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1da177e4 LT |
1 | #ifndef _LINUX_CPUSET_H |
2 | #define _LINUX_CPUSET_H | |
3 | /* | |
4 | * cpuset interface | |
5 | * | |
6 | * Copyright (C) 2003 BULL SA | |
825a46af | 7 | * Copyright (C) 2004-2006 Silicon Graphics, Inc. |
1da177e4 LT |
8 | * |
9 | */ | |
10 | ||
11 | #include <linux/sched.h> | |
105ab3d8 | 12 | #include <linux/sched/topology.h> |
f719ff9b | 13 | #include <linux/sched/task.h> |
1da177e4 LT |
14 | #include <linux/cpumask.h> |
15 | #include <linux/nodemask.h> | |
a1bc5a4e | 16 | #include <linux/mm.h> |
664eedde | 17 | #include <linux/jump_label.h> |
1da177e4 LT |
18 | |
19 | #ifdef CONFIG_CPUSETS | |
20 | ||
89affbf5 DZ |
21 | /* |
22 | * Static branch rewrites can happen in an arbitrary order for a given | |
23 | * key. In code paths where we need to loop with read_mems_allowed_begin() and | |
24 | * read_mems_allowed_retry() to get a consistent view of mems_allowed, we need | |
25 | * to ensure that begin() always gets rewritten before retry() in the | |
26 | * disabled -> enabled transition. If not, then if local irqs are disabled | |
27 | * around the loop, we can deadlock since retry() would always be | |
28 | * comparing the latest value of the mems_allowed seqcount against 0 as | |
29 | * begin() still would see cpusets_enabled() as false. The enabled -> disabled | |
30 | * transition should happen in reverse order for the same reasons (want to stop | |
31 | * looking at real value of mems_allowed.sequence in retry() first). | |
32 | */ | |
33 | extern struct static_key_false cpusets_pre_enable_key; | |
002f2906 | 34 | extern struct static_key_false cpusets_enabled_key; |
664eedde MG |
35 | static inline bool cpusets_enabled(void) |
36 | { | |
002f2906 | 37 | return static_branch_unlikely(&cpusets_enabled_key); |
664eedde MG |
38 | } |
39 | ||
40 | static inline int nr_cpusets(void) | |
41 | { | |
42 | /* jump label reference count + the top-level cpuset */ | |
002f2906 | 43 | return static_key_count(&cpusets_enabled_key.key) + 1; |
664eedde MG |
44 | } |
45 | ||
46 | static inline void cpuset_inc(void) | |
47 | { | |
89affbf5 | 48 | static_branch_inc(&cpusets_pre_enable_key); |
002f2906 | 49 | static_branch_inc(&cpusets_enabled_key); |
664eedde MG |
50 | } |
51 | ||
52 | static inline void cpuset_dec(void) | |
53 | { | |
002f2906 | 54 | static_branch_dec(&cpusets_enabled_key); |
89affbf5 | 55 | static_branch_dec(&cpusets_pre_enable_key); |
664eedde | 56 | } |
202f72d5 | 57 | |
1da177e4 LT |
58 | extern int cpuset_init(void); |
59 | extern void cpuset_init_smp(void); | |
bcd6860a | 60 | extern void cpuset_force_rebuild(void); |
30e03acd | 61 | extern void cpuset_update_active_cpus(void); |
bcd6860a | 62 | extern void cpuset_wait_for_hotplug(void); |
6af866af | 63 | extern void cpuset_cpus_allowed(struct task_struct *p, struct cpumask *mask); |
2baab4e9 | 64 | extern void cpuset_cpus_allowed_fallback(struct task_struct *p); |
909d75a3 | 65 | extern nodemask_t cpuset_mems_allowed(struct task_struct *p); |
9276b1bc | 66 | #define cpuset_current_mems_allowed (current->mems_allowed) |
1da177e4 | 67 | void cpuset_init_current_mems_allowed(void); |
19770b32 | 68 | int cpuset_nodemask_valid_mems_allowed(nodemask_t *nodemask); |
202f72d5 | 69 | |
002f2906 | 70 | extern bool __cpuset_node_allowed(int node, gfp_t gfp_mask); |
02a0e53d | 71 | |
002f2906 | 72 | static inline bool cpuset_node_allowed(int node, gfp_t gfp_mask) |
02a0e53d | 73 | { |
002f2906 VB |
74 | if (cpusets_enabled()) |
75 | return __cpuset_node_allowed(node, gfp_mask); | |
76 | return true; | |
02a0e53d PJ |
77 | } |
78 | ||
002f2906 | 79 | static inline bool __cpuset_zone_allowed(struct zone *z, gfp_t gfp_mask) |
202f72d5 | 80 | { |
002f2906 VB |
81 | return __cpuset_node_allowed(zone_to_nid(z), gfp_mask); |
82 | } | |
83 | ||
84 | static inline bool cpuset_zone_allowed(struct zone *z, gfp_t gfp_mask) | |
85 | { | |
86 | if (cpusets_enabled()) | |
87 | return __cpuset_zone_allowed(z, gfp_mask); | |
88 | return true; | |
202f72d5 PJ |
89 | } |
90 | ||
bbe373f2 DR |
91 | extern int cpuset_mems_allowed_intersects(const struct task_struct *tsk1, |
92 | const struct task_struct *tsk2); | |
3e0d98b9 PJ |
93 | |
94 | #define cpuset_memory_pressure_bump() \ | |
95 | do { \ | |
96 | if (cpuset_memory_pressure_enabled) \ | |
97 | __cpuset_memory_pressure_bump(); \ | |
98 | } while (0) | |
99 | extern int cpuset_memory_pressure_enabled; | |
100 | extern void __cpuset_memory_pressure_bump(void); | |
101 | ||
df5f8314 EB |
102 | extern void cpuset_task_status_allowed(struct seq_file *m, |
103 | struct task_struct *task); | |
52de4779 ZL |
104 | extern int proc_cpuset_show(struct seq_file *m, struct pid_namespace *ns, |
105 | struct pid *pid, struct task_struct *tsk); | |
1da177e4 | 106 | |
825a46af | 107 | extern int cpuset_mem_spread_node(void); |
6adef3eb | 108 | extern int cpuset_slab_spread_node(void); |
825a46af PJ |
109 | |
110 | static inline int cpuset_do_page_mem_spread(void) | |
111 | { | |
2ad654bc | 112 | return task_spread_page(current); |
825a46af PJ |
113 | } |
114 | ||
115 | static inline int cpuset_do_slab_mem_spread(void) | |
116 | { | |
2ad654bc | 117 | return task_spread_slab(current); |
825a46af PJ |
118 | } |
119 | ||
8793d854 PM |
120 | extern int current_cpuset_is_being_rebound(void); |
121 | ||
e761b772 MK |
122 | extern void rebuild_sched_domains(void); |
123 | ||
da39da3a | 124 | extern void cpuset_print_current_mems_allowed(void); |
75aa1994 | 125 | |
c0ff7453 | 126 | /* |
d26914d1 MG |
127 | * read_mems_allowed_begin is required when making decisions involving |
128 | * mems_allowed such as during page allocation. mems_allowed can be updated in | |
129 | * parallel and depending on the new value an operation can fail potentially | |
130 | * causing process failure. A retry loop with read_mems_allowed_begin and | |
131 | * read_mems_allowed_retry prevents these artificial failures. | |
c0ff7453 | 132 | */ |
d26914d1 | 133 | static inline unsigned int read_mems_allowed_begin(void) |
c0ff7453 | 134 | { |
89affbf5 | 135 | if (!static_branch_unlikely(&cpusets_pre_enable_key)) |
46e700ab MG |
136 | return 0; |
137 | ||
cc9a6c87 | 138 | return read_seqcount_begin(¤t->mems_allowed_seq); |
c0ff7453 MX |
139 | } |
140 | ||
cc9a6c87 | 141 | /* |
d26914d1 MG |
142 | * If this returns true, the operation that took place after |
143 | * read_mems_allowed_begin may have failed artificially due to a concurrent | |
144 | * update of mems_allowed. It is up to the caller to retry the operation if | |
cc9a6c87 MG |
145 | * appropriate. |
146 | */ | |
d26914d1 | 147 | static inline bool read_mems_allowed_retry(unsigned int seq) |
c0ff7453 | 148 | { |
89affbf5 | 149 | if (!static_branch_unlikely(&cpusets_enabled_key)) |
46e700ab MG |
150 | return false; |
151 | ||
d26914d1 | 152 | return read_seqcount_retry(¤t->mems_allowed_seq, seq); |
c0ff7453 MX |
153 | } |
154 | ||
58568d2a MX |
155 | static inline void set_mems_allowed(nodemask_t nodemask) |
156 | { | |
db751fe3 JS |
157 | unsigned long flags; |
158 | ||
c0ff7453 | 159 | task_lock(current); |
db751fe3 | 160 | local_irq_save(flags); |
cc9a6c87 | 161 | write_seqcount_begin(¤t->mems_allowed_seq); |
58568d2a | 162 | current->mems_allowed = nodemask; |
cc9a6c87 | 163 | write_seqcount_end(¤t->mems_allowed_seq); |
db751fe3 | 164 | local_irq_restore(flags); |
c0ff7453 | 165 | task_unlock(current); |
58568d2a MX |
166 | } |
167 | ||
1da177e4 LT |
168 | #else /* !CONFIG_CPUSETS */ |
169 | ||
664eedde MG |
170 | static inline bool cpusets_enabled(void) { return false; } |
171 | ||
1da177e4 LT |
172 | static inline int cpuset_init(void) { return 0; } |
173 | static inline void cpuset_init_smp(void) {} | |
1da177e4 | 174 | |
bcd6860a PZ |
175 | static inline void cpuset_force_rebuild(void) { } |
176 | ||
30e03acd | 177 | static inline void cpuset_update_active_cpus(void) |
3a101d05 TH |
178 | { |
179 | partition_sched_domains(1, NULL, NULL); | |
180 | } | |
181 | ||
bcd6860a PZ |
182 | static inline void cpuset_wait_for_hotplug(void) { } |
183 | ||
6af866af LZ |
184 | static inline void cpuset_cpus_allowed(struct task_struct *p, |
185 | struct cpumask *mask) | |
1da177e4 | 186 | { |
aa85ea5b | 187 | cpumask_copy(mask, cpu_possible_mask); |
1da177e4 LT |
188 | } |
189 | ||
2baab4e9 | 190 | static inline void cpuset_cpus_allowed_fallback(struct task_struct *p) |
9084bb82 | 191 | { |
9084bb82 ON |
192 | } |
193 | ||
909d75a3 PJ |
194 | static inline nodemask_t cpuset_mems_allowed(struct task_struct *p) |
195 | { | |
196 | return node_possible_map; | |
197 | } | |
198 | ||
38d7bee9 | 199 | #define cpuset_current_mems_allowed (node_states[N_MEMORY]) |
1da177e4 | 200 | static inline void cpuset_init_current_mems_allowed(void) {} |
1da177e4 | 201 | |
19770b32 | 202 | static inline int cpuset_nodemask_valid_mems_allowed(nodemask_t *nodemask) |
1da177e4 LT |
203 | { |
204 | return 1; | |
205 | } | |
206 | ||
002f2906 | 207 | static inline bool cpuset_node_allowed(int node, gfp_t gfp_mask) |
02a0e53d | 208 | { |
002f2906 | 209 | return true; |
02a0e53d PJ |
210 | } |
211 | ||
002f2906 | 212 | static inline bool __cpuset_zone_allowed(struct zone *z, gfp_t gfp_mask) |
1da177e4 | 213 | { |
002f2906 VB |
214 | return true; |
215 | } | |
216 | ||
217 | static inline bool cpuset_zone_allowed(struct zone *z, gfp_t gfp_mask) | |
218 | { | |
219 | return true; | |
1da177e4 LT |
220 | } |
221 | ||
bbe373f2 DR |
222 | static inline int cpuset_mems_allowed_intersects(const struct task_struct *tsk1, |
223 | const struct task_struct *tsk2) | |
ef08e3b4 PJ |
224 | { |
225 | return 1; | |
226 | } | |
227 | ||
3e0d98b9 PJ |
228 | static inline void cpuset_memory_pressure_bump(void) {} |
229 | ||
df5f8314 EB |
230 | static inline void cpuset_task_status_allowed(struct seq_file *m, |
231 | struct task_struct *task) | |
1da177e4 | 232 | { |
1da177e4 LT |
233 | } |
234 | ||
825a46af PJ |
235 | static inline int cpuset_mem_spread_node(void) |
236 | { | |
237 | return 0; | |
238 | } | |
239 | ||
6adef3eb JS |
240 | static inline int cpuset_slab_spread_node(void) |
241 | { | |
242 | return 0; | |
243 | } | |
244 | ||
825a46af PJ |
245 | static inline int cpuset_do_page_mem_spread(void) |
246 | { | |
247 | return 0; | |
248 | } | |
249 | ||
250 | static inline int cpuset_do_slab_mem_spread(void) | |
251 | { | |
252 | return 0; | |
253 | } | |
254 | ||
8793d854 PM |
255 | static inline int current_cpuset_is_being_rebound(void) |
256 | { | |
257 | return 0; | |
258 | } | |
259 | ||
e761b772 MK |
260 | static inline void rebuild_sched_domains(void) |
261 | { | |
dfb512ec | 262 | partition_sched_domains(1, NULL, NULL); |
e761b772 MK |
263 | } |
264 | ||
da39da3a | 265 | static inline void cpuset_print_current_mems_allowed(void) |
75aa1994 DR |
266 | { |
267 | } | |
268 | ||
58568d2a MX |
269 | static inline void set_mems_allowed(nodemask_t nodemask) |
270 | { | |
271 | } | |
272 | ||
d26914d1 | 273 | static inline unsigned int read_mems_allowed_begin(void) |
c0ff7453 | 274 | { |
cc9a6c87 | 275 | return 0; |
c0ff7453 MX |
276 | } |
277 | ||
d26914d1 | 278 | static inline bool read_mems_allowed_retry(unsigned int seq) |
c0ff7453 | 279 | { |
d26914d1 | 280 | return false; |
c0ff7453 MX |
281 | } |
282 | ||
1da177e4 LT |
283 | #endif /* !CONFIG_CPUSETS */ |
284 | ||
285 | #endif /* _LINUX_CPUSET_H */ |