72 struct sched_param param;
73 memset(¶m, 0, sizeof(param));
74 param.sched_priority = 0;
75 return !sched_setscheduler(0, SCHED_BATCH, ¶m);
76 #else
77 return false;
78 #endif
79 }
80
setIdleSchedulingPriority()81 bool setIdleSchedulingPriority()
82 {
83 #ifdef SCHED_IDLE
84 struct sched_param param;
85 memset(¶m, 0, sizeof(param));
86 param.sched_priority = 0;
87 return !sched_setscheduler(0, SCHED_IDLE, ¶m);
88 #else
89 return false;
90 #endif
91 }
92