]>
Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * kernel/cpuset.c | |
3 | * | |
4 | * Processor and Memory placement constraints for sets of tasks. | |
5 | * | |
6 | * Copyright (C) 2003 BULL SA. | |
029190c5 | 7 | * Copyright (C) 2004-2007 Silicon Graphics, Inc. |
8793d854 | 8 | * Copyright (C) 2006 Google, Inc |
1da177e4 LT |
9 | * |
10 | * Portions derived from Patrick Mochel's sysfs code. | |
11 | * sysfs is Copyright (c) 2001-3 Patrick Mochel | |
1da177e4 | 12 | * |
825a46af | 13 | * 2003-10-10 Written by Simon Derr. |
1da177e4 | 14 | * 2003-10-22 Updates by Stephen Hemminger. |
825a46af | 15 | * 2004 May-July Rework by Paul Jackson. |
8793d854 | 16 | * 2006 Rework by Paul Menage to use generic cgroups |
cf417141 MK |
17 | * 2008 Rework of the scheduler domains and CPU hotplug handling |
18 | * by Max Krasnyansky | |
1da177e4 LT |
19 | * |
20 | * This file is subject to the terms and conditions of the GNU General Public | |
21 | * License. See the file COPYING in the main directory of the Linux | |
22 | * distribution for more details. | |
23 | */ | |
24 | ||
1da177e4 LT |
25 | #include <linux/cpu.h> |
26 | #include <linux/cpumask.h> | |
27 | #include <linux/cpuset.h> | |
28 | #include <linux/err.h> | |
29 | #include <linux/errno.h> | |
30 | #include <linux/file.h> | |
31 | #include <linux/fs.h> | |
32 | #include <linux/init.h> | |
33 | #include <linux/interrupt.h> | |
34 | #include <linux/kernel.h> | |
35 | #include <linux/kmod.h> | |
36 | #include <linux/list.h> | |
68860ec1 | 37 | #include <linux/mempolicy.h> |
1da177e4 | 38 | #include <linux/mm.h> |
f481891f | 39 | #include <linux/memory.h> |
9984de1a | 40 | #include <linux/export.h> |
1da177e4 LT |
41 | #include <linux/mount.h> |
42 | #include <linux/namei.h> | |
43 | #include <linux/pagemap.h> | |
44 | #include <linux/proc_fs.h> | |
6b9c2603 | 45 | #include <linux/rcupdate.h> |
1da177e4 LT |
46 | #include <linux/sched.h> |
47 | #include <linux/seq_file.h> | |
22fb52dd | 48 | #include <linux/security.h> |
1da177e4 | 49 | #include <linux/slab.h> |
1da177e4 LT |
50 | #include <linux/spinlock.h> |
51 | #include <linux/stat.h> | |
52 | #include <linux/string.h> | |
53 | #include <linux/time.h> | |
54 | #include <linux/backing-dev.h> | |
55 | #include <linux/sort.h> | |
56 | ||
57 | #include <asm/uaccess.h> | |
60063497 | 58 | #include <linux/atomic.h> |
3d3f26a7 | 59 | #include <linux/mutex.h> |
956db3ca CW |
60 | #include <linux/workqueue.h> |
61 | #include <linux/cgroup.h> | |
1da177e4 | 62 | |
202f72d5 PJ |
63 | /* |
64 | * Tracks how many cpusets are currently defined in system. | |
65 | * When there is only one cpuset (the root cpuset) we can | |
66 | * short circuit some hooks. | |
67 | */ | |
7edc5962 | 68 | int number_of_cpusets __read_mostly; |
202f72d5 | 69 | |
2df167a3 | 70 | /* Forward declare cgroup structures */ |
8793d854 PM |
71 | struct cgroup_subsys cpuset_subsys; |
72 | struct cpuset; | |
73 | ||
3e0d98b9 PJ |
74 | /* See "Frequency meter" comments, below. */ |
75 | ||
76 | struct fmeter { | |
77 | int cnt; /* unprocessed events count */ | |
78 | int val; /* most recent output value */ | |
79 | time_t time; /* clock (secs) when val computed */ | |
80 | spinlock_t lock; /* guards read or write of above */ | |
81 | }; | |
82 | ||
1da177e4 | 83 | struct cpuset { |
8793d854 PM |
84 | struct cgroup_subsys_state css; |
85 | ||
1da177e4 | 86 | unsigned long flags; /* "unsigned long" so bitops work */ |
300ed6cb | 87 | cpumask_var_t cpus_allowed; /* CPUs allowed to tasks in cpuset */ |
1da177e4 LT |
88 | nodemask_t mems_allowed; /* Memory Nodes allowed to tasks */ |
89 | ||
1da177e4 | 90 | struct cpuset *parent; /* my parent */ |
1da177e4 | 91 | |
3e0d98b9 | 92 | struct fmeter fmeter; /* memory_pressure filter */ |
029190c5 PJ |
93 | |
94 | /* partition number for rebuild_sched_domains() */ | |
95 | int pn; | |
956db3ca | 96 | |
1d3504fc HS |
97 | /* for custom sched domain */ |
98 | int relax_domain_level; | |
99 | ||
732bee7a | 100 | /* used for walking a cpuset hierarchy */ |
956db3ca | 101 | struct list_head stack_list; |
1da177e4 LT |
102 | }; |
103 | ||
8793d854 PM |
104 | /* Retrieve the cpuset for a cgroup */ |
105 | static inline struct cpuset *cgroup_cs(struct cgroup *cont) | |
106 | { | |
107 | return container_of(cgroup_subsys_state(cont, cpuset_subsys_id), | |
108 | struct cpuset, css); | |
109 | } | |
110 | ||
111 | /* Retrieve the cpuset for a task */ | |
112 | static inline struct cpuset *task_cs(struct task_struct *task) | |
113 | { | |
114 | return container_of(task_subsys_state(task, cpuset_subsys_id), | |
115 | struct cpuset, css); | |
116 | } | |
8793d854 | 117 | |
b246272e DR |
118 | #ifdef CONFIG_NUMA |
119 | static inline bool task_has_mempolicy(struct task_struct *task) | |
120 | { | |
121 | return task->mempolicy; | |
122 | } | |
123 | #else | |
124 | static inline bool task_has_mempolicy(struct task_struct *task) | |
125 | { | |
126 | return false; | |
127 | } | |
128 | #endif | |
129 | ||
130 | ||
1da177e4 LT |
131 | /* bits in struct cpuset flags field */ |
132 | typedef enum { | |
efeb77b2 | 133 | CS_ONLINE, |
1da177e4 LT |
134 | CS_CPU_EXCLUSIVE, |
135 | CS_MEM_EXCLUSIVE, | |
78608366 | 136 | CS_MEM_HARDWALL, |
45b07ef3 | 137 | CS_MEMORY_MIGRATE, |
029190c5 | 138 | CS_SCHED_LOAD_BALANCE, |
825a46af PJ |
139 | CS_SPREAD_PAGE, |
140 | CS_SPREAD_SLAB, | |
1da177e4 LT |
141 | } cpuset_flagbits_t; |
142 | ||
143 | /* convenient tests for these bits */ | |
efeb77b2 TH |
144 | static inline bool is_cpuset_online(const struct cpuset *cs) |
145 | { | |
146 | return test_bit(CS_ONLINE, &cs->flags); | |
147 | } | |
148 | ||
1da177e4 LT |
149 | static inline int is_cpu_exclusive(const struct cpuset *cs) |
150 | { | |
7b5b9ef0 | 151 | return test_bit(CS_CPU_EXCLUSIVE, &cs->flags); |
1da177e4 LT |
152 | } |
153 | ||
154 | static inline int is_mem_exclusive(const struct cpuset *cs) | |
155 | { | |
7b5b9ef0 | 156 | return test_bit(CS_MEM_EXCLUSIVE, &cs->flags); |
1da177e4 LT |
157 | } |
158 | ||
78608366 PM |
159 | static inline int is_mem_hardwall(const struct cpuset *cs) |
160 | { | |
161 | return test_bit(CS_MEM_HARDWALL, &cs->flags); | |
162 | } | |
163 | ||
029190c5 PJ |
164 | static inline int is_sched_load_balance(const struct cpuset *cs) |
165 | { | |
166 | return test_bit(CS_SCHED_LOAD_BALANCE, &cs->flags); | |
167 | } | |
168 | ||
45b07ef3 PJ |
169 | static inline int is_memory_migrate(const struct cpuset *cs) |
170 | { | |
7b5b9ef0 | 171 | return test_bit(CS_MEMORY_MIGRATE, &cs->flags); |
45b07ef3 PJ |
172 | } |
173 | ||
825a46af PJ |
174 | static inline int is_spread_page(const struct cpuset *cs) |
175 | { | |
176 | return test_bit(CS_SPREAD_PAGE, &cs->flags); | |
177 | } | |
178 | ||
179 | static inline int is_spread_slab(const struct cpuset *cs) | |
180 | { | |
181 | return test_bit(CS_SPREAD_SLAB, &cs->flags); | |
182 | } | |
183 | ||
1da177e4 | 184 | static struct cpuset top_cpuset = { |
efeb77b2 TH |
185 | .flags = ((1 << CS_ONLINE) | (1 << CS_CPU_EXCLUSIVE) | |
186 | (1 << CS_MEM_EXCLUSIVE)), | |
1da177e4 LT |
187 | }; |
188 | ||
ae8086ce TH |
189 | /** |
190 | * cpuset_for_each_child - traverse online children of a cpuset | |
191 | * @child_cs: loop cursor pointing to the current child | |
192 | * @pos_cgrp: used for iteration | |
193 | * @parent_cs: target cpuset to walk children of | |
194 | * | |
195 | * Walk @child_cs through the online children of @parent_cs. Must be used | |
196 | * with RCU read locked. | |
197 | */ | |
198 | #define cpuset_for_each_child(child_cs, pos_cgrp, parent_cs) \ | |
199 | cgroup_for_each_child((pos_cgrp), (parent_cs)->css.cgroup) \ | |
200 | if (is_cpuset_online(((child_cs) = cgroup_cs((pos_cgrp))))) | |
201 | ||
1da177e4 | 202 | /* |
2df167a3 PM |
203 | * There are two global mutexes guarding cpuset structures. The first |
204 | * is the main control groups cgroup_mutex, accessed via | |
205 | * cgroup_lock()/cgroup_unlock(). The second is the cpuset-specific | |
206 | * callback_mutex, below. They can nest. It is ok to first take | |
207 | * cgroup_mutex, then nest callback_mutex. We also require taking | |
208 | * task_lock() when dereferencing a task's cpuset pointer. See "The | |
209 | * task_lock() exception", at the end of this comment. | |
053199ed | 210 | * |
3d3f26a7 | 211 | * A task must hold both mutexes to modify cpusets. If a task |
2df167a3 | 212 | * holds cgroup_mutex, then it blocks others wanting that mutex, |
3d3f26a7 | 213 | * ensuring that it is the only task able to also acquire callback_mutex |
053199ed PJ |
214 | * and be able to modify cpusets. It can perform various checks on |
215 | * the cpuset structure first, knowing nothing will change. It can | |
2df167a3 | 216 | * also allocate memory while just holding cgroup_mutex. While it is |
053199ed | 217 | * performing these checks, various callback routines can briefly |
3d3f26a7 IM |
218 | * acquire callback_mutex to query cpusets. Once it is ready to make |
219 | * the changes, it takes callback_mutex, blocking everyone else. | |
053199ed PJ |
220 | * |
221 | * Calls to the kernel memory allocator can not be made while holding | |
3d3f26a7 | 222 | * callback_mutex, as that would risk double tripping on callback_mutex |
053199ed PJ |
223 | * from one of the callbacks into the cpuset code from within |
224 | * __alloc_pages(). | |
225 | * | |
3d3f26a7 | 226 | * If a task is only holding callback_mutex, then it has read-only |
053199ed PJ |
227 | * access to cpusets. |
228 | * | |
58568d2a MX |
229 | * Now, the task_struct fields mems_allowed and mempolicy may be changed |
230 | * by other task, we use alloc_lock in the task_struct fields to protect | |
231 | * them. | |
053199ed | 232 | * |
3d3f26a7 | 233 | * The cpuset_common_file_read() handlers only hold callback_mutex across |
053199ed PJ |
234 | * small pieces of code, such as when reading out possibly multi-word |
235 | * cpumasks and nodemasks. | |
236 | * | |
2df167a3 PM |
237 | * Accessing a task's cpuset should be done in accordance with the |
238 | * guidelines for accessing subsystem state in kernel/cgroup.c | |
1da177e4 LT |
239 | */ |
240 | ||
3d3f26a7 | 241 | static DEFINE_MUTEX(callback_mutex); |
4247bdc6 | 242 | |
75aa1994 DR |
243 | /* |
244 | * cpuset_buffer_lock protects both the cpuset_name and cpuset_nodelist | |
245 | * buffers. They are statically allocated to prevent using excess stack | |
246 | * when calling cpuset_print_task_mems_allowed(). | |
247 | */ | |
248 | #define CPUSET_NAME_LEN (128) | |
249 | #define CPUSET_NODELIST_LEN (256) | |
250 | static char cpuset_name[CPUSET_NAME_LEN]; | |
251 | static char cpuset_nodelist[CPUSET_NODELIST_LEN]; | |
252 | static DEFINE_SPINLOCK(cpuset_buffer_lock); | |
253 | ||
3a5a6d0c TH |
254 | /* |
255 | * CPU / memory hotplug is handled asynchronously. | |
256 | */ | |
257 | static void cpuset_hotplug_workfn(struct work_struct *work); | |
258 | ||
259 | static DECLARE_WORK(cpuset_hotplug_work, cpuset_hotplug_workfn); | |
260 | ||
cf417141 MK |
261 | /* |
262 | * This is ugly, but preserves the userspace API for existing cpuset | |
8793d854 | 263 | * users. If someone tries to mount the "cpuset" filesystem, we |
cf417141 MK |
264 | * silently switch it to mount "cgroup" instead |
265 | */ | |
f7e83571 AV |
266 | static struct dentry *cpuset_mount(struct file_system_type *fs_type, |
267 | int flags, const char *unused_dev_name, void *data) | |
1da177e4 | 268 | { |
8793d854 | 269 | struct file_system_type *cgroup_fs = get_fs_type("cgroup"); |
f7e83571 | 270 | struct dentry *ret = ERR_PTR(-ENODEV); |
8793d854 PM |
271 | if (cgroup_fs) { |
272 | char mountopts[] = | |
273 | "cpuset,noprefix," | |
274 | "release_agent=/sbin/cpuset_release_agent"; | |
f7e83571 AV |
275 | ret = cgroup_fs->mount(cgroup_fs, flags, |
276 | unused_dev_name, mountopts); | |
8793d854 PM |
277 | put_filesystem(cgroup_fs); |
278 | } | |
279 | return ret; | |
1da177e4 LT |
280 | } |
281 | ||
282 | static struct file_system_type cpuset_fs_type = { | |
283 | .name = "cpuset", | |
f7e83571 | 284 | .mount = cpuset_mount, |
1da177e4 LT |
285 | }; |
286 | ||
1da177e4 | 287 | /* |
300ed6cb | 288 | * Return in pmask the portion of a cpusets's cpus_allowed that |
1da177e4 LT |
289 | * are online. If none are online, walk up the cpuset hierarchy |
290 | * until we find one that does have some online cpus. If we get | |
291 | * all the way to the top and still haven't found any online cpus, | |
5f054e31 RR |
292 | * return cpu_online_mask. Or if passed a NULL cs from an exit'ing |
293 | * task, return cpu_online_mask. | |
1da177e4 LT |
294 | * |
295 | * One way or another, we guarantee to return some non-empty subset | |
5f054e31 | 296 | * of cpu_online_mask. |
1da177e4 | 297 | * |
3d3f26a7 | 298 | * Call with callback_mutex held. |
1da177e4 LT |
299 | */ |
300 | ||
6af866af LZ |
301 | static void guarantee_online_cpus(const struct cpuset *cs, |
302 | struct cpumask *pmask) | |
1da177e4 | 303 | { |
300ed6cb | 304 | while (cs && !cpumask_intersects(cs->cpus_allowed, cpu_online_mask)) |
1da177e4 LT |
305 | cs = cs->parent; |
306 | if (cs) | |
300ed6cb | 307 | cpumask_and(pmask, cs->cpus_allowed, cpu_online_mask); |
1da177e4 | 308 | else |
300ed6cb LZ |
309 | cpumask_copy(pmask, cpu_online_mask); |
310 | BUG_ON(!cpumask_intersects(pmask, cpu_online_mask)); | |
1da177e4 LT |
311 | } |
312 | ||
313 | /* | |
314 | * Return in *pmask the portion of a cpusets's mems_allowed that | |
0e1e7c7a CL |
315 | * are online, with memory. If none are online with memory, walk |
316 | * up the cpuset hierarchy until we find one that does have some | |
317 | * online mems. If we get all the way to the top and still haven't | |
38d7bee9 | 318 | * found any online mems, return node_states[N_MEMORY]. |
1da177e4 LT |
319 | * |
320 | * One way or another, we guarantee to return some non-empty subset | |
38d7bee9 | 321 | * of node_states[N_MEMORY]. |
1da177e4 | 322 | * |
3d3f26a7 | 323 | * Call with callback_mutex held. |
1da177e4 LT |
324 | */ |
325 | ||
326 | static void guarantee_online_mems(const struct cpuset *cs, nodemask_t *pmask) | |
327 | { | |
0e1e7c7a | 328 | while (cs && !nodes_intersects(cs->mems_allowed, |
38d7bee9 | 329 | node_states[N_MEMORY])) |
1da177e4 LT |
330 | cs = cs->parent; |
331 | if (cs) | |
0e1e7c7a | 332 | nodes_and(*pmask, cs->mems_allowed, |
38d7bee9 | 333 | node_states[N_MEMORY]); |
1da177e4 | 334 | else |
38d7bee9 LJ |
335 | *pmask = node_states[N_MEMORY]; |
336 | BUG_ON(!nodes_intersects(*pmask, node_states[N_MEMORY])); | |
1da177e4 LT |
337 | } |
338 | ||
f3b39d47 MX |
339 | /* |
340 | * update task's spread flag if cpuset's page/slab spread flag is set | |
341 | * | |
342 | * Called with callback_mutex/cgroup_mutex held | |
343 | */ | |
344 | static void cpuset_update_task_spread_flag(struct cpuset *cs, | |
345 | struct task_struct *tsk) | |
346 | { | |
347 | if (is_spread_page(cs)) | |
348 | tsk->flags |= PF_SPREAD_PAGE; | |
349 | else | |
350 | tsk->flags &= ~PF_SPREAD_PAGE; | |
351 | if (is_spread_slab(cs)) | |
352 | tsk->flags |= PF_SPREAD_SLAB; | |
353 | else | |
354 | tsk->flags &= ~PF_SPREAD_SLAB; | |
355 | } | |
356 | ||
1da177e4 LT |
357 | /* |
358 | * is_cpuset_subset(p, q) - Is cpuset p a subset of cpuset q? | |
359 | * | |
360 | * One cpuset is a subset of another if all its allowed CPUs and | |
361 | * Memory Nodes are a subset of the other, and its exclusive flags | |
2df167a3 | 362 | * are only set if the other's are set. Call holding cgroup_mutex. |
1da177e4 LT |
363 | */ |
364 | ||
365 | static int is_cpuset_subset(const struct cpuset *p, const struct cpuset *q) | |
366 | { | |
300ed6cb | 367 | return cpumask_subset(p->cpus_allowed, q->cpus_allowed) && |
1da177e4 LT |
368 | nodes_subset(p->mems_allowed, q->mems_allowed) && |
369 | is_cpu_exclusive(p) <= is_cpu_exclusive(q) && | |
370 | is_mem_exclusive(p) <= is_mem_exclusive(q); | |
371 | } | |
372 | ||
645fcc9d LZ |
373 | /** |
374 | * alloc_trial_cpuset - allocate a trial cpuset | |
375 | * @cs: the cpuset that the trial cpuset duplicates | |
376 | */ | |
377 | static struct cpuset *alloc_trial_cpuset(const struct cpuset *cs) | |
378 | { | |
300ed6cb LZ |
379 | struct cpuset *trial; |
380 | ||
381 | trial = kmemdup(cs, sizeof(*cs), GFP_KERNEL); | |
382 | if (!trial) | |
383 | return NULL; | |
384 | ||
385 | if (!alloc_cpumask_var(&trial->cpus_allowed, GFP_KERNEL)) { | |
386 | kfree(trial); | |
387 | return NULL; | |
388 | } | |
389 | cpumask_copy(trial->cpus_allowed, cs->cpus_allowed); | |
390 | ||
391 | return trial; | |
645fcc9d LZ |
392 | } |
393 | ||
394 | /** | |
395 | * free_trial_cpuset - free the trial cpuset | |
396 | * @trial: the trial cpuset to be freed | |
397 | */ | |
398 | static void free_trial_cpuset(struct cpuset *trial) | |
399 | { | |
300ed6cb | 400 | free_cpumask_var(trial->cpus_allowed); |
645fcc9d LZ |
401 | kfree(trial); |
402 | } | |
403 | ||
1da177e4 LT |
404 | /* |
405 | * validate_change() - Used to validate that any proposed cpuset change | |
406 | * follows the structural rules for cpusets. | |
407 | * | |
408 | * If we replaced the flag and mask values of the current cpuset | |
409 | * (cur) with those values in the trial cpuset (trial), would | |
410 | * our various subset and exclusive rules still be valid? Presumes | |
2df167a3 | 411 | * cgroup_mutex held. |
1da177e4 LT |
412 | * |
413 | * 'cur' is the address of an actual, in-use cpuset. Operations | |
414 | * such as list traversal that depend on the actual address of the | |
415 | * cpuset in the list must use cur below, not trial. | |
416 | * | |
417 | * 'trial' is the address of bulk structure copy of cur, with | |
418 | * perhaps one or more of the fields cpus_allowed, mems_allowed, | |
419 | * or flags changed to new, trial values. | |
420 | * | |
421 | * Return 0 if valid, -errno if not. | |
422 | */ | |
423 | ||
424 | static int validate_change(const struct cpuset *cur, const struct cpuset *trial) | |
425 | { | |
8793d854 | 426 | struct cgroup *cont; |
1da177e4 | 427 | struct cpuset *c, *par; |
ae8086ce TH |
428 | int ret; |
429 | ||
430 | rcu_read_lock(); | |
1da177e4 LT |
431 | |
432 | /* Each of our child cpusets must be a subset of us */ | |
ae8086ce TH |
433 | ret = -EBUSY; |
434 | cpuset_for_each_child(c, cont, cur) | |
435 | if (!is_cpuset_subset(c, trial)) | |
436 | goto out; | |
1da177e4 LT |
437 | |
438 | /* Remaining checks don't apply to root cpuset */ | |
ae8086ce | 439 | ret = 0; |
69604067 | 440 | if (cur == &top_cpuset) |
ae8086ce | 441 | goto out; |
1da177e4 | 442 | |
69604067 PJ |
443 | par = cur->parent; |
444 | ||
1da177e4 | 445 | /* We must be a subset of our parent cpuset */ |
ae8086ce | 446 | ret = -EACCES; |
1da177e4 | 447 | if (!is_cpuset_subset(trial, par)) |
ae8086ce | 448 | goto out; |
1da177e4 | 449 | |
2df167a3 PM |
450 | /* |
451 | * If either I or some sibling (!= me) is exclusive, we can't | |
452 | * overlap | |
453 | */ | |
ae8086ce TH |
454 | ret = -EINVAL; |
455 | cpuset_for_each_child(c, cont, par) { | |
1da177e4 LT |
456 | if ((is_cpu_exclusive(trial) || is_cpu_exclusive(c)) && |
457 | c != cur && | |
300ed6cb | 458 | cpumask_intersects(trial->cpus_allowed, c->cpus_allowed)) |
ae8086ce | 459 | goto out; |
1da177e4 LT |
460 | if ((is_mem_exclusive(trial) || is_mem_exclusive(c)) && |
461 | c != cur && | |
462 | nodes_intersects(trial->mems_allowed, c->mems_allowed)) | |
ae8086ce | 463 | goto out; |
1da177e4 LT |
464 | } |
465 | ||
020958b6 | 466 | /* Cpusets with tasks can't have empty cpus_allowed or mems_allowed */ |
ae8086ce TH |
467 | ret = -ENOSPC; |
468 | if (cgroup_task_count(cur->css.cgroup) && | |
469 | (cpumask_empty(trial->cpus_allowed) || | |
470 | nodes_empty(trial->mems_allowed))) | |
471 | goto out; | |
020958b6 | 472 | |
ae8086ce TH |
473 | ret = 0; |
474 | out: | |
475 | rcu_read_unlock(); | |
476 | return ret; | |
1da177e4 LT |
477 | } |
478 | ||
db7f47cf | 479 | #ifdef CONFIG_SMP |
029190c5 | 480 | /* |
cf417141 | 481 | * Helper routine for generate_sched_domains(). |
029190c5 PJ |
482 | * Do cpusets a, b have overlapping cpus_allowed masks? |
483 | */ | |
029190c5 PJ |
484 | static int cpusets_overlap(struct cpuset *a, struct cpuset *b) |
485 | { | |
300ed6cb | 486 | return cpumask_intersects(a->cpus_allowed, b->cpus_allowed); |
029190c5 PJ |
487 | } |
488 | ||
1d3504fc HS |
489 | static void |
490 | update_domain_attr(struct sched_domain_attr *dattr, struct cpuset *c) | |
491 | { | |
1d3504fc HS |
492 | if (dattr->relax_domain_level < c->relax_domain_level) |
493 | dattr->relax_domain_level = c->relax_domain_level; | |
494 | return; | |
495 | } | |
496 | ||
f5393693 LJ |
497 | static void |
498 | update_domain_attr_tree(struct sched_domain_attr *dattr, struct cpuset *c) | |
499 | { | |
500 | LIST_HEAD(q); | |
501 | ||
502 | list_add(&c->stack_list, &q); | |
503 | while (!list_empty(&q)) { | |
504 | struct cpuset *cp; | |
505 | struct cgroup *cont; | |
506 | struct cpuset *child; | |
507 | ||
508 | cp = list_first_entry(&q, struct cpuset, stack_list); | |
509 | list_del(q.next); | |
510 | ||
300ed6cb | 511 | if (cpumask_empty(cp->cpus_allowed)) |
f5393693 LJ |
512 | continue; |
513 | ||
514 | if (is_sched_load_balance(cp)) | |
515 | update_domain_attr(dattr, cp); | |
516 | ||
ae8086ce TH |
517 | rcu_read_lock(); |
518 | cpuset_for_each_child(child, cont, cp) | |
f5393693 | 519 | list_add_tail(&child->stack_list, &q); |
ae8086ce | 520 | rcu_read_unlock(); |
f5393693 LJ |
521 | } |
522 | } | |
523 | ||
029190c5 | 524 | /* |
cf417141 MK |
525 | * generate_sched_domains() |
526 | * | |
527 | * This function builds a partial partition of the systems CPUs | |
528 | * A 'partial partition' is a set of non-overlapping subsets whose | |
529 | * union is a subset of that set. | |
530 | * The output of this function needs to be passed to kernel/sched.c | |
531 | * partition_sched_domains() routine, which will rebuild the scheduler's | |
532 | * load balancing domains (sched domains) as specified by that partial | |
533 | * partition. | |
029190c5 | 534 | * |
45ce80fb | 535 | * See "What is sched_load_balance" in Documentation/cgroups/cpusets.txt |
029190c5 PJ |
536 | * for a background explanation of this. |
537 | * | |
538 | * Does not return errors, on the theory that the callers of this | |
539 | * routine would rather not worry about failures to rebuild sched | |
540 | * domains when operating in the severe memory shortage situations | |
541 | * that could cause allocation failures below. | |
542 | * | |
cf417141 | 543 | * Must be called with cgroup_lock held. |
029190c5 PJ |
544 | * |
545 | * The three key local variables below are: | |
aeed6824 | 546 | * q - a linked-list queue of cpuset pointers, used to implement a |
029190c5 PJ |
547 | * top-down scan of all cpusets. This scan loads a pointer |
548 | * to each cpuset marked is_sched_load_balance into the | |
549 | * array 'csa'. For our purposes, rebuilding the schedulers | |
550 | * sched domains, we can ignore !is_sched_load_balance cpusets. | |
551 | * csa - (for CpuSet Array) Array of pointers to all the cpusets | |
552 | * that need to be load balanced, for convenient iterative | |
553 | * access by the subsequent code that finds the best partition, | |
554 | * i.e the set of domains (subsets) of CPUs such that the | |
555 | * cpus_allowed of every cpuset marked is_sched_load_balance | |
556 | * is a subset of one of these domains, while there are as | |
557 | * many such domains as possible, each as small as possible. | |
558 | * doms - Conversion of 'csa' to an array of cpumasks, for passing to | |
559 | * the kernel/sched.c routine partition_sched_domains() in a | |
560 | * convenient format, that can be easily compared to the prior | |
561 | * value to determine what partition elements (sched domains) | |
562 | * were changed (added or removed.) | |
563 | * | |
564 | * Finding the best partition (set of domains): | |
565 | * The triple nested loops below over i, j, k scan over the | |
566 | * load balanced cpusets (using the array of cpuset pointers in | |
567 | * csa[]) looking for pairs of cpusets that have overlapping | |
568 | * cpus_allowed, but which don't have the same 'pn' partition | |
569 | * number and gives them in the same partition number. It keeps | |
570 | * looping on the 'restart' label until it can no longer find | |
571 | * any such pairs. | |
572 | * | |
573 | * The union of the cpus_allowed masks from the set of | |
574 | * all cpusets having the same 'pn' value then form the one | |
575 | * element of the partition (one sched domain) to be passed to | |
576 | * partition_sched_domains(). | |
577 | */ | |
acc3f5d7 | 578 | static int generate_sched_domains(cpumask_var_t **domains, |
cf417141 | 579 | struct sched_domain_attr **attributes) |
029190c5 | 580 | { |
cf417141 | 581 | LIST_HEAD(q); /* queue of cpusets to be scanned */ |
029190c5 PJ |
582 | struct cpuset *cp; /* scans q */ |
583 | struct cpuset **csa; /* array of all cpuset ptrs */ | |
584 | int csn; /* how many cpuset ptrs in csa so far */ | |
585 | int i, j, k; /* indices for partition finding loops */ | |
acc3f5d7 | 586 | cpumask_var_t *doms; /* resulting partition; i.e. sched domains */ |
1d3504fc | 587 | struct sched_domain_attr *dattr; /* attributes for custom domains */ |
1583715d | 588 | int ndoms = 0; /* number of sched domains in result */ |
6af866af | 589 | int nslot; /* next empty doms[] struct cpumask slot */ |
029190c5 | 590 | |
029190c5 | 591 | doms = NULL; |
1d3504fc | 592 | dattr = NULL; |
cf417141 | 593 | csa = NULL; |
029190c5 PJ |
594 | |
595 | /* Special case for the 99% of systems with one, full, sched domain */ | |
596 | if (is_sched_load_balance(&top_cpuset)) { | |
acc3f5d7 RR |
597 | ndoms = 1; |
598 | doms = alloc_sched_domains(ndoms); | |
029190c5 | 599 | if (!doms) |
cf417141 MK |
600 | goto done; |
601 | ||
1d3504fc HS |
602 | dattr = kmalloc(sizeof(struct sched_domain_attr), GFP_KERNEL); |
603 | if (dattr) { | |
604 | *dattr = SD_ATTR_INIT; | |
93a65575 | 605 | update_domain_attr_tree(dattr, &top_cpuset); |
1d3504fc | 606 | } |
acc3f5d7 | 607 | cpumask_copy(doms[0], top_cpuset.cpus_allowed); |
cf417141 | 608 | |
cf417141 | 609 | goto done; |
029190c5 PJ |
610 | } |
611 | ||
029190c5 PJ |
612 | csa = kmalloc(number_of_cpusets * sizeof(cp), GFP_KERNEL); |
613 | if (!csa) | |
614 | goto done; | |
615 | csn = 0; | |
616 | ||
aeed6824 LZ |
617 | list_add(&top_cpuset.stack_list, &q); |
618 | while (!list_empty(&q)) { | |
029190c5 PJ |
619 | struct cgroup *cont; |
620 | struct cpuset *child; /* scans child cpusets of cp */ | |
489a5393 | 621 | |
aeed6824 LZ |
622 | cp = list_first_entry(&q, struct cpuset, stack_list); |
623 | list_del(q.next); | |
624 | ||
300ed6cb | 625 | if (cpumask_empty(cp->cpus_allowed)) |
489a5393 LJ |
626 | continue; |
627 | ||
f5393693 LJ |
628 | /* |
629 | * All child cpusets contain a subset of the parent's cpus, so | |
630 | * just skip them, and then we call update_domain_attr_tree() | |
631 | * to calc relax_domain_level of the corresponding sched | |
632 | * domain. | |
633 | */ | |
634 | if (is_sched_load_balance(cp)) { | |
029190c5 | 635 | csa[csn++] = cp; |
f5393693 LJ |
636 | continue; |
637 | } | |
489a5393 | 638 | |
ae8086ce TH |
639 | rcu_read_lock(); |
640 | cpuset_for_each_child(child, cont, cp) | |
aeed6824 | 641 | list_add_tail(&child->stack_list, &q); |
ae8086ce | 642 | rcu_read_unlock(); |
029190c5 PJ |
643 | } |
644 | ||
645 | for (i = 0; i < csn; i++) | |
646 | csa[i]->pn = i; | |
647 | ndoms = csn; | |
648 | ||
649 | restart: | |
650 | /* Find the best partition (set of sched domains) */ | |
651 | for (i = 0; i < csn; i++) { | |
652 | struct cpuset *a = csa[i]; | |
653 | int apn = a->pn; | |
654 | ||
655 | for (j = 0; j < csn; j++) { | |
656 | struct cpuset *b = csa[j]; | |
657 | int bpn = b->pn; | |
658 | ||
659 | if (apn != bpn && cpusets_overlap(a, b)) { | |
660 | for (k = 0; k < csn; k++) { | |
661 | struct cpuset *c = csa[k]; | |
662 | ||
663 | if (c->pn == bpn) | |
664 | c->pn = apn; | |
665 | } | |
666 | ndoms--; /* one less element */ | |
667 | goto restart; | |
668 | } | |
669 | } | |
670 | } | |
671 | ||
cf417141 MK |
672 | /* |
673 | * Now we know how many domains to create. | |
674 | * Convert <csn, csa> to <ndoms, doms> and populate cpu masks. | |
675 | */ | |
acc3f5d7 | 676 | doms = alloc_sched_domains(ndoms); |
700018e0 | 677 | if (!doms) |
cf417141 | 678 | goto done; |
cf417141 MK |
679 | |
680 | /* | |
681 | * The rest of the code, including the scheduler, can deal with | |
682 | * dattr==NULL case. No need to abort if alloc fails. | |
683 | */ | |
1d3504fc | 684 | dattr = kmalloc(ndoms * sizeof(struct sched_domain_attr), GFP_KERNEL); |
029190c5 PJ |
685 | |
686 | for (nslot = 0, i = 0; i < csn; i++) { | |
687 | struct cpuset *a = csa[i]; | |
6af866af | 688 | struct cpumask *dp; |
029190c5 PJ |
689 | int apn = a->pn; |
690 | ||
cf417141 MK |
691 | if (apn < 0) { |
692 | /* Skip completed partitions */ | |
693 | continue; | |
694 | } | |
695 | ||
acc3f5d7 | 696 | dp = doms[nslot]; |
cf417141 MK |
697 | |
698 | if (nslot == ndoms) { | |
699 | static int warnings = 10; | |
700 | if (warnings) { | |
701 | printk(KERN_WARNING | |
702 | "rebuild_sched_domains confused:" | |
703 | " nslot %d, ndoms %d, csn %d, i %d," | |
704 | " apn %d\n", | |
705 | nslot, ndoms, csn, i, apn); | |
706 | warnings--; | |
029190c5 | 707 | } |
cf417141 MK |
708 | continue; |
709 | } | |
029190c5 | 710 | |
6af866af | 711 | cpumask_clear(dp); |
cf417141 MK |
712 | if (dattr) |
713 | *(dattr + nslot) = SD_ATTR_INIT; | |
714 | for (j = i; j < csn; j++) { | |
715 | struct cpuset *b = csa[j]; | |
716 | ||
717 | if (apn == b->pn) { | |
300ed6cb | 718 | cpumask_or(dp, dp, b->cpus_allowed); |
cf417141 MK |
719 | if (dattr) |
720 | update_domain_attr_tree(dattr + nslot, b); | |
721 | ||
722 | /* Done with this partition */ | |
723 | b->pn = -1; | |
029190c5 | 724 | } |
029190c5 | 725 | } |
cf417141 | 726 | nslot++; |
029190c5 PJ |
727 | } |
728 | BUG_ON(nslot != ndoms); | |
729 | ||
cf417141 MK |
730 | done: |
731 | kfree(csa); | |
732 | ||
700018e0 LZ |
733 | /* |
734 | * Fallback to the default domain if kmalloc() failed. | |
735 | * See comments in partition_sched_domains(). | |
736 | */ | |
737 | if (doms == NULL) | |
738 | ndoms = 1; | |
739 | ||
cf417141 MK |
740 | *domains = doms; |
741 | *attributes = dattr; | |
742 | return ndoms; | |
743 | } | |
744 | ||
745 | /* | |
746 | * Rebuild scheduler domains. | |
747 | * | |
699140ba TH |
748 | * If the flag 'sched_load_balance' of any cpuset with non-empty |
749 | * 'cpus' changes, or if the 'cpus' allowed changes in any cpuset | |
750 | * which has that flag enabled, or if any cpuset with a non-empty | |
751 | * 'cpus' is removed, then call this routine to rebuild the | |
752 | * scheduler's dynamic sched domains. | |
cf417141 | 753 | * |
699140ba | 754 | * Call with cgroup_mutex held. Takes get_online_cpus(). |
cf417141 | 755 | */ |
699140ba | 756 | static void rebuild_sched_domains_locked(void) |
cf417141 MK |
757 | { |
758 | struct sched_domain_attr *attr; | |
acc3f5d7 | 759 | cpumask_var_t *doms; |
cf417141 MK |
760 | int ndoms; |
761 | ||
699140ba | 762 | WARN_ON_ONCE(!cgroup_lock_is_held()); |
86ef5c9a | 763 | get_online_cpus(); |
cf417141 MK |
764 | |
765 | /* Generate domain masks and attrs */ | |
cf417141 | 766 | ndoms = generate_sched_domains(&doms, &attr); |
cf417141 MK |
767 | |
768 | /* Have scheduler rebuild the domains */ | |
769 | partition_sched_domains(ndoms, doms, attr); | |
770 | ||
86ef5c9a | 771 | put_online_cpus(); |
cf417141 | 772 | } |
db7f47cf | 773 | #else /* !CONFIG_SMP */ |
699140ba | 774 | static void rebuild_sched_domains_locked(void) |
db7f47cf PM |
775 | { |
776 | } | |
777 | ||
e1b8090b | 778 | static int generate_sched_domains(cpumask_var_t **domains, |
db7f47cf PM |
779 | struct sched_domain_attr **attributes) |
780 | { | |
781 | *domains = NULL; | |
782 | return 1; | |
783 | } | |
784 | #endif /* CONFIG_SMP */ | |
029190c5 | 785 | |
cf417141 MK |
786 | void rebuild_sched_domains(void) |
787 | { | |
699140ba TH |
788 | cgroup_lock(); |
789 | rebuild_sched_domains_locked(); | |
790 | cgroup_unlock(); | |
029190c5 PJ |
791 | } |
792 | ||
58f4790b CW |
793 | /** |
794 | * cpuset_test_cpumask - test a task's cpus_allowed versus its cpuset's | |
795 | * @tsk: task to test | |
796 | * @scan: struct cgroup_scanner contained in its struct cpuset_hotplug_scanner | |
797 | * | |
2df167a3 | 798 | * Call with cgroup_mutex held. May take callback_mutex during call. |
58f4790b CW |
799 | * Called for each task in a cgroup by cgroup_scan_tasks(). |
800 | * Return nonzero if this tasks's cpus_allowed mask should be changed (in other | |
801 | * words, if its mask is not equal to its cpuset's mask). | |
053199ed | 802 | */ |
9e0c914c AB |
803 | static int cpuset_test_cpumask(struct task_struct *tsk, |
804 | struct cgroup_scanner *scan) | |
58f4790b | 805 | { |
300ed6cb | 806 | return !cpumask_equal(&tsk->cpus_allowed, |
58f4790b CW |
807 | (cgroup_cs(scan->cg))->cpus_allowed); |
808 | } | |
053199ed | 809 | |
58f4790b CW |
810 | /** |
811 | * cpuset_change_cpumask - make a task's cpus_allowed the same as its cpuset's | |
812 | * @tsk: task to test | |
813 | * @scan: struct cgroup_scanner containing the cgroup of the task | |
814 | * | |
815 | * Called by cgroup_scan_tasks() for each task in a cgroup whose | |
816 | * cpus_allowed mask needs to be changed. | |
817 | * | |
818 | * We don't need to re-check for the cgroup/cpuset membership, since we're | |
819 | * holding cgroup_lock() at this point. | |
820 | */ | |
9e0c914c AB |
821 | static void cpuset_change_cpumask(struct task_struct *tsk, |
822 | struct cgroup_scanner *scan) | |
58f4790b | 823 | { |
300ed6cb | 824 | set_cpus_allowed_ptr(tsk, ((cgroup_cs(scan->cg))->cpus_allowed)); |
58f4790b CW |
825 | } |
826 | ||
0b2f630a MX |
827 | /** |
828 | * update_tasks_cpumask - Update the cpumasks of tasks in the cpuset. | |
829 | * @cs: the cpuset in which each task's cpus_allowed mask needs to be changed | |
4e74339a | 830 | * @heap: if NULL, defer allocating heap memory to cgroup_scan_tasks() |
0b2f630a MX |
831 | * |
832 | * Called with cgroup_mutex held | |
833 | * | |
834 | * The cgroup_scan_tasks() function will scan all the tasks in a cgroup, | |
835 | * calling callback functions for each. | |
836 | * | |
4e74339a LZ |
837 | * No return value. It's guaranteed that cgroup_scan_tasks() always returns 0 |
838 | * if @heap != NULL. | |
0b2f630a | 839 | */ |
4e74339a | 840 | static void update_tasks_cpumask(struct cpuset *cs, struct ptr_heap *heap) |
0b2f630a MX |
841 | { |
842 | struct cgroup_scanner scan; | |
0b2f630a MX |
843 | |
844 | scan.cg = cs->css.cgroup; | |
845 | scan.test_task = cpuset_test_cpumask; | |
846 | scan.process_task = cpuset_change_cpumask; | |
4e74339a LZ |
847 | scan.heap = heap; |
848 | cgroup_scan_tasks(&scan); | |
0b2f630a MX |
849 | } |
850 | ||
58f4790b CW |
851 | /** |
852 | * update_cpumask - update the cpus_allowed mask of a cpuset and all tasks in it | |
853 | * @cs: the cpuset to consider | |
854 | * @buf: buffer of cpu numbers written to this cpuset | |
855 | */ | |
645fcc9d LZ |
856 | static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs, |
857 | const char *buf) | |
1da177e4 | 858 | { |
4e74339a | 859 | struct ptr_heap heap; |
58f4790b CW |
860 | int retval; |
861 | int is_load_balanced; | |
1da177e4 | 862 | |
5f054e31 | 863 | /* top_cpuset.cpus_allowed tracks cpu_online_mask; it's read-only */ |
4c4d50f7 PJ |
864 | if (cs == &top_cpuset) |
865 | return -EACCES; | |
866 | ||
6f7f02e7 | 867 | /* |
c8d9c90c | 868 | * An empty cpus_allowed is ok only if the cpuset has no tasks. |
020958b6 PJ |
869 | * Since cpulist_parse() fails on an empty mask, we special case |
870 | * that parsing. The validate_change() call ensures that cpusets | |
871 | * with tasks have cpus. | |
6f7f02e7 | 872 | */ |
020958b6 | 873 | if (!*buf) { |
300ed6cb | 874 | cpumask_clear(trialcs->cpus_allowed); |
6f7f02e7 | 875 | } else { |
300ed6cb | 876 | retval = cpulist_parse(buf, trialcs->cpus_allowed); |
6f7f02e7 DR |
877 | if (retval < 0) |
878 | return retval; | |
37340746 | 879 | |
6ad4c188 | 880 | if (!cpumask_subset(trialcs->cpus_allowed, cpu_active_mask)) |
37340746 | 881 | return -EINVAL; |
6f7f02e7 | 882 | } |
645fcc9d | 883 | retval = validate_change(cs, trialcs); |
85d7b949 DG |
884 | if (retval < 0) |
885 | return retval; | |
029190c5 | 886 | |
8707d8b8 | 887 | /* Nothing to do if the cpus didn't change */ |
300ed6cb | 888 | if (cpumask_equal(cs->cpus_allowed, trialcs->cpus_allowed)) |
8707d8b8 | 889 | return 0; |
58f4790b | 890 | |
4e74339a LZ |
891 | retval = heap_init(&heap, PAGE_SIZE, GFP_KERNEL, NULL); |
892 | if (retval) | |
893 | return retval; | |
894 | ||
645fcc9d | 895 | is_load_balanced = is_sched_load_balance(trialcs); |
029190c5 | 896 | |
3d3f26a7 | 897 | mutex_lock(&callback_mutex); |
300ed6cb | 898 | cpumask_copy(cs->cpus_allowed, trialcs->cpus_allowed); |
3d3f26a7 | 899 | mutex_unlock(&callback_mutex); |
029190c5 | 900 | |
8707d8b8 PM |
901 | /* |
902 | * Scan tasks in the cpuset, and update the cpumasks of any | |
58f4790b | 903 | * that need an update. |
8707d8b8 | 904 | */ |
4e74339a LZ |
905 | update_tasks_cpumask(cs, &heap); |
906 | ||
907 | heap_free(&heap); | |
58f4790b | 908 | |
8707d8b8 | 909 | if (is_load_balanced) |
699140ba | 910 | rebuild_sched_domains_locked(); |
85d7b949 | 911 | return 0; |
1da177e4 LT |
912 | } |
913 | ||
e4e364e8 PJ |
914 | /* |
915 | * cpuset_migrate_mm | |
916 | * | |
917 | * Migrate memory region from one set of nodes to another. | |
918 | * | |
919 | * Temporarilly set tasks mems_allowed to target nodes of migration, | |
920 | * so that the migration code can allocate pages on these nodes. | |
921 | * | |
2df167a3 | 922 | * Call holding cgroup_mutex, so current's cpuset won't change |
c8d9c90c | 923 | * during this call, as manage_mutex holds off any cpuset_attach() |
e4e364e8 PJ |
924 | * calls. Therefore we don't need to take task_lock around the |
925 | * call to guarantee_online_mems(), as we know no one is changing | |
2df167a3 | 926 | * our task's cpuset. |
e4e364e8 | 927 | * |
e4e364e8 PJ |
928 | * While the mm_struct we are migrating is typically from some |
929 | * other task, the task_struct mems_allowed that we are hacking | |
930 | * is for our current task, which must allocate new pages for that | |
931 | * migrating memory region. | |
e4e364e8 PJ |
932 | */ |
933 | ||
934 | static void cpuset_migrate_mm(struct mm_struct *mm, const nodemask_t *from, | |
935 | const nodemask_t *to) | |
936 | { | |
937 | struct task_struct *tsk = current; | |
938 | ||
e4e364e8 | 939 | tsk->mems_allowed = *to; |
e4e364e8 PJ |
940 | |
941 | do_migrate_pages(mm, from, to, MPOL_MF_MOVE_ALL); | |
942 | ||
8793d854 | 943 | guarantee_online_mems(task_cs(tsk),&tsk->mems_allowed); |
e4e364e8 PJ |
944 | } |
945 | ||
3b6766fe | 946 | /* |
58568d2a MX |
947 | * cpuset_change_task_nodemask - change task's mems_allowed and mempolicy |
948 | * @tsk: the task to change | |
949 | * @newmems: new nodes that the task will be set | |
950 | * | |
951 | * In order to avoid seeing no nodes if the old and new nodes are disjoint, | |
952 | * we structure updates as setting all new allowed nodes, then clearing newly | |
953 | * disallowed ones. | |
58568d2a MX |
954 | */ |
955 | static void cpuset_change_task_nodemask(struct task_struct *tsk, | |
956 | nodemask_t *newmems) | |
957 | { | |
b246272e | 958 | bool need_loop; |
89e8a244 | 959 | |
c0ff7453 MX |
960 | /* |
961 | * Allow tasks that have access to memory reserves because they have | |
962 | * been OOM killed to get memory anywhere. | |
963 | */ | |
964 | if (unlikely(test_thread_flag(TIF_MEMDIE))) | |
965 | return; | |
966 | if (current->flags & PF_EXITING) /* Let dying task have memory */ | |
967 | return; | |
968 | ||
969 | task_lock(tsk); | |
b246272e DR |
970 | /* |
971 | * Determine if a loop is necessary if another thread is doing | |
972 | * get_mems_allowed(). If at least one node remains unchanged and | |
973 | * tsk does not have a mempolicy, then an empty nodemask will not be | |
974 | * possible when mems_allowed is larger than a word. | |
975 | */ | |
976 | need_loop = task_has_mempolicy(tsk) || | |
977 | !nodes_intersects(*newmems, tsk->mems_allowed); | |
c0ff7453 | 978 | |
cc9a6c87 MG |
979 | if (need_loop) |
980 | write_seqcount_begin(&tsk->mems_allowed_seq); | |
c0ff7453 | 981 | |
cc9a6c87 MG |
982 | nodes_or(tsk->mems_allowed, tsk->mems_allowed, *newmems); |
983 | mpol_rebind_task(tsk, newmems, MPOL_REBIND_STEP1); | |
c0ff7453 MX |
984 | |
985 | mpol_rebind_task(tsk, newmems, MPOL_REBIND_STEP2); | |
58568d2a | 986 | tsk->mems_allowed = *newmems; |
cc9a6c87 MG |
987 | |
988 | if (need_loop) | |
989 | write_seqcount_end(&tsk->mems_allowed_seq); | |
990 | ||
c0ff7453 | 991 | task_unlock(tsk); |
58568d2a MX |
992 | } |
993 | ||
994 | /* | |
995 | * Update task's mems_allowed and rebind its mempolicy and vmas' mempolicy | |
996 | * of it to cpuset's new mems_allowed, and migrate pages to new nodes if | |
997 | * memory_migrate flag is set. Called with cgroup_mutex held. | |
3b6766fe LZ |
998 | */ |
999 | static void cpuset_change_nodemask(struct task_struct *p, | |
1000 | struct cgroup_scanner *scan) | |
1001 | { | |
1002 | struct mm_struct *mm; | |
1003 | struct cpuset *cs; | |
1004 | int migrate; | |
1005 | const nodemask_t *oldmem = scan->data; | |
ee24d379 | 1006 | static nodemask_t newmems; /* protected by cgroup_mutex */ |
58568d2a MX |
1007 | |
1008 | cs = cgroup_cs(scan->cg); | |
ee24d379 | 1009 | guarantee_online_mems(cs, &newmems); |
58568d2a | 1010 | |
ee24d379 | 1011 | cpuset_change_task_nodemask(p, &newmems); |
53feb297 | 1012 | |
3b6766fe LZ |
1013 | mm = get_task_mm(p); |
1014 | if (!mm) | |
1015 | return; | |
1016 | ||
3b6766fe LZ |
1017 | migrate = is_memory_migrate(cs); |
1018 | ||
1019 | mpol_rebind_mm(mm, &cs->mems_allowed); | |
1020 | if (migrate) | |
1021 | cpuset_migrate_mm(mm, oldmem, &cs->mems_allowed); | |
1022 | mmput(mm); | |
1023 | } | |
1024 | ||
8793d854 PM |
1025 | static void *cpuset_being_rebound; |
1026 | ||
0b2f630a MX |
1027 | /** |
1028 | * update_tasks_nodemask - Update the nodemasks of tasks in the cpuset. | |
1029 | * @cs: the cpuset in which each task's mems_allowed mask needs to be changed | |
1030 | * @oldmem: old mems_allowed of cpuset cs | |
010cfac4 | 1031 | * @heap: if NULL, defer allocating heap memory to cgroup_scan_tasks() |
0b2f630a MX |
1032 | * |
1033 | * Called with cgroup_mutex held | |
010cfac4 LZ |
1034 | * No return value. It's guaranteed that cgroup_scan_tasks() always returns 0 |
1035 | * if @heap != NULL. | |
0b2f630a | 1036 | */ |
010cfac4 LZ |
1037 | static void update_tasks_nodemask(struct cpuset *cs, const nodemask_t *oldmem, |
1038 | struct ptr_heap *heap) | |
1da177e4 | 1039 | { |
3b6766fe | 1040 | struct cgroup_scanner scan; |
59dac16f | 1041 | |
846a16bf | 1042 | cpuset_being_rebound = cs; /* causes mpol_dup() rebind */ |
4225399a | 1043 | |
3b6766fe LZ |
1044 | scan.cg = cs->css.cgroup; |
1045 | scan.test_task = NULL; | |
1046 | scan.process_task = cpuset_change_nodemask; | |
010cfac4 | 1047 | scan.heap = heap; |
3b6766fe | 1048 | scan.data = (nodemask_t *)oldmem; |
4225399a PJ |
1049 | |
1050 | /* | |
3b6766fe LZ |
1051 | * The mpol_rebind_mm() call takes mmap_sem, which we couldn't |
1052 | * take while holding tasklist_lock. Forks can happen - the | |
1053 | * mpol_dup() cpuset_being_rebound check will catch such forks, | |
1054 | * and rebind their vma mempolicies too. Because we still hold | |
1055 | * the global cgroup_mutex, we know that no other rebind effort | |
1056 | * will be contending for the global variable cpuset_being_rebound. | |
4225399a | 1057 | * It's ok if we rebind the same mm twice; mpol_rebind_mm() |
04c19fa6 | 1058 | * is idempotent. Also migrate pages in each mm to new nodes. |
4225399a | 1059 | */ |
010cfac4 | 1060 | cgroup_scan_tasks(&scan); |
4225399a | 1061 | |
2df167a3 | 1062 | /* We're done rebinding vmas to this cpuset's new mems_allowed. */ |
8793d854 | 1063 | cpuset_being_rebound = NULL; |
1da177e4 LT |
1064 | } |
1065 | ||
0b2f630a MX |
1066 | /* |
1067 | * Handle user request to change the 'mems' memory placement | |
1068 | * of a cpuset. Needs to validate the request, update the | |
58568d2a MX |
1069 | * cpusets mems_allowed, and for each task in the cpuset, |
1070 | * update mems_allowed and rebind task's mempolicy and any vma | |
1071 | * mempolicies and if the cpuset is marked 'memory_migrate', | |
1072 | * migrate the tasks pages to the new memory. | |
0b2f630a MX |
1073 | * |
1074 | * Call with cgroup_mutex held. May take callback_mutex during call. | |
1075 | * Will take tasklist_lock, scan tasklist for tasks in cpuset cs, | |
1076 | * lock each such tasks mm->mmap_sem, scan its vma's and rebind | |
1077 | * their mempolicies to the cpusets new mems_allowed. | |
1078 | */ | |
645fcc9d LZ |
1079 | static int update_nodemask(struct cpuset *cs, struct cpuset *trialcs, |
1080 | const char *buf) | |
0b2f630a | 1081 | { |
53feb297 | 1082 | NODEMASK_ALLOC(nodemask_t, oldmem, GFP_KERNEL); |
0b2f630a | 1083 | int retval; |
010cfac4 | 1084 | struct ptr_heap heap; |
0b2f630a | 1085 | |
53feb297 MX |
1086 | if (!oldmem) |
1087 | return -ENOMEM; | |
1088 | ||
0b2f630a | 1089 | /* |
38d7bee9 | 1090 | * top_cpuset.mems_allowed tracks node_stats[N_MEMORY]; |
0b2f630a MX |
1091 | * it's read-only |
1092 | */ | |
53feb297 MX |
1093 | if (cs == &top_cpuset) { |
1094 | retval = -EACCES; | |
1095 | goto done; | |
1096 | } | |
0b2f630a | 1097 | |
0b2f630a MX |
1098 | /* |
1099 | * An empty mems_allowed is ok iff there are no tasks in the cpuset. | |
1100 | * Since nodelist_parse() fails on an empty mask, we special case | |
1101 | * that parsing. The validate_change() call ensures that cpusets | |
1102 | * with tasks have memory. | |
1103 | */ | |
1104 | if (!*buf) { | |
645fcc9d | 1105 | nodes_clear(trialcs->mems_allowed); |
0b2f630a | 1106 | } else { |
645fcc9d | 1107 | retval = nodelist_parse(buf, trialcs->mems_allowed); |
0b2f630a MX |
1108 | if (retval < 0) |
1109 | goto done; | |
1110 | ||
645fcc9d | 1111 | if (!nodes_subset(trialcs->mems_allowed, |
38d7bee9 | 1112 | node_states[N_MEMORY])) { |
53feb297 MX |
1113 | retval = -EINVAL; |
1114 | goto done; | |
1115 | } | |
0b2f630a | 1116 | } |
53feb297 MX |
1117 | *oldmem = cs->mems_allowed; |
1118 | if (nodes_equal(*oldmem, trialcs->mems_allowed)) { | |
0b2f630a MX |
1119 | retval = 0; /* Too easy - nothing to do */ |
1120 | goto done; | |
1121 | } | |
645fcc9d | 1122 | retval = validate_change(cs, trialcs); |
0b2f630a MX |
1123 | if (retval < 0) |
1124 | goto done; | |
1125 | ||
010cfac4 LZ |
1126 | retval = heap_init(&heap, PAGE_SIZE, GFP_KERNEL, NULL); |
1127 | if (retval < 0) | |
1128 | goto done; | |
1129 | ||
0b2f630a | 1130 | mutex_lock(&callback_mutex); |
645fcc9d | 1131 | cs->mems_allowed = trialcs->mems_allowed; |
0b2f630a MX |
1132 | mutex_unlock(&callback_mutex); |
1133 | ||
53feb297 | 1134 | update_tasks_nodemask(cs, oldmem, &heap); |
010cfac4 LZ |
1135 | |
1136 | heap_free(&heap); | |
0b2f630a | 1137 | done: |
53feb297 | 1138 | NODEMASK_FREE(oldmem); |
0b2f630a MX |
1139 | return retval; |
1140 | } | |
1141 | ||
8793d854 PM |
1142 | int current_cpuset_is_being_rebound(void) |
1143 | { | |
1144 | return task_cs(current) == cpuset_being_rebound; | |
1145 | } | |
1146 | ||
5be7a479 | 1147 | static int update_relax_domain_level(struct cpuset *cs, s64 val) |
1d3504fc | 1148 | { |
db7f47cf | 1149 | #ifdef CONFIG_SMP |
60495e77 | 1150 | if (val < -1 || val >= sched_domain_level_max) |
30e0e178 | 1151 | return -EINVAL; |
db7f47cf | 1152 | #endif |
1d3504fc HS |
1153 | |
1154 | if (val != cs->relax_domain_level) { | |
1155 | cs->relax_domain_level = val; | |
300ed6cb LZ |
1156 | if (!cpumask_empty(cs->cpus_allowed) && |
1157 | is_sched_load_balance(cs)) | |
699140ba | 1158 | rebuild_sched_domains_locked(); |
1d3504fc HS |
1159 | } |
1160 | ||
1161 | return 0; | |
1162 | } | |
1163 | ||
950592f7 MX |
1164 | /* |
1165 | * cpuset_change_flag - make a task's spread flags the same as its cpuset's | |
1166 | * @tsk: task to be updated | |
1167 | * @scan: struct cgroup_scanner containing the cgroup of the task | |
1168 | * | |
1169 | * Called by cgroup_scan_tasks() for each task in a cgroup. | |
1170 | * | |
1171 | * We don't need to re-check for the cgroup/cpuset membership, since we're | |
1172 | * holding cgroup_lock() at this point. | |
1173 | */ | |
1174 | static void cpuset_change_flag(struct task_struct *tsk, | |
1175 | struct cgroup_scanner *scan) | |
1176 | { | |
1177 | cpuset_update_task_spread_flag(cgroup_cs(scan->cg), tsk); | |
1178 | } | |
1179 | ||
1180 | /* | |
1181 | * update_tasks_flags - update the spread flags of tasks in the cpuset. | |
1182 | * @cs: the cpuset in which each task's spread flags needs to be changed | |
1183 | * @heap: if NULL, defer allocating heap memory to cgroup_scan_tasks() | |
1184 | * | |
1185 | * Called with cgroup_mutex held | |
1186 | * | |
1187 | * The cgroup_scan_tasks() function will scan all the tasks in a cgroup, | |
1188 | * calling callback functions for each. | |
1189 | * | |
1190 | * No return value. It's guaranteed that cgroup_scan_tasks() always returns 0 | |
1191 | * if @heap != NULL. | |
1192 | */ | |
1193 | static void update_tasks_flags(struct cpuset *cs, struct ptr_heap *heap) | |
1194 | { | |
1195 | struct cgroup_scanner scan; | |
1196 | ||
1197 | scan.cg = cs->css.cgroup; | |
1198 | scan.test_task = NULL; | |
1199 | scan.process_task = cpuset_change_flag; | |
1200 | scan.heap = heap; | |
1201 | cgroup_scan_tasks(&scan); | |
1202 | } | |
1203 | ||
1da177e4 LT |
1204 | /* |
1205 | * update_flag - read a 0 or a 1 in a file and update associated flag | |
78608366 PM |
1206 | * bit: the bit to update (see cpuset_flagbits_t) |
1207 | * cs: the cpuset to update | |
1208 | * turning_on: whether the flag is being set or cleared | |
053199ed | 1209 | * |
2df167a3 | 1210 | * Call with cgroup_mutex held. |
1da177e4 LT |
1211 | */ |
1212 | ||
700fe1ab PM |
1213 | static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs, |
1214 | int turning_on) | |
1da177e4 | 1215 | { |
645fcc9d | 1216 | struct cpuset *trialcs; |
40b6a762 | 1217 | int balance_flag_changed; |
950592f7 MX |
1218 | int spread_flag_changed; |
1219 | struct ptr_heap heap; | |
1220 | int err; | |
1da177e4 | 1221 | |
645fcc9d LZ |
1222 | trialcs = alloc_trial_cpuset(cs); |
1223 | if (!trialcs) | |
1224 | return -ENOMEM; | |
1225 | ||
1da177e4 | 1226 | if (turning_on) |
645fcc9d | 1227 | set_bit(bit, &trialcs->flags); |
1da177e4 | 1228 | else |
645fcc9d | 1229 | clear_bit(bit, &trialcs->flags); |
1da177e4 | 1230 | |
645fcc9d | 1231 | err = validate_change(cs, trialcs); |
85d7b949 | 1232 | if (err < 0) |
645fcc9d | 1233 | goto out; |
029190c5 | 1234 | |
950592f7 MX |
1235 | err = heap_init(&heap, PAGE_SIZE, GFP_KERNEL, NULL); |
1236 | if (err < 0) | |
1237 | goto out; | |
1238 | ||
029190c5 | 1239 | balance_flag_changed = (is_sched_load_balance(cs) != |
645fcc9d | 1240 | is_sched_load_balance(trialcs)); |
029190c5 | 1241 | |
950592f7 MX |
1242 | spread_flag_changed = ((is_spread_slab(cs) != is_spread_slab(trialcs)) |
1243 | || (is_spread_page(cs) != is_spread_page(trialcs))); | |
1244 | ||
3d3f26a7 | 1245 | mutex_lock(&callback_mutex); |
645fcc9d | 1246 | cs->flags = trialcs->flags; |
3d3f26a7 | 1247 | mutex_unlock(&callback_mutex); |
85d7b949 | 1248 | |
300ed6cb | 1249 | if (!cpumask_empty(trialcs->cpus_allowed) && balance_flag_changed) |
699140ba | 1250 | rebuild_sched_domains_locked(); |
029190c5 | 1251 | |
950592f7 MX |
1252 | if (spread_flag_changed) |
1253 | update_tasks_flags(cs, &heap); | |
1254 | heap_free(&heap); | |
645fcc9d LZ |
1255 | out: |
1256 | free_trial_cpuset(trialcs); | |
1257 | return err; | |
1da177e4 LT |
1258 | } |
1259 | ||
3e0d98b9 | 1260 | /* |
80f7228b | 1261 | * Frequency meter - How fast is some event occurring? |
3e0d98b9 PJ |
1262 | * |
1263 | * These routines manage a digitally filtered, constant time based, | |
1264 | * event frequency meter. There are four routines: | |
1265 | * fmeter_init() - initialize a frequency meter. | |
1266 | * fmeter_markevent() - called each time the event happens. | |
1267 | * fmeter_getrate() - returns the recent rate of such events. | |
1268 | * fmeter_update() - internal routine used to update fmeter. | |
1269 | * | |
1270 | * A common data structure is passed to each of these routines, | |
1271 | * which is used to keep track of the state required to manage the | |
1272 | * frequency meter and its digital filter. | |
1273 | * | |
1274 | * The filter works on the number of events marked per unit time. | |
1275 | * The filter is single-pole low-pass recursive (IIR). The time unit | |
1276 | * is 1 second. Arithmetic is done using 32-bit integers scaled to | |
1277 | * simulate 3 decimal digits of precision (multiplied by 1000). | |
1278 | * | |
1279 | * With an FM_COEF of 933, and a time base of 1 second, the filter | |
1280 | * has a half-life of 10 seconds, meaning that if the events quit | |
1281 | * happening, then the rate returned from the fmeter_getrate() | |
1282 | * will be cut in half each 10 seconds, until it converges to zero. | |
1283 | * | |
1284 | * It is not worth doing a real infinitely recursive filter. If more | |
1285 | * than FM_MAXTICKS ticks have elapsed since the last filter event, | |
1286 | * just compute FM_MAXTICKS ticks worth, by which point the level | |
1287 | * will be stable. | |
1288 | * | |
1289 | * Limit the count of unprocessed events to FM_MAXCNT, so as to avoid | |
1290 | * arithmetic overflow in the fmeter_update() routine. | |
1291 | * | |
1292 | * Given the simple 32 bit integer arithmetic used, this meter works | |
1293 | * best for reporting rates between one per millisecond (msec) and | |
1294 | * one per 32 (approx) seconds. At constant rates faster than one | |
1295 | * per msec it maxes out at values just under 1,000,000. At constant | |
1296 | * rates between one per msec, and one per second it will stabilize | |
1297 | * to a value N*1000, where N is the rate of events per second. | |
1298 | * At constant rates between one per second and one per 32 seconds, | |
1299 | * it will be choppy, moving up on the seconds that have an event, | |
1300 | * and then decaying until the next event. At rates slower than | |
1301 | * about one in 32 seconds, it decays all the way back to zero between | |
1302 | * each event. | |
1303 | */ | |
1304 | ||
1305 | #define FM_COEF 933 /* coefficient for half-life of 10 secs */ | |
1306 | #define FM_MAXTICKS ((time_t)99) /* useless computing more ticks than this */ | |
1307 | #define FM_MAXCNT 1000000 /* limit cnt to avoid overflow */ | |
1308 | #define FM_SCALE 1000 /* faux fixed point scale */ | |
1309 | ||
1310 | /* Initialize a frequency meter */ | |
1311 | static void fmeter_init(struct fmeter *fmp) | |
1312 | { | |
1313 | fmp->cnt = 0; | |
1314 | fmp->val = 0; | |
1315 | fmp->time = 0; | |
1316 | spin_lock_init(&fmp->lock); | |
1317 | } | |
1318 | ||
1319 | /* Internal meter update - process cnt events and update value */ | |
1320 | static void fmeter_update(struct fmeter *fmp) | |
1321 | { | |
1322 | time_t now = get_seconds(); | |
1323 | time_t ticks = now - fmp->time; | |
1324 | ||
1325 | if (ticks == 0) | |
1326 | return; | |
1327 | ||
1328 | ticks = min(FM_MAXTICKS, ticks); | |
1329 | while (ticks-- > 0) | |
1330 | fmp->val = (FM_COEF * fmp->val) / FM_SCALE; | |
1331 | fmp->time = now; | |
1332 | ||
1333 | fmp->val += ((FM_SCALE - FM_COEF) * fmp->cnt) / FM_SCALE; | |
1334 | fmp->cnt = 0; | |
1335 | } | |
1336 | ||
1337 | /* Process any previous ticks, then bump cnt by one (times scale). */ | |
1338 | static void fmeter_markevent(struct fmeter *fmp) | |
1339 | { | |
1340 | spin_lock(&fmp->lock); | |
1341 | fmeter_update(fmp); | |
1342 | fmp->cnt = min(FM_MAXCNT, fmp->cnt + FM_SCALE); | |
1343 | spin_unlock(&fmp->lock); | |
1344 | } | |
1345 | ||
1346 | /* Process any previous ticks, then return current value. */ | |
1347 | static int fmeter_getrate(struct fmeter *fmp) | |
1348 | { | |
1349 | int val; | |
1350 | ||
1351 | spin_lock(&fmp->lock); | |
1352 | fmeter_update(fmp); | |
1353 | val = fmp->val; | |
1354 | spin_unlock(&fmp->lock); | |
1355 | return val; | |
1356 | } | |
1357 | ||
2df167a3 | 1358 | /* Called by cgroups to determine if a cpuset is usable; cgroup_mutex held */ |
761b3ef5 | 1359 | static int cpuset_can_attach(struct cgroup *cgrp, struct cgroup_taskset *tset) |
f780bdb7 | 1360 | { |
2f7ee569 | 1361 | struct cpuset *cs = cgroup_cs(cgrp); |
bb9d97b6 TH |
1362 | struct task_struct *task; |
1363 | int ret; | |
1da177e4 | 1364 | |
300ed6cb | 1365 | if (cpumask_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed)) |
1da177e4 | 1366 | return -ENOSPC; |
9985b0ba | 1367 | |
bb9d97b6 TH |
1368 | cgroup_taskset_for_each(task, cgrp, tset) { |
1369 | /* | |
1370 | * Kthreads bound to specific cpus cannot be moved to a new | |
1371 | * cpuset; we cannot change their cpu affinity and | |
1372 | * isolating such threads by their set of allowed nodes is | |
1373 | * unnecessary. Thus, cpusets are not applicable for such | |
1374 | * threads. This prevents checking for success of | |
1375 | * set_cpus_allowed_ptr() on all attached tasks before | |
1376 | * cpus_allowed may be changed. | |
1377 | */ | |
1378 | if (task->flags & PF_THREAD_BOUND) | |
1379 | return -EINVAL; | |
1380 | if ((ret = security_task_setscheduler(task))) | |
1381 | return ret; | |
1382 | } | |
f780bdb7 | 1383 | |
94196f51 | 1384 | return 0; |
8793d854 | 1385 | } |
1da177e4 | 1386 | |
4e4c9a14 TH |
1387 | /* |
1388 | * Protected by cgroup_mutex. cpus_attach is used only by cpuset_attach() | |
1389 | * but we can't allocate it dynamically there. Define it global and | |
1390 | * allocate from cpuset_init(). | |
1391 | */ | |
1392 | static cpumask_var_t cpus_attach; | |
1393 | ||
761b3ef5 | 1394 | static void cpuset_attach(struct cgroup *cgrp, struct cgroup_taskset *tset) |
8793d854 | 1395 | { |
4e4c9a14 TH |
1396 | /* static bufs protected by cgroup_mutex */ |
1397 | static nodemask_t cpuset_attach_nodemask_from; | |
1398 | static nodemask_t cpuset_attach_nodemask_to; | |
8793d854 | 1399 | struct mm_struct *mm; |
bb9d97b6 TH |
1400 | struct task_struct *task; |
1401 | struct task_struct *leader = cgroup_taskset_first(tset); | |
2f7ee569 TH |
1402 | struct cgroup *oldcgrp = cgroup_taskset_cur_cgroup(tset); |
1403 | struct cpuset *cs = cgroup_cs(cgrp); | |
1404 | struct cpuset *oldcs = cgroup_cs(oldcgrp); | |
22fb52dd | 1405 | |
4e4c9a14 TH |
1406 | /* prepare for attach */ |
1407 | if (cs == &top_cpuset) | |
1408 | cpumask_copy(cpus_attach, cpu_possible_mask); | |
1409 | else | |
1410 | guarantee_online_cpus(cs, cpus_attach); | |
1411 | ||
1412 | guarantee_online_mems(cs, &cpuset_attach_nodemask_to); | |
1413 | ||
bb9d97b6 TH |
1414 | cgroup_taskset_for_each(task, cgrp, tset) { |
1415 | /* | |
1416 | * can_attach beforehand should guarantee that this doesn't | |
1417 | * fail. TODO: have a better way to handle failure here | |
1418 | */ | |
1419 | WARN_ON_ONCE(set_cpus_allowed_ptr(task, cpus_attach)); | |
1420 | ||
1421 | cpuset_change_task_nodemask(task, &cpuset_attach_nodemask_to); | |
1422 | cpuset_update_task_spread_flag(cs, task); | |
1423 | } | |
22fb52dd | 1424 | |
f780bdb7 BB |
1425 | /* |
1426 | * Change mm, possibly for multiple threads in a threadgroup. This is | |
1427 | * expensive and may sleep. | |
1428 | */ | |
1429 | cpuset_attach_nodemask_from = oldcs->mems_allowed; | |
1430 | cpuset_attach_nodemask_to = cs->mems_allowed; | |
bb9d97b6 | 1431 | mm = get_task_mm(leader); |
4225399a | 1432 | if (mm) { |
f780bdb7 | 1433 | mpol_rebind_mm(mm, &cpuset_attach_nodemask_to); |
2741a559 | 1434 | if (is_memory_migrate(cs)) |
f780bdb7 BB |
1435 | cpuset_migrate_mm(mm, &cpuset_attach_nodemask_from, |
1436 | &cpuset_attach_nodemask_to); | |
4225399a PJ |
1437 | mmput(mm); |
1438 | } | |
1da177e4 LT |
1439 | } |
1440 | ||
1441 | /* The various types of files and directories in a cpuset file system */ | |
1442 | ||
1443 | typedef enum { | |
45b07ef3 | 1444 | FILE_MEMORY_MIGRATE, |
1da177e4 LT |
1445 | FILE_CPULIST, |
1446 | FILE_MEMLIST, | |
1447 | FILE_CPU_EXCLUSIVE, | |
1448 | FILE_MEM_EXCLUSIVE, | |
78608366 | 1449 | FILE_MEM_HARDWALL, |
029190c5 | 1450 | FILE_SCHED_LOAD_BALANCE, |
1d3504fc | 1451 | FILE_SCHED_RELAX_DOMAIN_LEVEL, |
3e0d98b9 PJ |
1452 | FILE_MEMORY_PRESSURE_ENABLED, |
1453 | FILE_MEMORY_PRESSURE, | |
825a46af PJ |
1454 | FILE_SPREAD_PAGE, |
1455 | FILE_SPREAD_SLAB, | |
1da177e4 LT |
1456 | } cpuset_filetype_t; |
1457 | ||
700fe1ab PM |
1458 | static int cpuset_write_u64(struct cgroup *cgrp, struct cftype *cft, u64 val) |
1459 | { | |
1460 | int retval = 0; | |
1461 | struct cpuset *cs = cgroup_cs(cgrp); | |
1462 | cpuset_filetype_t type = cft->private; | |
1463 | ||
e3712395 | 1464 | if (!cgroup_lock_live_group(cgrp)) |
700fe1ab | 1465 | return -ENODEV; |
700fe1ab PM |
1466 | |
1467 | switch (type) { | |
1da177e4 | 1468 | case FILE_CPU_EXCLUSIVE: |
700fe1ab | 1469 | retval = update_flag(CS_CPU_EXCLUSIVE, cs, val); |
1da177e4 LT |
1470 | break; |
1471 | case FILE_MEM_EXCLUSIVE: | |
700fe1ab | 1472 | retval = update_flag(CS_MEM_EXCLUSIVE, cs, val); |
1da177e4 | 1473 | break; |
78608366 PM |
1474 | case FILE_MEM_HARDWALL: |
1475 | retval = update_flag(CS_MEM_HARDWALL, cs, val); | |
1476 | break; | |
029190c5 | 1477 | case FILE_SCHED_LOAD_BALANCE: |
700fe1ab | 1478 | retval = update_flag(CS_SCHED_LOAD_BALANCE, cs, val); |
1d3504fc | 1479 | break; |
45b07ef3 | 1480 | case FILE_MEMORY_MIGRATE: |
700fe1ab | 1481 | retval = update_flag(CS_MEMORY_MIGRATE, cs, val); |
45b07ef3 | 1482 | break; |
3e0d98b9 | 1483 | case FILE_MEMORY_PRESSURE_ENABLED: |
700fe1ab | 1484 | cpuset_memory_pressure_enabled = !!val; |
3e0d98b9 PJ |
1485 | break; |
1486 | case FILE_MEMORY_PRESSURE: | |
1487 | retval = -EACCES; | |
1488 | break; | |
825a46af | 1489 | case FILE_SPREAD_PAGE: |
700fe1ab | 1490 | retval = update_flag(CS_SPREAD_PAGE, cs, val); |
825a46af PJ |
1491 | break; |
1492 | case FILE_SPREAD_SLAB: | |
700fe1ab | 1493 | retval = update_flag(CS_SPREAD_SLAB, cs, val); |
825a46af | 1494 | break; |
1da177e4 LT |
1495 | default: |
1496 | retval = -EINVAL; | |
700fe1ab | 1497 | break; |
1da177e4 | 1498 | } |
8793d854 | 1499 | cgroup_unlock(); |
1da177e4 LT |
1500 | return retval; |
1501 | } | |
1502 | ||
5be7a479 PM |
1503 | static int cpuset_write_s64(struct cgroup *cgrp, struct cftype *cft, s64 val) |
1504 | { | |
1505 | int retval = 0; | |
1506 | struct cpuset *cs = cgroup_cs(cgrp); | |
1507 | cpuset_filetype_t type = cft->private; | |
1508 | ||
e3712395 | 1509 | if (!cgroup_lock_live_group(cgrp)) |
5be7a479 | 1510 | return -ENODEV; |
e3712395 | 1511 | |
5be7a479 PM |
1512 | switch (type) { |
1513 | case FILE_SCHED_RELAX_DOMAIN_LEVEL: | |
1514 | retval = update_relax_domain_level(cs, val); | |
1515 | break; | |
1516 | default: | |
1517 | retval = -EINVAL; | |
1518 | break; | |
1519 | } | |
1520 | cgroup_unlock(); | |
1521 | return retval; | |
1522 | } | |
1523 | ||
e3712395 PM |
1524 | /* |
1525 | * Common handling for a write to a "cpus" or "mems" file. | |
1526 | */ | |
1527 | static int cpuset_write_resmask(struct cgroup *cgrp, struct cftype *cft, | |
1528 | const char *buf) | |
1529 | { | |
1530 | int retval = 0; | |
645fcc9d LZ |
1531 | struct cpuset *cs = cgroup_cs(cgrp); |
1532 | struct cpuset *trialcs; | |
e3712395 | 1533 | |
3a5a6d0c TH |
1534 | /* |
1535 | * CPU or memory hotunplug may leave @cs w/o any execution | |
1536 | * resources, in which case the hotplug code asynchronously updates | |
1537 | * configuration and transfers all tasks to the nearest ancestor | |
1538 | * which can execute. | |
1539 | * | |
1540 | * As writes to "cpus" or "mems" may restore @cs's execution | |
1541 | * resources, wait for the previously scheduled operations before | |
1542 | * proceeding, so that we don't end up keep removing tasks added | |
1543 | * after execution capability is restored. | |
1544 | */ | |
1545 | flush_work(&cpuset_hotplug_work); | |
1546 | ||
e3712395 PM |
1547 | if (!cgroup_lock_live_group(cgrp)) |
1548 | return -ENODEV; | |
1549 | ||
645fcc9d | 1550 | trialcs = alloc_trial_cpuset(cs); |
b75f38d6 LZ |
1551 | if (!trialcs) { |
1552 | retval = -ENOMEM; | |
1553 | goto out; | |
1554 | } | |
645fcc9d | 1555 | |
e3712395 PM |
1556 | switch (cft->private) { |
1557 | case FILE_CPULIST: | |
645fcc9d | 1558 | retval = update_cpumask(cs, trialcs, buf); |
e3712395 PM |
1559 | break; |
1560 | case FILE_MEMLIST: | |
645fcc9d | 1561 | retval = update_nodemask(cs, trialcs, buf); |
e3712395 PM |
1562 | break; |
1563 | default: | |
1564 | retval = -EINVAL; | |
1565 | break; | |
1566 | } | |
645fcc9d LZ |
1567 | |
1568 | free_trial_cpuset(trialcs); | |
b75f38d6 | 1569 | out: |
e3712395 PM |
1570 | cgroup_unlock(); |
1571 | return retval; | |
1572 | } | |
1573 | ||
1da177e4 LT |
1574 | /* |
1575 | * These ascii lists should be read in a single call, by using a user | |
1576 | * buffer large enough to hold the entire map. If read in smaller | |
1577 | * chunks, there is no guarantee of atomicity. Since the display format | |
1578 | * used, list of ranges of sequential numbers, is variable length, | |
1579 | * and since these maps can change value dynamically, one could read | |
1580 | * gibberish by doing partial reads while a list was changing. | |
1581 | * A single large read to a buffer that crosses a page boundary is | |
1582 | * ok, because the result being copied to user land is not recomputed | |
1583 | * across a page fault. | |
1584 | */ | |
1585 | ||
9303e0c4 | 1586 | static size_t cpuset_sprintf_cpulist(char *page, struct cpuset *cs) |
1da177e4 | 1587 | { |
9303e0c4 | 1588 | size_t count; |
1da177e4 | 1589 | |
3d3f26a7 | 1590 | mutex_lock(&callback_mutex); |
9303e0c4 | 1591 | count = cpulist_scnprintf(page, PAGE_SIZE, cs->cpus_allowed); |
3d3f26a7 | 1592 | mutex_unlock(&callback_mutex); |
1da177e4 | 1593 | |
9303e0c4 | 1594 | return count; |
1da177e4 LT |
1595 | } |
1596 | ||
9303e0c4 | 1597 | static size_t cpuset_sprintf_memlist(char *page, struct cpuset *cs) |
1da177e4 | 1598 | { |
9303e0c4 | 1599 | size_t count; |
1da177e4 | 1600 | |
3d3f26a7 | 1601 | mutex_lock(&callback_mutex); |
9303e0c4 | 1602 | count = nodelist_scnprintf(page, PAGE_SIZE, cs->mems_allowed); |
3d3f26a7 | 1603 | mutex_unlock(&callback_mutex); |
1da177e4 | 1604 | |
9303e0c4 | 1605 | return count; |
1da177e4 LT |
1606 | } |
1607 | ||
8793d854 PM |
1608 | static ssize_t cpuset_common_file_read(struct cgroup *cont, |
1609 | struct cftype *cft, | |
1610 | struct file *file, | |
1611 | char __user *buf, | |
1612 | size_t nbytes, loff_t *ppos) | |
1da177e4 | 1613 | { |
8793d854 | 1614 | struct cpuset *cs = cgroup_cs(cont); |
1da177e4 LT |
1615 | cpuset_filetype_t type = cft->private; |
1616 | char *page; | |
1617 | ssize_t retval = 0; | |
1618 | char *s; | |
1da177e4 | 1619 | |
e12ba74d | 1620 | if (!(page = (char *)__get_free_page(GFP_TEMPORARY))) |
1da177e4 LT |
1621 | return -ENOMEM; |
1622 | ||
1623 | s = page; | |
1624 | ||
1625 | switch (type) { | |
1626 | case FILE_CPULIST: | |
1627 | s += cpuset_sprintf_cpulist(s, cs); | |
1628 | break; | |
1629 | case FILE_MEMLIST: | |
1630 | s += cpuset_sprintf_memlist(s, cs); | |
1631 | break; | |
1da177e4 LT |
1632 | default: |
1633 | retval = -EINVAL; | |
1634 | goto out; | |
1635 | } | |
1636 | *s++ = '\n'; | |
1da177e4 | 1637 | |
eacaa1f5 | 1638 | retval = simple_read_from_buffer(buf, nbytes, ppos, page, s - page); |
1da177e4 LT |
1639 | out: |
1640 | free_page((unsigned long)page); | |
1641 | return retval; | |
1642 | } | |
1643 | ||
700fe1ab PM |
1644 | static u64 cpuset_read_u64(struct cgroup *cont, struct cftype *cft) |
1645 | { | |
1646 | struct cpuset *cs = cgroup_cs(cont); | |
1647 | cpuset_filetype_t type = cft->private; | |
1648 | switch (type) { | |
1649 | case FILE_CPU_EXCLUSIVE: | |
1650 | return is_cpu_exclusive(cs); | |
1651 | case FILE_MEM_EXCLUSIVE: | |
1652 | return is_mem_exclusive(cs); | |
78608366 PM |
1653 | case FILE_MEM_HARDWALL: |
1654 | return is_mem_hardwall(cs); | |
700fe1ab PM |
1655 | case FILE_SCHED_LOAD_BALANCE: |
1656 | return is_sched_load_balance(cs); | |
1657 | case FILE_MEMORY_MIGRATE: | |
1658 | return is_memory_migrate(cs); | |
1659 | case FILE_MEMORY_PRESSURE_ENABLED: | |
1660 | return cpuset_memory_pressure_enabled; | |
1661 | case FILE_MEMORY_PRESSURE: | |
1662 | return fmeter_getrate(&cs->fmeter); | |
1663 | case FILE_SPREAD_PAGE: | |
1664 | return is_spread_page(cs); | |
1665 | case FILE_SPREAD_SLAB: | |
1666 | return is_spread_slab(cs); | |
1667 | default: | |
1668 | BUG(); | |
1669 | } | |
cf417141 MK |
1670 | |
1671 | /* Unreachable but makes gcc happy */ | |
1672 | return 0; | |
700fe1ab | 1673 | } |
1da177e4 | 1674 | |
5be7a479 PM |
1675 | static s64 cpuset_read_s64(struct cgroup *cont, struct cftype *cft) |
1676 | { | |
1677 | struct cpuset *cs = cgroup_cs(cont); | |
1678 | cpuset_filetype_t type = cft->private; | |
1679 | switch (type) { | |
1680 | case FILE_SCHED_RELAX_DOMAIN_LEVEL: | |
1681 | return cs->relax_domain_level; | |
1682 | default: | |
1683 | BUG(); | |
1684 | } | |
cf417141 MK |
1685 | |
1686 | /* Unrechable but makes gcc happy */ | |
1687 | return 0; | |
5be7a479 PM |
1688 | } |
1689 | ||
1da177e4 LT |
1690 | |
1691 | /* | |
1692 | * for the common functions, 'private' gives the type of file | |
1693 | */ | |
1694 | ||
addf2c73 PM |
1695 | static struct cftype files[] = { |
1696 | { | |
1697 | .name = "cpus", | |
1698 | .read = cpuset_common_file_read, | |
e3712395 PM |
1699 | .write_string = cpuset_write_resmask, |
1700 | .max_write_len = (100U + 6 * NR_CPUS), | |
addf2c73 PM |
1701 | .private = FILE_CPULIST, |
1702 | }, | |
1703 | ||
1704 | { | |
1705 | .name = "mems", | |
1706 | .read = cpuset_common_file_read, | |
e3712395 PM |
1707 | .write_string = cpuset_write_resmask, |
1708 | .max_write_len = (100U + 6 * MAX_NUMNODES), | |
addf2c73 PM |
1709 | .private = FILE_MEMLIST, |
1710 | }, | |
1711 | ||
1712 | { | |
1713 | .name = "cpu_exclusive", | |
1714 | .read_u64 = cpuset_read_u64, | |
1715 | .write_u64 = cpuset_write_u64, | |
1716 | .private = FILE_CPU_EXCLUSIVE, | |
1717 | }, | |
1718 | ||
1719 | { | |
1720 | .name = "mem_exclusive", | |
1721 | .read_u64 = cpuset_read_u64, | |
1722 | .write_u64 = cpuset_write_u64, | |
1723 | .private = FILE_MEM_EXCLUSIVE, | |
1724 | }, | |
1725 | ||
78608366 PM |
1726 | { |
1727 | .name = "mem_hardwall", | |
1728 | .read_u64 = cpuset_read_u64, | |
1729 | .write_u64 = cpuset_write_u64, | |
1730 | .private = FILE_MEM_HARDWALL, | |
1731 | }, | |
1732 | ||
addf2c73 PM |
1733 | { |
1734 | .name = "sched_load_balance", | |
1735 | .read_u64 = cpuset_read_u64, | |
1736 | .write_u64 = cpuset_write_u64, | |
1737 | .private = FILE_SCHED_LOAD_BALANCE, | |
1738 | }, | |
1739 | ||
1740 | { | |
1741 | .name = "sched_relax_domain_level", | |
5be7a479 PM |
1742 | .read_s64 = cpuset_read_s64, |
1743 | .write_s64 = cpuset_write_s64, | |
addf2c73 PM |
1744 | .private = FILE_SCHED_RELAX_DOMAIN_LEVEL, |
1745 | }, | |
1746 | ||
1747 | { | |
1748 | .name = "memory_migrate", | |
1749 | .read_u64 = cpuset_read_u64, | |
1750 | .write_u64 = cpuset_write_u64, | |
1751 | .private = FILE_MEMORY_MIGRATE, | |
1752 | }, | |
1753 | ||
1754 | { | |
1755 | .name = "memory_pressure", | |
1756 | .read_u64 = cpuset_read_u64, | |
1757 | .write_u64 = cpuset_write_u64, | |
1758 | .private = FILE_MEMORY_PRESSURE, | |
099fca32 | 1759 | .mode = S_IRUGO, |
addf2c73 PM |
1760 | }, |
1761 | ||
1762 | { | |
1763 | .name = "memory_spread_page", | |
1764 | .read_u64 = cpuset_read_u64, | |
1765 | .write_u64 = cpuset_write_u64, | |
1766 | .private = FILE_SPREAD_PAGE, | |
1767 | }, | |
1768 | ||
1769 | { | |
1770 | .name = "memory_spread_slab", | |
1771 | .read_u64 = cpuset_read_u64, | |
1772 | .write_u64 = cpuset_write_u64, | |
1773 | .private = FILE_SPREAD_SLAB, | |
1774 | }, | |
3e0d98b9 | 1775 | |
4baf6e33 TH |
1776 | { |
1777 | .name = "memory_pressure_enabled", | |
1778 | .flags = CFTYPE_ONLY_ON_ROOT, | |
1779 | .read_u64 = cpuset_read_u64, | |
1780 | .write_u64 = cpuset_write_u64, | |
1781 | .private = FILE_MEMORY_PRESSURE_ENABLED, | |
1782 | }, | |
1da177e4 | 1783 | |
4baf6e33 TH |
1784 | { } /* terminate */ |
1785 | }; | |
1da177e4 LT |
1786 | |
1787 | /* | |
92fb9748 | 1788 | * cpuset_css_alloc - allocate a cpuset css |
2df167a3 | 1789 | * cont: control group that the new cpuset will be part of |
1da177e4 LT |
1790 | */ |
1791 | ||
92fb9748 | 1792 | static struct cgroup_subsys_state *cpuset_css_alloc(struct cgroup *cont) |
1da177e4 | 1793 | { |
c8f699bb | 1794 | struct cpuset *cs; |
1da177e4 | 1795 | |
c8f699bb | 1796 | if (!cont->parent) |
8793d854 | 1797 | return &top_cpuset.css; |
033fa1c5 | 1798 | |
c8f699bb | 1799 | cs = kzalloc(sizeof(*cs), GFP_KERNEL); |
1da177e4 | 1800 | if (!cs) |
8793d854 | 1801 | return ERR_PTR(-ENOMEM); |
300ed6cb LZ |
1802 | if (!alloc_cpumask_var(&cs->cpus_allowed, GFP_KERNEL)) { |
1803 | kfree(cs); | |
1804 | return ERR_PTR(-ENOMEM); | |
1805 | } | |
1da177e4 | 1806 | |
029190c5 | 1807 | set_bit(CS_SCHED_LOAD_BALANCE, &cs->flags); |
300ed6cb | 1808 | cpumask_clear(cs->cpus_allowed); |
f9a86fcb | 1809 | nodes_clear(cs->mems_allowed); |
3e0d98b9 | 1810 | fmeter_init(&cs->fmeter); |
1d3504fc | 1811 | cs->relax_domain_level = -1; |
c8f699bb TH |
1812 | cs->parent = cgroup_cs(cont->parent); |
1813 | ||
1814 | return &cs->css; | |
1815 | } | |
1816 | ||
1817 | static int cpuset_css_online(struct cgroup *cgrp) | |
1818 | { | |
1819 | struct cpuset *cs = cgroup_cs(cgrp); | |
1820 | struct cpuset *parent = cs->parent; | |
ae8086ce TH |
1821 | struct cpuset *tmp_cs; |
1822 | struct cgroup *pos_cg; | |
c8f699bb TH |
1823 | |
1824 | if (!parent) | |
1825 | return 0; | |
1826 | ||
efeb77b2 | 1827 | set_bit(CS_ONLINE, &cs->flags); |
c8f699bb TH |
1828 | if (is_spread_page(parent)) |
1829 | set_bit(CS_SPREAD_PAGE, &cs->flags); | |
1830 | if (is_spread_slab(parent)) | |
1831 | set_bit(CS_SPREAD_SLAB, &cs->flags); | |
1da177e4 | 1832 | |
202f72d5 | 1833 | number_of_cpusets++; |
033fa1c5 | 1834 | |
c8f699bb TH |
1835 | if (!test_bit(CGRP_CPUSET_CLONE_CHILDREN, &cgrp->flags)) |
1836 | return 0; | |
033fa1c5 TH |
1837 | |
1838 | /* | |
1839 | * Clone @parent's configuration if CGRP_CPUSET_CLONE_CHILDREN is | |
1840 | * set. This flag handling is implemented in cgroup core for | |
1841 | * histrical reasons - the flag may be specified during mount. | |
1842 | * | |
1843 | * Currently, if any sibling cpusets have exclusive cpus or mem, we | |
1844 | * refuse to clone the configuration - thereby refusing the task to | |
1845 | * be entered, and as a result refusing the sys_unshare() or | |
1846 | * clone() which initiated it. If this becomes a problem for some | |
1847 | * users who wish to allow that scenario, then this could be | |
1848 | * changed to grant parent->cpus_allowed-sibling_cpus_exclusive | |
1849 | * (and likewise for mems) to the new cgroup. | |
1850 | */ | |
ae8086ce TH |
1851 | rcu_read_lock(); |
1852 | cpuset_for_each_child(tmp_cs, pos_cg, parent) { | |
1853 | if (is_mem_exclusive(tmp_cs) || is_cpu_exclusive(tmp_cs)) { | |
1854 | rcu_read_unlock(); | |
c8f699bb | 1855 | return 0; |
ae8086ce | 1856 | } |
033fa1c5 | 1857 | } |
ae8086ce | 1858 | rcu_read_unlock(); |
033fa1c5 TH |
1859 | |
1860 | mutex_lock(&callback_mutex); | |
1861 | cs->mems_allowed = parent->mems_allowed; | |
1862 | cpumask_copy(cs->cpus_allowed, parent->cpus_allowed); | |
1863 | mutex_unlock(&callback_mutex); | |
c8f699bb TH |
1864 | |
1865 | return 0; | |
1866 | } | |
1867 | ||
1868 | static void cpuset_css_offline(struct cgroup *cgrp) | |
1869 | { | |
1870 | struct cpuset *cs = cgroup_cs(cgrp); | |
1871 | ||
1872 | /* css_offline is called w/o cgroup_mutex, grab it */ | |
1873 | cgroup_lock(); | |
1874 | ||
1875 | if (is_sched_load_balance(cs)) | |
1876 | update_flag(CS_SCHED_LOAD_BALANCE, cs, 0); | |
1877 | ||
1878 | number_of_cpusets--; | |
efeb77b2 | 1879 | clear_bit(CS_ONLINE, &cs->flags); |
c8f699bb TH |
1880 | |
1881 | cgroup_unlock(); | |
1da177e4 LT |
1882 | } |
1883 | ||
029190c5 | 1884 | /* |
029190c5 PJ |
1885 | * If the cpuset being removed has its flag 'sched_load_balance' |
1886 | * enabled, then simulate turning sched_load_balance off, which | |
699140ba | 1887 | * will call rebuild_sched_domains_locked(). |
029190c5 PJ |
1888 | */ |
1889 | ||
92fb9748 | 1890 | static void cpuset_css_free(struct cgroup *cont) |
1da177e4 | 1891 | { |
8793d854 | 1892 | struct cpuset *cs = cgroup_cs(cont); |
1da177e4 | 1893 | |
300ed6cb | 1894 | free_cpumask_var(cs->cpus_allowed); |
8793d854 | 1895 | kfree(cs); |
1da177e4 LT |
1896 | } |
1897 | ||
8793d854 PM |
1898 | struct cgroup_subsys cpuset_subsys = { |
1899 | .name = "cpuset", | |
92fb9748 | 1900 | .css_alloc = cpuset_css_alloc, |
c8f699bb TH |
1901 | .css_online = cpuset_css_online, |
1902 | .css_offline = cpuset_css_offline, | |
92fb9748 | 1903 | .css_free = cpuset_css_free, |
8793d854 PM |
1904 | .can_attach = cpuset_can_attach, |
1905 | .attach = cpuset_attach, | |
8793d854 | 1906 | .subsys_id = cpuset_subsys_id, |
4baf6e33 | 1907 | .base_cftypes = files, |
8793d854 PM |
1908 | .early_init = 1, |
1909 | }; | |
1910 | ||
1da177e4 LT |
1911 | /** |
1912 | * cpuset_init - initialize cpusets at system boot | |
1913 | * | |
1914 | * Description: Initialize top_cpuset and the cpuset internal file system, | |
1915 | **/ | |
1916 | ||
1917 | int __init cpuset_init(void) | |
1918 | { | |
8793d854 | 1919 | int err = 0; |
1da177e4 | 1920 | |
58568d2a MX |
1921 | if (!alloc_cpumask_var(&top_cpuset.cpus_allowed, GFP_KERNEL)) |
1922 | BUG(); | |
1923 | ||
300ed6cb | 1924 | cpumask_setall(top_cpuset.cpus_allowed); |
f9a86fcb | 1925 | nodes_setall(top_cpuset.mems_allowed); |
1da177e4 | 1926 | |
3e0d98b9 | 1927 | fmeter_init(&top_cpuset.fmeter); |
029190c5 | 1928 | set_bit(CS_SCHED_LOAD_BALANCE, &top_cpuset.flags); |
1d3504fc | 1929 | top_cpuset.relax_domain_level = -1; |
1da177e4 | 1930 | |
1da177e4 LT |
1931 | err = register_filesystem(&cpuset_fs_type); |
1932 | if (err < 0) | |
8793d854 PM |
1933 | return err; |
1934 | ||
2341d1b6 LZ |
1935 | if (!alloc_cpumask_var(&cpus_attach, GFP_KERNEL)) |
1936 | BUG(); | |
1937 | ||
202f72d5 | 1938 | number_of_cpusets = 1; |
8793d854 | 1939 | return 0; |
1da177e4 LT |
1940 | } |
1941 | ||
956db3ca CW |
1942 | /** |
1943 | * cpuset_do_move_task - move a given task to another cpuset | |
1944 | * @tsk: pointer to task_struct the task to move | |
1945 | * @scan: struct cgroup_scanner contained in its struct cpuset_hotplug_scanner | |
1946 | * | |
1947 | * Called by cgroup_scan_tasks() for each task in a cgroup. | |
1948 | * Return nonzero to stop the walk through the tasks. | |
1949 | */ | |
9e0c914c AB |
1950 | static void cpuset_do_move_task(struct task_struct *tsk, |
1951 | struct cgroup_scanner *scan) | |
956db3ca | 1952 | { |
7f81b1ae | 1953 | struct cgroup *new_cgroup = scan->data; |
956db3ca | 1954 | |
7f81b1ae | 1955 | cgroup_attach_task(new_cgroup, tsk); |
956db3ca CW |
1956 | } |
1957 | ||
1958 | /** | |
1959 | * move_member_tasks_to_cpuset - move tasks from one cpuset to another | |
1960 | * @from: cpuset in which the tasks currently reside | |
1961 | * @to: cpuset to which the tasks will be moved | |
1962 | * | |
c8d9c90c PJ |
1963 | * Called with cgroup_mutex held |
1964 | * callback_mutex must not be held, as cpuset_attach() will take it. | |
956db3ca CW |
1965 | * |
1966 | * The cgroup_scan_tasks() function will scan all the tasks in a cgroup, | |
1967 | * calling callback functions for each. | |
1968 | */ | |
1969 | static void move_member_tasks_to_cpuset(struct cpuset *from, struct cpuset *to) | |
1970 | { | |
7f81b1ae | 1971 | struct cgroup_scanner scan; |
956db3ca | 1972 | |
7f81b1ae LZ |
1973 | scan.cg = from->css.cgroup; |
1974 | scan.test_task = NULL; /* select all tasks in cgroup */ | |
1975 | scan.process_task = cpuset_do_move_task; | |
1976 | scan.heap = NULL; | |
1977 | scan.data = to->css.cgroup; | |
956db3ca | 1978 | |
7f81b1ae | 1979 | if (cgroup_scan_tasks(&scan)) |
956db3ca CW |
1980 | printk(KERN_ERR "move_member_tasks_to_cpuset: " |
1981 | "cgroup_scan_tasks failed\n"); | |
1982 | } | |
1983 | ||
b1aac8bb | 1984 | /* |
cf417141 | 1985 | * If CPU and/or memory hotplug handlers, below, unplug any CPUs |
b1aac8bb PJ |
1986 | * or memory nodes, we need to walk over the cpuset hierarchy, |
1987 | * removing that CPU or node from all cpusets. If this removes the | |
956db3ca CW |
1988 | * last CPU or node from a cpuset, then move the tasks in the empty |
1989 | * cpuset to its next-highest non-empty parent. | |
b1aac8bb | 1990 | * |
c8d9c90c PJ |
1991 | * Called with cgroup_mutex held |
1992 | * callback_mutex must not be held, as cpuset_attach() will take it. | |
b1aac8bb | 1993 | */ |
956db3ca CW |
1994 | static void remove_tasks_in_empty_cpuset(struct cpuset *cs) |
1995 | { | |
1996 | struct cpuset *parent; | |
1997 | ||
956db3ca CW |
1998 | /* |
1999 | * Find its next-highest non-empty parent, (top cpuset | |
2000 | * has online cpus, so can't be empty). | |
2001 | */ | |
2002 | parent = cs->parent; | |
300ed6cb | 2003 | while (cpumask_empty(parent->cpus_allowed) || |
b4501295 | 2004 | nodes_empty(parent->mems_allowed)) |
956db3ca | 2005 | parent = parent->parent; |
956db3ca CW |
2006 | |
2007 | move_member_tasks_to_cpuset(cs, parent); | |
2008 | } | |
2009 | ||
80d1fa64 SB |
2010 | /* |
2011 | * Helper function to traverse cpusets. | |
2012 | * It can be used to walk the cpuset tree from top to bottom, completing | |
2013 | * one layer before dropping down to the next (thus always processing a | |
2014 | * node before any of its children). | |
2015 | */ | |
2016 | static struct cpuset *cpuset_next(struct list_head *queue) | |
2017 | { | |
2018 | struct cpuset *cp; | |
2019 | struct cpuset *child; /* scans child cpusets of cp */ | |
2020 | struct cgroup *cont; | |
2021 | ||
2022 | if (list_empty(queue)) | |
2023 | return NULL; | |
2024 | ||
2025 | cp = list_first_entry(queue, struct cpuset, stack_list); | |
2026 | list_del(queue->next); | |
ae8086ce TH |
2027 | rcu_read_lock(); |
2028 | cpuset_for_each_child(child, cont, cp) | |
80d1fa64 | 2029 | list_add_tail(&child->stack_list, queue); |
ae8086ce | 2030 | rcu_read_unlock(); |
80d1fa64 SB |
2031 | |
2032 | return cp; | |
2033 | } | |
2034 | ||
deb7aa30 TH |
2035 | /** |
2036 | * cpuset_propagate_hotplug - propagate CPU/memory hotplug to a cpuset | |
2037 | * @cs: cpuset in interest | |
956db3ca | 2038 | * |
deb7aa30 TH |
2039 | * Compare @cs's cpu and mem masks against top_cpuset and if some have gone |
2040 | * offline, update @cs accordingly. If @cs ends up with no CPU or memory, | |
2041 | * all its tasks are moved to the nearest ancestor with both resources. | |
956db3ca | 2042 | * |
deb7aa30 | 2043 | * Should be called with cgroup_mutex held. |
956db3ca | 2044 | */ |
deb7aa30 | 2045 | static void cpuset_propagate_hotplug(struct cpuset *cs) |
b1aac8bb | 2046 | { |
deb7aa30 TH |
2047 | static cpumask_t off_cpus; |
2048 | static nodemask_t off_mems, tmp_mems; | |
7ddf96b0 | 2049 | |
deb7aa30 | 2050 | WARN_ON_ONCE(!cgroup_lock_is_held()); |
7ddf96b0 | 2051 | |
deb7aa30 TH |
2052 | cpumask_andnot(&off_cpus, cs->cpus_allowed, top_cpuset.cpus_allowed); |
2053 | nodes_andnot(off_mems, cs->mems_allowed, top_cpuset.mems_allowed); | |
7ddf96b0 | 2054 | |
deb7aa30 TH |
2055 | /* remove offline cpus from @cs */ |
2056 | if (!cpumask_empty(&off_cpus)) { | |
2057 | mutex_lock(&callback_mutex); | |
2058 | cpumask_andnot(cs->cpus_allowed, cs->cpus_allowed, &off_cpus); | |
2059 | mutex_unlock(&callback_mutex); | |
2060 | update_tasks_cpumask(cs, NULL); | |
2061 | } | |
b4501295 | 2062 | |
deb7aa30 TH |
2063 | /* remove offline mems from @cs */ |
2064 | if (!nodes_empty(off_mems)) { | |
2065 | tmp_mems = cs->mems_allowed; | |
2066 | mutex_lock(&callback_mutex); | |
2067 | nodes_andnot(cs->mems_allowed, cs->mems_allowed, off_mems); | |
2068 | mutex_unlock(&callback_mutex); | |
2069 | update_tasks_nodemask(cs, &tmp_mems, NULL); | |
b1aac8bb | 2070 | } |
deb7aa30 TH |
2071 | |
2072 | if (cpumask_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed)) | |
2073 | remove_tasks_in_empty_cpuset(cs); | |
b1aac8bb PJ |
2074 | } |
2075 | ||
deb7aa30 | 2076 | /** |
3a5a6d0c | 2077 | * cpuset_hotplug_workfn - handle CPU/memory hotunplug for a cpuset |
d35be8ba | 2078 | * |
deb7aa30 TH |
2079 | * This function is called after either CPU or memory configuration has |
2080 | * changed and updates cpuset accordingly. The top_cpuset is always | |
2081 | * synchronized to cpu_active_mask and N_MEMORY, which is necessary in | |
2082 | * order to make cpusets transparent (of no affect) on systems that are | |
2083 | * actively using CPU hotplug but making no active use of cpusets. | |
cf417141 | 2084 | * |
deb7aa30 TH |
2085 | * Non-root cpusets are only affected by offlining. If any CPUs or memory |
2086 | * nodes have been taken down, cpuset_propagate_hotplug() is invoked on all | |
2087 | * descendants. | |
7ddf96b0 | 2088 | * |
deb7aa30 TH |
2089 | * Note that CPU offlining during suspend is ignored. We don't modify |
2090 | * cpusets across suspend/resume cycles at all. | |
4c4d50f7 | 2091 | */ |
3a5a6d0c | 2092 | static void cpuset_hotplug_workfn(struct work_struct *work) |
4c4d50f7 | 2093 | { |
deb7aa30 TH |
2094 | static cpumask_t new_cpus, tmp_cpus; |
2095 | static nodemask_t new_mems, tmp_mems; | |
2096 | bool cpus_updated, mems_updated; | |
2097 | bool cpus_offlined, mems_offlined; | |
cf417141 | 2098 | |
cf417141 | 2099 | cgroup_lock(); |
7ddf96b0 | 2100 | |
deb7aa30 TH |
2101 | /* fetch the available cpus/mems and find out which changed how */ |
2102 | cpumask_copy(&new_cpus, cpu_active_mask); | |
2103 | new_mems = node_states[N_MEMORY]; | |
2104 | ||
2105 | cpus_updated = !cpumask_equal(top_cpuset.cpus_allowed, &new_cpus); | |
2106 | cpus_offlined = cpumask_andnot(&tmp_cpus, top_cpuset.cpus_allowed, | |
2107 | &new_cpus); | |
2108 | ||
2109 | mems_updated = !nodes_equal(top_cpuset.mems_allowed, new_mems); | |
2110 | nodes_andnot(tmp_mems, top_cpuset.mems_allowed, new_mems); | |
2111 | mems_offlined = !nodes_empty(tmp_mems); | |
2112 | ||
2113 | /* synchronize cpus_allowed to cpu_active_mask */ | |
2114 | if (cpus_updated) { | |
2115 | mutex_lock(&callback_mutex); | |
2116 | cpumask_copy(top_cpuset.cpus_allowed, &new_cpus); | |
2117 | mutex_unlock(&callback_mutex); | |
2118 | /* we don't mess with cpumasks of tasks in top_cpuset */ | |
2119 | } | |
2120 | ||
2121 | /* synchronize mems_allowed to N_MEMORY */ | |
2122 | if (mems_updated) { | |
2123 | tmp_mems = top_cpuset.mems_allowed; | |
2124 | mutex_lock(&callback_mutex); | |
2125 | top_cpuset.mems_allowed = new_mems; | |
2126 | mutex_unlock(&callback_mutex); | |
2127 | update_tasks_nodemask(&top_cpuset, &tmp_mems, NULL); | |
2128 | } | |
2129 | ||
2130 | /* if cpus or mems went down, we need to propagate to descendants */ | |
2131 | if (cpus_offlined || mems_offlined) { | |
2132 | struct cpuset *cs; | |
2133 | LIST_HEAD(queue); | |
2134 | ||
2135 | list_add_tail(&top_cpuset.stack_list, &queue); | |
2136 | while ((cs = cpuset_next(&queue))) | |
2137 | if (cs != &top_cpuset) | |
2138 | cpuset_propagate_hotplug(cs); | |
2139 | } | |
7ddf96b0 | 2140 | |
cf417141 MK |
2141 | cgroup_unlock(); |
2142 | ||
deb7aa30 TH |
2143 | /* rebuild sched domains if cpus_allowed has changed */ |
2144 | if (cpus_updated) { | |
2145 | struct sched_domain_attr *attr; | |
2146 | cpumask_var_t *doms; | |
2147 | int ndoms; | |
2148 | ||
2149 | cgroup_lock(); | |
2150 | ndoms = generate_sched_domains(&doms, &attr); | |
2151 | cgroup_unlock(); | |
2152 | ||
2153 | partition_sched_domains(ndoms, doms, attr); | |
2154 | } | |
2155 | } | |
2156 | ||
2157 | void cpuset_update_active_cpus(bool cpu_online) | |
2158 | { | |
3a5a6d0c TH |
2159 | /* |
2160 | * We're inside cpu hotplug critical region which usually nests | |
2161 | * inside cgroup synchronization. Bounce actual hotplug processing | |
2162 | * to a work item to avoid reverse locking order. | |
2163 | * | |
2164 | * We still need to do partition_sched_domains() synchronously; | |
2165 | * otherwise, the scheduler will get confused and put tasks to the | |
2166 | * dead CPU. Fall back to the default single domain. | |
2167 | * cpuset_hotplug_workfn() will rebuild it as necessary. | |
2168 | */ | |
2169 | partition_sched_domains(1, NULL, NULL); | |
2170 | schedule_work(&cpuset_hotplug_work); | |
4c4d50f7 | 2171 | } |
4c4d50f7 | 2172 | |
b1aac8bb | 2173 | #ifdef CONFIG_MEMORY_HOTPLUG |
38837fc7 | 2174 | /* |
38d7bee9 LJ |
2175 | * Keep top_cpuset.mems_allowed tracking node_states[N_MEMORY]. |
2176 | * Call this routine anytime after node_states[N_MEMORY] changes. | |
a1cd2b13 | 2177 | * See cpuset_update_active_cpus() for CPU hotplug handling. |
38837fc7 | 2178 | */ |
f481891f MX |
2179 | static int cpuset_track_online_nodes(struct notifier_block *self, |
2180 | unsigned long action, void *arg) | |
38837fc7 | 2181 | { |
3a5a6d0c | 2182 | schedule_work(&cpuset_hotplug_work); |
f481891f | 2183 | return NOTIFY_OK; |
38837fc7 PJ |
2184 | } |
2185 | #endif | |
2186 | ||
1da177e4 LT |
2187 | /** |
2188 | * cpuset_init_smp - initialize cpus_allowed | |
2189 | * | |
2190 | * Description: Finish top cpuset after cpu, node maps are initialized | |
2191 | **/ | |
2192 | ||
2193 | void __init cpuset_init_smp(void) | |
2194 | { | |
6ad4c188 | 2195 | cpumask_copy(top_cpuset.cpus_allowed, cpu_active_mask); |
38d7bee9 | 2196 | top_cpuset.mems_allowed = node_states[N_MEMORY]; |
4c4d50f7 | 2197 | |
f481891f | 2198 | hotplug_memory_notifier(cpuset_track_online_nodes, 10); |
1da177e4 LT |
2199 | } |
2200 | ||
2201 | /** | |
1da177e4 LT |
2202 | * cpuset_cpus_allowed - return cpus_allowed mask from a tasks cpuset. |
2203 | * @tsk: pointer to task_struct from which to obtain cpuset->cpus_allowed. | |
6af866af | 2204 | * @pmask: pointer to struct cpumask variable to receive cpus_allowed set. |
1da177e4 | 2205 | * |
300ed6cb | 2206 | * Description: Returns the cpumask_var_t cpus_allowed of the cpuset |
1da177e4 | 2207 | * attached to the specified @tsk. Guaranteed to return some non-empty |
5f054e31 | 2208 | * subset of cpu_online_mask, even if this means going outside the |
1da177e4 LT |
2209 | * tasks cpuset. |
2210 | **/ | |
2211 | ||
6af866af | 2212 | void cpuset_cpus_allowed(struct task_struct *tsk, struct cpumask *pmask) |
1da177e4 | 2213 | { |
3d3f26a7 | 2214 | mutex_lock(&callback_mutex); |
909d75a3 | 2215 | task_lock(tsk); |
f9a86fcb | 2216 | guarantee_online_cpus(task_cs(tsk), pmask); |
909d75a3 | 2217 | task_unlock(tsk); |
897f0b3c | 2218 | mutex_unlock(&callback_mutex); |
1da177e4 LT |
2219 | } |
2220 | ||
2baab4e9 | 2221 | void cpuset_cpus_allowed_fallback(struct task_struct *tsk) |
9084bb82 ON |
2222 | { |
2223 | const struct cpuset *cs; | |
9084bb82 ON |
2224 | |
2225 | rcu_read_lock(); | |
2226 | cs = task_cs(tsk); | |
2227 | if (cs) | |
1e1b6c51 | 2228 | do_set_cpus_allowed(tsk, cs->cpus_allowed); |
9084bb82 ON |
2229 | rcu_read_unlock(); |
2230 | ||
2231 | /* | |
2232 | * We own tsk->cpus_allowed, nobody can change it under us. | |
2233 | * | |
2234 | * But we used cs && cs->cpus_allowed lockless and thus can | |
2235 | * race with cgroup_attach_task() or update_cpumask() and get | |
2236 | * the wrong tsk->cpus_allowed. However, both cases imply the | |
2237 | * subsequent cpuset_change_cpumask()->set_cpus_allowed_ptr() | |
2238 | * which takes task_rq_lock(). | |
2239 | * | |
2240 | * If we are called after it dropped the lock we must see all | |
2241 | * changes in tsk_cs()->cpus_allowed. Otherwise we can temporary | |
2242 | * set any mask even if it is not right from task_cs() pov, | |
2243 | * the pending set_cpus_allowed_ptr() will fix things. | |
2baab4e9 PZ |
2244 | * |
2245 | * select_fallback_rq() will fix things ups and set cpu_possible_mask | |
2246 | * if required. | |
9084bb82 | 2247 | */ |
9084bb82 ON |
2248 | } |
2249 | ||
1da177e4 LT |
2250 | void cpuset_init_current_mems_allowed(void) |
2251 | { | |
f9a86fcb | 2252 | nodes_setall(current->mems_allowed); |
1da177e4 LT |
2253 | } |
2254 | ||
909d75a3 PJ |
2255 | /** |
2256 | * cpuset_mems_allowed - return mems_allowed mask from a tasks cpuset. | |
2257 | * @tsk: pointer to task_struct from which to obtain cpuset->mems_allowed. | |
2258 | * | |
2259 | * Description: Returns the nodemask_t mems_allowed of the cpuset | |
2260 | * attached to the specified @tsk. Guaranteed to return some non-empty | |
38d7bee9 | 2261 | * subset of node_states[N_MEMORY], even if this means going outside the |
909d75a3 PJ |
2262 | * tasks cpuset. |
2263 | **/ | |
2264 | ||
2265 | nodemask_t cpuset_mems_allowed(struct task_struct *tsk) | |
2266 | { | |
2267 | nodemask_t mask; | |
2268 | ||
3d3f26a7 | 2269 | mutex_lock(&callback_mutex); |
909d75a3 | 2270 | task_lock(tsk); |
8793d854 | 2271 | guarantee_online_mems(task_cs(tsk), &mask); |
909d75a3 | 2272 | task_unlock(tsk); |
3d3f26a7 | 2273 | mutex_unlock(&callback_mutex); |
909d75a3 PJ |
2274 | |
2275 | return mask; | |
2276 | } | |
2277 | ||
d9fd8a6d | 2278 | /** |
19770b32 MG |
2279 | * cpuset_nodemask_valid_mems_allowed - check nodemask vs. curremt mems_allowed |
2280 | * @nodemask: the nodemask to be checked | |
d9fd8a6d | 2281 | * |
19770b32 | 2282 | * Are any of the nodes in the nodemask allowed in current->mems_allowed? |
1da177e4 | 2283 | */ |
19770b32 | 2284 | int cpuset_nodemask_valid_mems_allowed(nodemask_t *nodemask) |
1da177e4 | 2285 | { |
19770b32 | 2286 | return nodes_intersects(*nodemask, current->mems_allowed); |
1da177e4 LT |
2287 | } |
2288 | ||
9bf2229f | 2289 | /* |
78608366 PM |
2290 | * nearest_hardwall_ancestor() - Returns the nearest mem_exclusive or |
2291 | * mem_hardwall ancestor to the specified cpuset. Call holding | |
2292 | * callback_mutex. If no ancestor is mem_exclusive or mem_hardwall | |
2293 | * (an unusual configuration), then returns the root cpuset. | |
9bf2229f | 2294 | */ |
78608366 | 2295 | static const struct cpuset *nearest_hardwall_ancestor(const struct cpuset *cs) |
9bf2229f | 2296 | { |
78608366 | 2297 | while (!(is_mem_exclusive(cs) || is_mem_hardwall(cs)) && cs->parent) |
9bf2229f PJ |
2298 | cs = cs->parent; |
2299 | return cs; | |
2300 | } | |
2301 | ||
d9fd8a6d | 2302 | /** |
a1bc5a4e DR |
2303 | * cpuset_node_allowed_softwall - Can we allocate on a memory node? |
2304 | * @node: is this an allowed node? | |
02a0e53d | 2305 | * @gfp_mask: memory allocation flags |
d9fd8a6d | 2306 | * |
a1bc5a4e DR |
2307 | * If we're in interrupt, yes, we can always allocate. If __GFP_THISNODE is |
2308 | * set, yes, we can always allocate. If node is in our task's mems_allowed, | |
2309 | * yes. If it's not a __GFP_HARDWALL request and this node is in the nearest | |
2310 | * hardwalled cpuset ancestor to this task's cpuset, yes. If the task has been | |
2311 | * OOM killed and has access to memory reserves as specified by the TIF_MEMDIE | |
2312 | * flag, yes. | |
9bf2229f PJ |
2313 | * Otherwise, no. |
2314 | * | |
a1bc5a4e DR |
2315 | * If __GFP_HARDWALL is set, cpuset_node_allowed_softwall() reduces to |
2316 | * cpuset_node_allowed_hardwall(). Otherwise, cpuset_node_allowed_softwall() | |
2317 | * might sleep, and might allow a node from an enclosing cpuset. | |
02a0e53d | 2318 | * |
a1bc5a4e DR |
2319 | * cpuset_node_allowed_hardwall() only handles the simpler case of hardwall |
2320 | * cpusets, and never sleeps. | |
02a0e53d PJ |
2321 | * |
2322 | * The __GFP_THISNODE placement logic is really handled elsewhere, | |
2323 | * by forcibly using a zonelist starting at a specified node, and by | |
2324 | * (in get_page_from_freelist()) refusing to consider the zones for | |
2325 | * any node on the zonelist except the first. By the time any such | |
2326 | * calls get to this routine, we should just shut up and say 'yes'. | |
2327 | * | |
9bf2229f | 2328 | * GFP_USER allocations are marked with the __GFP_HARDWALL bit, |
c596d9f3 DR |
2329 | * and do not allow allocations outside the current tasks cpuset |
2330 | * unless the task has been OOM killed as is marked TIF_MEMDIE. | |
9bf2229f | 2331 | * GFP_KERNEL allocations are not so marked, so can escape to the |
78608366 | 2332 | * nearest enclosing hardwalled ancestor cpuset. |
9bf2229f | 2333 | * |
02a0e53d PJ |
2334 | * Scanning up parent cpusets requires callback_mutex. The |
2335 | * __alloc_pages() routine only calls here with __GFP_HARDWALL bit | |
2336 | * _not_ set if it's a GFP_KERNEL allocation, and all nodes in the | |
2337 | * current tasks mems_allowed came up empty on the first pass over | |
2338 | * the zonelist. So only GFP_KERNEL allocations, if all nodes in the | |
2339 | * cpuset are short of memory, might require taking the callback_mutex | |
2340 | * mutex. | |
9bf2229f | 2341 | * |
36be57ff | 2342 | * The first call here from mm/page_alloc:get_page_from_freelist() |
02a0e53d PJ |
2343 | * has __GFP_HARDWALL set in gfp_mask, enforcing hardwall cpusets, |
2344 | * so no allocation on a node outside the cpuset is allowed (unless | |
2345 | * in interrupt, of course). | |
36be57ff PJ |
2346 | * |
2347 | * The second pass through get_page_from_freelist() doesn't even call | |
2348 | * here for GFP_ATOMIC calls. For those calls, the __alloc_pages() | |
2349 | * variable 'wait' is not set, and the bit ALLOC_CPUSET is not set | |
2350 | * in alloc_flags. That logic and the checks below have the combined | |
2351 | * affect that: | |
9bf2229f PJ |
2352 | * in_interrupt - any node ok (current task context irrelevant) |
2353 | * GFP_ATOMIC - any node ok | |
c596d9f3 | 2354 | * TIF_MEMDIE - any node ok |
78608366 | 2355 | * GFP_KERNEL - any node in enclosing hardwalled cpuset ok |
9bf2229f | 2356 | * GFP_USER - only nodes in current tasks mems allowed ok. |
36be57ff PJ |
2357 | * |
2358 | * Rule: | |
a1bc5a4e | 2359 | * Don't call cpuset_node_allowed_softwall if you can't sleep, unless you |
36be57ff PJ |
2360 | * pass in the __GFP_HARDWALL flag set in gfp_flag, which disables |
2361 | * the code that might scan up ancestor cpusets and sleep. | |
02a0e53d | 2362 | */ |
a1bc5a4e | 2363 | int __cpuset_node_allowed_softwall(int node, gfp_t gfp_mask) |
1da177e4 | 2364 | { |
9bf2229f | 2365 | const struct cpuset *cs; /* current cpuset ancestors */ |
29afd49b | 2366 | int allowed; /* is allocation in zone z allowed? */ |
9bf2229f | 2367 | |
9b819d20 | 2368 | if (in_interrupt() || (gfp_mask & __GFP_THISNODE)) |
9bf2229f | 2369 | return 1; |
92d1dbd2 | 2370 | might_sleep_if(!(gfp_mask & __GFP_HARDWALL)); |
9bf2229f PJ |
2371 | if (node_isset(node, current->mems_allowed)) |
2372 | return 1; | |
c596d9f3 DR |
2373 | /* |
2374 | * Allow tasks that have access to memory reserves because they have | |
2375 | * been OOM killed to get memory anywhere. | |
2376 | */ | |
2377 | if (unlikely(test_thread_flag(TIF_MEMDIE))) | |
2378 | return 1; | |
9bf2229f PJ |
2379 | if (gfp_mask & __GFP_HARDWALL) /* If hardwall request, stop here */ |
2380 | return 0; | |
2381 | ||
5563e770 BP |
2382 | if (current->flags & PF_EXITING) /* Let dying task have memory */ |
2383 | return 1; | |
2384 | ||
9bf2229f | 2385 | /* Not hardwall and node outside mems_allowed: scan up cpusets */ |
3d3f26a7 | 2386 | mutex_lock(&callback_mutex); |
053199ed | 2387 | |
053199ed | 2388 | task_lock(current); |
78608366 | 2389 | cs = nearest_hardwall_ancestor(task_cs(current)); |
053199ed PJ |
2390 | task_unlock(current); |
2391 | ||
9bf2229f | 2392 | allowed = node_isset(node, cs->mems_allowed); |
3d3f26a7 | 2393 | mutex_unlock(&callback_mutex); |
9bf2229f | 2394 | return allowed; |
1da177e4 LT |
2395 | } |
2396 | ||
02a0e53d | 2397 | /* |
a1bc5a4e DR |
2398 | * cpuset_node_allowed_hardwall - Can we allocate on a memory node? |
2399 | * @node: is this an allowed node? | |
02a0e53d PJ |
2400 | * @gfp_mask: memory allocation flags |
2401 | * | |
a1bc5a4e DR |
2402 | * If we're in interrupt, yes, we can always allocate. If __GFP_THISNODE is |
2403 | * set, yes, we can always allocate. If node is in our task's mems_allowed, | |
2404 | * yes. If the task has been OOM killed and has access to memory reserves as | |
2405 | * specified by the TIF_MEMDIE flag, yes. | |
2406 | * Otherwise, no. | |
02a0e53d PJ |
2407 | * |
2408 | * The __GFP_THISNODE placement logic is really handled elsewhere, | |
2409 | * by forcibly using a zonelist starting at a specified node, and by | |
2410 | * (in get_page_from_freelist()) refusing to consider the zones for | |
2411 | * any node on the zonelist except the first. By the time any such | |
2412 | * calls get to this routine, we should just shut up and say 'yes'. | |
2413 | * | |
a1bc5a4e DR |
2414 | * Unlike the cpuset_node_allowed_softwall() variant, above, |
2415 | * this variant requires that the node be in the current task's | |
02a0e53d PJ |
2416 | * mems_allowed or that we're in interrupt. It does not scan up the |
2417 | * cpuset hierarchy for the nearest enclosing mem_exclusive cpuset. | |
2418 | * It never sleeps. | |
2419 | */ | |
a1bc5a4e | 2420 | int __cpuset_node_allowed_hardwall(int node, gfp_t gfp_mask) |
02a0e53d | 2421 | { |
02a0e53d PJ |
2422 | if (in_interrupt() || (gfp_mask & __GFP_THISNODE)) |
2423 | return 1; | |
02a0e53d PJ |
2424 | if (node_isset(node, current->mems_allowed)) |
2425 | return 1; | |
dedf8b79 DW |
2426 | /* |
2427 | * Allow tasks that have access to memory reserves because they have | |
2428 | * been OOM killed to get memory anywhere. | |
2429 | */ | |
2430 | if (unlikely(test_thread_flag(TIF_MEMDIE))) | |
2431 | return 1; | |
02a0e53d PJ |
2432 | return 0; |
2433 | } | |
2434 | ||
825a46af | 2435 | /** |
6adef3eb JS |
2436 | * cpuset_mem_spread_node() - On which node to begin search for a file page |
2437 | * cpuset_slab_spread_node() - On which node to begin search for a slab page | |
825a46af PJ |
2438 | * |
2439 | * If a task is marked PF_SPREAD_PAGE or PF_SPREAD_SLAB (as for | |
2440 | * tasks in a cpuset with is_spread_page or is_spread_slab set), | |
2441 | * and if the memory allocation used cpuset_mem_spread_node() | |
2442 | * to determine on which node to start looking, as it will for | |
2443 | * certain page cache or slab cache pages such as used for file | |
2444 | * system buffers and inode caches, then instead of starting on the | |
2445 | * local node to look for a free page, rather spread the starting | |
2446 | * node around the tasks mems_allowed nodes. | |
2447 | * | |
2448 | * We don't have to worry about the returned node being offline | |
2449 | * because "it can't happen", and even if it did, it would be ok. | |
2450 | * | |
2451 | * The routines calling guarantee_online_mems() are careful to | |
2452 | * only set nodes in task->mems_allowed that are online. So it | |
2453 | * should not be possible for the following code to return an | |
2454 | * offline node. But if it did, that would be ok, as this routine | |
2455 | * is not returning the node where the allocation must be, only | |
2456 | * the node where the search should start. The zonelist passed to | |
2457 | * __alloc_pages() will include all nodes. If the slab allocator | |
2458 | * is passed an offline node, it will fall back to the local node. | |
2459 | * See kmem_cache_alloc_node(). | |
2460 | */ | |
2461 | ||
6adef3eb | 2462 | static int cpuset_spread_node(int *rotor) |
825a46af PJ |
2463 | { |
2464 | int node; | |
2465 | ||
6adef3eb | 2466 | node = next_node(*rotor, current->mems_allowed); |
825a46af PJ |
2467 | if (node == MAX_NUMNODES) |
2468 | node = first_node(current->mems_allowed); | |
6adef3eb | 2469 | *rotor = node; |
825a46af PJ |
2470 | return node; |
2471 | } | |
6adef3eb JS |
2472 | |
2473 | int cpuset_mem_spread_node(void) | |
2474 | { | |
778d3b0f MH |
2475 | if (current->cpuset_mem_spread_rotor == NUMA_NO_NODE) |
2476 | current->cpuset_mem_spread_rotor = | |
2477 | node_random(¤t->mems_allowed); | |
2478 | ||
6adef3eb JS |
2479 | return cpuset_spread_node(¤t->cpuset_mem_spread_rotor); |
2480 | } | |
2481 | ||
2482 | int cpuset_slab_spread_node(void) | |
2483 | { | |
778d3b0f MH |
2484 | if (current->cpuset_slab_spread_rotor == NUMA_NO_NODE) |
2485 | current->cpuset_slab_spread_rotor = | |
2486 | node_random(¤t->mems_allowed); | |
2487 | ||
6adef3eb JS |
2488 | return cpuset_spread_node(¤t->cpuset_slab_spread_rotor); |
2489 | } | |
2490 | ||
825a46af PJ |
2491 | EXPORT_SYMBOL_GPL(cpuset_mem_spread_node); |
2492 | ||
ef08e3b4 | 2493 | /** |
bbe373f2 DR |
2494 | * cpuset_mems_allowed_intersects - Does @tsk1's mems_allowed intersect @tsk2's? |
2495 | * @tsk1: pointer to task_struct of some task. | |
2496 | * @tsk2: pointer to task_struct of some other task. | |
2497 | * | |
2498 | * Description: Return true if @tsk1's mems_allowed intersects the | |
2499 | * mems_allowed of @tsk2. Used by the OOM killer to determine if | |
2500 | * one of the task's memory usage might impact the memory available | |
2501 | * to the other. | |
ef08e3b4 PJ |
2502 | **/ |
2503 | ||
bbe373f2 DR |
2504 | int cpuset_mems_allowed_intersects(const struct task_struct *tsk1, |
2505 | const struct task_struct *tsk2) | |
ef08e3b4 | 2506 | { |
bbe373f2 | 2507 | return nodes_intersects(tsk1->mems_allowed, tsk2->mems_allowed); |
ef08e3b4 PJ |
2508 | } |
2509 | ||
75aa1994 DR |
2510 | /** |
2511 | * cpuset_print_task_mems_allowed - prints task's cpuset and mems_allowed | |
2512 | * @task: pointer to task_struct of some task. | |
2513 | * | |
2514 | * Description: Prints @task's name, cpuset name, and cached copy of its | |
2515 | * mems_allowed to the kernel log. Must hold task_lock(task) to allow | |
2516 | * dereferencing task_cs(task). | |
2517 | */ | |
2518 | void cpuset_print_task_mems_allowed(struct task_struct *tsk) | |
2519 | { | |
2520 | struct dentry *dentry; | |
2521 | ||
2522 | dentry = task_cs(tsk)->css.cgroup->dentry; | |
2523 | spin_lock(&cpuset_buffer_lock); | |
2524 | snprintf(cpuset_name, CPUSET_NAME_LEN, | |
2525 | dentry ? (const char *)dentry->d_name.name : "/"); | |
2526 | nodelist_scnprintf(cpuset_nodelist, CPUSET_NODELIST_LEN, | |
2527 | tsk->mems_allowed); | |
2528 | printk(KERN_INFO "%s cpuset=%s mems_allowed=%s\n", | |
2529 | tsk->comm, cpuset_name, cpuset_nodelist); | |
2530 | spin_unlock(&cpuset_buffer_lock); | |
2531 | } | |
2532 | ||
3e0d98b9 PJ |
2533 | /* |
2534 | * Collection of memory_pressure is suppressed unless | |
2535 | * this flag is enabled by writing "1" to the special | |
2536 | * cpuset file 'memory_pressure_enabled' in the root cpuset. | |
2537 | */ | |
2538 | ||
c5b2aff8 | 2539 | int cpuset_memory_pressure_enabled __read_mostly; |
3e0d98b9 PJ |
2540 | |
2541 | /** | |
2542 | * cpuset_memory_pressure_bump - keep stats of per-cpuset reclaims. | |
2543 | * | |
2544 | * Keep a running average of the rate of synchronous (direct) | |
2545 | * page reclaim efforts initiated by tasks in each cpuset. | |
2546 | * | |
2547 | * This represents the rate at which some task in the cpuset | |
2548 | * ran low on memory on all nodes it was allowed to use, and | |
2549 | * had to enter the kernels page reclaim code in an effort to | |
2550 | * create more free memory by tossing clean pages or swapping | |
2551 | * or writing dirty pages. | |
2552 | * | |
2553 | * Display to user space in the per-cpuset read-only file | |
2554 | * "memory_pressure". Value displayed is an integer | |
2555 | * representing the recent rate of entry into the synchronous | |
2556 | * (direct) page reclaim by any task attached to the cpuset. | |
2557 | **/ | |
2558 | ||
2559 | void __cpuset_memory_pressure_bump(void) | |
2560 | { | |
3e0d98b9 | 2561 | task_lock(current); |
8793d854 | 2562 | fmeter_markevent(&task_cs(current)->fmeter); |
3e0d98b9 PJ |
2563 | task_unlock(current); |
2564 | } | |
2565 | ||
8793d854 | 2566 | #ifdef CONFIG_PROC_PID_CPUSET |
1da177e4 LT |
2567 | /* |
2568 | * proc_cpuset_show() | |
2569 | * - Print tasks cpuset path into seq_file. | |
2570 | * - Used for /proc/<pid>/cpuset. | |
053199ed PJ |
2571 | * - No need to task_lock(tsk) on this tsk->cpuset reference, as it |
2572 | * doesn't really matter if tsk->cpuset changes after we read it, | |
c8d9c90c | 2573 | * and we take cgroup_mutex, keeping cpuset_attach() from changing it |
2df167a3 | 2574 | * anyway. |
1da177e4 | 2575 | */ |
029190c5 | 2576 | static int proc_cpuset_show(struct seq_file *m, void *unused_v) |
1da177e4 | 2577 | { |
13b41b09 | 2578 | struct pid *pid; |
1da177e4 LT |
2579 | struct task_struct *tsk; |
2580 | char *buf; | |
8793d854 | 2581 | struct cgroup_subsys_state *css; |
99f89551 | 2582 | int retval; |
1da177e4 | 2583 | |
99f89551 | 2584 | retval = -ENOMEM; |
1da177e4 LT |
2585 | buf = kmalloc(PAGE_SIZE, GFP_KERNEL); |
2586 | if (!buf) | |
99f89551 EB |
2587 | goto out; |
2588 | ||
2589 | retval = -ESRCH; | |
13b41b09 EB |
2590 | pid = m->private; |
2591 | tsk = get_pid_task(pid, PIDTYPE_PID); | |
99f89551 EB |
2592 | if (!tsk) |
2593 | goto out_free; | |
1da177e4 | 2594 | |
99f89551 | 2595 | retval = -EINVAL; |
8793d854 PM |
2596 | cgroup_lock(); |
2597 | css = task_subsys_state(tsk, cpuset_subsys_id); | |
2598 | retval = cgroup_path(css->cgroup, buf, PAGE_SIZE); | |
1da177e4 | 2599 | if (retval < 0) |
99f89551 | 2600 | goto out_unlock; |
1da177e4 LT |
2601 | seq_puts(m, buf); |
2602 | seq_putc(m, '\n'); | |
99f89551 | 2603 | out_unlock: |
8793d854 | 2604 | cgroup_unlock(); |
99f89551 EB |
2605 | put_task_struct(tsk); |
2606 | out_free: | |
1da177e4 | 2607 | kfree(buf); |
99f89551 | 2608 | out: |
1da177e4 LT |
2609 | return retval; |
2610 | } | |
2611 | ||
2612 | static int cpuset_open(struct inode *inode, struct file *file) | |
2613 | { | |
13b41b09 EB |
2614 | struct pid *pid = PROC_I(inode)->pid; |
2615 | return single_open(file, proc_cpuset_show, pid); | |
1da177e4 LT |
2616 | } |
2617 | ||
9a32144e | 2618 | const struct file_operations proc_cpuset_operations = { |
1da177e4 LT |
2619 | .open = cpuset_open, |
2620 | .read = seq_read, | |
2621 | .llseek = seq_lseek, | |
2622 | .release = single_release, | |
2623 | }; | |
8793d854 | 2624 | #endif /* CONFIG_PROC_PID_CPUSET */ |
1da177e4 | 2625 | |
d01d4827 | 2626 | /* Display task mems_allowed in /proc/<pid>/status file. */ |
df5f8314 EB |
2627 | void cpuset_task_status_allowed(struct seq_file *m, struct task_struct *task) |
2628 | { | |
df5f8314 | 2629 | seq_printf(m, "Mems_allowed:\t"); |
30e8e136 | 2630 | seq_nodemask(m, &task->mems_allowed); |
df5f8314 | 2631 | seq_printf(m, "\n"); |
39106dcf | 2632 | seq_printf(m, "Mems_allowed_list:\t"); |
30e8e136 | 2633 | seq_nodemask_list(m, &task->mems_allowed); |
39106dcf | 2634 | seq_printf(m, "\n"); |
1da177e4 | 2635 | } |