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 | 66 | #ifdef CONFIG_CGROUP_FREEZER |
5a7aadfe | 67 | extern int cgroup_freezing_or_frozen(struct task_struct *task); |
dc52ddc0 | 68 | #else /* !CONFIG_CGROUP_FREEZER */ |
5a7aadfe MH |
69 | static inline int cgroup_freezing_or_frozen(struct task_struct *task) |
70 | { | |
71 | return 0; | |
72 | } | |
dc52ddc0 MH |
73 | #endif /* !CONFIG_CGROUP_FREEZER */ |
74 | ||
ba96a0c8 RW |
75 | /* |
76 | * The PF_FREEZER_SKIP flag should be set by a vfork parent right before it | |
77 | * calls wait_for_completion(&vfork) and reset right after it returns from this | |
78 | * function. Next, the parent should call try_to_freeze() to freeze itself | |
79 | * appropriately in case the child has exited before the freezing of tasks is | |
80 | * complete. However, we don't want kernel threads to be frozen in unexpected | |
81 | * places, so we allow them to block freeze_processes() instead or to set | |
82 | * PF_NOFREEZE if needed and PF_FREEZER_SKIP is only set for userland vfork | |
83 | * parents. Fortunately, in the ____call_usermodehelper() case the parent won't | |
84 | * really block freeze_processes(), since ____call_usermodehelper() (the child) | |
85 | * does a little before exec/exit and it can't be frozen before waking up the | |
86 | * parent. | |
87 | */ | |
88 | ||
89 | /* | |
90 | * If the current task is a user space one, tell the freezer not to count it as | |
91 | * freezable. | |
92 | */ | |
93 | static inline void freezer_do_not_count(void) | |
94 | { | |
95 | if (current->mm) | |
96 | current->flags |= PF_FREEZER_SKIP; | |
97 | } | |
98 | ||
99 | /* | |
100 | * If the current task is a user space one, tell the freezer to count it as | |
101 | * freezable again and try to freeze it. | |
102 | */ | |
103 | static inline void freezer_count(void) | |
104 | { | |
105 | if (current->mm) { | |
106 | current->flags &= ~PF_FREEZER_SKIP; | |
107 | try_to_freeze(); | |
108 | } | |
109 | } | |
110 | ||
111 | /* | |
112 | * Check if the task should be counted as freezeable by the freezer | |
113 | */ | |
114 | static inline int freezer_should_skip(struct task_struct *p) | |
115 | { | |
116 | return !!(p->flags & PF_FREEZER_SKIP); | |
117 | } | |
ff39593a | 118 | |
83144186 RW |
119 | /* |
120 | * Tell the freezer that the current task should be frozen by it | |
121 | */ | |
122 | static inline void set_freezable(void) | |
123 | { | |
124 | current->flags &= ~PF_NOFREEZE; | |
125 | } | |
126 | ||
ebb12db5 RW |
127 | /* |
128 | * Tell the freezer that the current task should be frozen by it and that it | |
129 | * should send a fake signal to the task to freeze it. | |
130 | */ | |
131 | static inline void set_freezable_with_signal(void) | |
132 | { | |
133 | current->flags &= ~(PF_NOFREEZE | PF_FREEZER_NOSIG); | |
134 | } | |
135 | ||
e42837bc RW |
136 | /* |
137 | * Freezer-friendly wrappers around wait_event_interruptible() and | |
138 | * wait_event_interruptible_timeout(), originally defined in <linux/wait.h> | |
139 | */ | |
140 | ||
141 | #define wait_event_freezable(wq, condition) \ | |
142 | ({ \ | |
143 | int __retval; \ | |
144 | do { \ | |
145 | __retval = wait_event_interruptible(wq, \ | |
146 | (condition) || freezing(current)); \ | |
147 | if (__retval && !freezing(current)) \ | |
148 | break; \ | |
149 | else if (!(condition)) \ | |
150 | __retval = -ERESTARTSYS; \ | |
151 | } while (try_to_freeze()); \ | |
152 | __retval; \ | |
153 | }) | |
154 | ||
155 | ||
156 | #define wait_event_freezable_timeout(wq, condition, timeout) \ | |
157 | ({ \ | |
158 | long __retval = timeout; \ | |
159 | do { \ | |
160 | __retval = wait_event_interruptible_timeout(wq, \ | |
161 | (condition) || freezing(current), \ | |
162 | __retval); \ | |
163 | } while (try_to_freeze()); \ | |
164 | __retval; \ | |
165 | }) | |
8174f150 | 166 | #else /* !CONFIG_FREEZER */ |
7dfb7103 NC |
167 | static inline int frozen(struct task_struct *p) { return 0; } |
168 | static inline int freezing(struct task_struct *p) { return 0; } | |
0c1eecfb RW |
169 | static inline void set_freeze_flag(struct task_struct *p) {} |
170 | static inline void clear_freeze_flag(struct task_struct *p) {} | |
7dfb7103 | 171 | static inline int thaw_process(struct task_struct *p) { return 1; } |
7dfb7103 NC |
172 | |
173 | static inline void refrigerator(void) {} | |
174 | static inline int freeze_processes(void) { BUG(); return 0; } | |
175 | static inline void thaw_processes(void) {} | |
176 | ||
177 | static inline int try_to_freeze(void) { return 0; } | |
178 | ||
ba96a0c8 RW |
179 | static inline void freezer_do_not_count(void) {} |
180 | static inline void freezer_count(void) {} | |
181 | static inline int freezer_should_skip(struct task_struct *p) { return 0; } | |
83144186 | 182 | static inline void set_freezable(void) {} |
ebb12db5 | 183 | static inline void set_freezable_with_signal(void) {} |
e42837bc RW |
184 | |
185 | #define wait_event_freezable(wq, condition) \ | |
186 | wait_event_interruptible(wq, condition) | |
187 | ||
188 | #define wait_event_freezable_timeout(wq, condition, timeout) \ | |
189 | wait_event_interruptible_timeout(wq, condition, timeout) | |
190 | ||
8174f150 | 191 | #endif /* !CONFIG_FREEZER */ |
83144186 RW |
192 | |
193 | #endif /* FREEZER_H_INCLUDED */ |