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> | |
e44193d3 | 62 | #include <linux/wait.h> |
1da177e4 | 63 | |
202f72d5 PJ |
64 | /* |
65 | * Tracks how many cpusets are currently defined in system. | |
66 | * When there is only one cpuset (the root cpuset) we can | |
67 | * short circuit some hooks. | |
68 | */ | |
7edc5962 | 69 | int number_of_cpusets __read_mostly; |
202f72d5 | 70 | |
2df167a3 | 71 | /* Forward declare cgroup structures */ |
8793d854 PM |
72 | struct cgroup_subsys cpuset_subsys; |
73 | struct cpuset; | |
74 | ||
3e0d98b9 PJ |
75 | /* See "Frequency meter" comments, below. */ |
76 | ||
77 | struct fmeter { | |
78 | int cnt; /* unprocessed events count */ | |
79 | int val; /* most recent output value */ | |
80 | time_t time; /* clock (secs) when val computed */ | |
81 | spinlock_t lock; /* guards read or write of above */ | |
82 | }; | |
83 | ||
1da177e4 | 84 | struct cpuset { |
8793d854 PM |
85 | struct cgroup_subsys_state css; |
86 | ||
1da177e4 | 87 | unsigned long flags; /* "unsigned long" so bitops work */ |
300ed6cb | 88 | cpumask_var_t cpus_allowed; /* CPUs allowed to tasks in cpuset */ |
1da177e4 LT |
89 | nodemask_t mems_allowed; /* Memory Nodes allowed to tasks */ |
90 | ||
33ad801d LZ |
91 | /* |
92 | * This is old Memory Nodes tasks took on. | |
93 | * | |
94 | * - top_cpuset.old_mems_allowed is initialized to mems_allowed. | |
95 | * - A new cpuset's old_mems_allowed is initialized when some | |
96 | * task is moved into it. | |
97 | * - old_mems_allowed is used in cpuset_migrate_mm() when we change | |
98 | * cpuset.mems_allowed and have tasks' nodemask updated, and | |
99 | * then old_mems_allowed is updated to mems_allowed. | |
100 | */ | |
101 | nodemask_t old_mems_allowed; | |
102 | ||
3e0d98b9 | 103 | struct fmeter fmeter; /* memory_pressure filter */ |
029190c5 | 104 | |
452477fa TH |
105 | /* |
106 | * Tasks are being attached to this cpuset. Used to prevent | |
107 | * zeroing cpus/mems_allowed between ->can_attach() and ->attach(). | |
108 | */ | |
109 | int attach_in_progress; | |
110 | ||
029190c5 PJ |
111 | /* partition number for rebuild_sched_domains() */ |
112 | int pn; | |
956db3ca | 113 | |
1d3504fc HS |
114 | /* for custom sched domain */ |
115 | int relax_domain_level; | |
1da177e4 LT |
116 | }; |
117 | ||
8793d854 | 118 | /* Retrieve the cpuset for a cgroup */ |
c9e5fe66 | 119 | static inline struct cpuset *cgroup_cs(struct cgroup *cgrp) |
8793d854 | 120 | { |
c9e5fe66 | 121 | return container_of(cgroup_subsys_state(cgrp, cpuset_subsys_id), |
8793d854 PM |
122 | struct cpuset, css); |
123 | } | |
124 | ||
125 | /* Retrieve the cpuset for a task */ | |
126 | static inline struct cpuset *task_cs(struct task_struct *task) | |
127 | { | |
128 | return container_of(task_subsys_state(task, cpuset_subsys_id), | |
129 | struct cpuset, css); | |
130 | } | |
8793d854 | 131 | |
c431069f TH |
132 | static inline struct cpuset *parent_cs(const struct cpuset *cs) |
133 | { | |
134 | struct cgroup *pcgrp = cs->css.cgroup->parent; | |
135 | ||
136 | if (pcgrp) | |
137 | return cgroup_cs(pcgrp); | |
138 | return NULL; | |
139 | } | |
140 | ||
b246272e DR |
141 | #ifdef CONFIG_NUMA |
142 | static inline bool task_has_mempolicy(struct task_struct *task) | |
143 | { | |
144 | return task->mempolicy; | |
145 | } | |
146 | #else | |
147 | static inline bool task_has_mempolicy(struct task_struct *task) | |
148 | { | |
149 | return false; | |
150 | } | |
151 | #endif | |
152 | ||
153 | ||
1da177e4 LT |
154 | /* bits in struct cpuset flags field */ |
155 | typedef enum { | |
efeb77b2 | 156 | CS_ONLINE, |
1da177e4 LT |
157 | CS_CPU_EXCLUSIVE, |
158 | CS_MEM_EXCLUSIVE, | |
78608366 | 159 | CS_MEM_HARDWALL, |
45b07ef3 | 160 | CS_MEMORY_MIGRATE, |
029190c5 | 161 | CS_SCHED_LOAD_BALANCE, |
825a46af PJ |
162 | CS_SPREAD_PAGE, |
163 | CS_SPREAD_SLAB, | |
1da177e4 LT |
164 | } cpuset_flagbits_t; |
165 | ||
166 | /* convenient tests for these bits */ | |
efeb77b2 TH |
167 | static inline bool is_cpuset_online(const struct cpuset *cs) |
168 | { | |
169 | return test_bit(CS_ONLINE, &cs->flags); | |
170 | } | |
171 | ||
1da177e4 LT |
172 | static inline int is_cpu_exclusive(const struct cpuset *cs) |
173 | { | |
7b5b9ef0 | 174 | return test_bit(CS_CPU_EXCLUSIVE, &cs->flags); |
1da177e4 LT |
175 | } |
176 | ||
177 | static inline int is_mem_exclusive(const struct cpuset *cs) | |
178 | { | |
7b5b9ef0 | 179 | return test_bit(CS_MEM_EXCLUSIVE, &cs->flags); |
1da177e4 LT |
180 | } |
181 | ||
78608366 PM |
182 | static inline int is_mem_hardwall(const struct cpuset *cs) |
183 | { | |
184 | return test_bit(CS_MEM_HARDWALL, &cs->flags); | |
185 | } | |
186 | ||
029190c5 PJ |
187 | static inline int is_sched_load_balance(const struct cpuset *cs) |
188 | { | |
189 | return test_bit(CS_SCHED_LOAD_BALANCE, &cs->flags); | |
190 | } | |
191 | ||
45b07ef3 PJ |
192 | static inline int is_memory_migrate(const struct cpuset *cs) |
193 | { | |
7b5b9ef0 | 194 | return test_bit(CS_MEMORY_MIGRATE, &cs->flags); |
45b07ef3 PJ |
195 | } |
196 | ||
825a46af PJ |
197 | static inline int is_spread_page(const struct cpuset *cs) |
198 | { | |
199 | return test_bit(CS_SPREAD_PAGE, &cs->flags); | |
200 | } | |
201 | ||
202 | static inline int is_spread_slab(const struct cpuset *cs) | |
203 | { | |
204 | return test_bit(CS_SPREAD_SLAB, &cs->flags); | |
205 | } | |
206 | ||
1da177e4 | 207 | static struct cpuset top_cpuset = { |
efeb77b2 TH |
208 | .flags = ((1 << CS_ONLINE) | (1 << CS_CPU_EXCLUSIVE) | |
209 | (1 << CS_MEM_EXCLUSIVE)), | |
1da177e4 LT |
210 | }; |
211 | ||
ae8086ce TH |
212 | /** |
213 | * cpuset_for_each_child - traverse online children of a cpuset | |
214 | * @child_cs: loop cursor pointing to the current child | |
215 | * @pos_cgrp: used for iteration | |
216 | * @parent_cs: target cpuset to walk children of | |
217 | * | |
218 | * Walk @child_cs through the online children of @parent_cs. Must be used | |
219 | * with RCU read locked. | |
220 | */ | |
221 | #define cpuset_for_each_child(child_cs, pos_cgrp, parent_cs) \ | |
222 | cgroup_for_each_child((pos_cgrp), (parent_cs)->css.cgroup) \ | |
223 | if (is_cpuset_online(((child_cs) = cgroup_cs((pos_cgrp))))) | |
224 | ||
fc560a26 TH |
225 | /** |
226 | * cpuset_for_each_descendant_pre - pre-order walk of a cpuset's descendants | |
227 | * @des_cs: loop cursor pointing to the current descendant | |
228 | * @pos_cgrp: used for iteration | |
229 | * @root_cs: target cpuset to walk ancestor of | |
230 | * | |
231 | * Walk @des_cs through the online descendants of @root_cs. Must be used | |
232 | * with RCU read locked. The caller may modify @pos_cgrp by calling | |
233 | * cgroup_rightmost_descendant() to skip subtree. | |
234 | */ | |
235 | #define cpuset_for_each_descendant_pre(des_cs, pos_cgrp, root_cs) \ | |
236 | cgroup_for_each_descendant_pre((pos_cgrp), (root_cs)->css.cgroup) \ | |
237 | if (is_cpuset_online(((des_cs) = cgroup_cs((pos_cgrp))))) | |
238 | ||
1da177e4 | 239 | /* |
5d21cc2d TH |
240 | * There are two global mutexes guarding cpuset structures - cpuset_mutex |
241 | * and callback_mutex. The latter may nest inside the former. We also | |
242 | * require taking task_lock() when dereferencing a task's cpuset pointer. | |
243 | * See "The task_lock() exception", at the end of this comment. | |
244 | * | |
245 | * A task must hold both mutexes to modify cpusets. If a task holds | |
246 | * cpuset_mutex, then it blocks others wanting that mutex, ensuring that it | |
247 | * is the only task able to also acquire callback_mutex and be able to | |
248 | * modify cpusets. It can perform various checks on the cpuset structure | |
249 | * first, knowing nothing will change. It can also allocate memory while | |
250 | * just holding cpuset_mutex. While it is performing these checks, various | |
251 | * callback routines can briefly acquire callback_mutex to query cpusets. | |
252 | * Once it is ready to make the changes, it takes callback_mutex, blocking | |
253 | * everyone else. | |
053199ed PJ |
254 | * |
255 | * Calls to the kernel memory allocator can not be made while holding | |
3d3f26a7 | 256 | * callback_mutex, as that would risk double tripping on callback_mutex |
053199ed PJ |
257 | * from one of the callbacks into the cpuset code from within |
258 | * __alloc_pages(). | |
259 | * | |
3d3f26a7 | 260 | * If a task is only holding callback_mutex, then it has read-only |
053199ed PJ |
261 | * access to cpusets. |
262 | * | |
58568d2a MX |
263 | * Now, the task_struct fields mems_allowed and mempolicy may be changed |
264 | * by other task, we use alloc_lock in the task_struct fields to protect | |
265 | * them. | |
053199ed | 266 | * |
3d3f26a7 | 267 | * The cpuset_common_file_read() handlers only hold callback_mutex across |
053199ed PJ |
268 | * small pieces of code, such as when reading out possibly multi-word |
269 | * cpumasks and nodemasks. | |
270 | * | |
2df167a3 PM |
271 | * Accessing a task's cpuset should be done in accordance with the |
272 | * guidelines for accessing subsystem state in kernel/cgroup.c | |
1da177e4 LT |
273 | */ |
274 | ||
5d21cc2d | 275 | static DEFINE_MUTEX(cpuset_mutex); |
3d3f26a7 | 276 | static DEFINE_MUTEX(callback_mutex); |
4247bdc6 | 277 | |
3a5a6d0c TH |
278 | /* |
279 | * CPU / memory hotplug is handled asynchronously. | |
280 | */ | |
281 | static void cpuset_hotplug_workfn(struct work_struct *work); | |
3a5a6d0c TH |
282 | static DECLARE_WORK(cpuset_hotplug_work, cpuset_hotplug_workfn); |
283 | ||
e44193d3 LZ |
284 | static DECLARE_WAIT_QUEUE_HEAD(cpuset_attach_wq); |
285 | ||
cf417141 MK |
286 | /* |
287 | * This is ugly, but preserves the userspace API for existing cpuset | |
8793d854 | 288 | * users. If someone tries to mount the "cpuset" filesystem, we |
cf417141 MK |
289 | * silently switch it to mount "cgroup" instead |
290 | */ | |
f7e83571 AV |
291 | static struct dentry *cpuset_mount(struct file_system_type *fs_type, |
292 | int flags, const char *unused_dev_name, void *data) | |
1da177e4 | 293 | { |
8793d854 | 294 | struct file_system_type *cgroup_fs = get_fs_type("cgroup"); |
f7e83571 | 295 | struct dentry *ret = ERR_PTR(-ENODEV); |
8793d854 PM |
296 | if (cgroup_fs) { |
297 | char mountopts[] = | |
298 | "cpuset,noprefix," | |
299 | "release_agent=/sbin/cpuset_release_agent"; | |
f7e83571 AV |
300 | ret = cgroup_fs->mount(cgroup_fs, flags, |
301 | unused_dev_name, mountopts); | |
8793d854 PM |
302 | put_filesystem(cgroup_fs); |
303 | } | |
304 | return ret; | |
1da177e4 LT |
305 | } |
306 | ||
307 | static struct file_system_type cpuset_fs_type = { | |
308 | .name = "cpuset", | |
f7e83571 | 309 | .mount = cpuset_mount, |
1da177e4 LT |
310 | }; |
311 | ||
1da177e4 | 312 | /* |
300ed6cb | 313 | * Return in pmask the portion of a cpusets's cpus_allowed that |
1da177e4 | 314 | * are online. If none are online, walk up the cpuset hierarchy |
40df2deb LZ |
315 | * until we find one that does have some online cpus. The top |
316 | * cpuset always has some cpus online. | |
1da177e4 LT |
317 | * |
318 | * One way or another, we guarantee to return some non-empty subset | |
5f054e31 | 319 | * of cpu_online_mask. |
1da177e4 | 320 | * |
3d3f26a7 | 321 | * Call with callback_mutex held. |
1da177e4 | 322 | */ |
6af866af LZ |
323 | static void guarantee_online_cpus(const struct cpuset *cs, |
324 | struct cpumask *pmask) | |
1da177e4 | 325 | { |
40df2deb | 326 | while (!cpumask_intersects(cs->cpus_allowed, cpu_online_mask)) |
c431069f | 327 | cs = parent_cs(cs); |
40df2deb | 328 | cpumask_and(pmask, cs->cpus_allowed, cpu_online_mask); |
1da177e4 LT |
329 | } |
330 | ||
331 | /* | |
332 | * Return in *pmask the portion of a cpusets's mems_allowed that | |
0e1e7c7a CL |
333 | * are online, with memory. If none are online with memory, walk |
334 | * up the cpuset hierarchy until we find one that does have some | |
40df2deb | 335 | * online mems. The top cpuset always has some mems online. |
1da177e4 LT |
336 | * |
337 | * One way or another, we guarantee to return some non-empty subset | |
38d7bee9 | 338 | * of node_states[N_MEMORY]. |
1da177e4 | 339 | * |
3d3f26a7 | 340 | * Call with callback_mutex held. |
1da177e4 | 341 | */ |
1da177e4 LT |
342 | static void guarantee_online_mems(const struct cpuset *cs, nodemask_t *pmask) |
343 | { | |
40df2deb | 344 | while (!nodes_intersects(cs->mems_allowed, node_states[N_MEMORY])) |
c431069f | 345 | cs = parent_cs(cs); |
40df2deb | 346 | nodes_and(*pmask, cs->mems_allowed, node_states[N_MEMORY]); |
1da177e4 LT |
347 | } |
348 | ||
f3b39d47 MX |
349 | /* |
350 | * update task's spread flag if cpuset's page/slab spread flag is set | |
351 | * | |
5d21cc2d | 352 | * Called with callback_mutex/cpuset_mutex held |
f3b39d47 MX |
353 | */ |
354 | static void cpuset_update_task_spread_flag(struct cpuset *cs, | |
355 | struct task_struct *tsk) | |
356 | { | |
357 | if (is_spread_page(cs)) | |
358 | tsk->flags |= PF_SPREAD_PAGE; | |
359 | else | |
360 | tsk->flags &= ~PF_SPREAD_PAGE; | |
361 | if (is_spread_slab(cs)) | |
362 | tsk->flags |= PF_SPREAD_SLAB; | |
363 | else | |
364 | tsk->flags &= ~PF_SPREAD_SLAB; | |
365 | } | |
366 | ||
1da177e4 LT |
367 | /* |
368 | * is_cpuset_subset(p, q) - Is cpuset p a subset of cpuset q? | |
369 | * | |
370 | * One cpuset is a subset of another if all its allowed CPUs and | |
371 | * Memory Nodes are a subset of the other, and its exclusive flags | |
5d21cc2d | 372 | * are only set if the other's are set. Call holding cpuset_mutex. |
1da177e4 LT |
373 | */ |
374 | ||
375 | static int is_cpuset_subset(const struct cpuset *p, const struct cpuset *q) | |
376 | { | |
300ed6cb | 377 | return cpumask_subset(p->cpus_allowed, q->cpus_allowed) && |
1da177e4 LT |
378 | nodes_subset(p->mems_allowed, q->mems_allowed) && |
379 | is_cpu_exclusive(p) <= is_cpu_exclusive(q) && | |
380 | is_mem_exclusive(p) <= is_mem_exclusive(q); | |
381 | } | |
382 | ||
645fcc9d LZ |
383 | /** |
384 | * alloc_trial_cpuset - allocate a trial cpuset | |
385 | * @cs: the cpuset that the trial cpuset duplicates | |
386 | */ | |
387 | static struct cpuset *alloc_trial_cpuset(const struct cpuset *cs) | |
388 | { | |
300ed6cb LZ |
389 | struct cpuset *trial; |
390 | ||
391 | trial = kmemdup(cs, sizeof(*cs), GFP_KERNEL); | |
392 | if (!trial) | |
393 | return NULL; | |
394 | ||
395 | if (!alloc_cpumask_var(&trial->cpus_allowed, GFP_KERNEL)) { | |
396 | kfree(trial); | |
397 | return NULL; | |
398 | } | |
399 | cpumask_copy(trial->cpus_allowed, cs->cpus_allowed); | |
400 | ||
401 | return trial; | |
645fcc9d LZ |
402 | } |
403 | ||
404 | /** | |
405 | * free_trial_cpuset - free the trial cpuset | |
406 | * @trial: the trial cpuset to be freed | |
407 | */ | |
408 | static void free_trial_cpuset(struct cpuset *trial) | |
409 | { | |
300ed6cb | 410 | free_cpumask_var(trial->cpus_allowed); |
645fcc9d LZ |
411 | kfree(trial); |
412 | } | |
413 | ||
1da177e4 LT |
414 | /* |
415 | * validate_change() - Used to validate that any proposed cpuset change | |
416 | * follows the structural rules for cpusets. | |
417 | * | |
418 | * If we replaced the flag and mask values of the current cpuset | |
419 | * (cur) with those values in the trial cpuset (trial), would | |
420 | * our various subset and exclusive rules still be valid? Presumes | |
5d21cc2d | 421 | * cpuset_mutex held. |
1da177e4 LT |
422 | * |
423 | * 'cur' is the address of an actual, in-use cpuset. Operations | |
424 | * such as list traversal that depend on the actual address of the | |
425 | * cpuset in the list must use cur below, not trial. | |
426 | * | |
427 | * 'trial' is the address of bulk structure copy of cur, with | |
428 | * perhaps one or more of the fields cpus_allowed, mems_allowed, | |
429 | * or flags changed to new, trial values. | |
430 | * | |
431 | * Return 0 if valid, -errno if not. | |
432 | */ | |
433 | ||
434 | static int validate_change(const struct cpuset *cur, const struct cpuset *trial) | |
435 | { | |
c9e5fe66 | 436 | struct cgroup *cgrp; |
1da177e4 | 437 | struct cpuset *c, *par; |
ae8086ce TH |
438 | int ret; |
439 | ||
440 | rcu_read_lock(); | |
1da177e4 LT |
441 | |
442 | /* Each of our child cpusets must be a subset of us */ | |
ae8086ce | 443 | ret = -EBUSY; |
c9e5fe66 | 444 | cpuset_for_each_child(c, cgrp, cur) |
ae8086ce TH |
445 | if (!is_cpuset_subset(c, trial)) |
446 | goto out; | |
1da177e4 LT |
447 | |
448 | /* Remaining checks don't apply to root cpuset */ | |
ae8086ce | 449 | ret = 0; |
69604067 | 450 | if (cur == &top_cpuset) |
ae8086ce | 451 | goto out; |
1da177e4 | 452 | |
c431069f | 453 | par = parent_cs(cur); |
69604067 | 454 | |
1da177e4 | 455 | /* We must be a subset of our parent cpuset */ |
ae8086ce | 456 | ret = -EACCES; |
1da177e4 | 457 | if (!is_cpuset_subset(trial, par)) |
ae8086ce | 458 | goto out; |
1da177e4 | 459 | |
2df167a3 PM |
460 | /* |
461 | * If either I or some sibling (!= me) is exclusive, we can't | |
462 | * overlap | |
463 | */ | |
ae8086ce | 464 | ret = -EINVAL; |
c9e5fe66 | 465 | cpuset_for_each_child(c, cgrp, par) { |
1da177e4 LT |
466 | if ((is_cpu_exclusive(trial) || is_cpu_exclusive(c)) && |
467 | c != cur && | |
300ed6cb | 468 | cpumask_intersects(trial->cpus_allowed, c->cpus_allowed)) |
ae8086ce | 469 | goto out; |
1da177e4 LT |
470 | if ((is_mem_exclusive(trial) || is_mem_exclusive(c)) && |
471 | c != cur && | |
472 | nodes_intersects(trial->mems_allowed, c->mems_allowed)) | |
ae8086ce | 473 | goto out; |
1da177e4 LT |
474 | } |
475 | ||
452477fa TH |
476 | /* |
477 | * Cpusets with tasks - existing or newly being attached - can't | |
1c09b195 | 478 | * be changed to have empty cpus_allowed or mems_allowed. |
452477fa | 479 | */ |
ae8086ce | 480 | ret = -ENOSPC; |
1c09b195 LZ |
481 | if ((cgroup_task_count(cur->css.cgroup) || cur->attach_in_progress)) { |
482 | if (!cpumask_empty(cur->cpus_allowed) && | |
483 | cpumask_empty(trial->cpus_allowed)) | |
484 | goto out; | |
485 | if (!nodes_empty(cur->mems_allowed) && | |
486 | nodes_empty(trial->mems_allowed)) | |
487 | goto out; | |
488 | } | |
020958b6 | 489 | |
ae8086ce TH |
490 | ret = 0; |
491 | out: | |
492 | rcu_read_unlock(); | |
493 | return ret; | |
1da177e4 LT |
494 | } |
495 | ||
db7f47cf | 496 | #ifdef CONFIG_SMP |
029190c5 | 497 | /* |
cf417141 | 498 | * Helper routine for generate_sched_domains(). |
029190c5 PJ |
499 | * Do cpusets a, b have overlapping cpus_allowed masks? |
500 | */ | |
029190c5 PJ |
501 | static int cpusets_overlap(struct cpuset *a, struct cpuset *b) |
502 | { | |
300ed6cb | 503 | return cpumask_intersects(a->cpus_allowed, b->cpus_allowed); |
029190c5 PJ |
504 | } |
505 | ||
1d3504fc HS |
506 | static void |
507 | update_domain_attr(struct sched_domain_attr *dattr, struct cpuset *c) | |
508 | { | |
1d3504fc HS |
509 | if (dattr->relax_domain_level < c->relax_domain_level) |
510 | dattr->relax_domain_level = c->relax_domain_level; | |
511 | return; | |
512 | } | |
513 | ||
fc560a26 TH |
514 | static void update_domain_attr_tree(struct sched_domain_attr *dattr, |
515 | struct cpuset *root_cs) | |
f5393693 | 516 | { |
fc560a26 TH |
517 | struct cpuset *cp; |
518 | struct cgroup *pos_cgrp; | |
f5393693 | 519 | |
fc560a26 TH |
520 | rcu_read_lock(); |
521 | cpuset_for_each_descendant_pre(cp, pos_cgrp, root_cs) { | |
522 | /* skip the whole subtree if @cp doesn't have any CPU */ | |
523 | if (cpumask_empty(cp->cpus_allowed)) { | |
524 | pos_cgrp = cgroup_rightmost_descendant(pos_cgrp); | |
f5393693 | 525 | continue; |
fc560a26 | 526 | } |
f5393693 LJ |
527 | |
528 | if (is_sched_load_balance(cp)) | |
529 | update_domain_attr(dattr, cp); | |
f5393693 | 530 | } |
fc560a26 | 531 | rcu_read_unlock(); |
f5393693 LJ |
532 | } |
533 | ||
029190c5 | 534 | /* |
cf417141 MK |
535 | * generate_sched_domains() |
536 | * | |
537 | * This function builds a partial partition of the systems CPUs | |
538 | * A 'partial partition' is a set of non-overlapping subsets whose | |
539 | * union is a subset of that set. | |
0a0fca9d | 540 | * The output of this function needs to be passed to kernel/sched/core.c |
cf417141 MK |
541 | * partition_sched_domains() routine, which will rebuild the scheduler's |
542 | * load balancing domains (sched domains) as specified by that partial | |
543 | * partition. | |
029190c5 | 544 | * |
45ce80fb | 545 | * See "What is sched_load_balance" in Documentation/cgroups/cpusets.txt |
029190c5 PJ |
546 | * for a background explanation of this. |
547 | * | |
548 | * Does not return errors, on the theory that the callers of this | |
549 | * routine would rather not worry about failures to rebuild sched | |
550 | * domains when operating in the severe memory shortage situations | |
551 | * that could cause allocation failures below. | |
552 | * | |
5d21cc2d | 553 | * Must be called with cpuset_mutex held. |
029190c5 PJ |
554 | * |
555 | * The three key local variables below are: | |
aeed6824 | 556 | * q - a linked-list queue of cpuset pointers, used to implement a |
029190c5 PJ |
557 | * top-down scan of all cpusets. This scan loads a pointer |
558 | * to each cpuset marked is_sched_load_balance into the | |
559 | * array 'csa'. For our purposes, rebuilding the schedulers | |
560 | * sched domains, we can ignore !is_sched_load_balance cpusets. | |
561 | * csa - (for CpuSet Array) Array of pointers to all the cpusets | |
562 | * that need to be load balanced, for convenient iterative | |
563 | * access by the subsequent code that finds the best partition, | |
564 | * i.e the set of domains (subsets) of CPUs such that the | |
565 | * cpus_allowed of every cpuset marked is_sched_load_balance | |
566 | * is a subset of one of these domains, while there are as | |
567 | * many such domains as possible, each as small as possible. | |
568 | * doms - Conversion of 'csa' to an array of cpumasks, for passing to | |
0a0fca9d | 569 | * the kernel/sched/core.c routine partition_sched_domains() in a |
029190c5 PJ |
570 | * convenient format, that can be easily compared to the prior |
571 | * value to determine what partition elements (sched domains) | |
572 | * were changed (added or removed.) | |
573 | * | |
574 | * Finding the best partition (set of domains): | |
575 | * The triple nested loops below over i, j, k scan over the | |
576 | * load balanced cpusets (using the array of cpuset pointers in | |
577 | * csa[]) looking for pairs of cpusets that have overlapping | |
578 | * cpus_allowed, but which don't have the same 'pn' partition | |
579 | * number and gives them in the same partition number. It keeps | |
580 | * looping on the 'restart' label until it can no longer find | |
581 | * any such pairs. | |
582 | * | |
583 | * The union of the cpus_allowed masks from the set of | |
584 | * all cpusets having the same 'pn' value then form the one | |
585 | * element of the partition (one sched domain) to be passed to | |
586 | * partition_sched_domains(). | |
587 | */ | |
acc3f5d7 | 588 | static int generate_sched_domains(cpumask_var_t **domains, |
cf417141 | 589 | struct sched_domain_attr **attributes) |
029190c5 | 590 | { |
029190c5 PJ |
591 | struct cpuset *cp; /* scans q */ |
592 | struct cpuset **csa; /* array of all cpuset ptrs */ | |
593 | int csn; /* how many cpuset ptrs in csa so far */ | |
594 | int i, j, k; /* indices for partition finding loops */ | |
acc3f5d7 | 595 | cpumask_var_t *doms; /* resulting partition; i.e. sched domains */ |
1d3504fc | 596 | struct sched_domain_attr *dattr; /* attributes for custom domains */ |
1583715d | 597 | int ndoms = 0; /* number of sched domains in result */ |
6af866af | 598 | int nslot; /* next empty doms[] struct cpumask slot */ |
fc560a26 | 599 | struct cgroup *pos_cgrp; |
029190c5 | 600 | |
029190c5 | 601 | doms = NULL; |
1d3504fc | 602 | dattr = NULL; |
cf417141 | 603 | csa = NULL; |
029190c5 PJ |
604 | |
605 | /* Special case for the 99% of systems with one, full, sched domain */ | |
606 | if (is_sched_load_balance(&top_cpuset)) { | |
acc3f5d7 RR |
607 | ndoms = 1; |
608 | doms = alloc_sched_domains(ndoms); | |
029190c5 | 609 | if (!doms) |
cf417141 MK |
610 | goto done; |
611 | ||
1d3504fc HS |
612 | dattr = kmalloc(sizeof(struct sched_domain_attr), GFP_KERNEL); |
613 | if (dattr) { | |
614 | *dattr = SD_ATTR_INIT; | |
93a65575 | 615 | update_domain_attr_tree(dattr, &top_cpuset); |
1d3504fc | 616 | } |
acc3f5d7 | 617 | cpumask_copy(doms[0], top_cpuset.cpus_allowed); |
cf417141 | 618 | |
cf417141 | 619 | goto done; |
029190c5 PJ |
620 | } |
621 | ||
029190c5 PJ |
622 | csa = kmalloc(number_of_cpusets * sizeof(cp), GFP_KERNEL); |
623 | if (!csa) | |
624 | goto done; | |
625 | csn = 0; | |
626 | ||
fc560a26 TH |
627 | rcu_read_lock(); |
628 | cpuset_for_each_descendant_pre(cp, pos_cgrp, &top_cpuset) { | |
f5393693 | 629 | /* |
fc560a26 TH |
630 | * Continue traversing beyond @cp iff @cp has some CPUs and |
631 | * isn't load balancing. The former is obvious. The | |
632 | * latter: All child cpusets contain a subset of the | |
633 | * parent's cpus, so just skip them, and then we call | |
634 | * update_domain_attr_tree() to calc relax_domain_level of | |
635 | * the corresponding sched domain. | |
f5393693 | 636 | */ |
fc560a26 TH |
637 | if (!cpumask_empty(cp->cpus_allowed) && |
638 | !is_sched_load_balance(cp)) | |
f5393693 | 639 | continue; |
489a5393 | 640 | |
fc560a26 TH |
641 | if (is_sched_load_balance(cp)) |
642 | csa[csn++] = cp; | |
643 | ||
644 | /* skip @cp's subtree */ | |
645 | pos_cgrp = cgroup_rightmost_descendant(pos_cgrp); | |
646 | } | |
647 | rcu_read_unlock(); | |
029190c5 PJ |
648 | |
649 | for (i = 0; i < csn; i++) | |
650 | csa[i]->pn = i; | |
651 | ndoms = csn; | |
652 | ||
653 | restart: | |
654 | /* Find the best partition (set of sched domains) */ | |
655 | for (i = 0; i < csn; i++) { | |
656 | struct cpuset *a = csa[i]; | |
657 | int apn = a->pn; | |
658 | ||
659 | for (j = 0; j < csn; j++) { | |
660 | struct cpuset *b = csa[j]; | |
661 | int bpn = b->pn; | |
662 | ||
663 | if (apn != bpn && cpusets_overlap(a, b)) { | |
664 | for (k = 0; k < csn; k++) { | |
665 | struct cpuset *c = csa[k]; | |
666 | ||
667 | if (c->pn == bpn) | |
668 | c->pn = apn; | |
669 | } | |
670 | ndoms--; /* one less element */ | |
671 | goto restart; | |
672 | } | |
673 | } | |
674 | } | |
675 | ||
cf417141 MK |
676 | /* |
677 | * Now we know how many domains to create. | |
678 | * Convert <csn, csa> to <ndoms, doms> and populate cpu masks. | |
679 | */ | |
acc3f5d7 | 680 | doms = alloc_sched_domains(ndoms); |
700018e0 | 681 | if (!doms) |
cf417141 | 682 | goto done; |
cf417141 MK |
683 | |
684 | /* | |
685 | * The rest of the code, including the scheduler, can deal with | |
686 | * dattr==NULL case. No need to abort if alloc fails. | |
687 | */ | |
1d3504fc | 688 | dattr = kmalloc(ndoms * sizeof(struct sched_domain_attr), GFP_KERNEL); |
029190c5 PJ |
689 | |
690 | for (nslot = 0, i = 0; i < csn; i++) { | |
691 | struct cpuset *a = csa[i]; | |
6af866af | 692 | struct cpumask *dp; |
029190c5 PJ |
693 | int apn = a->pn; |
694 | ||
cf417141 MK |
695 | if (apn < 0) { |
696 | /* Skip completed partitions */ | |
697 | continue; | |
698 | } | |
699 | ||
acc3f5d7 | 700 | dp = doms[nslot]; |
cf417141 MK |
701 | |
702 | if (nslot == ndoms) { | |
703 | static int warnings = 10; | |
704 | if (warnings) { | |
705 | printk(KERN_WARNING | |
706 | "rebuild_sched_domains confused:" | |
707 | " nslot %d, ndoms %d, csn %d, i %d," | |
708 | " apn %d\n", | |
709 | nslot, ndoms, csn, i, apn); | |
710 | warnings--; | |
029190c5 | 711 | } |
cf417141 MK |
712 | continue; |
713 | } | |
029190c5 | 714 | |
6af866af | 715 | cpumask_clear(dp); |
cf417141 MK |
716 | if (dattr) |
717 | *(dattr + nslot) = SD_ATTR_INIT; | |
718 | for (j = i; j < csn; j++) { | |
719 | struct cpuset *b = csa[j]; | |
720 | ||
721 | if (apn == b->pn) { | |
300ed6cb | 722 | cpumask_or(dp, dp, b->cpus_allowed); |
cf417141 MK |
723 | if (dattr) |
724 | update_domain_attr_tree(dattr + nslot, b); | |
725 | ||
726 | /* Done with this partition */ | |
727 | b->pn = -1; | |
029190c5 | 728 | } |
029190c5 | 729 | } |
cf417141 | 730 | nslot++; |
029190c5 PJ |
731 | } |
732 | BUG_ON(nslot != ndoms); | |
733 | ||
cf417141 MK |
734 | done: |
735 | kfree(csa); | |
736 | ||
700018e0 LZ |
737 | /* |
738 | * Fallback to the default domain if kmalloc() failed. | |
739 | * See comments in partition_sched_domains(). | |
740 | */ | |
741 | if (doms == NULL) | |
742 | ndoms = 1; | |
743 | ||
cf417141 MK |
744 | *domains = doms; |
745 | *attributes = dattr; | |
746 | return ndoms; | |
747 | } | |
748 | ||
749 | /* | |
750 | * Rebuild scheduler domains. | |
751 | * | |
699140ba TH |
752 | * If the flag 'sched_load_balance' of any cpuset with non-empty |
753 | * 'cpus' changes, or if the 'cpus' allowed changes in any cpuset | |
754 | * which has that flag enabled, or if any cpuset with a non-empty | |
755 | * 'cpus' is removed, then call this routine to rebuild the | |
756 | * scheduler's dynamic sched domains. | |
cf417141 | 757 | * |
5d21cc2d | 758 | * Call with cpuset_mutex held. Takes get_online_cpus(). |
cf417141 | 759 | */ |
699140ba | 760 | static void rebuild_sched_domains_locked(void) |
cf417141 MK |
761 | { |
762 | struct sched_domain_attr *attr; | |
acc3f5d7 | 763 | cpumask_var_t *doms; |
cf417141 MK |
764 | int ndoms; |
765 | ||
5d21cc2d | 766 | lockdep_assert_held(&cpuset_mutex); |
86ef5c9a | 767 | get_online_cpus(); |
cf417141 | 768 | |
5b16c2a4 LZ |
769 | /* |
770 | * We have raced with CPU hotplug. Don't do anything to avoid | |
771 | * passing doms with offlined cpu to partition_sched_domains(). | |
772 | * Anyways, hotplug work item will rebuild sched domains. | |
773 | */ | |
774 | if (!cpumask_equal(top_cpuset.cpus_allowed, cpu_active_mask)) | |
775 | goto out; | |
776 | ||
cf417141 | 777 | /* Generate domain masks and attrs */ |
cf417141 | 778 | ndoms = generate_sched_domains(&doms, &attr); |
cf417141 MK |
779 | |
780 | /* Have scheduler rebuild the domains */ | |
781 | partition_sched_domains(ndoms, doms, attr); | |
5b16c2a4 | 782 | out: |
86ef5c9a | 783 | put_online_cpus(); |
cf417141 | 784 | } |
db7f47cf | 785 | #else /* !CONFIG_SMP */ |
699140ba | 786 | static void rebuild_sched_domains_locked(void) |
db7f47cf PM |
787 | { |
788 | } | |
db7f47cf | 789 | #endif /* CONFIG_SMP */ |
029190c5 | 790 | |
cf417141 MK |
791 | void rebuild_sched_domains(void) |
792 | { | |
5d21cc2d | 793 | mutex_lock(&cpuset_mutex); |
699140ba | 794 | rebuild_sched_domains_locked(); |
5d21cc2d | 795 | mutex_unlock(&cpuset_mutex); |
029190c5 PJ |
796 | } |
797 | ||
070b57fc LZ |
798 | /* |
799 | * effective_cpumask_cpuset - return nearest ancestor with non-empty cpus | |
800 | * @cs: the cpuset in interest | |
58f4790b | 801 | * |
070b57fc LZ |
802 | * A cpuset's effective cpumask is the cpumask of the nearest ancestor |
803 | * with non-empty cpus. We use effective cpumask whenever: | |
804 | * - we update tasks' cpus_allowed. (they take on the ancestor's cpumask | |
805 | * if the cpuset they reside in has no cpus) | |
806 | * - we want to retrieve task_cs(tsk)'s cpus_allowed. | |
807 | * | |
808 | * Called with cpuset_mutex held. cpuset_cpus_allowed_fallback() is an | |
809 | * exception. See comments there. | |
810 | */ | |
811 | static struct cpuset *effective_cpumask_cpuset(struct cpuset *cs) | |
812 | { | |
813 | while (cpumask_empty(cs->cpus_allowed)) | |
814 | cs = parent_cs(cs); | |
815 | return cs; | |
816 | } | |
817 | ||
818 | /* | |
819 | * effective_nodemask_cpuset - return nearest ancestor with non-empty mems | |
820 | * @cs: the cpuset in interest | |
821 | * | |
822 | * A cpuset's effective nodemask is the nodemask of the nearest ancestor | |
823 | * with non-empty memss. We use effective nodemask whenever: | |
824 | * - we update tasks' mems_allowed. (they take on the ancestor's nodemask | |
825 | * if the cpuset they reside in has no mems) | |
826 | * - we want to retrieve task_cs(tsk)'s mems_allowed. | |
827 | * | |
828 | * Called with cpuset_mutex held. | |
053199ed | 829 | */ |
070b57fc | 830 | static struct cpuset *effective_nodemask_cpuset(struct cpuset *cs) |
58f4790b | 831 | { |
070b57fc LZ |
832 | while (nodes_empty(cs->mems_allowed)) |
833 | cs = parent_cs(cs); | |
834 | return cs; | |
58f4790b | 835 | } |
053199ed | 836 | |
58f4790b CW |
837 | /** |
838 | * cpuset_change_cpumask - make a task's cpus_allowed the same as its cpuset's | |
839 | * @tsk: task to test | |
840 | * @scan: struct cgroup_scanner containing the cgroup of the task | |
841 | * | |
842 | * Called by cgroup_scan_tasks() for each task in a cgroup whose | |
843 | * cpus_allowed mask needs to be changed. | |
844 | * | |
845 | * We don't need to re-check for the cgroup/cpuset membership, since we're | |
5d21cc2d | 846 | * holding cpuset_mutex at this point. |
58f4790b | 847 | */ |
9e0c914c AB |
848 | static void cpuset_change_cpumask(struct task_struct *tsk, |
849 | struct cgroup_scanner *scan) | |
58f4790b | 850 | { |
070b57fc LZ |
851 | struct cpuset *cpus_cs; |
852 | ||
853 | cpus_cs = effective_cpumask_cpuset(cgroup_cs(scan->cg)); | |
854 | set_cpus_allowed_ptr(tsk, cpus_cs->cpus_allowed); | |
58f4790b CW |
855 | } |
856 | ||
0b2f630a MX |
857 | /** |
858 | * update_tasks_cpumask - Update the cpumasks of tasks in the cpuset. | |
859 | * @cs: the cpuset in which each task's cpus_allowed mask needs to be changed | |
4e74339a | 860 | * @heap: if NULL, defer allocating heap memory to cgroup_scan_tasks() |
0b2f630a | 861 | * |
5d21cc2d | 862 | * Called with cpuset_mutex held |
0b2f630a MX |
863 | * |
864 | * The cgroup_scan_tasks() function will scan all the tasks in a cgroup, | |
865 | * calling callback functions for each. | |
866 | * | |
4e74339a LZ |
867 | * No return value. It's guaranteed that cgroup_scan_tasks() always returns 0 |
868 | * if @heap != NULL. | |
0b2f630a | 869 | */ |
4e74339a | 870 | static void update_tasks_cpumask(struct cpuset *cs, struct ptr_heap *heap) |
0b2f630a MX |
871 | { |
872 | struct cgroup_scanner scan; | |
0b2f630a MX |
873 | |
874 | scan.cg = cs->css.cgroup; | |
249cc86d | 875 | scan.test_task = NULL; |
0b2f630a | 876 | scan.process_task = cpuset_change_cpumask; |
4e74339a LZ |
877 | scan.heap = heap; |
878 | cgroup_scan_tasks(&scan); | |
0b2f630a MX |
879 | } |
880 | ||
5c5cc623 LZ |
881 | /* |
882 | * update_tasks_cpumask_hier - Update the cpumasks of tasks in the hierarchy. | |
883 | * @root_cs: the root cpuset of the hierarchy | |
884 | * @update_root: update root cpuset or not? | |
885 | * @heap: the heap used by cgroup_scan_tasks() | |
886 | * | |
887 | * This will update cpumasks of tasks in @root_cs and all other empty cpusets | |
888 | * which take on cpumask of @root_cs. | |
889 | * | |
890 | * Called with cpuset_mutex held | |
891 | */ | |
892 | static void update_tasks_cpumask_hier(struct cpuset *root_cs, | |
893 | bool update_root, struct ptr_heap *heap) | |
894 | { | |
895 | struct cpuset *cp; | |
896 | struct cgroup *pos_cgrp; | |
897 | ||
898 | if (update_root) | |
899 | update_tasks_cpumask(root_cs, heap); | |
900 | ||
901 | rcu_read_lock(); | |
902 | cpuset_for_each_descendant_pre(cp, pos_cgrp, root_cs) { | |
903 | /* skip the whole subtree if @cp have some CPU */ | |
904 | if (!cpumask_empty(cp->cpus_allowed)) { | |
905 | pos_cgrp = cgroup_rightmost_descendant(pos_cgrp); | |
906 | continue; | |
907 | } | |
908 | if (!css_tryget(&cp->css)) | |
909 | continue; | |
910 | rcu_read_unlock(); | |
911 | ||
912 | update_tasks_cpumask(cp, heap); | |
913 | ||
914 | rcu_read_lock(); | |
915 | css_put(&cp->css); | |
916 | } | |
917 | rcu_read_unlock(); | |
918 | } | |
919 | ||
58f4790b CW |
920 | /** |
921 | * update_cpumask - update the cpus_allowed mask of a cpuset and all tasks in it | |
922 | * @cs: the cpuset to consider | |
923 | * @buf: buffer of cpu numbers written to this cpuset | |
924 | */ | |
645fcc9d LZ |
925 | static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs, |
926 | const char *buf) | |
1da177e4 | 927 | { |
4e74339a | 928 | struct ptr_heap heap; |
58f4790b CW |
929 | int retval; |
930 | int is_load_balanced; | |
1da177e4 | 931 | |
5f054e31 | 932 | /* top_cpuset.cpus_allowed tracks cpu_online_mask; it's read-only */ |
4c4d50f7 PJ |
933 | if (cs == &top_cpuset) |
934 | return -EACCES; | |
935 | ||
6f7f02e7 | 936 | /* |
c8d9c90c | 937 | * An empty cpus_allowed is ok only if the cpuset has no tasks. |
020958b6 PJ |
938 | * Since cpulist_parse() fails on an empty mask, we special case |
939 | * that parsing. The validate_change() call ensures that cpusets | |
940 | * with tasks have cpus. | |
6f7f02e7 | 941 | */ |
020958b6 | 942 | if (!*buf) { |
300ed6cb | 943 | cpumask_clear(trialcs->cpus_allowed); |
6f7f02e7 | 944 | } else { |
300ed6cb | 945 | retval = cpulist_parse(buf, trialcs->cpus_allowed); |
6f7f02e7 DR |
946 | if (retval < 0) |
947 | return retval; | |
37340746 | 948 | |
6ad4c188 | 949 | if (!cpumask_subset(trialcs->cpus_allowed, cpu_active_mask)) |
37340746 | 950 | return -EINVAL; |
6f7f02e7 | 951 | } |
029190c5 | 952 | |
8707d8b8 | 953 | /* Nothing to do if the cpus didn't change */ |
300ed6cb | 954 | if (cpumask_equal(cs->cpus_allowed, trialcs->cpus_allowed)) |
8707d8b8 | 955 | return 0; |
58f4790b | 956 | |
a73456f3 LZ |
957 | retval = validate_change(cs, trialcs); |
958 | if (retval < 0) | |
959 | return retval; | |
960 | ||
4e74339a LZ |
961 | retval = heap_init(&heap, PAGE_SIZE, GFP_KERNEL, NULL); |
962 | if (retval) | |
963 | return retval; | |
964 | ||
645fcc9d | 965 | is_load_balanced = is_sched_load_balance(trialcs); |
029190c5 | 966 | |
3d3f26a7 | 967 | mutex_lock(&callback_mutex); |
300ed6cb | 968 | cpumask_copy(cs->cpus_allowed, trialcs->cpus_allowed); |
3d3f26a7 | 969 | mutex_unlock(&callback_mutex); |
029190c5 | 970 | |
5c5cc623 | 971 | update_tasks_cpumask_hier(cs, true, &heap); |
4e74339a LZ |
972 | |
973 | heap_free(&heap); | |
58f4790b | 974 | |
8707d8b8 | 975 | if (is_load_balanced) |
699140ba | 976 | rebuild_sched_domains_locked(); |
85d7b949 | 977 | return 0; |
1da177e4 LT |
978 | } |
979 | ||
e4e364e8 PJ |
980 | /* |
981 | * cpuset_migrate_mm | |
982 | * | |
983 | * Migrate memory region from one set of nodes to another. | |
984 | * | |
985 | * Temporarilly set tasks mems_allowed to target nodes of migration, | |
986 | * so that the migration code can allocate pages on these nodes. | |
987 | * | |
5d21cc2d | 988 | * Call holding cpuset_mutex, so current's cpuset won't change |
c8d9c90c | 989 | * during this call, as manage_mutex holds off any cpuset_attach() |
e4e364e8 PJ |
990 | * calls. Therefore we don't need to take task_lock around the |
991 | * call to guarantee_online_mems(), as we know no one is changing | |
2df167a3 | 992 | * our task's cpuset. |
e4e364e8 | 993 | * |
e4e364e8 PJ |
994 | * While the mm_struct we are migrating is typically from some |
995 | * other task, the task_struct mems_allowed that we are hacking | |
996 | * is for our current task, which must allocate new pages for that | |
997 | * migrating memory region. | |
e4e364e8 PJ |
998 | */ |
999 | ||
1000 | static void cpuset_migrate_mm(struct mm_struct *mm, const nodemask_t *from, | |
1001 | const nodemask_t *to) | |
1002 | { | |
1003 | struct task_struct *tsk = current; | |
070b57fc | 1004 | struct cpuset *mems_cs; |
e4e364e8 | 1005 | |
e4e364e8 | 1006 | tsk->mems_allowed = *to; |
e4e364e8 PJ |
1007 | |
1008 | do_migrate_pages(mm, from, to, MPOL_MF_MOVE_ALL); | |
1009 | ||
070b57fc LZ |
1010 | mems_cs = effective_nodemask_cpuset(task_cs(tsk)); |
1011 | guarantee_online_mems(mems_cs, &tsk->mems_allowed); | |
e4e364e8 PJ |
1012 | } |
1013 | ||
3b6766fe | 1014 | /* |
58568d2a MX |
1015 | * cpuset_change_task_nodemask - change task's mems_allowed and mempolicy |
1016 | * @tsk: the task to change | |
1017 | * @newmems: new nodes that the task will be set | |
1018 | * | |
1019 | * In order to avoid seeing no nodes if the old and new nodes are disjoint, | |
1020 | * we structure updates as setting all new allowed nodes, then clearing newly | |
1021 | * disallowed ones. | |
58568d2a MX |
1022 | */ |
1023 | static void cpuset_change_task_nodemask(struct task_struct *tsk, | |
1024 | nodemask_t *newmems) | |
1025 | { | |
b246272e | 1026 | bool need_loop; |
89e8a244 | 1027 | |
c0ff7453 MX |
1028 | /* |
1029 | * Allow tasks that have access to memory reserves because they have | |
1030 | * been OOM killed to get memory anywhere. | |
1031 | */ | |
1032 | if (unlikely(test_thread_flag(TIF_MEMDIE))) | |
1033 | return; | |
1034 | if (current->flags & PF_EXITING) /* Let dying task have memory */ | |
1035 | return; | |
1036 | ||
1037 | task_lock(tsk); | |
b246272e DR |
1038 | /* |
1039 | * Determine if a loop is necessary if another thread is doing | |
1040 | * get_mems_allowed(). If at least one node remains unchanged and | |
1041 | * tsk does not have a mempolicy, then an empty nodemask will not be | |
1042 | * possible when mems_allowed is larger than a word. | |
1043 | */ | |
1044 | need_loop = task_has_mempolicy(tsk) || | |
1045 | !nodes_intersects(*newmems, tsk->mems_allowed); | |
c0ff7453 | 1046 | |
cc9a6c87 MG |
1047 | if (need_loop) |
1048 | write_seqcount_begin(&tsk->mems_allowed_seq); | |
c0ff7453 | 1049 | |
cc9a6c87 MG |
1050 | nodes_or(tsk->mems_allowed, tsk->mems_allowed, *newmems); |
1051 | mpol_rebind_task(tsk, newmems, MPOL_REBIND_STEP1); | |
c0ff7453 MX |
1052 | |
1053 | mpol_rebind_task(tsk, newmems, MPOL_REBIND_STEP2); | |
58568d2a | 1054 | tsk->mems_allowed = *newmems; |
cc9a6c87 MG |
1055 | |
1056 | if (need_loop) | |
1057 | write_seqcount_end(&tsk->mems_allowed_seq); | |
1058 | ||
c0ff7453 | 1059 | task_unlock(tsk); |
58568d2a MX |
1060 | } |
1061 | ||
1062 | /* | |
1063 | * Update task's mems_allowed and rebind its mempolicy and vmas' mempolicy | |
1064 | * of it to cpuset's new mems_allowed, and migrate pages to new nodes if | |
5d21cc2d | 1065 | * memory_migrate flag is set. Called with cpuset_mutex held. |
3b6766fe LZ |
1066 | */ |
1067 | static void cpuset_change_nodemask(struct task_struct *p, | |
1068 | struct cgroup_scanner *scan) | |
1069 | { | |
33ad801d | 1070 | struct cpuset *cs = cgroup_cs(scan->cg); |
3b6766fe | 1071 | struct mm_struct *mm; |
3b6766fe | 1072 | int migrate; |
33ad801d | 1073 | nodemask_t *newmems = scan->data; |
58568d2a | 1074 | |
33ad801d | 1075 | cpuset_change_task_nodemask(p, newmems); |
53feb297 | 1076 | |
3b6766fe LZ |
1077 | mm = get_task_mm(p); |
1078 | if (!mm) | |
1079 | return; | |
1080 | ||
3b6766fe LZ |
1081 | migrate = is_memory_migrate(cs); |
1082 | ||
1083 | mpol_rebind_mm(mm, &cs->mems_allowed); | |
1084 | if (migrate) | |
33ad801d | 1085 | cpuset_migrate_mm(mm, &cs->old_mems_allowed, newmems); |
3b6766fe LZ |
1086 | mmput(mm); |
1087 | } | |
1088 | ||
8793d854 PM |
1089 | static void *cpuset_being_rebound; |
1090 | ||
0b2f630a MX |
1091 | /** |
1092 | * update_tasks_nodemask - Update the nodemasks of tasks in the cpuset. | |
1093 | * @cs: the cpuset in which each task's mems_allowed mask needs to be changed | |
010cfac4 | 1094 | * @heap: if NULL, defer allocating heap memory to cgroup_scan_tasks() |
0b2f630a | 1095 | * |
5d21cc2d | 1096 | * Called with cpuset_mutex held |
010cfac4 LZ |
1097 | * No return value. It's guaranteed that cgroup_scan_tasks() always returns 0 |
1098 | * if @heap != NULL. | |
0b2f630a | 1099 | */ |
33ad801d | 1100 | static void update_tasks_nodemask(struct cpuset *cs, struct ptr_heap *heap) |
1da177e4 | 1101 | { |
33ad801d | 1102 | static nodemask_t newmems; /* protected by cpuset_mutex */ |
3b6766fe | 1103 | struct cgroup_scanner scan; |
070b57fc | 1104 | struct cpuset *mems_cs = effective_nodemask_cpuset(cs); |
59dac16f | 1105 | |
846a16bf | 1106 | cpuset_being_rebound = cs; /* causes mpol_dup() rebind */ |
4225399a | 1107 | |
070b57fc | 1108 | guarantee_online_mems(mems_cs, &newmems); |
33ad801d | 1109 | |
3b6766fe LZ |
1110 | scan.cg = cs->css.cgroup; |
1111 | scan.test_task = NULL; | |
1112 | scan.process_task = cpuset_change_nodemask; | |
010cfac4 | 1113 | scan.heap = heap; |
33ad801d | 1114 | scan.data = &newmems; |
4225399a PJ |
1115 | |
1116 | /* | |
3b6766fe LZ |
1117 | * The mpol_rebind_mm() call takes mmap_sem, which we couldn't |
1118 | * take while holding tasklist_lock. Forks can happen - the | |
1119 | * mpol_dup() cpuset_being_rebound check will catch such forks, | |
1120 | * and rebind their vma mempolicies too. Because we still hold | |
5d21cc2d | 1121 | * the global cpuset_mutex, we know that no other rebind effort |
3b6766fe | 1122 | * will be contending for the global variable cpuset_being_rebound. |
4225399a | 1123 | * It's ok if we rebind the same mm twice; mpol_rebind_mm() |
04c19fa6 | 1124 | * is idempotent. Also migrate pages in each mm to new nodes. |
4225399a | 1125 | */ |
010cfac4 | 1126 | cgroup_scan_tasks(&scan); |
4225399a | 1127 | |
33ad801d LZ |
1128 | /* |
1129 | * All the tasks' nodemasks have been updated, update | |
1130 | * cs->old_mems_allowed. | |
1131 | */ | |
1132 | cs->old_mems_allowed = newmems; | |
1133 | ||
2df167a3 | 1134 | /* We're done rebinding vmas to this cpuset's new mems_allowed. */ |
8793d854 | 1135 | cpuset_being_rebound = NULL; |
1da177e4 LT |
1136 | } |
1137 | ||
5c5cc623 LZ |
1138 | /* |
1139 | * update_tasks_nodemask_hier - Update the nodemasks of tasks in the hierarchy. | |
1140 | * @cs: the root cpuset of the hierarchy | |
1141 | * @update_root: update the root cpuset or not? | |
1142 | * @heap: the heap used by cgroup_scan_tasks() | |
1143 | * | |
1144 | * This will update nodemasks of tasks in @root_cs and all other empty cpusets | |
1145 | * which take on nodemask of @root_cs. | |
1146 | * | |
1147 | * Called with cpuset_mutex held | |
1148 | */ | |
1149 | static void update_tasks_nodemask_hier(struct cpuset *root_cs, | |
1150 | bool update_root, struct ptr_heap *heap) | |
1151 | { | |
1152 | struct cpuset *cp; | |
1153 | struct cgroup *pos_cgrp; | |
1154 | ||
1155 | if (update_root) | |
1156 | update_tasks_nodemask(root_cs, heap); | |
1157 | ||
1158 | rcu_read_lock(); | |
1159 | cpuset_for_each_descendant_pre(cp, pos_cgrp, root_cs) { | |
1160 | /* skip the whole subtree if @cp have some CPU */ | |
1161 | if (!nodes_empty(cp->mems_allowed)) { | |
1162 | pos_cgrp = cgroup_rightmost_descendant(pos_cgrp); | |
1163 | continue; | |
1164 | } | |
1165 | if (!css_tryget(&cp->css)) | |
1166 | continue; | |
1167 | rcu_read_unlock(); | |
1168 | ||
1169 | update_tasks_nodemask(cp, heap); | |
1170 | ||
1171 | rcu_read_lock(); | |
1172 | css_put(&cp->css); | |
1173 | } | |
1174 | rcu_read_unlock(); | |
1175 | } | |
1176 | ||
0b2f630a MX |
1177 | /* |
1178 | * Handle user request to change the 'mems' memory placement | |
1179 | * of a cpuset. Needs to validate the request, update the | |
58568d2a MX |
1180 | * cpusets mems_allowed, and for each task in the cpuset, |
1181 | * update mems_allowed and rebind task's mempolicy and any vma | |
1182 | * mempolicies and if the cpuset is marked 'memory_migrate', | |
1183 | * migrate the tasks pages to the new memory. | |
0b2f630a | 1184 | * |
5d21cc2d | 1185 | * Call with cpuset_mutex held. May take callback_mutex during call. |
0b2f630a MX |
1186 | * Will take tasklist_lock, scan tasklist for tasks in cpuset cs, |
1187 | * lock each such tasks mm->mmap_sem, scan its vma's and rebind | |
1188 | * their mempolicies to the cpusets new mems_allowed. | |
1189 | */ | |
645fcc9d LZ |
1190 | static int update_nodemask(struct cpuset *cs, struct cpuset *trialcs, |
1191 | const char *buf) | |
0b2f630a | 1192 | { |
0b2f630a | 1193 | int retval; |
010cfac4 | 1194 | struct ptr_heap heap; |
0b2f630a MX |
1195 | |
1196 | /* | |
38d7bee9 | 1197 | * top_cpuset.mems_allowed tracks node_stats[N_MEMORY]; |
0b2f630a MX |
1198 | * it's read-only |
1199 | */ | |
53feb297 MX |
1200 | if (cs == &top_cpuset) { |
1201 | retval = -EACCES; | |
1202 | goto done; | |
1203 | } | |
0b2f630a | 1204 | |
0b2f630a MX |
1205 | /* |
1206 | * An empty mems_allowed is ok iff there are no tasks in the cpuset. | |
1207 | * Since nodelist_parse() fails on an empty mask, we special case | |
1208 | * that parsing. The validate_change() call ensures that cpusets | |
1209 | * with tasks have memory. | |
1210 | */ | |
1211 | if (!*buf) { | |
645fcc9d | 1212 | nodes_clear(trialcs->mems_allowed); |
0b2f630a | 1213 | } else { |
645fcc9d | 1214 | retval = nodelist_parse(buf, trialcs->mems_allowed); |
0b2f630a MX |
1215 | if (retval < 0) |
1216 | goto done; | |
1217 | ||
645fcc9d | 1218 | if (!nodes_subset(trialcs->mems_allowed, |
38d7bee9 | 1219 | node_states[N_MEMORY])) { |
53feb297 MX |
1220 | retval = -EINVAL; |
1221 | goto done; | |
1222 | } | |
0b2f630a | 1223 | } |
33ad801d LZ |
1224 | |
1225 | if (nodes_equal(cs->mems_allowed, trialcs->mems_allowed)) { | |
0b2f630a MX |
1226 | retval = 0; /* Too easy - nothing to do */ |
1227 | goto done; | |
1228 | } | |
645fcc9d | 1229 | retval = validate_change(cs, trialcs); |
0b2f630a MX |
1230 | if (retval < 0) |
1231 | goto done; | |
1232 | ||
010cfac4 LZ |
1233 | retval = heap_init(&heap, PAGE_SIZE, GFP_KERNEL, NULL); |
1234 | if (retval < 0) | |
1235 | goto done; | |
1236 | ||
0b2f630a | 1237 | mutex_lock(&callback_mutex); |
645fcc9d | 1238 | cs->mems_allowed = trialcs->mems_allowed; |
0b2f630a MX |
1239 | mutex_unlock(&callback_mutex); |
1240 | ||
5c5cc623 | 1241 | update_tasks_nodemask_hier(cs, true, &heap); |
010cfac4 LZ |
1242 | |
1243 | heap_free(&heap); | |
0b2f630a MX |
1244 | done: |
1245 | return retval; | |
1246 | } | |
1247 | ||
8793d854 PM |
1248 | int current_cpuset_is_being_rebound(void) |
1249 | { | |
1250 | return task_cs(current) == cpuset_being_rebound; | |
1251 | } | |
1252 | ||
5be7a479 | 1253 | static int update_relax_domain_level(struct cpuset *cs, s64 val) |
1d3504fc | 1254 | { |
db7f47cf | 1255 | #ifdef CONFIG_SMP |
60495e77 | 1256 | if (val < -1 || val >= sched_domain_level_max) |
30e0e178 | 1257 | return -EINVAL; |
db7f47cf | 1258 | #endif |
1d3504fc HS |
1259 | |
1260 | if (val != cs->relax_domain_level) { | |
1261 | cs->relax_domain_level = val; | |
300ed6cb LZ |
1262 | if (!cpumask_empty(cs->cpus_allowed) && |
1263 | is_sched_load_balance(cs)) | |
699140ba | 1264 | rebuild_sched_domains_locked(); |
1d3504fc HS |
1265 | } |
1266 | ||
1267 | return 0; | |
1268 | } | |
1269 | ||
950592f7 MX |
1270 | /* |
1271 | * cpuset_change_flag - make a task's spread flags the same as its cpuset's | |
1272 | * @tsk: task to be updated | |
1273 | * @scan: struct cgroup_scanner containing the cgroup of the task | |
1274 | * | |
1275 | * Called by cgroup_scan_tasks() for each task in a cgroup. | |
1276 | * | |
1277 | * We don't need to re-check for the cgroup/cpuset membership, since we're | |
5d21cc2d | 1278 | * holding cpuset_mutex at this point. |
950592f7 MX |
1279 | */ |
1280 | static void cpuset_change_flag(struct task_struct *tsk, | |
1281 | struct cgroup_scanner *scan) | |
1282 | { | |
1283 | cpuset_update_task_spread_flag(cgroup_cs(scan->cg), tsk); | |
1284 | } | |
1285 | ||
1286 | /* | |
1287 | * update_tasks_flags - update the spread flags of tasks in the cpuset. | |
1288 | * @cs: the cpuset in which each task's spread flags needs to be changed | |
1289 | * @heap: if NULL, defer allocating heap memory to cgroup_scan_tasks() | |
1290 | * | |
5d21cc2d | 1291 | * Called with cpuset_mutex held |
950592f7 MX |
1292 | * |
1293 | * The cgroup_scan_tasks() function will scan all the tasks in a cgroup, | |
1294 | * calling callback functions for each. | |
1295 | * | |
1296 | * No return value. It's guaranteed that cgroup_scan_tasks() always returns 0 | |
1297 | * if @heap != NULL. | |
1298 | */ | |
1299 | static void update_tasks_flags(struct cpuset *cs, struct ptr_heap *heap) | |
1300 | { | |
1301 | struct cgroup_scanner scan; | |
1302 | ||
1303 | scan.cg = cs->css.cgroup; | |
1304 | scan.test_task = NULL; | |
1305 | scan.process_task = cpuset_change_flag; | |
1306 | scan.heap = heap; | |
1307 | cgroup_scan_tasks(&scan); | |
1308 | } | |
1309 | ||
1da177e4 LT |
1310 | /* |
1311 | * update_flag - read a 0 or a 1 in a file and update associated flag | |
78608366 PM |
1312 | * bit: the bit to update (see cpuset_flagbits_t) |
1313 | * cs: the cpuset to update | |
1314 | * turning_on: whether the flag is being set or cleared | |
053199ed | 1315 | * |
5d21cc2d | 1316 | * Call with cpuset_mutex held. |
1da177e4 LT |
1317 | */ |
1318 | ||
700fe1ab PM |
1319 | static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs, |
1320 | int turning_on) | |
1da177e4 | 1321 | { |
645fcc9d | 1322 | struct cpuset *trialcs; |
40b6a762 | 1323 | int balance_flag_changed; |
950592f7 MX |
1324 | int spread_flag_changed; |
1325 | struct ptr_heap heap; | |
1326 | int err; | |
1da177e4 | 1327 | |
645fcc9d LZ |
1328 | trialcs = alloc_trial_cpuset(cs); |
1329 | if (!trialcs) | |
1330 | return -ENOMEM; | |
1331 | ||
1da177e4 | 1332 | if (turning_on) |
645fcc9d | 1333 | set_bit(bit, &trialcs->flags); |
1da177e4 | 1334 | else |
645fcc9d | 1335 | clear_bit(bit, &trialcs->flags); |
1da177e4 | 1336 | |
645fcc9d | 1337 | err = validate_change(cs, trialcs); |
85d7b949 | 1338 | if (err < 0) |
645fcc9d | 1339 | goto out; |
029190c5 | 1340 | |
950592f7 MX |
1341 | err = heap_init(&heap, PAGE_SIZE, GFP_KERNEL, NULL); |
1342 | if (err < 0) | |
1343 | goto out; | |
1344 | ||
029190c5 | 1345 | balance_flag_changed = (is_sched_load_balance(cs) != |
645fcc9d | 1346 | is_sched_load_balance(trialcs)); |
029190c5 | 1347 | |
950592f7 MX |
1348 | spread_flag_changed = ((is_spread_slab(cs) != is_spread_slab(trialcs)) |
1349 | || (is_spread_page(cs) != is_spread_page(trialcs))); | |
1350 | ||
3d3f26a7 | 1351 | mutex_lock(&callback_mutex); |
645fcc9d | 1352 | cs->flags = trialcs->flags; |
3d3f26a7 | 1353 | mutex_unlock(&callback_mutex); |
85d7b949 | 1354 | |
300ed6cb | 1355 | if (!cpumask_empty(trialcs->cpus_allowed) && balance_flag_changed) |
699140ba | 1356 | rebuild_sched_domains_locked(); |
029190c5 | 1357 | |
950592f7 MX |
1358 | if (spread_flag_changed) |
1359 | update_tasks_flags(cs, &heap); | |
1360 | heap_free(&heap); | |
645fcc9d LZ |
1361 | out: |
1362 | free_trial_cpuset(trialcs); | |
1363 | return err; | |
1da177e4 LT |
1364 | } |
1365 | ||
3e0d98b9 | 1366 | /* |
80f7228b | 1367 | * Frequency meter - How fast is some event occurring? |
3e0d98b9 PJ |
1368 | * |
1369 | * These routines manage a digitally filtered, constant time based, | |
1370 | * event frequency meter. There are four routines: | |
1371 | * fmeter_init() - initialize a frequency meter. | |
1372 | * fmeter_markevent() - called each time the event happens. | |
1373 | * fmeter_getrate() - returns the recent rate of such events. | |
1374 | * fmeter_update() - internal routine used to update fmeter. | |
1375 | * | |
1376 | * A common data structure is passed to each of these routines, | |
1377 | * which is used to keep track of the state required to manage the | |
1378 | * frequency meter and its digital filter. | |
1379 | * | |
1380 | * The filter works on the number of events marked per unit time. | |
1381 | * The filter is single-pole low-pass recursive (IIR). The time unit | |
1382 | * is 1 second. Arithmetic is done using 32-bit integers scaled to | |
1383 | * simulate 3 decimal digits of precision (multiplied by 1000). | |
1384 | * | |
1385 | * With an FM_COEF of 933, and a time base of 1 second, the filter | |
1386 | * has a half-life of 10 seconds, meaning that if the events quit | |
1387 | * happening, then the rate returned from the fmeter_getrate() | |
1388 | * will be cut in half each 10 seconds, until it converges to zero. | |
1389 | * | |
1390 | * It is not worth doing a real infinitely recursive filter. If more | |
1391 | * than FM_MAXTICKS ticks have elapsed since the last filter event, | |
1392 | * just compute FM_MAXTICKS ticks worth, by which point the level | |
1393 | * will be stable. | |
1394 | * | |
1395 | * Limit the count of unprocessed events to FM_MAXCNT, so as to avoid | |
1396 | * arithmetic overflow in the fmeter_update() routine. | |
1397 | * | |
1398 | * Given the simple 32 bit integer arithmetic used, this meter works | |
1399 | * best for reporting rates between one per millisecond (msec) and | |
1400 | * one per 32 (approx) seconds. At constant rates faster than one | |
1401 | * per msec it maxes out at values just under 1,000,000. At constant | |
1402 | * rates between one per msec, and one per second it will stabilize | |
1403 | * to a value N*1000, where N is the rate of events per second. | |
1404 | * At constant rates between one per second and one per 32 seconds, | |
1405 | * it will be choppy, moving up on the seconds that have an event, | |
1406 | * and then decaying until the next event. At rates slower than | |
1407 | * about one in 32 seconds, it decays all the way back to zero between | |
1408 | * each event. | |
1409 | */ | |
1410 | ||
1411 | #define FM_COEF 933 /* coefficient for half-life of 10 secs */ | |
1412 | #define FM_MAXTICKS ((time_t)99) /* useless computing more ticks than this */ | |
1413 | #define FM_MAXCNT 1000000 /* limit cnt to avoid overflow */ | |
1414 | #define FM_SCALE 1000 /* faux fixed point scale */ | |
1415 | ||
1416 | /* Initialize a frequency meter */ | |
1417 | static void fmeter_init(struct fmeter *fmp) | |
1418 | { | |
1419 | fmp->cnt = 0; | |
1420 | fmp->val = 0; | |
1421 | fmp->time = 0; | |
1422 | spin_lock_init(&fmp->lock); | |
1423 | } | |
1424 | ||
1425 | /* Internal meter update - process cnt events and update value */ | |
1426 | static void fmeter_update(struct fmeter *fmp) | |
1427 | { | |
1428 | time_t now = get_seconds(); | |
1429 | time_t ticks = now - fmp->time; | |
1430 | ||
1431 | if (ticks == 0) | |
1432 | return; | |
1433 | ||
1434 | ticks = min(FM_MAXTICKS, ticks); | |
1435 | while (ticks-- > 0) | |
1436 | fmp->val = (FM_COEF * fmp->val) / FM_SCALE; | |
1437 | fmp->time = now; | |
1438 | ||
1439 | fmp->val += ((FM_SCALE - FM_COEF) * fmp->cnt) / FM_SCALE; | |
1440 | fmp->cnt = 0; | |
1441 | } | |
1442 | ||
1443 | /* Process any previous ticks, then bump cnt by one (times scale). */ | |
1444 | static void fmeter_markevent(struct fmeter *fmp) | |
1445 | { | |
1446 | spin_lock(&fmp->lock); | |
1447 | fmeter_update(fmp); | |
1448 | fmp->cnt = min(FM_MAXCNT, fmp->cnt + FM_SCALE); | |
1449 | spin_unlock(&fmp->lock); | |
1450 | } | |
1451 | ||
1452 | /* Process any previous ticks, then return current value. */ | |
1453 | static int fmeter_getrate(struct fmeter *fmp) | |
1454 | { | |
1455 | int val; | |
1456 | ||
1457 | spin_lock(&fmp->lock); | |
1458 | fmeter_update(fmp); | |
1459 | val = fmp->val; | |
1460 | spin_unlock(&fmp->lock); | |
1461 | return val; | |
1462 | } | |
1463 | ||
5d21cc2d | 1464 | /* Called by cgroups to determine if a cpuset is usable; cpuset_mutex held */ |
761b3ef5 | 1465 | static int cpuset_can_attach(struct cgroup *cgrp, struct cgroup_taskset *tset) |
f780bdb7 | 1466 | { |
2f7ee569 | 1467 | struct cpuset *cs = cgroup_cs(cgrp); |
bb9d97b6 TH |
1468 | struct task_struct *task; |
1469 | int ret; | |
1da177e4 | 1470 | |
5d21cc2d TH |
1471 | mutex_lock(&cpuset_mutex); |
1472 | ||
88fa523b LZ |
1473 | /* |
1474 | * We allow to move tasks into an empty cpuset if sane_behavior | |
1475 | * flag is set. | |
1476 | */ | |
5d21cc2d | 1477 | ret = -ENOSPC; |
88fa523b LZ |
1478 | if (!cgroup_sane_behavior(cgrp) && |
1479 | (cpumask_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed))) | |
5d21cc2d | 1480 | goto out_unlock; |
9985b0ba | 1481 | |
bb9d97b6 TH |
1482 | cgroup_taskset_for_each(task, cgrp, tset) { |
1483 | /* | |
14a40ffc TH |
1484 | * Kthreads which disallow setaffinity shouldn't be moved |
1485 | * to a new cpuset; we don't want to change their cpu | |
1486 | * affinity and isolating such threads by their set of | |
1487 | * allowed nodes is unnecessary. Thus, cpusets are not | |
1488 | * applicable for such threads. This prevents checking for | |
1489 | * success of set_cpus_allowed_ptr() on all attached tasks | |
1490 | * before cpus_allowed may be changed. | |
bb9d97b6 | 1491 | */ |
5d21cc2d | 1492 | ret = -EINVAL; |
14a40ffc | 1493 | if (task->flags & PF_NO_SETAFFINITY) |
5d21cc2d TH |
1494 | goto out_unlock; |
1495 | ret = security_task_setscheduler(task); | |
1496 | if (ret) | |
1497 | goto out_unlock; | |
bb9d97b6 | 1498 | } |
f780bdb7 | 1499 | |
452477fa TH |
1500 | /* |
1501 | * Mark attach is in progress. This makes validate_change() fail | |
1502 | * changes which zero cpus/mems_allowed. | |
1503 | */ | |
1504 | cs->attach_in_progress++; | |
5d21cc2d TH |
1505 | ret = 0; |
1506 | out_unlock: | |
1507 | mutex_unlock(&cpuset_mutex); | |
1508 | return ret; | |
8793d854 | 1509 | } |
f780bdb7 | 1510 | |
452477fa TH |
1511 | static void cpuset_cancel_attach(struct cgroup *cgrp, |
1512 | struct cgroup_taskset *tset) | |
1513 | { | |
5d21cc2d | 1514 | mutex_lock(&cpuset_mutex); |
452477fa | 1515 | cgroup_cs(cgrp)->attach_in_progress--; |
5d21cc2d | 1516 | mutex_unlock(&cpuset_mutex); |
8793d854 | 1517 | } |
1da177e4 | 1518 | |
4e4c9a14 | 1519 | /* |
5d21cc2d | 1520 | * Protected by cpuset_mutex. cpus_attach is used only by cpuset_attach() |
4e4c9a14 TH |
1521 | * but we can't allocate it dynamically there. Define it global and |
1522 | * allocate from cpuset_init(). | |
1523 | */ | |
1524 | static cpumask_var_t cpus_attach; | |
1525 | ||
761b3ef5 | 1526 | static void cpuset_attach(struct cgroup *cgrp, struct cgroup_taskset *tset) |
8793d854 | 1527 | { |
67bd2c59 | 1528 | /* static buf protected by cpuset_mutex */ |
4e4c9a14 | 1529 | static nodemask_t cpuset_attach_nodemask_to; |
8793d854 | 1530 | struct mm_struct *mm; |
bb9d97b6 TH |
1531 | struct task_struct *task; |
1532 | struct task_struct *leader = cgroup_taskset_first(tset); | |
2f7ee569 TH |
1533 | struct cgroup *oldcgrp = cgroup_taskset_cur_cgroup(tset); |
1534 | struct cpuset *cs = cgroup_cs(cgrp); | |
1535 | struct cpuset *oldcs = cgroup_cs(oldcgrp); | |
070b57fc LZ |
1536 | struct cpuset *cpus_cs = effective_cpumask_cpuset(cs); |
1537 | struct cpuset *mems_cs = effective_nodemask_cpuset(cs); | |
22fb52dd | 1538 | |
5d21cc2d TH |
1539 | mutex_lock(&cpuset_mutex); |
1540 | ||
4e4c9a14 TH |
1541 | /* prepare for attach */ |
1542 | if (cs == &top_cpuset) | |
1543 | cpumask_copy(cpus_attach, cpu_possible_mask); | |
1544 | else | |
070b57fc | 1545 | guarantee_online_cpus(cpus_cs, cpus_attach); |
4e4c9a14 | 1546 | |
070b57fc | 1547 | guarantee_online_mems(mems_cs, &cpuset_attach_nodemask_to); |
4e4c9a14 | 1548 | |
bb9d97b6 TH |
1549 | cgroup_taskset_for_each(task, cgrp, tset) { |
1550 | /* | |
1551 | * can_attach beforehand should guarantee that this doesn't | |
1552 | * fail. TODO: have a better way to handle failure here | |
1553 | */ | |
1554 | WARN_ON_ONCE(set_cpus_allowed_ptr(task, cpus_attach)); | |
1555 | ||
1556 | cpuset_change_task_nodemask(task, &cpuset_attach_nodemask_to); | |
1557 | cpuset_update_task_spread_flag(cs, task); | |
1558 | } | |
22fb52dd | 1559 | |
f780bdb7 BB |
1560 | /* |
1561 | * Change mm, possibly for multiple threads in a threadgroup. This is | |
1562 | * expensive and may sleep. | |
1563 | */ | |
f780bdb7 | 1564 | cpuset_attach_nodemask_to = cs->mems_allowed; |
bb9d97b6 | 1565 | mm = get_task_mm(leader); |
4225399a | 1566 | if (mm) { |
070b57fc LZ |
1567 | struct cpuset *mems_oldcs = effective_nodemask_cpuset(oldcs); |
1568 | ||
f780bdb7 | 1569 | mpol_rebind_mm(mm, &cpuset_attach_nodemask_to); |
f047cecf LZ |
1570 | |
1571 | /* | |
1572 | * old_mems_allowed is the same with mems_allowed here, except | |
1573 | * if this task is being moved automatically due to hotplug. | |
1574 | * In that case @mems_allowed has been updated and is empty, | |
1575 | * so @old_mems_allowed is the right nodesets that we migrate | |
1576 | * mm from. | |
1577 | */ | |
1578 | if (is_memory_migrate(cs)) { | |
1579 | cpuset_migrate_mm(mm, &mems_oldcs->old_mems_allowed, | |
f780bdb7 | 1580 | &cpuset_attach_nodemask_to); |
f047cecf | 1581 | } |
4225399a PJ |
1582 | mmput(mm); |
1583 | } | |
452477fa | 1584 | |
33ad801d | 1585 | cs->old_mems_allowed = cpuset_attach_nodemask_to; |
02bb5863 | 1586 | |
452477fa | 1587 | cs->attach_in_progress--; |
e44193d3 LZ |
1588 | if (!cs->attach_in_progress) |
1589 | wake_up(&cpuset_attach_wq); | |
5d21cc2d TH |
1590 | |
1591 | mutex_unlock(&cpuset_mutex); | |
1da177e4 LT |
1592 | } |
1593 | ||
1594 | /* The various types of files and directories in a cpuset file system */ | |
1595 | ||
1596 | typedef enum { | |
45b07ef3 | 1597 | FILE_MEMORY_MIGRATE, |
1da177e4 LT |
1598 | FILE_CPULIST, |
1599 | FILE_MEMLIST, | |
1600 | FILE_CPU_EXCLUSIVE, | |
1601 | FILE_MEM_EXCLUSIVE, | |
78608366 | 1602 | FILE_MEM_HARDWALL, |
029190c5 | 1603 | FILE_SCHED_LOAD_BALANCE, |
1d3504fc | 1604 | FILE_SCHED_RELAX_DOMAIN_LEVEL, |
3e0d98b9 PJ |
1605 | FILE_MEMORY_PRESSURE_ENABLED, |
1606 | FILE_MEMORY_PRESSURE, | |
825a46af PJ |
1607 | FILE_SPREAD_PAGE, |
1608 | FILE_SPREAD_SLAB, | |
1da177e4 LT |
1609 | } cpuset_filetype_t; |
1610 | ||
700fe1ab PM |
1611 | static int cpuset_write_u64(struct cgroup *cgrp, struct cftype *cft, u64 val) |
1612 | { | |
700fe1ab PM |
1613 | struct cpuset *cs = cgroup_cs(cgrp); |
1614 | cpuset_filetype_t type = cft->private; | |
a903f086 | 1615 | int retval = 0; |
700fe1ab | 1616 | |
5d21cc2d | 1617 | mutex_lock(&cpuset_mutex); |
a903f086 LZ |
1618 | if (!is_cpuset_online(cs)) { |
1619 | retval = -ENODEV; | |
5d21cc2d | 1620 | goto out_unlock; |
a903f086 | 1621 | } |
700fe1ab PM |
1622 | |
1623 | switch (type) { | |
1da177e4 | 1624 | case FILE_CPU_EXCLUSIVE: |
700fe1ab | 1625 | retval = update_flag(CS_CPU_EXCLUSIVE, cs, val); |
1da177e4 LT |
1626 | break; |
1627 | case FILE_MEM_EXCLUSIVE: | |
700fe1ab | 1628 | retval = update_flag(CS_MEM_EXCLUSIVE, cs, val); |
1da177e4 | 1629 | break; |
78608366 PM |
1630 | case FILE_MEM_HARDWALL: |
1631 | retval = update_flag(CS_MEM_HARDWALL, cs, val); | |
1632 | break; | |
029190c5 | 1633 | case FILE_SCHED_LOAD_BALANCE: |
700fe1ab | 1634 | retval = update_flag(CS_SCHED_LOAD_BALANCE, cs, val); |
1d3504fc | 1635 | break; |
45b07ef3 | 1636 | case FILE_MEMORY_MIGRATE: |
700fe1ab | 1637 | retval = update_flag(CS_MEMORY_MIGRATE, cs, val); |
45b07ef3 | 1638 | break; |
3e0d98b9 | 1639 | case FILE_MEMORY_PRESSURE_ENABLED: |
700fe1ab | 1640 | cpuset_memory_pressure_enabled = !!val; |
3e0d98b9 PJ |
1641 | break; |
1642 | case FILE_MEMORY_PRESSURE: | |
1643 | retval = -EACCES; | |
1644 | break; | |
825a46af | 1645 | case FILE_SPREAD_PAGE: |
700fe1ab | 1646 | retval = update_flag(CS_SPREAD_PAGE, cs, val); |
825a46af PJ |
1647 | break; |
1648 | case FILE_SPREAD_SLAB: | |
700fe1ab | 1649 | retval = update_flag(CS_SPREAD_SLAB, cs, val); |
825a46af | 1650 | break; |
1da177e4 LT |
1651 | default: |
1652 | retval = -EINVAL; | |
700fe1ab | 1653 | break; |
1da177e4 | 1654 | } |
5d21cc2d TH |
1655 | out_unlock: |
1656 | mutex_unlock(&cpuset_mutex); | |
1da177e4 LT |
1657 | return retval; |
1658 | } | |
1659 | ||
5be7a479 PM |
1660 | static int cpuset_write_s64(struct cgroup *cgrp, struct cftype *cft, s64 val) |
1661 | { | |
5be7a479 PM |
1662 | struct cpuset *cs = cgroup_cs(cgrp); |
1663 | cpuset_filetype_t type = cft->private; | |
5d21cc2d | 1664 | int retval = -ENODEV; |
5be7a479 | 1665 | |
5d21cc2d TH |
1666 | mutex_lock(&cpuset_mutex); |
1667 | if (!is_cpuset_online(cs)) | |
1668 | goto out_unlock; | |
e3712395 | 1669 | |
5be7a479 PM |
1670 | switch (type) { |
1671 | case FILE_SCHED_RELAX_DOMAIN_LEVEL: | |
1672 | retval = update_relax_domain_level(cs, val); | |
1673 | break; | |
1674 | default: | |
1675 | retval = -EINVAL; | |
1676 | break; | |
1677 | } | |
5d21cc2d TH |
1678 | out_unlock: |
1679 | mutex_unlock(&cpuset_mutex); | |
5be7a479 PM |
1680 | return retval; |
1681 | } | |
1682 | ||
e3712395 PM |
1683 | /* |
1684 | * Common handling for a write to a "cpus" or "mems" file. | |
1685 | */ | |
1686 | static int cpuset_write_resmask(struct cgroup *cgrp, struct cftype *cft, | |
1687 | const char *buf) | |
1688 | { | |
645fcc9d LZ |
1689 | struct cpuset *cs = cgroup_cs(cgrp); |
1690 | struct cpuset *trialcs; | |
5d21cc2d | 1691 | int retval = -ENODEV; |
e3712395 | 1692 | |
3a5a6d0c TH |
1693 | /* |
1694 | * CPU or memory hotunplug may leave @cs w/o any execution | |
1695 | * resources, in which case the hotplug code asynchronously updates | |
1696 | * configuration and transfers all tasks to the nearest ancestor | |
1697 | * which can execute. | |
1698 | * | |
1699 | * As writes to "cpus" or "mems" may restore @cs's execution | |
1700 | * resources, wait for the previously scheduled operations before | |
1701 | * proceeding, so that we don't end up keep removing tasks added | |
1702 | * after execution capability is restored. | |
1703 | */ | |
1704 | flush_work(&cpuset_hotplug_work); | |
1705 | ||
5d21cc2d TH |
1706 | mutex_lock(&cpuset_mutex); |
1707 | if (!is_cpuset_online(cs)) | |
1708 | goto out_unlock; | |
e3712395 | 1709 | |
645fcc9d | 1710 | trialcs = alloc_trial_cpuset(cs); |
b75f38d6 LZ |
1711 | if (!trialcs) { |
1712 | retval = -ENOMEM; | |
5d21cc2d | 1713 | goto out_unlock; |
b75f38d6 | 1714 | } |
645fcc9d | 1715 | |
e3712395 PM |
1716 | switch (cft->private) { |
1717 | case FILE_CPULIST: | |
645fcc9d | 1718 | retval = update_cpumask(cs, trialcs, buf); |
e3712395 PM |
1719 | break; |
1720 | case FILE_MEMLIST: | |
645fcc9d | 1721 | retval = update_nodemask(cs, trialcs, buf); |
e3712395 PM |
1722 | break; |
1723 | default: | |
1724 | retval = -EINVAL; | |
1725 | break; | |
1726 | } | |
645fcc9d LZ |
1727 | |
1728 | free_trial_cpuset(trialcs); | |
5d21cc2d TH |
1729 | out_unlock: |
1730 | mutex_unlock(&cpuset_mutex); | |
e3712395 PM |
1731 | return retval; |
1732 | } | |
1733 | ||
1da177e4 LT |
1734 | /* |
1735 | * These ascii lists should be read in a single call, by using a user | |
1736 | * buffer large enough to hold the entire map. If read in smaller | |
1737 | * chunks, there is no guarantee of atomicity. Since the display format | |
1738 | * used, list of ranges of sequential numbers, is variable length, | |
1739 | * and since these maps can change value dynamically, one could read | |
1740 | * gibberish by doing partial reads while a list was changing. | |
1741 | * A single large read to a buffer that crosses a page boundary is | |
1742 | * ok, because the result being copied to user land is not recomputed | |
1743 | * across a page fault. | |
1744 | */ | |
1745 | ||
9303e0c4 | 1746 | static size_t cpuset_sprintf_cpulist(char *page, struct cpuset *cs) |
1da177e4 | 1747 | { |
9303e0c4 | 1748 | size_t count; |
1da177e4 | 1749 | |
3d3f26a7 | 1750 | mutex_lock(&callback_mutex); |
9303e0c4 | 1751 | count = cpulist_scnprintf(page, PAGE_SIZE, cs->cpus_allowed); |
3d3f26a7 | 1752 | mutex_unlock(&callback_mutex); |
1da177e4 | 1753 | |
9303e0c4 | 1754 | return count; |
1da177e4 LT |
1755 | } |
1756 | ||
9303e0c4 | 1757 | static size_t cpuset_sprintf_memlist(char *page, struct cpuset *cs) |
1da177e4 | 1758 | { |
9303e0c4 | 1759 | size_t count; |
1da177e4 | 1760 | |
3d3f26a7 | 1761 | mutex_lock(&callback_mutex); |
9303e0c4 | 1762 | count = nodelist_scnprintf(page, PAGE_SIZE, cs->mems_allowed); |
3d3f26a7 | 1763 | mutex_unlock(&callback_mutex); |
1da177e4 | 1764 | |
9303e0c4 | 1765 | return count; |
1da177e4 LT |
1766 | } |
1767 | ||
c9e5fe66 | 1768 | static ssize_t cpuset_common_file_read(struct cgroup *cgrp, |
8793d854 PM |
1769 | struct cftype *cft, |
1770 | struct file *file, | |
1771 | char __user *buf, | |
1772 | size_t nbytes, loff_t *ppos) | |
1da177e4 | 1773 | { |
c9e5fe66 | 1774 | struct cpuset *cs = cgroup_cs(cgrp); |
1da177e4 LT |
1775 | cpuset_filetype_t type = cft->private; |
1776 | char *page; | |
1777 | ssize_t retval = 0; | |
1778 | char *s; | |
1da177e4 | 1779 | |
e12ba74d | 1780 | if (!(page = (char *)__get_free_page(GFP_TEMPORARY))) |
1da177e4 LT |
1781 | return -ENOMEM; |
1782 | ||
1783 | s = page; | |
1784 | ||
1785 | switch (type) { | |
1786 | case FILE_CPULIST: | |
1787 | s += cpuset_sprintf_cpulist(s, cs); | |
1788 | break; | |
1789 | case FILE_MEMLIST: | |
1790 | s += cpuset_sprintf_memlist(s, cs); | |
1791 | break; | |
1da177e4 LT |
1792 | default: |
1793 | retval = -EINVAL; | |
1794 | goto out; | |
1795 | } | |
1796 | *s++ = '\n'; | |
1da177e4 | 1797 | |
eacaa1f5 | 1798 | retval = simple_read_from_buffer(buf, nbytes, ppos, page, s - page); |
1da177e4 LT |
1799 | out: |
1800 | free_page((unsigned long)page); | |
1801 | return retval; | |
1802 | } | |
1803 | ||
c9e5fe66 | 1804 | static u64 cpuset_read_u64(struct cgroup *cgrp, struct cftype *cft) |
700fe1ab | 1805 | { |
c9e5fe66 | 1806 | struct cpuset *cs = cgroup_cs(cgrp); |
700fe1ab PM |
1807 | cpuset_filetype_t type = cft->private; |
1808 | switch (type) { | |
1809 | case FILE_CPU_EXCLUSIVE: | |
1810 | return is_cpu_exclusive(cs); | |
1811 | case FILE_MEM_EXCLUSIVE: | |
1812 | return is_mem_exclusive(cs); | |
78608366 PM |
1813 | case FILE_MEM_HARDWALL: |
1814 | return is_mem_hardwall(cs); | |
700fe1ab PM |
1815 | case FILE_SCHED_LOAD_BALANCE: |
1816 | return is_sched_load_balance(cs); | |
1817 | case FILE_MEMORY_MIGRATE: | |
1818 | return is_memory_migrate(cs); | |
1819 | case FILE_MEMORY_PRESSURE_ENABLED: | |
1820 | return cpuset_memory_pressure_enabled; | |
1821 | case FILE_MEMORY_PRESSURE: | |
1822 | return fmeter_getrate(&cs->fmeter); | |
1823 | case FILE_SPREAD_PAGE: | |
1824 | return is_spread_page(cs); | |
1825 | case FILE_SPREAD_SLAB: | |
1826 | return is_spread_slab(cs); | |
1827 | default: | |
1828 | BUG(); | |
1829 | } | |
cf417141 MK |
1830 | |
1831 | /* Unreachable but makes gcc happy */ | |
1832 | return 0; | |
700fe1ab | 1833 | } |
1da177e4 | 1834 | |
c9e5fe66 | 1835 | static s64 cpuset_read_s64(struct cgroup *cgrp, struct cftype *cft) |
5be7a479 | 1836 | { |
c9e5fe66 | 1837 | struct cpuset *cs = cgroup_cs(cgrp); |
5be7a479 PM |
1838 | cpuset_filetype_t type = cft->private; |
1839 | switch (type) { | |
1840 | case FILE_SCHED_RELAX_DOMAIN_LEVEL: | |
1841 | return cs->relax_domain_level; | |
1842 | default: | |
1843 | BUG(); | |
1844 | } | |
cf417141 MK |
1845 | |
1846 | /* Unrechable but makes gcc happy */ | |
1847 | return 0; | |
5be7a479 PM |
1848 | } |
1849 | ||
1da177e4 LT |
1850 | |
1851 | /* | |
1852 | * for the common functions, 'private' gives the type of file | |
1853 | */ | |
1854 | ||
addf2c73 PM |
1855 | static struct cftype files[] = { |
1856 | { | |
1857 | .name = "cpus", | |
1858 | .read = cpuset_common_file_read, | |
e3712395 PM |
1859 | .write_string = cpuset_write_resmask, |
1860 | .max_write_len = (100U + 6 * NR_CPUS), | |
addf2c73 PM |
1861 | .private = FILE_CPULIST, |
1862 | }, | |
1863 | ||
1864 | { | |
1865 | .name = "mems", | |
1866 | .read = cpuset_common_file_read, | |
e3712395 PM |
1867 | .write_string = cpuset_write_resmask, |
1868 | .max_write_len = (100U + 6 * MAX_NUMNODES), | |
addf2c73 PM |
1869 | .private = FILE_MEMLIST, |
1870 | }, | |
1871 | ||
1872 | { | |
1873 | .name = "cpu_exclusive", | |
1874 | .read_u64 = cpuset_read_u64, | |
1875 | .write_u64 = cpuset_write_u64, | |
1876 | .private = FILE_CPU_EXCLUSIVE, | |
1877 | }, | |
1878 | ||
1879 | { | |
1880 | .name = "mem_exclusive", | |
1881 | .read_u64 = cpuset_read_u64, | |
1882 | .write_u64 = cpuset_write_u64, | |
1883 | .private = FILE_MEM_EXCLUSIVE, | |
1884 | }, | |
1885 | ||
78608366 PM |
1886 | { |
1887 | .name = "mem_hardwall", | |
1888 | .read_u64 = cpuset_read_u64, | |
1889 | .write_u64 = cpuset_write_u64, | |
1890 | .private = FILE_MEM_HARDWALL, | |
1891 | }, | |
1892 | ||
addf2c73 PM |
1893 | { |
1894 | .name = "sched_load_balance", | |
1895 | .read_u64 = cpuset_read_u64, | |
1896 | .write_u64 = cpuset_write_u64, | |
1897 | .private = FILE_SCHED_LOAD_BALANCE, | |
1898 | }, | |
1899 | ||
1900 | { | |
1901 | .name = "sched_relax_domain_level", | |
5be7a479 PM |
1902 | .read_s64 = cpuset_read_s64, |
1903 | .write_s64 = cpuset_write_s64, | |
addf2c73 PM |
1904 | .private = FILE_SCHED_RELAX_DOMAIN_LEVEL, |
1905 | }, | |
1906 | ||
1907 | { | |
1908 | .name = "memory_migrate", | |
1909 | .read_u64 = cpuset_read_u64, | |
1910 | .write_u64 = cpuset_write_u64, | |
1911 | .private = FILE_MEMORY_MIGRATE, | |
1912 | }, | |
1913 | ||
1914 | { | |
1915 | .name = "memory_pressure", | |
1916 | .read_u64 = cpuset_read_u64, | |
1917 | .write_u64 = cpuset_write_u64, | |
1918 | .private = FILE_MEMORY_PRESSURE, | |
099fca32 | 1919 | .mode = S_IRUGO, |
addf2c73 PM |
1920 | }, |
1921 | ||
1922 | { | |
1923 | .name = "memory_spread_page", | |
1924 | .read_u64 = cpuset_read_u64, | |
1925 | .write_u64 = cpuset_write_u64, | |
1926 | .private = FILE_SPREAD_PAGE, | |
1927 | }, | |
1928 | ||
1929 | { | |
1930 | .name = "memory_spread_slab", | |
1931 | .read_u64 = cpuset_read_u64, | |
1932 | .write_u64 = cpuset_write_u64, | |
1933 | .private = FILE_SPREAD_SLAB, | |
1934 | }, | |
3e0d98b9 | 1935 | |
4baf6e33 TH |
1936 | { |
1937 | .name = "memory_pressure_enabled", | |
1938 | .flags = CFTYPE_ONLY_ON_ROOT, | |
1939 | .read_u64 = cpuset_read_u64, | |
1940 | .write_u64 = cpuset_write_u64, | |
1941 | .private = FILE_MEMORY_PRESSURE_ENABLED, | |
1942 | }, | |
1da177e4 | 1943 | |
4baf6e33 TH |
1944 | { } /* terminate */ |
1945 | }; | |
1da177e4 LT |
1946 | |
1947 | /* | |
92fb9748 | 1948 | * cpuset_css_alloc - allocate a cpuset css |
c9e5fe66 | 1949 | * cgrp: control group that the new cpuset will be part of |
1da177e4 LT |
1950 | */ |
1951 | ||
c9e5fe66 | 1952 | static struct cgroup_subsys_state *cpuset_css_alloc(struct cgroup *cgrp) |
1da177e4 | 1953 | { |
c8f699bb | 1954 | struct cpuset *cs; |
1da177e4 | 1955 | |
c9e5fe66 | 1956 | if (!cgrp->parent) |
8793d854 | 1957 | return &top_cpuset.css; |
033fa1c5 | 1958 | |
c8f699bb | 1959 | cs = kzalloc(sizeof(*cs), GFP_KERNEL); |
1da177e4 | 1960 | if (!cs) |
8793d854 | 1961 | return ERR_PTR(-ENOMEM); |
300ed6cb LZ |
1962 | if (!alloc_cpumask_var(&cs->cpus_allowed, GFP_KERNEL)) { |
1963 | kfree(cs); | |
1964 | return ERR_PTR(-ENOMEM); | |
1965 | } | |
1da177e4 | 1966 | |
029190c5 | 1967 | set_bit(CS_SCHED_LOAD_BALANCE, &cs->flags); |
300ed6cb | 1968 | cpumask_clear(cs->cpus_allowed); |
f9a86fcb | 1969 | nodes_clear(cs->mems_allowed); |
3e0d98b9 | 1970 | fmeter_init(&cs->fmeter); |
1d3504fc | 1971 | cs->relax_domain_level = -1; |
1da177e4 | 1972 | |
c8f699bb TH |
1973 | return &cs->css; |
1974 | } | |
1975 | ||
1976 | static int cpuset_css_online(struct cgroup *cgrp) | |
1977 | { | |
1978 | struct cpuset *cs = cgroup_cs(cgrp); | |
c431069f | 1979 | struct cpuset *parent = parent_cs(cs); |
ae8086ce TH |
1980 | struct cpuset *tmp_cs; |
1981 | struct cgroup *pos_cg; | |
c8f699bb TH |
1982 | |
1983 | if (!parent) | |
1984 | return 0; | |
1985 | ||
5d21cc2d TH |
1986 | mutex_lock(&cpuset_mutex); |
1987 | ||
efeb77b2 | 1988 | set_bit(CS_ONLINE, &cs->flags); |
c8f699bb TH |
1989 | if (is_spread_page(parent)) |
1990 | set_bit(CS_SPREAD_PAGE, &cs->flags); | |
1991 | if (is_spread_slab(parent)) | |
1992 | set_bit(CS_SPREAD_SLAB, &cs->flags); | |
1da177e4 | 1993 | |
202f72d5 | 1994 | number_of_cpusets++; |
033fa1c5 | 1995 | |
c8f699bb | 1996 | if (!test_bit(CGRP_CPUSET_CLONE_CHILDREN, &cgrp->flags)) |
5d21cc2d | 1997 | goto out_unlock; |
033fa1c5 TH |
1998 | |
1999 | /* | |
2000 | * Clone @parent's configuration if CGRP_CPUSET_CLONE_CHILDREN is | |
2001 | * set. This flag handling is implemented in cgroup core for | |
2002 | * histrical reasons - the flag may be specified during mount. | |
2003 | * | |
2004 | * Currently, if any sibling cpusets have exclusive cpus or mem, we | |
2005 | * refuse to clone the configuration - thereby refusing the task to | |
2006 | * be entered, and as a result refusing the sys_unshare() or | |
2007 | * clone() which initiated it. If this becomes a problem for some | |
2008 | * users who wish to allow that scenario, then this could be | |
2009 | * changed to grant parent->cpus_allowed-sibling_cpus_exclusive | |
2010 | * (and likewise for mems) to the new cgroup. | |
2011 | */ | |
ae8086ce TH |
2012 | rcu_read_lock(); |
2013 | cpuset_for_each_child(tmp_cs, pos_cg, parent) { | |
2014 | if (is_mem_exclusive(tmp_cs) || is_cpu_exclusive(tmp_cs)) { | |
2015 | rcu_read_unlock(); | |
5d21cc2d | 2016 | goto out_unlock; |
ae8086ce | 2017 | } |
033fa1c5 | 2018 | } |
ae8086ce | 2019 | rcu_read_unlock(); |
033fa1c5 TH |
2020 | |
2021 | mutex_lock(&callback_mutex); | |
2022 | cs->mems_allowed = parent->mems_allowed; | |
2023 | cpumask_copy(cs->cpus_allowed, parent->cpus_allowed); | |
2024 | mutex_unlock(&callback_mutex); | |
5d21cc2d TH |
2025 | out_unlock: |
2026 | mutex_unlock(&cpuset_mutex); | |
c8f699bb TH |
2027 | return 0; |
2028 | } | |
2029 | ||
2030 | static void cpuset_css_offline(struct cgroup *cgrp) | |
2031 | { | |
2032 | struct cpuset *cs = cgroup_cs(cgrp); | |
2033 | ||
5d21cc2d | 2034 | mutex_lock(&cpuset_mutex); |
c8f699bb TH |
2035 | |
2036 | if (is_sched_load_balance(cs)) | |
2037 | update_flag(CS_SCHED_LOAD_BALANCE, cs, 0); | |
2038 | ||
2039 | number_of_cpusets--; | |
efeb77b2 | 2040 | clear_bit(CS_ONLINE, &cs->flags); |
c8f699bb | 2041 | |
5d21cc2d | 2042 | mutex_unlock(&cpuset_mutex); |
1da177e4 LT |
2043 | } |
2044 | ||
029190c5 | 2045 | /* |
029190c5 PJ |
2046 | * If the cpuset being removed has its flag 'sched_load_balance' |
2047 | * enabled, then simulate turning sched_load_balance off, which | |
699140ba | 2048 | * will call rebuild_sched_domains_locked(). |
029190c5 PJ |
2049 | */ |
2050 | ||
c9e5fe66 | 2051 | static void cpuset_css_free(struct cgroup *cgrp) |
1da177e4 | 2052 | { |
c9e5fe66 | 2053 | struct cpuset *cs = cgroup_cs(cgrp); |
1da177e4 | 2054 | |
300ed6cb | 2055 | free_cpumask_var(cs->cpus_allowed); |
8793d854 | 2056 | kfree(cs); |
1da177e4 LT |
2057 | } |
2058 | ||
8793d854 PM |
2059 | struct cgroup_subsys cpuset_subsys = { |
2060 | .name = "cpuset", | |
92fb9748 | 2061 | .css_alloc = cpuset_css_alloc, |
c8f699bb TH |
2062 | .css_online = cpuset_css_online, |
2063 | .css_offline = cpuset_css_offline, | |
92fb9748 | 2064 | .css_free = cpuset_css_free, |
8793d854 | 2065 | .can_attach = cpuset_can_attach, |
452477fa | 2066 | .cancel_attach = cpuset_cancel_attach, |
8793d854 | 2067 | .attach = cpuset_attach, |
8793d854 | 2068 | .subsys_id = cpuset_subsys_id, |
4baf6e33 | 2069 | .base_cftypes = files, |
8793d854 PM |
2070 | .early_init = 1, |
2071 | }; | |
2072 | ||
1da177e4 LT |
2073 | /** |
2074 | * cpuset_init - initialize cpusets at system boot | |
2075 | * | |
2076 | * Description: Initialize top_cpuset and the cpuset internal file system, | |
2077 | **/ | |
2078 | ||
2079 | int __init cpuset_init(void) | |
2080 | { | |
8793d854 | 2081 | int err = 0; |
1da177e4 | 2082 | |
58568d2a MX |
2083 | if (!alloc_cpumask_var(&top_cpuset.cpus_allowed, GFP_KERNEL)) |
2084 | BUG(); | |
2085 | ||
300ed6cb | 2086 | cpumask_setall(top_cpuset.cpus_allowed); |
f9a86fcb | 2087 | nodes_setall(top_cpuset.mems_allowed); |
1da177e4 | 2088 | |
3e0d98b9 | 2089 | fmeter_init(&top_cpuset.fmeter); |
029190c5 | 2090 | set_bit(CS_SCHED_LOAD_BALANCE, &top_cpuset.flags); |
1d3504fc | 2091 | top_cpuset.relax_domain_level = -1; |
1da177e4 | 2092 | |
1da177e4 LT |
2093 | err = register_filesystem(&cpuset_fs_type); |
2094 | if (err < 0) | |
8793d854 PM |
2095 | return err; |
2096 | ||
2341d1b6 LZ |
2097 | if (!alloc_cpumask_var(&cpus_attach, GFP_KERNEL)) |
2098 | BUG(); | |
2099 | ||
202f72d5 | 2100 | number_of_cpusets = 1; |
8793d854 | 2101 | return 0; |
1da177e4 LT |
2102 | } |
2103 | ||
b1aac8bb | 2104 | /* |
cf417141 | 2105 | * If CPU and/or memory hotplug handlers, below, unplug any CPUs |
b1aac8bb PJ |
2106 | * or memory nodes, we need to walk over the cpuset hierarchy, |
2107 | * removing that CPU or node from all cpusets. If this removes the | |
956db3ca CW |
2108 | * last CPU or node from a cpuset, then move the tasks in the empty |
2109 | * cpuset to its next-highest non-empty parent. | |
b1aac8bb | 2110 | */ |
956db3ca CW |
2111 | static void remove_tasks_in_empty_cpuset(struct cpuset *cs) |
2112 | { | |
2113 | struct cpuset *parent; | |
2114 | ||
956db3ca CW |
2115 | /* |
2116 | * Find its next-highest non-empty parent, (top cpuset | |
2117 | * has online cpus, so can't be empty). | |
2118 | */ | |
c431069f | 2119 | parent = parent_cs(cs); |
300ed6cb | 2120 | while (cpumask_empty(parent->cpus_allowed) || |
b4501295 | 2121 | nodes_empty(parent->mems_allowed)) |
c431069f | 2122 | parent = parent_cs(parent); |
956db3ca | 2123 | |
8cc99345 TH |
2124 | if (cgroup_transfer_tasks(parent->css.cgroup, cs->css.cgroup)) { |
2125 | rcu_read_lock(); | |
2126 | printk(KERN_ERR "cpuset: failed to transfer tasks out of empty cpuset %s\n", | |
2127 | cgroup_name(cs->css.cgroup)); | |
2128 | rcu_read_unlock(); | |
2129 | } | |
956db3ca CW |
2130 | } |
2131 | ||
deb7aa30 | 2132 | /** |
388afd85 | 2133 | * cpuset_hotplug_update_tasks - update tasks in a cpuset for hotunplug |
deb7aa30 | 2134 | * @cs: cpuset in interest |
956db3ca | 2135 | * |
deb7aa30 TH |
2136 | * Compare @cs's cpu and mem masks against top_cpuset and if some have gone |
2137 | * offline, update @cs accordingly. If @cs ends up with no CPU or memory, | |
2138 | * all its tasks are moved to the nearest ancestor with both resources. | |
80d1fa64 | 2139 | */ |
388afd85 | 2140 | static void cpuset_hotplug_update_tasks(struct cpuset *cs) |
80d1fa64 | 2141 | { |
deb7aa30 | 2142 | static cpumask_t off_cpus; |
33ad801d | 2143 | static nodemask_t off_mems; |
5d21cc2d | 2144 | bool is_empty; |
5c5cc623 | 2145 | bool sane = cgroup_sane_behavior(cs->css.cgroup); |
80d1fa64 | 2146 | |
e44193d3 LZ |
2147 | retry: |
2148 | wait_event(cpuset_attach_wq, cs->attach_in_progress == 0); | |
80d1fa64 | 2149 | |
5d21cc2d | 2150 | mutex_lock(&cpuset_mutex); |
7ddf96b0 | 2151 | |
e44193d3 LZ |
2152 | /* |
2153 | * We have raced with task attaching. We wait until attaching | |
2154 | * is finished, so we won't attach a task to an empty cpuset. | |
2155 | */ | |
2156 | if (cs->attach_in_progress) { | |
2157 | mutex_unlock(&cpuset_mutex); | |
2158 | goto retry; | |
2159 | } | |
2160 | ||
deb7aa30 TH |
2161 | cpumask_andnot(&off_cpus, cs->cpus_allowed, top_cpuset.cpus_allowed); |
2162 | nodes_andnot(off_mems, cs->mems_allowed, top_cpuset.mems_allowed); | |
80d1fa64 | 2163 | |
5c5cc623 LZ |
2164 | mutex_lock(&callback_mutex); |
2165 | cpumask_andnot(cs->cpus_allowed, cs->cpus_allowed, &off_cpus); | |
2166 | mutex_unlock(&callback_mutex); | |
2167 | ||
2168 | /* | |
2169 | * If sane_behavior flag is set, we need to update tasks' cpumask | |
f047cecf LZ |
2170 | * for empty cpuset to take on ancestor's cpumask. Otherwise, don't |
2171 | * call update_tasks_cpumask() if the cpuset becomes empty, as | |
2172 | * the tasks in it will be migrated to an ancestor. | |
5c5cc623 LZ |
2173 | */ |
2174 | if ((sane && cpumask_empty(cs->cpus_allowed)) || | |
f047cecf | 2175 | (!cpumask_empty(&off_cpus) && !cpumask_empty(cs->cpus_allowed))) |
deb7aa30 | 2176 | update_tasks_cpumask(cs, NULL); |
80d1fa64 | 2177 | |
5c5cc623 LZ |
2178 | mutex_lock(&callback_mutex); |
2179 | nodes_andnot(cs->mems_allowed, cs->mems_allowed, off_mems); | |
2180 | mutex_unlock(&callback_mutex); | |
2181 | ||
2182 | /* | |
2183 | * If sane_behavior flag is set, we need to update tasks' nodemask | |
f047cecf LZ |
2184 | * for empty cpuset to take on ancestor's nodemask. Otherwise, don't |
2185 | * call update_tasks_nodemask() if the cpuset becomes empty, as | |
2186 | * the tasks in it will be migratd to an ancestor. | |
5c5cc623 LZ |
2187 | */ |
2188 | if ((sane && nodes_empty(cs->mems_allowed)) || | |
f047cecf | 2189 | (!nodes_empty(off_mems) && !nodes_empty(cs->mems_allowed))) |
33ad801d | 2190 | update_tasks_nodemask(cs, NULL); |
deb7aa30 | 2191 | |
5d21cc2d TH |
2192 | is_empty = cpumask_empty(cs->cpus_allowed) || |
2193 | nodes_empty(cs->mems_allowed); | |
8d033948 | 2194 | |
5d21cc2d TH |
2195 | mutex_unlock(&cpuset_mutex); |
2196 | ||
2197 | /* | |
5c5cc623 LZ |
2198 | * If sane_behavior flag is set, we'll keep tasks in empty cpusets. |
2199 | * | |
2200 | * Otherwise move tasks to the nearest ancestor with execution | |
2201 | * resources. This is full cgroup operation which will | |
5d21cc2d TH |
2202 | * also call back into cpuset. Should be done outside any lock. |
2203 | */ | |
5c5cc623 | 2204 | if (!sane && is_empty) |
5d21cc2d | 2205 | remove_tasks_in_empty_cpuset(cs); |
b1aac8bb PJ |
2206 | } |
2207 | ||
deb7aa30 | 2208 | /** |
3a5a6d0c | 2209 | * cpuset_hotplug_workfn - handle CPU/memory hotunplug for a cpuset |
956db3ca | 2210 | * |
deb7aa30 TH |
2211 | * This function is called after either CPU or memory configuration has |
2212 | * changed and updates cpuset accordingly. The top_cpuset is always | |
2213 | * synchronized to cpu_active_mask and N_MEMORY, which is necessary in | |
2214 | * order to make cpusets transparent (of no affect) on systems that are | |
2215 | * actively using CPU hotplug but making no active use of cpusets. | |
956db3ca | 2216 | * |
deb7aa30 | 2217 | * Non-root cpusets are only affected by offlining. If any CPUs or memory |
388afd85 LZ |
2218 | * nodes have been taken down, cpuset_hotplug_update_tasks() is invoked on |
2219 | * all descendants. | |
956db3ca | 2220 | * |
deb7aa30 TH |
2221 | * Note that CPU offlining during suspend is ignored. We don't modify |
2222 | * cpusets across suspend/resume cycles at all. | |
956db3ca | 2223 | */ |
3a5a6d0c | 2224 | static void cpuset_hotplug_workfn(struct work_struct *work) |
b1aac8bb | 2225 | { |
5c5cc623 LZ |
2226 | static cpumask_t new_cpus; |
2227 | static nodemask_t new_mems; | |
deb7aa30 | 2228 | bool cpus_updated, mems_updated; |
b1aac8bb | 2229 | |
5d21cc2d | 2230 | mutex_lock(&cpuset_mutex); |
956db3ca | 2231 | |
deb7aa30 TH |
2232 | /* fetch the available cpus/mems and find out which changed how */ |
2233 | cpumask_copy(&new_cpus, cpu_active_mask); | |
2234 | new_mems = node_states[N_MEMORY]; | |
7ddf96b0 | 2235 | |
deb7aa30 | 2236 | cpus_updated = !cpumask_equal(top_cpuset.cpus_allowed, &new_cpus); |
deb7aa30 | 2237 | mems_updated = !nodes_equal(top_cpuset.mems_allowed, new_mems); |
7ddf96b0 | 2238 | |
deb7aa30 TH |
2239 | /* synchronize cpus_allowed to cpu_active_mask */ |
2240 | if (cpus_updated) { | |
2241 | mutex_lock(&callback_mutex); | |
2242 | cpumask_copy(top_cpuset.cpus_allowed, &new_cpus); | |
2243 | mutex_unlock(&callback_mutex); | |
2244 | /* we don't mess with cpumasks of tasks in top_cpuset */ | |
2245 | } | |
b4501295 | 2246 | |
deb7aa30 TH |
2247 | /* synchronize mems_allowed to N_MEMORY */ |
2248 | if (mems_updated) { | |
deb7aa30 TH |
2249 | mutex_lock(&callback_mutex); |
2250 | top_cpuset.mems_allowed = new_mems; | |
2251 | mutex_unlock(&callback_mutex); | |
33ad801d | 2252 | update_tasks_nodemask(&top_cpuset, NULL); |
deb7aa30 | 2253 | } |
b4501295 | 2254 | |
388afd85 LZ |
2255 | mutex_unlock(&cpuset_mutex); |
2256 | ||
5c5cc623 LZ |
2257 | /* if cpus or mems changed, we need to propagate to descendants */ |
2258 | if (cpus_updated || mems_updated) { | |
deb7aa30 | 2259 | struct cpuset *cs; |
fc560a26 | 2260 | struct cgroup *pos_cgrp; |
f9b4fb8d | 2261 | |
fc560a26 | 2262 | rcu_read_lock(); |
388afd85 LZ |
2263 | cpuset_for_each_descendant_pre(cs, pos_cgrp, &top_cpuset) { |
2264 | if (!css_tryget(&cs->css)) | |
2265 | continue; | |
2266 | rcu_read_unlock(); | |
7ddf96b0 | 2267 | |
388afd85 | 2268 | cpuset_hotplug_update_tasks(cs); |
b4501295 | 2269 | |
388afd85 LZ |
2270 | rcu_read_lock(); |
2271 | css_put(&cs->css); | |
2272 | } | |
2273 | rcu_read_unlock(); | |
2274 | } | |
8d033948 | 2275 | |
deb7aa30 | 2276 | /* rebuild sched domains if cpus_allowed has changed */ |
e0e80a02 LZ |
2277 | if (cpus_updated) |
2278 | rebuild_sched_domains(); | |
b1aac8bb PJ |
2279 | } |
2280 | ||
7ddf96b0 | 2281 | void cpuset_update_active_cpus(bool cpu_online) |
4c4d50f7 | 2282 | { |
3a5a6d0c TH |
2283 | /* |
2284 | * We're inside cpu hotplug critical region which usually nests | |
2285 | * inside cgroup synchronization. Bounce actual hotplug processing | |
2286 | * to a work item to avoid reverse locking order. | |
2287 | * | |
2288 | * We still need to do partition_sched_domains() synchronously; | |
2289 | * otherwise, the scheduler will get confused and put tasks to the | |
2290 | * dead CPU. Fall back to the default single domain. | |
2291 | * cpuset_hotplug_workfn() will rebuild it as necessary. | |
2292 | */ | |
2293 | partition_sched_domains(1, NULL, NULL); | |
2294 | schedule_work(&cpuset_hotplug_work); | |
4c4d50f7 | 2295 | } |
4c4d50f7 | 2296 | |
38837fc7 | 2297 | /* |
38d7bee9 LJ |
2298 | * Keep top_cpuset.mems_allowed tracking node_states[N_MEMORY]. |
2299 | * Call this routine anytime after node_states[N_MEMORY] changes. | |
a1cd2b13 | 2300 | * See cpuset_update_active_cpus() for CPU hotplug handling. |
38837fc7 | 2301 | */ |
f481891f MX |
2302 | static int cpuset_track_online_nodes(struct notifier_block *self, |
2303 | unsigned long action, void *arg) | |
38837fc7 | 2304 | { |
3a5a6d0c | 2305 | schedule_work(&cpuset_hotplug_work); |
f481891f | 2306 | return NOTIFY_OK; |
38837fc7 | 2307 | } |
d8f10cb3 AM |
2308 | |
2309 | static struct notifier_block cpuset_track_online_nodes_nb = { | |
2310 | .notifier_call = cpuset_track_online_nodes, | |
2311 | .priority = 10, /* ??! */ | |
2312 | }; | |
38837fc7 | 2313 | |
1da177e4 LT |
2314 | /** |
2315 | * cpuset_init_smp - initialize cpus_allowed | |
2316 | * | |
2317 | * Description: Finish top cpuset after cpu, node maps are initialized | |
d8f10cb3 | 2318 | */ |
1da177e4 LT |
2319 | void __init cpuset_init_smp(void) |
2320 | { | |
6ad4c188 | 2321 | cpumask_copy(top_cpuset.cpus_allowed, cpu_active_mask); |
38d7bee9 | 2322 | top_cpuset.mems_allowed = node_states[N_MEMORY]; |
33ad801d | 2323 | top_cpuset.old_mems_allowed = top_cpuset.mems_allowed; |
4c4d50f7 | 2324 | |
d8f10cb3 | 2325 | register_hotmemory_notifier(&cpuset_track_online_nodes_nb); |
1da177e4 LT |
2326 | } |
2327 | ||
2328 | /** | |
1da177e4 LT |
2329 | * cpuset_cpus_allowed - return cpus_allowed mask from a tasks cpuset. |
2330 | * @tsk: pointer to task_struct from which to obtain cpuset->cpus_allowed. | |
6af866af | 2331 | * @pmask: pointer to struct cpumask variable to receive cpus_allowed set. |
1da177e4 | 2332 | * |
300ed6cb | 2333 | * Description: Returns the cpumask_var_t cpus_allowed of the cpuset |
1da177e4 | 2334 | * attached to the specified @tsk. Guaranteed to return some non-empty |
5f054e31 | 2335 | * subset of cpu_online_mask, even if this means going outside the |
1da177e4 LT |
2336 | * tasks cpuset. |
2337 | **/ | |
2338 | ||
6af866af | 2339 | void cpuset_cpus_allowed(struct task_struct *tsk, struct cpumask *pmask) |
1da177e4 | 2340 | { |
070b57fc LZ |
2341 | struct cpuset *cpus_cs; |
2342 | ||
3d3f26a7 | 2343 | mutex_lock(&callback_mutex); |
909d75a3 | 2344 | task_lock(tsk); |
070b57fc LZ |
2345 | cpus_cs = effective_cpumask_cpuset(task_cs(tsk)); |
2346 | guarantee_online_cpus(cpus_cs, pmask); | |
909d75a3 | 2347 | task_unlock(tsk); |
897f0b3c | 2348 | mutex_unlock(&callback_mutex); |
1da177e4 LT |
2349 | } |
2350 | ||
2baab4e9 | 2351 | void cpuset_cpus_allowed_fallback(struct task_struct *tsk) |
9084bb82 | 2352 | { |
070b57fc | 2353 | const struct cpuset *cpus_cs; |
9084bb82 ON |
2354 | |
2355 | rcu_read_lock(); | |
070b57fc LZ |
2356 | cpus_cs = effective_cpumask_cpuset(task_cs(tsk)); |
2357 | do_set_cpus_allowed(tsk, cpus_cs->cpus_allowed); | |
9084bb82 ON |
2358 | rcu_read_unlock(); |
2359 | ||
2360 | /* | |
2361 | * We own tsk->cpus_allowed, nobody can change it under us. | |
2362 | * | |
2363 | * But we used cs && cs->cpus_allowed lockless and thus can | |
2364 | * race with cgroup_attach_task() or update_cpumask() and get | |
2365 | * the wrong tsk->cpus_allowed. However, both cases imply the | |
2366 | * subsequent cpuset_change_cpumask()->set_cpus_allowed_ptr() | |
2367 | * which takes task_rq_lock(). | |
2368 | * | |
2369 | * If we are called after it dropped the lock we must see all | |
2370 | * changes in tsk_cs()->cpus_allowed. Otherwise we can temporary | |
2371 | * set any mask even if it is not right from task_cs() pov, | |
2372 | * the pending set_cpus_allowed_ptr() will fix things. | |
2baab4e9 PZ |
2373 | * |
2374 | * select_fallback_rq() will fix things ups and set cpu_possible_mask | |
2375 | * if required. | |
9084bb82 | 2376 | */ |
9084bb82 ON |
2377 | } |
2378 | ||
1da177e4 LT |
2379 | void cpuset_init_current_mems_allowed(void) |
2380 | { | |
f9a86fcb | 2381 | nodes_setall(current->mems_allowed); |
1da177e4 LT |
2382 | } |
2383 | ||
909d75a3 PJ |
2384 | /** |
2385 | * cpuset_mems_allowed - return mems_allowed mask from a tasks cpuset. | |
2386 | * @tsk: pointer to task_struct from which to obtain cpuset->mems_allowed. | |
2387 | * | |
2388 | * Description: Returns the nodemask_t mems_allowed of the cpuset | |
2389 | * attached to the specified @tsk. Guaranteed to return some non-empty | |
38d7bee9 | 2390 | * subset of node_states[N_MEMORY], even if this means going outside the |
909d75a3 PJ |
2391 | * tasks cpuset. |
2392 | **/ | |
2393 | ||
2394 | nodemask_t cpuset_mems_allowed(struct task_struct *tsk) | |
2395 | { | |
070b57fc | 2396 | struct cpuset *mems_cs; |
909d75a3 PJ |
2397 | nodemask_t mask; |
2398 | ||
3d3f26a7 | 2399 | mutex_lock(&callback_mutex); |
909d75a3 | 2400 | task_lock(tsk); |
070b57fc LZ |
2401 | mems_cs = effective_nodemask_cpuset(task_cs(tsk)); |
2402 | guarantee_online_mems(mems_cs, &mask); | |
909d75a3 | 2403 | task_unlock(tsk); |
3d3f26a7 | 2404 | mutex_unlock(&callback_mutex); |
909d75a3 PJ |
2405 | |
2406 | return mask; | |
2407 | } | |
2408 | ||
d9fd8a6d | 2409 | /** |
19770b32 MG |
2410 | * cpuset_nodemask_valid_mems_allowed - check nodemask vs. curremt mems_allowed |
2411 | * @nodemask: the nodemask to be checked | |
d9fd8a6d | 2412 | * |
19770b32 | 2413 | * Are any of the nodes in the nodemask allowed in current->mems_allowed? |
1da177e4 | 2414 | */ |
19770b32 | 2415 | int cpuset_nodemask_valid_mems_allowed(nodemask_t *nodemask) |
1da177e4 | 2416 | { |
19770b32 | 2417 | return nodes_intersects(*nodemask, current->mems_allowed); |
1da177e4 LT |
2418 | } |
2419 | ||
9bf2229f | 2420 | /* |
78608366 PM |
2421 | * nearest_hardwall_ancestor() - Returns the nearest mem_exclusive or |
2422 | * mem_hardwall ancestor to the specified cpuset. Call holding | |
2423 | * callback_mutex. If no ancestor is mem_exclusive or mem_hardwall | |
2424 | * (an unusual configuration), then returns the root cpuset. | |
9bf2229f | 2425 | */ |
78608366 | 2426 | static const struct cpuset *nearest_hardwall_ancestor(const struct cpuset *cs) |
9bf2229f | 2427 | { |
c431069f TH |
2428 | while (!(is_mem_exclusive(cs) || is_mem_hardwall(cs)) && parent_cs(cs)) |
2429 | cs = parent_cs(cs); | |
9bf2229f PJ |
2430 | return cs; |
2431 | } | |
2432 | ||
d9fd8a6d | 2433 | /** |
a1bc5a4e DR |
2434 | * cpuset_node_allowed_softwall - Can we allocate on a memory node? |
2435 | * @node: is this an allowed node? | |
02a0e53d | 2436 | * @gfp_mask: memory allocation flags |
d9fd8a6d | 2437 | * |
a1bc5a4e DR |
2438 | * If we're in interrupt, yes, we can always allocate. If __GFP_THISNODE is |
2439 | * set, yes, we can always allocate. If node is in our task's mems_allowed, | |
2440 | * yes. If it's not a __GFP_HARDWALL request and this node is in the nearest | |
2441 | * hardwalled cpuset ancestor to this task's cpuset, yes. If the task has been | |
2442 | * OOM killed and has access to memory reserves as specified by the TIF_MEMDIE | |
2443 | * flag, yes. | |
9bf2229f PJ |
2444 | * Otherwise, no. |
2445 | * | |
a1bc5a4e DR |
2446 | * If __GFP_HARDWALL is set, cpuset_node_allowed_softwall() reduces to |
2447 | * cpuset_node_allowed_hardwall(). Otherwise, cpuset_node_allowed_softwall() | |
2448 | * might sleep, and might allow a node from an enclosing cpuset. | |
02a0e53d | 2449 | * |
a1bc5a4e DR |
2450 | * cpuset_node_allowed_hardwall() only handles the simpler case of hardwall |
2451 | * cpusets, and never sleeps. | |
02a0e53d PJ |
2452 | * |
2453 | * The __GFP_THISNODE placement logic is really handled elsewhere, | |
2454 | * by forcibly using a zonelist starting at a specified node, and by | |
2455 | * (in get_page_from_freelist()) refusing to consider the zones for | |
2456 | * any node on the zonelist except the first. By the time any such | |
2457 | * calls get to this routine, we should just shut up and say 'yes'. | |
2458 | * | |
9bf2229f | 2459 | * GFP_USER allocations are marked with the __GFP_HARDWALL bit, |
c596d9f3 DR |
2460 | * and do not allow allocations outside the current tasks cpuset |
2461 | * unless the task has been OOM killed as is marked TIF_MEMDIE. | |
9bf2229f | 2462 | * GFP_KERNEL allocations are not so marked, so can escape to the |
78608366 | 2463 | * nearest enclosing hardwalled ancestor cpuset. |
9bf2229f | 2464 | * |
02a0e53d PJ |
2465 | * Scanning up parent cpusets requires callback_mutex. The |
2466 | * __alloc_pages() routine only calls here with __GFP_HARDWALL bit | |
2467 | * _not_ set if it's a GFP_KERNEL allocation, and all nodes in the | |
2468 | * current tasks mems_allowed came up empty on the first pass over | |
2469 | * the zonelist. So only GFP_KERNEL allocations, if all nodes in the | |
2470 | * cpuset are short of memory, might require taking the callback_mutex | |
2471 | * mutex. | |
9bf2229f | 2472 | * |
36be57ff | 2473 | * The first call here from mm/page_alloc:get_page_from_freelist() |
02a0e53d PJ |
2474 | * has __GFP_HARDWALL set in gfp_mask, enforcing hardwall cpusets, |
2475 | * so no allocation on a node outside the cpuset is allowed (unless | |
2476 | * in interrupt, of course). | |
36be57ff PJ |
2477 | * |
2478 | * The second pass through get_page_from_freelist() doesn't even call | |
2479 | * here for GFP_ATOMIC calls. For those calls, the __alloc_pages() | |
2480 | * variable 'wait' is not set, and the bit ALLOC_CPUSET is not set | |
2481 | * in alloc_flags. That logic and the checks below have the combined | |
2482 | * affect that: | |
9bf2229f PJ |
2483 | * in_interrupt - any node ok (current task context irrelevant) |
2484 | * GFP_ATOMIC - any node ok | |
c596d9f3 | 2485 | * TIF_MEMDIE - any node ok |
78608366 | 2486 | * GFP_KERNEL - any node in enclosing hardwalled cpuset ok |
9bf2229f | 2487 | * GFP_USER - only nodes in current tasks mems allowed ok. |
36be57ff PJ |
2488 | * |
2489 | * Rule: | |
a1bc5a4e | 2490 | * Don't call cpuset_node_allowed_softwall if you can't sleep, unless you |
36be57ff PJ |
2491 | * pass in the __GFP_HARDWALL flag set in gfp_flag, which disables |
2492 | * the code that might scan up ancestor cpusets and sleep. | |
02a0e53d | 2493 | */ |
a1bc5a4e | 2494 | int __cpuset_node_allowed_softwall(int node, gfp_t gfp_mask) |
1da177e4 | 2495 | { |
9bf2229f | 2496 | const struct cpuset *cs; /* current cpuset ancestors */ |
29afd49b | 2497 | int allowed; /* is allocation in zone z allowed? */ |
9bf2229f | 2498 | |
9b819d20 | 2499 | if (in_interrupt() || (gfp_mask & __GFP_THISNODE)) |
9bf2229f | 2500 | return 1; |
92d1dbd2 | 2501 | might_sleep_if(!(gfp_mask & __GFP_HARDWALL)); |
9bf2229f PJ |
2502 | if (node_isset(node, current->mems_allowed)) |
2503 | return 1; | |
c596d9f3 DR |
2504 | /* |
2505 | * Allow tasks that have access to memory reserves because they have | |
2506 | * been OOM killed to get memory anywhere. | |
2507 | */ | |
2508 | if (unlikely(test_thread_flag(TIF_MEMDIE))) | |
2509 | return 1; | |
9bf2229f PJ |
2510 | if (gfp_mask & __GFP_HARDWALL) /* If hardwall request, stop here */ |
2511 | return 0; | |
2512 | ||
5563e770 BP |
2513 | if (current->flags & PF_EXITING) /* Let dying task have memory */ |
2514 | return 1; | |
2515 | ||
9bf2229f | 2516 | /* Not hardwall and node outside mems_allowed: scan up cpusets */ |
3d3f26a7 | 2517 | mutex_lock(&callback_mutex); |
053199ed | 2518 | |
053199ed | 2519 | task_lock(current); |
78608366 | 2520 | cs = nearest_hardwall_ancestor(task_cs(current)); |
053199ed PJ |
2521 | task_unlock(current); |
2522 | ||
9bf2229f | 2523 | allowed = node_isset(node, cs->mems_allowed); |
3d3f26a7 | 2524 | mutex_unlock(&callback_mutex); |
9bf2229f | 2525 | return allowed; |
1da177e4 LT |
2526 | } |
2527 | ||
02a0e53d | 2528 | /* |
a1bc5a4e DR |
2529 | * cpuset_node_allowed_hardwall - Can we allocate on a memory node? |
2530 | * @node: is this an allowed node? | |
02a0e53d PJ |
2531 | * @gfp_mask: memory allocation flags |
2532 | * | |
a1bc5a4e DR |
2533 | * If we're in interrupt, yes, we can always allocate. If __GFP_THISNODE is |
2534 | * set, yes, we can always allocate. If node is in our task's mems_allowed, | |
2535 | * yes. If the task has been OOM killed and has access to memory reserves as | |
2536 | * specified by the TIF_MEMDIE flag, yes. | |
2537 | * Otherwise, no. | |
02a0e53d PJ |
2538 | * |
2539 | * The __GFP_THISNODE placement logic is really handled elsewhere, | |
2540 | * by forcibly using a zonelist starting at a specified node, and by | |
2541 | * (in get_page_from_freelist()) refusing to consider the zones for | |
2542 | * any node on the zonelist except the first. By the time any such | |
2543 | * calls get to this routine, we should just shut up and say 'yes'. | |
2544 | * | |
a1bc5a4e DR |
2545 | * Unlike the cpuset_node_allowed_softwall() variant, above, |
2546 | * this variant requires that the node be in the current task's | |
02a0e53d PJ |
2547 | * mems_allowed or that we're in interrupt. It does not scan up the |
2548 | * cpuset hierarchy for the nearest enclosing mem_exclusive cpuset. | |
2549 | * It never sleeps. | |
2550 | */ | |
a1bc5a4e | 2551 | int __cpuset_node_allowed_hardwall(int node, gfp_t gfp_mask) |
02a0e53d | 2552 | { |
02a0e53d PJ |
2553 | if (in_interrupt() || (gfp_mask & __GFP_THISNODE)) |
2554 | return 1; | |
02a0e53d PJ |
2555 | if (node_isset(node, current->mems_allowed)) |
2556 | return 1; | |
dedf8b79 DW |
2557 | /* |
2558 | * Allow tasks that have access to memory reserves because they have | |
2559 | * been OOM killed to get memory anywhere. | |
2560 | */ | |
2561 | if (unlikely(test_thread_flag(TIF_MEMDIE))) | |
2562 | return 1; | |
02a0e53d PJ |
2563 | return 0; |
2564 | } | |
2565 | ||
825a46af | 2566 | /** |
6adef3eb JS |
2567 | * cpuset_mem_spread_node() - On which node to begin search for a file page |
2568 | * cpuset_slab_spread_node() - On which node to begin search for a slab page | |
825a46af PJ |
2569 | * |
2570 | * If a task is marked PF_SPREAD_PAGE or PF_SPREAD_SLAB (as for | |
2571 | * tasks in a cpuset with is_spread_page or is_spread_slab set), | |
2572 | * and if the memory allocation used cpuset_mem_spread_node() | |
2573 | * to determine on which node to start looking, as it will for | |
2574 | * certain page cache or slab cache pages such as used for file | |
2575 | * system buffers and inode caches, then instead of starting on the | |
2576 | * local node to look for a free page, rather spread the starting | |
2577 | * node around the tasks mems_allowed nodes. | |
2578 | * | |
2579 | * We don't have to worry about the returned node being offline | |
2580 | * because "it can't happen", and even if it did, it would be ok. | |
2581 | * | |
2582 | * The routines calling guarantee_online_mems() are careful to | |
2583 | * only set nodes in task->mems_allowed that are online. So it | |
2584 | * should not be possible for the following code to return an | |
2585 | * offline node. But if it did, that would be ok, as this routine | |
2586 | * is not returning the node where the allocation must be, only | |
2587 | * the node where the search should start. The zonelist passed to | |
2588 | * __alloc_pages() will include all nodes. If the slab allocator | |
2589 | * is passed an offline node, it will fall back to the local node. | |
2590 | * See kmem_cache_alloc_node(). | |
2591 | */ | |
2592 | ||
6adef3eb | 2593 | static int cpuset_spread_node(int *rotor) |
825a46af PJ |
2594 | { |
2595 | int node; | |
2596 | ||
6adef3eb | 2597 | node = next_node(*rotor, current->mems_allowed); |
825a46af PJ |
2598 | if (node == MAX_NUMNODES) |
2599 | node = first_node(current->mems_allowed); | |
6adef3eb | 2600 | *rotor = node; |
825a46af PJ |
2601 | return node; |
2602 | } | |
6adef3eb JS |
2603 | |
2604 | int cpuset_mem_spread_node(void) | |
2605 | { | |
778d3b0f MH |
2606 | if (current->cpuset_mem_spread_rotor == NUMA_NO_NODE) |
2607 | current->cpuset_mem_spread_rotor = | |
2608 | node_random(¤t->mems_allowed); | |
2609 | ||
6adef3eb JS |
2610 | return cpuset_spread_node(¤t->cpuset_mem_spread_rotor); |
2611 | } | |
2612 | ||
2613 | int cpuset_slab_spread_node(void) | |
2614 | { | |
778d3b0f MH |
2615 | if (current->cpuset_slab_spread_rotor == NUMA_NO_NODE) |
2616 | current->cpuset_slab_spread_rotor = | |
2617 | node_random(¤t->mems_allowed); | |
2618 | ||
6adef3eb JS |
2619 | return cpuset_spread_node(¤t->cpuset_slab_spread_rotor); |
2620 | } | |
2621 | ||
825a46af PJ |
2622 | EXPORT_SYMBOL_GPL(cpuset_mem_spread_node); |
2623 | ||
ef08e3b4 | 2624 | /** |
bbe373f2 DR |
2625 | * cpuset_mems_allowed_intersects - Does @tsk1's mems_allowed intersect @tsk2's? |
2626 | * @tsk1: pointer to task_struct of some task. | |
2627 | * @tsk2: pointer to task_struct of some other task. | |
2628 | * | |
2629 | * Description: Return true if @tsk1's mems_allowed intersects the | |
2630 | * mems_allowed of @tsk2. Used by the OOM killer to determine if | |
2631 | * one of the task's memory usage might impact the memory available | |
2632 | * to the other. | |
ef08e3b4 PJ |
2633 | **/ |
2634 | ||
bbe373f2 DR |
2635 | int cpuset_mems_allowed_intersects(const struct task_struct *tsk1, |
2636 | const struct task_struct *tsk2) | |
ef08e3b4 | 2637 | { |
bbe373f2 | 2638 | return nodes_intersects(tsk1->mems_allowed, tsk2->mems_allowed); |
ef08e3b4 PJ |
2639 | } |
2640 | ||
f440d98f LZ |
2641 | #define CPUSET_NODELIST_LEN (256) |
2642 | ||
75aa1994 DR |
2643 | /** |
2644 | * cpuset_print_task_mems_allowed - prints task's cpuset and mems_allowed | |
2645 | * @task: pointer to task_struct of some task. | |
2646 | * | |
2647 | * Description: Prints @task's name, cpuset name, and cached copy of its | |
2648 | * mems_allowed to the kernel log. Must hold task_lock(task) to allow | |
2649 | * dereferencing task_cs(task). | |
2650 | */ | |
2651 | void cpuset_print_task_mems_allowed(struct task_struct *tsk) | |
2652 | { | |
f440d98f LZ |
2653 | /* Statically allocated to prevent using excess stack. */ |
2654 | static char cpuset_nodelist[CPUSET_NODELIST_LEN]; | |
2655 | static DEFINE_SPINLOCK(cpuset_buffer_lock); | |
75aa1994 | 2656 | |
f440d98f | 2657 | struct cgroup *cgrp = task_cs(tsk)->css.cgroup; |
63f43f55 | 2658 | |
cfb5966b | 2659 | rcu_read_lock(); |
f440d98f | 2660 | spin_lock(&cpuset_buffer_lock); |
63f43f55 | 2661 | |
75aa1994 DR |
2662 | nodelist_scnprintf(cpuset_nodelist, CPUSET_NODELIST_LEN, |
2663 | tsk->mems_allowed); | |
2664 | printk(KERN_INFO "%s cpuset=%s mems_allowed=%s\n", | |
f440d98f LZ |
2665 | tsk->comm, cgroup_name(cgrp), cpuset_nodelist); |
2666 | ||
75aa1994 | 2667 | spin_unlock(&cpuset_buffer_lock); |
cfb5966b | 2668 | rcu_read_unlock(); |
75aa1994 DR |
2669 | } |
2670 | ||
3e0d98b9 PJ |
2671 | /* |
2672 | * Collection of memory_pressure is suppressed unless | |
2673 | * this flag is enabled by writing "1" to the special | |
2674 | * cpuset file 'memory_pressure_enabled' in the root cpuset. | |
2675 | */ | |
2676 | ||
c5b2aff8 | 2677 | int cpuset_memory_pressure_enabled __read_mostly; |
3e0d98b9 PJ |
2678 | |
2679 | /** | |
2680 | * cpuset_memory_pressure_bump - keep stats of per-cpuset reclaims. | |
2681 | * | |
2682 | * Keep a running average of the rate of synchronous (direct) | |
2683 | * page reclaim efforts initiated by tasks in each cpuset. | |
2684 | * | |
2685 | * This represents the rate at which some task in the cpuset | |
2686 | * ran low on memory on all nodes it was allowed to use, and | |
2687 | * had to enter the kernels page reclaim code in an effort to | |
2688 | * create more free memory by tossing clean pages or swapping | |
2689 | * or writing dirty pages. | |
2690 | * | |
2691 | * Display to user space in the per-cpuset read-only file | |
2692 | * "memory_pressure". Value displayed is an integer | |
2693 | * representing the recent rate of entry into the synchronous | |
2694 | * (direct) page reclaim by any task attached to the cpuset. | |
2695 | **/ | |
2696 | ||
2697 | void __cpuset_memory_pressure_bump(void) | |
2698 | { | |
3e0d98b9 | 2699 | task_lock(current); |
8793d854 | 2700 | fmeter_markevent(&task_cs(current)->fmeter); |
3e0d98b9 PJ |
2701 | task_unlock(current); |
2702 | } | |
2703 | ||
8793d854 | 2704 | #ifdef CONFIG_PROC_PID_CPUSET |
1da177e4 LT |
2705 | /* |
2706 | * proc_cpuset_show() | |
2707 | * - Print tasks cpuset path into seq_file. | |
2708 | * - Used for /proc/<pid>/cpuset. | |
053199ed PJ |
2709 | * - No need to task_lock(tsk) on this tsk->cpuset reference, as it |
2710 | * doesn't really matter if tsk->cpuset changes after we read it, | |
5d21cc2d | 2711 | * and we take cpuset_mutex, keeping cpuset_attach() from changing it |
2df167a3 | 2712 | * anyway. |
1da177e4 | 2713 | */ |
8d8b97ba | 2714 | int proc_cpuset_show(struct seq_file *m, void *unused_v) |
1da177e4 | 2715 | { |
13b41b09 | 2716 | struct pid *pid; |
1da177e4 LT |
2717 | struct task_struct *tsk; |
2718 | char *buf; | |
8793d854 | 2719 | struct cgroup_subsys_state *css; |
99f89551 | 2720 | int retval; |
1da177e4 | 2721 | |
99f89551 | 2722 | retval = -ENOMEM; |
1da177e4 LT |
2723 | buf = kmalloc(PAGE_SIZE, GFP_KERNEL); |
2724 | if (!buf) | |
99f89551 EB |
2725 | goto out; |
2726 | ||
2727 | retval = -ESRCH; | |
13b41b09 EB |
2728 | pid = m->private; |
2729 | tsk = get_pid_task(pid, PIDTYPE_PID); | |
99f89551 EB |
2730 | if (!tsk) |
2731 | goto out_free; | |
1da177e4 | 2732 | |
27e89ae5 | 2733 | rcu_read_lock(); |
8793d854 PM |
2734 | css = task_subsys_state(tsk, cpuset_subsys_id); |
2735 | retval = cgroup_path(css->cgroup, buf, PAGE_SIZE); | |
27e89ae5 | 2736 | rcu_read_unlock(); |
1da177e4 | 2737 | if (retval < 0) |
27e89ae5 | 2738 | goto out_put_task; |
1da177e4 LT |
2739 | seq_puts(m, buf); |
2740 | seq_putc(m, '\n'); | |
27e89ae5 | 2741 | out_put_task: |
99f89551 EB |
2742 | put_task_struct(tsk); |
2743 | out_free: | |
1da177e4 | 2744 | kfree(buf); |
99f89551 | 2745 | out: |
1da177e4 LT |
2746 | return retval; |
2747 | } | |
8793d854 | 2748 | #endif /* CONFIG_PROC_PID_CPUSET */ |
1da177e4 | 2749 | |
d01d4827 | 2750 | /* Display task mems_allowed in /proc/<pid>/status file. */ |
df5f8314 EB |
2751 | void cpuset_task_status_allowed(struct seq_file *m, struct task_struct *task) |
2752 | { | |
df5f8314 | 2753 | seq_printf(m, "Mems_allowed:\t"); |
30e8e136 | 2754 | seq_nodemask(m, &task->mems_allowed); |
df5f8314 | 2755 | seq_printf(m, "\n"); |
39106dcf | 2756 | seq_printf(m, "Mems_allowed_list:\t"); |
30e8e136 | 2757 | seq_nodemask_list(m, &task->mems_allowed); |
39106dcf | 2758 | seq_printf(m, "\n"); |
1da177e4 | 2759 | } |