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> |
a3201227 | 8 | #include <linux/atomic.h> |
5c543eff | 9 | |
8174f150 | 10 | #ifdef CONFIG_FREEZER |
a3201227 TH |
11 | extern atomic_t system_freezing_cnt; /* nr of freezing conds in effect */ |
12 | extern bool pm_freezing; /* PM freezing in effect */ | |
13 | extern bool pm_nosig_freezing; /* PM nosig freezing in effect */ | |
14 | ||
7dfb7103 NC |
15 | /* |
16 | * Check if a process has been frozen | |
17 | */ | |
948246f7 | 18 | static inline bool frozen(struct task_struct *p) |
7dfb7103 NC |
19 | { |
20 | return p->flags & PF_FROZEN; | |
21 | } | |
22 | ||
a3201227 | 23 | extern bool freezing_slow_path(struct task_struct *p); |
7dfb7103 NC |
24 | |
25 | /* | |
a3201227 | 26 | * Check if there is a request to freeze a process |
7dfb7103 | 27 | */ |
a3201227 | 28 | static inline bool freezing(struct task_struct *p) |
7dfb7103 | 29 | { |
a3201227 TH |
30 | if (likely(!atomic_read(&system_freezing_cnt))) |
31 | return false; | |
32 | return freezing_slow_path(p); | |
7dfb7103 NC |
33 | } |
34 | ||
dc52ddc0 | 35 | /* Takes and releases task alloc lock using task_lock() */ |
a5be2d0d | 36 | extern void __thaw_task(struct task_struct *t); |
7dfb7103 | 37 | |
8a32c441 | 38 | extern bool __refrigerator(bool check_kthr_stop); |
7dfb7103 | 39 | extern int freeze_processes(void); |
2aede851 | 40 | extern int freeze_kernel_threads(void); |
a9b6f562 | 41 | extern void thaw_processes(void); |
7dfb7103 | 42 | |
a0acae0e | 43 | static inline bool try_to_freeze(void) |
7dfb7103 | 44 | { |
a0acae0e TH |
45 | might_sleep(); |
46 | if (likely(!freezing(current))) | |
47 | return false; | |
8a32c441 | 48 | return __refrigerator(false); |
7dfb7103 | 49 | } |
ff39593a | 50 | |
839e3407 | 51 | extern bool freeze_task(struct task_struct *p); |
34b087e4 | 52 | extern bool set_freezable(void); |
8174f150 | 53 | |
dc52ddc0 | 54 | #ifdef CONFIG_CGROUP_FREEZER |
22b4e111 | 55 | extern bool cgroup_freezing(struct task_struct *task); |
dc52ddc0 | 56 | #else /* !CONFIG_CGROUP_FREEZER */ |
22b4e111 | 57 | static inline bool cgroup_freezing(struct task_struct *task) |
5a7aadfe | 58 | { |
22b4e111 | 59 | return false; |
5a7aadfe | 60 | } |
dc52ddc0 MH |
61 | #endif /* !CONFIG_CGROUP_FREEZER */ |
62 | ||
ba96a0c8 RW |
63 | /* |
64 | * The PF_FREEZER_SKIP flag should be set by a vfork parent right before it | |
65 | * calls wait_for_completion(&vfork) and reset right after it returns from this | |
66 | * function. Next, the parent should call try_to_freeze() to freeze itself | |
67 | * appropriately in case the child has exited before the freezing of tasks is | |
68 | * complete. However, we don't want kernel threads to be frozen in unexpected | |
69 | * places, so we allow them to block freeze_processes() instead or to set | |
70 | * PF_NOFREEZE if needed and PF_FREEZER_SKIP is only set for userland vfork | |
71 | * parents. Fortunately, in the ____call_usermodehelper() case the parent won't | |
72 | * really block freeze_processes(), since ____call_usermodehelper() (the child) | |
73 | * does a little before exec/exit and it can't be frozen before waking up the | |
74 | * parent. | |
75 | */ | |
76 | ||
77 | /* | |
78 | * If the current task is a user space one, tell the freezer not to count it as | |
79 | * freezable. | |
80 | */ | |
81 | static inline void freezer_do_not_count(void) | |
82 | { | |
83 | if (current->mm) | |
84 | current->flags |= PF_FREEZER_SKIP; | |
85 | } | |
86 | ||
87 | /* | |
88 | * If the current task is a user space one, tell the freezer to count it as | |
89 | * freezable again and try to freeze it. | |
90 | */ | |
91 | static inline void freezer_count(void) | |
92 | { | |
93 | if (current->mm) { | |
94 | current->flags &= ~PF_FREEZER_SKIP; | |
95 | try_to_freeze(); | |
96 | } | |
97 | } | |
98 | ||
99 | /* | |
58a69cb4 | 100 | * Check if the task should be counted as freezable by the freezer |
ba96a0c8 RW |
101 | */ |
102 | static inline int freezer_should_skip(struct task_struct *p) | |
103 | { | |
104 | return !!(p->flags & PF_FREEZER_SKIP); | |
105 | } | |
ff39593a | 106 | |
d310310c JL |
107 | /* |
108 | * These macros are intended to be used whenever you want allow a task that's | |
109 | * sleeping in TASK_UNINTERRUPTIBLE or TASK_KILLABLE state to be frozen. Note | |
110 | * that neither return any clear indication of whether a freeze event happened | |
111 | * while in this function. | |
112 | */ | |
113 | ||
114 | /* Like schedule(), but should not block the freezer. */ | |
115 | #define freezable_schedule() \ | |
116 | ({ \ | |
117 | freezer_do_not_count(); \ | |
118 | schedule(); \ | |
119 | freezer_count(); \ | |
120 | }) | |
121 | ||
122 | /* Like schedule_timeout_killable(), but should not block the freezer. */ | |
123 | #define freezable_schedule_timeout_killable(timeout) \ | |
124 | ({ \ | |
125 | freezer_do_not_count(); \ | |
126 | schedule_timeout_killable(timeout); \ | |
127 | freezer_count(); \ | |
128 | }) | |
129 | ||
e42837bc | 130 | /* |
f06ac72e JL |
131 | * Freezer-friendly wrappers around wait_event_interruptible(), |
132 | * wait_event_killable() and wait_event_interruptible_timeout(), originally | |
133 | * defined in <linux/wait.h> | |
e42837bc RW |
134 | */ |
135 | ||
f06ac72e JL |
136 | #define wait_event_freezekillable(wq, condition) \ |
137 | ({ \ | |
138 | int __retval; \ | |
6f35c4ab ON |
139 | freezer_do_not_count(); \ |
140 | __retval = wait_event_killable(wq, (condition)); \ | |
141 | freezer_count(); \ | |
f06ac72e JL |
142 | __retval; \ |
143 | }) | |
144 | ||
e42837bc RW |
145 | #define wait_event_freezable(wq, condition) \ |
146 | ({ \ | |
147 | int __retval; \ | |
24b7ead3 | 148 | for (;;) { \ |
e42837bc RW |
149 | __retval = wait_event_interruptible(wq, \ |
150 | (condition) || freezing(current)); \ | |
24b7ead3 | 151 | if (__retval || (condition)) \ |
e42837bc | 152 | break; \ |
24b7ead3 ON |
153 | try_to_freeze(); \ |
154 | } \ | |
e42837bc RW |
155 | __retval; \ |
156 | }) | |
157 | ||
e42837bc RW |
158 | #define wait_event_freezable_timeout(wq, condition, timeout) \ |
159 | ({ \ | |
160 | long __retval = timeout; \ | |
24b7ead3 | 161 | for (;;) { \ |
e42837bc RW |
162 | __retval = wait_event_interruptible_timeout(wq, \ |
163 | (condition) || freezing(current), \ | |
164 | __retval); \ | |
24b7ead3 ON |
165 | if (__retval <= 0 || (condition)) \ |
166 | break; \ | |
167 | try_to_freeze(); \ | |
168 | } \ | |
e42837bc RW |
169 | __retval; \ |
170 | }) | |
24b7ead3 | 171 | |
8174f150 | 172 | #else /* !CONFIG_FREEZER */ |
948246f7 | 173 | static inline bool frozen(struct task_struct *p) { return false; } |
a3201227 | 174 | static inline bool freezing(struct task_struct *p) { return false; } |
62c9ea6b | 175 | static inline void __thaw_task(struct task_struct *t) {} |
7dfb7103 | 176 | |
8a32c441 | 177 | static inline bool __refrigerator(bool check_kthr_stop) { return false; } |
2aede851 RW |
178 | static inline int freeze_processes(void) { return -ENOSYS; } |
179 | static inline int freeze_kernel_threads(void) { return -ENOSYS; } | |
7dfb7103 NC |
180 | static inline void thaw_processes(void) {} |
181 | ||
a0acae0e | 182 | static inline bool try_to_freeze(void) { return false; } |
7dfb7103 | 183 | |
ba96a0c8 RW |
184 | static inline void freezer_do_not_count(void) {} |
185 | static inline void freezer_count(void) {} | |
186 | static inline int freezer_should_skip(struct task_struct *p) { return 0; } | |
83144186 | 187 | static inline void set_freezable(void) {} |
e42837bc | 188 | |
d310310c JL |
189 | #define freezable_schedule() schedule() |
190 | ||
191 | #define freezable_schedule_timeout_killable(timeout) \ | |
192 | schedule_timeout_killable(timeout) | |
193 | ||
e42837bc RW |
194 | #define wait_event_freezable(wq, condition) \ |
195 | wait_event_interruptible(wq, condition) | |
196 | ||
197 | #define wait_event_freezable_timeout(wq, condition, timeout) \ | |
198 | wait_event_interruptible_timeout(wq, condition, timeout) | |
199 | ||
e0c8ea1a SF |
200 | #define wait_event_freezekillable(wq, condition) \ |
201 | wait_event_killable(wq, condition) | |
202 | ||
8174f150 | 203 | #endif /* !CONFIG_FREEZER */ |
83144186 RW |
204 | |
205 | #endif /* FREEZER_H_INCLUDED */ |