Commit | Line | Data |
---|---|---|
7dfb7103 NC |
1 | /* Freezer declarations */ |
2 | ||
83144186 RW |
3 | #ifndef FREEZER_H_INCLUDED |
4 | #define FREEZER_H_INCLUDED | |
5 | ||
5c543eff | 6 | #include <linux/sched.h> |
e42837bc | 7 | #include <linux/wait.h> |
5c543eff | 8 | |
8174f150 | 9 | #ifdef CONFIG_FREEZER |
7dfb7103 NC |
10 | /* |
11 | * Check if a process has been frozen | |
12 | */ | |
13 | static inline int frozen(struct task_struct *p) | |
14 | { | |
15 | return p->flags & PF_FROZEN; | |
16 | } | |
17 | ||
18 | /* | |
19 | * Check if there is a request to freeze a process | |
20 | */ | |
21 | static inline int freezing(struct task_struct *p) | |
22 | { | |
8a102eed | 23 | return test_tsk_thread_flag(p, TIF_FREEZE); |
7dfb7103 NC |
24 | } |
25 | ||
26 | /* | |
27 | * Request that a process be frozen | |
7dfb7103 | 28 | */ |
0c1eecfb | 29 | static inline void set_freeze_flag(struct task_struct *p) |
7dfb7103 | 30 | { |
8a102eed | 31 | set_tsk_thread_flag(p, TIF_FREEZE); |
7dfb7103 NC |
32 | } |
33 | ||
34 | /* | |
35 | * Sometimes we may need to cancel the previous 'freeze' request | |
36 | */ | |
0c1eecfb | 37 | static inline void clear_freeze_flag(struct task_struct *p) |
7dfb7103 | 38 | { |
8a102eed | 39 | clear_tsk_thread_flag(p, TIF_FREEZE); |
7dfb7103 NC |
40 | } |
41 | ||
8174f150 MH |
42 | static inline bool should_send_signal(struct task_struct *p) |
43 | { | |
44 | return !(p->flags & PF_FREEZER_NOSIG); | |
45 | } | |
46 | ||
dc52ddc0 MH |
47 | /* Takes and releases task alloc lock using task_lock() */ |
48 | extern int thaw_process(struct task_struct *p); | |
7dfb7103 | 49 | |
7dfb7103 NC |
50 | extern void refrigerator(void); |
51 | extern int freeze_processes(void); | |
a9b6f562 | 52 | extern void thaw_processes(void); |
7dfb7103 NC |
53 | |
54 | static inline int try_to_freeze(void) | |
55 | { | |
56 | if (freezing(current)) { | |
57 | refrigerator(); | |
58 | return 1; | |
59 | } else | |
60 | return 0; | |
61 | } | |
ff39593a | 62 | |
8174f150 MH |
63 | extern bool freeze_task(struct task_struct *p, bool sig_only); |
64 | extern void cancel_freezing(struct task_struct *p); | |
65 | ||
dc52ddc0 MH |
66 | #ifdef CONFIG_CGROUP_FREEZER |
67 | extern int cgroup_frozen(struct task_struct *task); | |
68 | #else /* !CONFIG_CGROUP_FREEZER */ | |
69 | static inline int cgroup_frozen(struct task_struct *task) { return 0; } | |
70 | #endif /* !CONFIG_CGROUP_FREEZER */ | |
71 | ||
ba96a0c8 RW |
72 | /* |
73 | * The PF_FREEZER_SKIP flag should be set by a vfork parent right before it | |
74 | * calls wait_for_completion(&vfork) and reset right after it returns from this | |
75 | * function. Next, the parent should call try_to_freeze() to freeze itself | |
76 | * appropriately in case the child has exited before the freezing of tasks is | |
77 | * complete. However, we don't want kernel threads to be frozen in unexpected | |
78 | * places, so we allow them to block freeze_processes() instead or to set | |
79 | * PF_NOFREEZE if needed and PF_FREEZER_SKIP is only set for userland vfork | |
80 | * parents. Fortunately, in the ____call_usermodehelper() case the parent won't | |
81 | * really block freeze_processes(), since ____call_usermodehelper() (the child) | |
82 | * does a little before exec/exit and it can't be frozen before waking up the | |
83 | * parent. | |
84 | */ | |
85 | ||
86 | /* | |
87 | * If the current task is a user space one, tell the freezer not to count it as | |
88 | * freezable. | |
89 | */ | |
90 | static inline void freezer_do_not_count(void) | |
91 | { | |
92 | if (current->mm) | |
93 | current->flags |= PF_FREEZER_SKIP; | |
94 | } | |
95 | ||
96 | /* | |
97 | * If the current task is a user space one, tell the freezer to count it as | |
98 | * freezable again and try to freeze it. | |
99 | */ | |
100 | static inline void freezer_count(void) | |
101 | { | |
102 | if (current->mm) { | |
103 | current->flags &= ~PF_FREEZER_SKIP; | |
104 | try_to_freeze(); | |
105 | } | |
106 | } | |
107 | ||
108 | /* | |
109 | * Check if the task should be counted as freezeable by the freezer | |
110 | */ | |
111 | static inline int freezer_should_skip(struct task_struct *p) | |
112 | { | |
113 | return !!(p->flags & PF_FREEZER_SKIP); | |
114 | } | |
ff39593a | 115 | |
83144186 RW |
116 | /* |
117 | * Tell the freezer that the current task should be frozen by it | |
118 | */ | |
119 | static inline void set_freezable(void) | |
120 | { | |
121 | current->flags &= ~PF_NOFREEZE; | |
122 | } | |
123 | ||
ebb12db5 RW |
124 | /* |
125 | * Tell the freezer that the current task should be frozen by it and that it | |
126 | * should send a fake signal to the task to freeze it. | |
127 | */ | |
128 | static inline void set_freezable_with_signal(void) | |
129 | { | |
130 | current->flags &= ~(PF_NOFREEZE | PF_FREEZER_NOSIG); | |
131 | } | |
132 | ||
e42837bc RW |
133 | /* |
134 | * Freezer-friendly wrappers around wait_event_interruptible() and | |
135 | * wait_event_interruptible_timeout(), originally defined in <linux/wait.h> | |
136 | */ | |
137 | ||
138 | #define wait_event_freezable(wq, condition) \ | |
139 | ({ \ | |
140 | int __retval; \ | |
141 | do { \ | |
142 | __retval = wait_event_interruptible(wq, \ | |
143 | (condition) || freezing(current)); \ | |
144 | if (__retval && !freezing(current)) \ | |
145 | break; \ | |
146 | else if (!(condition)) \ | |
147 | __retval = -ERESTARTSYS; \ | |
148 | } while (try_to_freeze()); \ | |
149 | __retval; \ | |
150 | }) | |
151 | ||
152 | ||
153 | #define wait_event_freezable_timeout(wq, condition, timeout) \ | |
154 | ({ \ | |
155 | long __retval = timeout; \ | |
156 | do { \ | |
157 | __retval = wait_event_interruptible_timeout(wq, \ | |
158 | (condition) || freezing(current), \ | |
159 | __retval); \ | |
160 | } while (try_to_freeze()); \ | |
161 | __retval; \ | |
162 | }) | |
8174f150 | 163 | #else /* !CONFIG_FREEZER */ |
7dfb7103 NC |
164 | static inline int frozen(struct task_struct *p) { return 0; } |
165 | static inline int freezing(struct task_struct *p) { return 0; } | |
0c1eecfb RW |
166 | static inline void set_freeze_flag(struct task_struct *p) {} |
167 | static inline void clear_freeze_flag(struct task_struct *p) {} | |
7dfb7103 | 168 | static inline int thaw_process(struct task_struct *p) { return 1; } |
7dfb7103 NC |
169 | |
170 | static inline void refrigerator(void) {} | |
171 | static inline int freeze_processes(void) { BUG(); return 0; } | |
172 | static inline void thaw_processes(void) {} | |
173 | ||
174 | static inline int try_to_freeze(void) { return 0; } | |
175 | ||
ba96a0c8 RW |
176 | static inline void freezer_do_not_count(void) {} |
177 | static inline void freezer_count(void) {} | |
178 | static inline int freezer_should_skip(struct task_struct *p) { return 0; } | |
83144186 | 179 | static inline void set_freezable(void) {} |
ebb12db5 | 180 | static inline void set_freezable_with_signal(void) {} |
e42837bc RW |
181 | |
182 | #define wait_event_freezable(wq, condition) \ | |
183 | wait_event_interruptible(wq, condition) | |
184 | ||
185 | #define wait_event_freezable_timeout(wq, condition, timeout) \ | |
186 | wait_event_interruptible_timeout(wq, condition, timeout) | |
187 | ||
8174f150 | 188 | #endif /* !CONFIG_FREEZER */ |
83144186 RW |
189 | |
190 | #endif /* FREEZER_H_INCLUDED */ |