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mm: only build per-node scan_unevictable functions when NUMA is enabled
[net-next-2.6.git] / mm / mempolicy.c
CommitLineData
1da177e4
LT
1/*
2 * Simple NUMA memory policy for the Linux kernel.
3 *
4 * Copyright 2003,2004 Andi Kleen, SuSE Labs.
8bccd85f 5 * (C) Copyright 2005 Christoph Lameter, Silicon Graphics, Inc.
1da177e4
LT
6 * Subject to the GNU Public License, version 2.
7 *
8 * NUMA policy allows the user to give hints in which node(s) memory should
9 * be allocated.
10 *
11 * Support four policies per VMA and per process:
12 *
13 * The VMA policy has priority over the process policy for a page fault.
14 *
15 * interleave Allocate memory interleaved over a set of nodes,
16 * with normal fallback if it fails.
17 * For VMA based allocations this interleaves based on the
18 * offset into the backing object or offset into the mapping
19 * for anonymous memory. For process policy an process counter
20 * is used.
8bccd85f 21 *
1da177e4
LT
22 * bind Only allocate memory on a specific set of nodes,
23 * no fallback.
8bccd85f
CL
24 * FIXME: memory is allocated starting with the first node
25 * to the last. It would be better if bind would truly restrict
26 * the allocation to memory nodes instead
27 *
1da177e4
LT
28 * preferred Try a specific node first before normal fallback.
29 * As a special case node -1 here means do the allocation
30 * on the local CPU. This is normally identical to default,
31 * but useful to set in a VMA when you have a non default
32 * process policy.
8bccd85f 33 *
1da177e4
LT
34 * default Allocate on the local node first, or when on a VMA
35 * use the process policy. This is what Linux always did
36 * in a NUMA aware kernel and still does by, ahem, default.
37 *
38 * The process policy is applied for most non interrupt memory allocations
39 * in that process' context. Interrupts ignore the policies and always
40 * try to allocate on the local CPU. The VMA policy is only applied for memory
41 * allocations for a VMA in the VM.
42 *
43 * Currently there are a few corner cases in swapping where the policy
44 * is not applied, but the majority should be handled. When process policy
45 * is used it is not remembered over swap outs/swap ins.
46 *
47 * Only the highest zone in the zone hierarchy gets policied. Allocations
48 * requesting a lower zone just use default policy. This implies that
49 * on systems with highmem kernel lowmem allocation don't get policied.
50 * Same with GFP_DMA allocations.
51 *
52 * For shmfs/tmpfs/hugetlbfs shared memory the policy is shared between
53 * all users and remembered even when nobody has memory mapped.
54 */
55
56/* Notebook:
57 fix mmap readahead to honour policy and enable policy for any page cache
58 object
59 statistics for bigpages
60 global policy for page cache? currently it uses process policy. Requires
61 first item above.
62 handle mremap for shared memory (currently ignored for the policy)
63 grows down?
64 make bind policy root only? It can trigger oom much faster and the
65 kernel is not always grateful with that.
1da177e4
LT
66*/
67
68#include <linux/mempolicy.h>
69#include <linux/mm.h>
70#include <linux/highmem.h>
71#include <linux/hugetlb.h>
72#include <linux/kernel.h>
73#include <linux/sched.h>
1da177e4
LT
74#include <linux/nodemask.h>
75#include <linux/cpuset.h>
1da177e4
LT
76#include <linux/slab.h>
77#include <linux/string.h>
78#include <linux/module.h>
b488893a 79#include <linux/nsproxy.h>
1da177e4
LT
80#include <linux/interrupt.h>
81#include <linux/init.h>
82#include <linux/compat.h>
dc9aa5b9 83#include <linux/swap.h>
1a75a6c8
CL
84#include <linux/seq_file.h>
85#include <linux/proc_fs.h>
b20a3503 86#include <linux/migrate.h>
62b61f61 87#include <linux/ksm.h>
95a402c3 88#include <linux/rmap.h>
86c3a764 89#include <linux/security.h>
dbcb0f19 90#include <linux/syscalls.h>
095f1fc4 91#include <linux/ctype.h>
6d9c285a 92#include <linux/mm_inline.h>
dc9aa5b9 93
1da177e4
LT
94#include <asm/tlbflush.h>
95#include <asm/uaccess.h>
96
62695a84
NP
97#include "internal.h"
98
38e35860 99/* Internal flags */
dc9aa5b9 100#define MPOL_MF_DISCONTIG_OK (MPOL_MF_INTERNAL << 0) /* Skip checks for continuous vmas */
38e35860 101#define MPOL_MF_INVERT (MPOL_MF_INTERNAL << 1) /* Invert check for nodemask */
1a75a6c8 102#define MPOL_MF_STATS (MPOL_MF_INTERNAL << 2) /* Gather statistics */
dc9aa5b9 103
fcc234f8
PE
104static struct kmem_cache *policy_cache;
105static struct kmem_cache *sn_cache;
1da177e4 106
1da177e4
LT
107/* Highest zone. An specific allocation for a zone below that is not
108 policied. */
6267276f 109enum zone_type policy_zone = 0;
1da177e4 110
bea904d5
LS
111/*
112 * run-time system-wide default policy => local allocation
113 */
d42c6997 114struct mempolicy default_policy = {
1da177e4 115 .refcnt = ATOMIC_INIT(1), /* never free it */
bea904d5 116 .mode = MPOL_PREFERRED,
fc36b8d3 117 .flags = MPOL_F_LOCAL,
1da177e4
LT
118};
119
37012946
DR
120static const struct mempolicy_operations {
121 int (*create)(struct mempolicy *pol, const nodemask_t *nodes);
708c1bbc
MX
122 /*
123 * If read-side task has no lock to protect task->mempolicy, write-side
124 * task will rebind the task->mempolicy by two step. The first step is
125 * setting all the newly nodes, and the second step is cleaning all the
126 * disallowed nodes. In this way, we can avoid finding no node to alloc
127 * page.
128 * If we have a lock to protect task->mempolicy in read-side, we do
129 * rebind directly.
130 *
131 * step:
132 * MPOL_REBIND_ONCE - do rebind work at once
133 * MPOL_REBIND_STEP1 - set all the newly nodes
134 * MPOL_REBIND_STEP2 - clean all the disallowed nodes
135 */
136 void (*rebind)(struct mempolicy *pol, const nodemask_t *nodes,
137 enum mpol_rebind_step step);
37012946
DR
138} mpol_ops[MPOL_MAX];
139
19770b32 140/* Check that the nodemask contains at least one populated zone */
37012946 141static int is_valid_nodemask(const nodemask_t *nodemask)
1da177e4 142{
19770b32 143 int nd, k;
1da177e4 144
19770b32
MG
145 for_each_node_mask(nd, *nodemask) {
146 struct zone *z;
147
148 for (k = 0; k <= policy_zone; k++) {
149 z = &NODE_DATA(nd)->node_zones[k];
150 if (z->present_pages > 0)
151 return 1;
dd942ae3 152 }
8af5e2eb 153 }
19770b32
MG
154
155 return 0;
1da177e4
LT
156}
157
f5b087b5
DR
158static inline int mpol_store_user_nodemask(const struct mempolicy *pol)
159{
6d556294 160 return pol->flags & MPOL_MODE_FLAGS;
4c50bc01
DR
161}
162
163static void mpol_relative_nodemask(nodemask_t *ret, const nodemask_t *orig,
164 const nodemask_t *rel)
165{
166 nodemask_t tmp;
167 nodes_fold(tmp, *orig, nodes_weight(*rel));
168 nodes_onto(*ret, tmp, *rel);
f5b087b5
DR
169}
170
37012946
DR
171static int mpol_new_interleave(struct mempolicy *pol, const nodemask_t *nodes)
172{
173 if (nodes_empty(*nodes))
174 return -EINVAL;
175 pol->v.nodes = *nodes;
176 return 0;
177}
178
179static int mpol_new_preferred(struct mempolicy *pol, const nodemask_t *nodes)
180{
181 if (!nodes)
fc36b8d3 182 pol->flags |= MPOL_F_LOCAL; /* local allocation */
37012946
DR
183 else if (nodes_empty(*nodes))
184 return -EINVAL; /* no allowed nodes */
185 else
186 pol->v.preferred_node = first_node(*nodes);
187 return 0;
188}
189
190static int mpol_new_bind(struct mempolicy *pol, const nodemask_t *nodes)
191{
192 if (!is_valid_nodemask(nodes))
193 return -EINVAL;
194 pol->v.nodes = *nodes;
195 return 0;
196}
197
58568d2a
MX
198/*
199 * mpol_set_nodemask is called after mpol_new() to set up the nodemask, if
200 * any, for the new policy. mpol_new() has already validated the nodes
201 * parameter with respect to the policy mode and flags. But, we need to
202 * handle an empty nodemask with MPOL_PREFERRED here.
203 *
204 * Must be called holding task's alloc_lock to protect task's mems_allowed
205 * and mempolicy. May also be called holding the mmap_semaphore for write.
206 */
4bfc4495
KH
207static int mpol_set_nodemask(struct mempolicy *pol,
208 const nodemask_t *nodes, struct nodemask_scratch *nsc)
58568d2a 209{
58568d2a
MX
210 int ret;
211
212 /* if mode is MPOL_DEFAULT, pol is NULL. This is right. */
213 if (pol == NULL)
214 return 0;
4bfc4495
KH
215 /* Check N_HIGH_MEMORY */
216 nodes_and(nsc->mask1,
217 cpuset_current_mems_allowed, node_states[N_HIGH_MEMORY]);
58568d2a
MX
218
219 VM_BUG_ON(!nodes);
220 if (pol->mode == MPOL_PREFERRED && nodes_empty(*nodes))
221 nodes = NULL; /* explicit local allocation */
222 else {
223 if (pol->flags & MPOL_F_RELATIVE_NODES)
4bfc4495 224 mpol_relative_nodemask(&nsc->mask2, nodes,&nsc->mask1);
58568d2a 225 else
4bfc4495
KH
226 nodes_and(nsc->mask2, *nodes, nsc->mask1);
227
58568d2a
MX
228 if (mpol_store_user_nodemask(pol))
229 pol->w.user_nodemask = *nodes;
230 else
231 pol->w.cpuset_mems_allowed =
232 cpuset_current_mems_allowed;
233 }
234
4bfc4495
KH
235 if (nodes)
236 ret = mpol_ops[pol->mode].create(pol, &nsc->mask2);
237 else
238 ret = mpol_ops[pol->mode].create(pol, NULL);
58568d2a
MX
239 return ret;
240}
241
242/*
243 * This function just creates a new policy, does some check and simple
244 * initialization. You must invoke mpol_set_nodemask() to set nodes.
245 */
028fec41
DR
246static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags,
247 nodemask_t *nodes)
1da177e4
LT
248{
249 struct mempolicy *policy;
250
028fec41
DR
251 pr_debug("setting mode %d flags %d nodes[0] %lx\n",
252 mode, flags, nodes ? nodes_addr(*nodes)[0] : -1);
140d5a49 253
3e1f0645
DR
254 if (mode == MPOL_DEFAULT) {
255 if (nodes && !nodes_empty(*nodes))
37012946 256 return ERR_PTR(-EINVAL);
bea904d5 257 return NULL; /* simply delete any existing policy */
37012946 258 }
3e1f0645
DR
259 VM_BUG_ON(!nodes);
260
261 /*
262 * MPOL_PREFERRED cannot be used with MPOL_F_STATIC_NODES or
263 * MPOL_F_RELATIVE_NODES if the nodemask is empty (local allocation).
264 * All other modes require a valid pointer to a non-empty nodemask.
265 */
266 if (mode == MPOL_PREFERRED) {
267 if (nodes_empty(*nodes)) {
268 if (((flags & MPOL_F_STATIC_NODES) ||
269 (flags & MPOL_F_RELATIVE_NODES)))
270 return ERR_PTR(-EINVAL);
3e1f0645
DR
271 }
272 } else if (nodes_empty(*nodes))
273 return ERR_PTR(-EINVAL);
1da177e4
LT
274 policy = kmem_cache_alloc(policy_cache, GFP_KERNEL);
275 if (!policy)
276 return ERR_PTR(-ENOMEM);
277 atomic_set(&policy->refcnt, 1);
45c4745a 278 policy->mode = mode;
3e1f0645 279 policy->flags = flags;
37012946 280
1da177e4 281 return policy;
37012946
DR
282}
283
52cd3b07
LS
284/* Slow path of a mpol destructor. */
285void __mpol_put(struct mempolicy *p)
286{
287 if (!atomic_dec_and_test(&p->refcnt))
288 return;
52cd3b07
LS
289 kmem_cache_free(policy_cache, p);
290}
291
708c1bbc
MX
292static void mpol_rebind_default(struct mempolicy *pol, const nodemask_t *nodes,
293 enum mpol_rebind_step step)
37012946
DR
294{
295}
296
708c1bbc
MX
297/*
298 * step:
299 * MPOL_REBIND_ONCE - do rebind work at once
300 * MPOL_REBIND_STEP1 - set all the newly nodes
301 * MPOL_REBIND_STEP2 - clean all the disallowed nodes
302 */
303static void mpol_rebind_nodemask(struct mempolicy *pol, const nodemask_t *nodes,
304 enum mpol_rebind_step step)
37012946
DR
305{
306 nodemask_t tmp;
307
308 if (pol->flags & MPOL_F_STATIC_NODES)
309 nodes_and(tmp, pol->w.user_nodemask, *nodes);
310 else if (pol->flags & MPOL_F_RELATIVE_NODES)
311 mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes);
312 else {
708c1bbc
MX
313 /*
314 * if step == 1, we use ->w.cpuset_mems_allowed to cache the
315 * result
316 */
317 if (step == MPOL_REBIND_ONCE || step == MPOL_REBIND_STEP1) {
318 nodes_remap(tmp, pol->v.nodes,
319 pol->w.cpuset_mems_allowed, *nodes);
320 pol->w.cpuset_mems_allowed = step ? tmp : *nodes;
321 } else if (step == MPOL_REBIND_STEP2) {
322 tmp = pol->w.cpuset_mems_allowed;
323 pol->w.cpuset_mems_allowed = *nodes;
324 } else
325 BUG();
37012946 326 }
f5b087b5 327
708c1bbc
MX
328 if (nodes_empty(tmp))
329 tmp = *nodes;
330
331 if (step == MPOL_REBIND_STEP1)
332 nodes_or(pol->v.nodes, pol->v.nodes, tmp);
333 else if (step == MPOL_REBIND_ONCE || step == MPOL_REBIND_STEP2)
334 pol->v.nodes = tmp;
335 else
336 BUG();
337
37012946
DR
338 if (!node_isset(current->il_next, tmp)) {
339 current->il_next = next_node(current->il_next, tmp);
340 if (current->il_next >= MAX_NUMNODES)
341 current->il_next = first_node(tmp);
342 if (current->il_next >= MAX_NUMNODES)
343 current->il_next = numa_node_id();
344 }
345}
346
347static void mpol_rebind_preferred(struct mempolicy *pol,
708c1bbc
MX
348 const nodemask_t *nodes,
349 enum mpol_rebind_step step)
37012946
DR
350{
351 nodemask_t tmp;
352
37012946
DR
353 if (pol->flags & MPOL_F_STATIC_NODES) {
354 int node = first_node(pol->w.user_nodemask);
355
fc36b8d3 356 if (node_isset(node, *nodes)) {
37012946 357 pol->v.preferred_node = node;
fc36b8d3
LS
358 pol->flags &= ~MPOL_F_LOCAL;
359 } else
360 pol->flags |= MPOL_F_LOCAL;
37012946
DR
361 } else if (pol->flags & MPOL_F_RELATIVE_NODES) {
362 mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes);
363 pol->v.preferred_node = first_node(tmp);
fc36b8d3 364 } else if (!(pol->flags & MPOL_F_LOCAL)) {
37012946
DR
365 pol->v.preferred_node = node_remap(pol->v.preferred_node,
366 pol->w.cpuset_mems_allowed,
367 *nodes);
368 pol->w.cpuset_mems_allowed = *nodes;
369 }
1da177e4
LT
370}
371
708c1bbc
MX
372/*
373 * mpol_rebind_policy - Migrate a policy to a different set of nodes
374 *
375 * If read-side task has no lock to protect task->mempolicy, write-side
376 * task will rebind the task->mempolicy by two step. The first step is
377 * setting all the newly nodes, and the second step is cleaning all the
378 * disallowed nodes. In this way, we can avoid finding no node to alloc
379 * page.
380 * If we have a lock to protect task->mempolicy in read-side, we do
381 * rebind directly.
382 *
383 * step:
384 * MPOL_REBIND_ONCE - do rebind work at once
385 * MPOL_REBIND_STEP1 - set all the newly nodes
386 * MPOL_REBIND_STEP2 - clean all the disallowed nodes
387 */
388static void mpol_rebind_policy(struct mempolicy *pol, const nodemask_t *newmask,
389 enum mpol_rebind_step step)
1d0d2680 390{
1d0d2680
DR
391 if (!pol)
392 return;
708c1bbc 393 if (!mpol_store_user_nodemask(pol) && step == 0 &&
1d0d2680
DR
394 nodes_equal(pol->w.cpuset_mems_allowed, *newmask))
395 return;
708c1bbc
MX
396
397 if (step == MPOL_REBIND_STEP1 && (pol->flags & MPOL_F_REBINDING))
398 return;
399
400 if (step == MPOL_REBIND_STEP2 && !(pol->flags & MPOL_F_REBINDING))
401 BUG();
402
403 if (step == MPOL_REBIND_STEP1)
404 pol->flags |= MPOL_F_REBINDING;
405 else if (step == MPOL_REBIND_STEP2)
406 pol->flags &= ~MPOL_F_REBINDING;
407 else if (step >= MPOL_REBIND_NSTEP)
408 BUG();
409
410 mpol_ops[pol->mode].rebind(pol, newmask, step);
1d0d2680
DR
411}
412
413/*
414 * Wrapper for mpol_rebind_policy() that just requires task
415 * pointer, and updates task mempolicy.
58568d2a
MX
416 *
417 * Called with task's alloc_lock held.
1d0d2680
DR
418 */
419
708c1bbc
MX
420void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new,
421 enum mpol_rebind_step step)
1d0d2680 422{
708c1bbc 423 mpol_rebind_policy(tsk->mempolicy, new, step);
1d0d2680
DR
424}
425
426/*
427 * Rebind each vma in mm to new nodemask.
428 *
429 * Call holding a reference to mm. Takes mm->mmap_sem during call.
430 */
431
432void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new)
433{
434 struct vm_area_struct *vma;
435
436 down_write(&mm->mmap_sem);
437 for (vma = mm->mmap; vma; vma = vma->vm_next)
708c1bbc 438 mpol_rebind_policy(vma->vm_policy, new, MPOL_REBIND_ONCE);
1d0d2680
DR
439 up_write(&mm->mmap_sem);
440}
441
37012946
DR
442static const struct mempolicy_operations mpol_ops[MPOL_MAX] = {
443 [MPOL_DEFAULT] = {
444 .rebind = mpol_rebind_default,
445 },
446 [MPOL_INTERLEAVE] = {
447 .create = mpol_new_interleave,
448 .rebind = mpol_rebind_nodemask,
449 },
450 [MPOL_PREFERRED] = {
451 .create = mpol_new_preferred,
452 .rebind = mpol_rebind_preferred,
453 },
454 [MPOL_BIND] = {
455 .create = mpol_new_bind,
456 .rebind = mpol_rebind_nodemask,
457 },
458};
459
397874df 460static void gather_stats(struct page *, void *, int pte_dirty);
fc301289
CL
461static void migrate_page_add(struct page *page, struct list_head *pagelist,
462 unsigned long flags);
1a75a6c8 463
38e35860 464/* Scan through pages checking if pages follow certain conditions. */
b5810039 465static int check_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
dc9aa5b9
CL
466 unsigned long addr, unsigned long end,
467 const nodemask_t *nodes, unsigned long flags,
38e35860 468 void *private)
1da177e4 469{
91612e0d
HD
470 pte_t *orig_pte;
471 pte_t *pte;
705e87c0 472 spinlock_t *ptl;
941150a3 473
705e87c0 474 orig_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
91612e0d 475 do {
6aab341e 476 struct page *page;
25ba77c1 477 int nid;
91612e0d
HD
478
479 if (!pte_present(*pte))
1da177e4 480 continue;
6aab341e
LT
481 page = vm_normal_page(vma, addr, *pte);
482 if (!page)
1da177e4 483 continue;
053837fc 484 /*
62b61f61
HD
485 * vm_normal_page() filters out zero pages, but there might
486 * still be PageReserved pages to skip, perhaps in a VDSO.
487 * And we cannot move PageKsm pages sensibly or safely yet.
053837fc 488 */
62b61f61 489 if (PageReserved(page) || PageKsm(page))
f4598c8b 490 continue;
6aab341e 491 nid = page_to_nid(page);
38e35860
CL
492 if (node_isset(nid, *nodes) == !!(flags & MPOL_MF_INVERT))
493 continue;
494
1a75a6c8 495 if (flags & MPOL_MF_STATS)
397874df 496 gather_stats(page, private, pte_dirty(*pte));
053837fc 497 else if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
fc301289 498 migrate_page_add(page, private, flags);
38e35860
CL
499 else
500 break;
91612e0d 501 } while (pte++, addr += PAGE_SIZE, addr != end);
705e87c0 502 pte_unmap_unlock(orig_pte, ptl);
91612e0d
HD
503 return addr != end;
504}
505
b5810039 506static inline int check_pmd_range(struct vm_area_struct *vma, pud_t *pud,
dc9aa5b9
CL
507 unsigned long addr, unsigned long end,
508 const nodemask_t *nodes, unsigned long flags,
38e35860 509 void *private)
91612e0d
HD
510{
511 pmd_t *pmd;
512 unsigned long next;
513
514 pmd = pmd_offset(pud, addr);
515 do {
516 next = pmd_addr_end(addr, end);
517 if (pmd_none_or_clear_bad(pmd))
518 continue;
dc9aa5b9 519 if (check_pte_range(vma, pmd, addr, next, nodes,
38e35860 520 flags, private))
91612e0d
HD
521 return -EIO;
522 } while (pmd++, addr = next, addr != end);
523 return 0;
524}
525
b5810039 526static inline int check_pud_range(struct vm_area_struct *vma, pgd_t *pgd,
dc9aa5b9
CL
527 unsigned long addr, unsigned long end,
528 const nodemask_t *nodes, unsigned long flags,
38e35860 529 void *private)
91612e0d
HD
530{
531 pud_t *pud;
532 unsigned long next;
533
534 pud = pud_offset(pgd, addr);
535 do {
536 next = pud_addr_end(addr, end);
537 if (pud_none_or_clear_bad(pud))
538 continue;
dc9aa5b9 539 if (check_pmd_range(vma, pud, addr, next, nodes,
38e35860 540 flags, private))
91612e0d
HD
541 return -EIO;
542 } while (pud++, addr = next, addr != end);
543 return 0;
544}
545
b5810039 546static inline int check_pgd_range(struct vm_area_struct *vma,
dc9aa5b9
CL
547 unsigned long addr, unsigned long end,
548 const nodemask_t *nodes, unsigned long flags,
38e35860 549 void *private)
91612e0d
HD
550{
551 pgd_t *pgd;
552 unsigned long next;
553
b5810039 554 pgd = pgd_offset(vma->vm_mm, addr);
91612e0d
HD
555 do {
556 next = pgd_addr_end(addr, end);
557 if (pgd_none_or_clear_bad(pgd))
558 continue;
dc9aa5b9 559 if (check_pud_range(vma, pgd, addr, next, nodes,
38e35860 560 flags, private))
91612e0d
HD
561 return -EIO;
562 } while (pgd++, addr = next, addr != end);
563 return 0;
1da177e4
LT
564}
565
dc9aa5b9
CL
566/*
567 * Check if all pages in a range are on a set of nodes.
568 * If pagelist != NULL then isolate pages from the LRU and
569 * put them on the pagelist.
570 */
1da177e4
LT
571static struct vm_area_struct *
572check_range(struct mm_struct *mm, unsigned long start, unsigned long end,
38e35860 573 const nodemask_t *nodes, unsigned long flags, void *private)
1da177e4
LT
574{
575 int err;
576 struct vm_area_struct *first, *vma, *prev;
577
053837fc 578
1da177e4
LT
579 first = find_vma(mm, start);
580 if (!first)
581 return ERR_PTR(-EFAULT);
582 prev = NULL;
583 for (vma = first; vma && vma->vm_start < end; vma = vma->vm_next) {
dc9aa5b9
CL
584 if (!(flags & MPOL_MF_DISCONTIG_OK)) {
585 if (!vma->vm_next && vma->vm_end < end)
586 return ERR_PTR(-EFAULT);
587 if (prev && prev->vm_end < vma->vm_start)
588 return ERR_PTR(-EFAULT);
589 }
590 if (!is_vm_hugetlb_page(vma) &&
591 ((flags & MPOL_MF_STRICT) ||
592 ((flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) &&
593 vma_migratable(vma)))) {
5b952b3c 594 unsigned long endvma = vma->vm_end;
dc9aa5b9 595
5b952b3c
AK
596 if (endvma > end)
597 endvma = end;
598 if (vma->vm_start > start)
599 start = vma->vm_start;
dc9aa5b9 600 err = check_pgd_range(vma, start, endvma, nodes,
38e35860 601 flags, private);
1da177e4
LT
602 if (err) {
603 first = ERR_PTR(err);
604 break;
605 }
606 }
607 prev = vma;
608 }
609 return first;
610}
611
612/* Apply policy to a single VMA */
613static int policy_vma(struct vm_area_struct *vma, struct mempolicy *new)
614{
615 int err = 0;
616 struct mempolicy *old = vma->vm_policy;
617
140d5a49 618 pr_debug("vma %lx-%lx/%lx vm_ops %p vm_file %p set_policy %p\n",
1da177e4
LT
619 vma->vm_start, vma->vm_end, vma->vm_pgoff,
620 vma->vm_ops, vma->vm_file,
621 vma->vm_ops ? vma->vm_ops->set_policy : NULL);
622
623 if (vma->vm_ops && vma->vm_ops->set_policy)
624 err = vma->vm_ops->set_policy(vma, new);
625 if (!err) {
626 mpol_get(new);
627 vma->vm_policy = new;
f0be3d32 628 mpol_put(old);
1da177e4
LT
629 }
630 return err;
631}
632
633/* Step 2: apply policy to a range and do splits. */
9d8cebd4
KM
634static int mbind_range(struct mm_struct *mm, unsigned long start,
635 unsigned long end, struct mempolicy *new_pol)
1da177e4
LT
636{
637 struct vm_area_struct *next;
9d8cebd4
KM
638 struct vm_area_struct *prev;
639 struct vm_area_struct *vma;
640 int err = 0;
641 pgoff_t pgoff;
642 unsigned long vmstart;
643 unsigned long vmend;
1da177e4 644
9d8cebd4
KM
645 vma = find_vma_prev(mm, start, &prev);
646 if (!vma || vma->vm_start > start)
647 return -EFAULT;
648
649 for (; vma && vma->vm_start < end; prev = vma, vma = next) {
1da177e4 650 next = vma->vm_next;
9d8cebd4
KM
651 vmstart = max(start, vma->vm_start);
652 vmend = min(end, vma->vm_end);
653
654 pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
655 prev = vma_merge(mm, prev, vmstart, vmend, vma->vm_flags,
656 vma->anon_vma, vma->vm_file, pgoff, new_pol);
657 if (prev) {
658 vma = prev;
659 next = vma->vm_next;
660 continue;
661 }
662 if (vma->vm_start != vmstart) {
663 err = split_vma(vma->vm_mm, vma, vmstart, 1);
664 if (err)
665 goto out;
666 }
667 if (vma->vm_end != vmend) {
668 err = split_vma(vma->vm_mm, vma, vmend, 0);
669 if (err)
670 goto out;
671 }
672 err = policy_vma(vma, new_pol);
1da177e4 673 if (err)
9d8cebd4 674 goto out;
1da177e4 675 }
9d8cebd4
KM
676
677 out:
1da177e4
LT
678 return err;
679}
680
c61afb18
PJ
681/*
682 * Update task->flags PF_MEMPOLICY bit: set iff non-default
683 * mempolicy. Allows more rapid checking of this (combined perhaps
684 * with other PF_* flag bits) on memory allocation hot code paths.
685 *
686 * If called from outside this file, the task 'p' should -only- be
687 * a newly forked child not yet visible on the task list, because
688 * manipulating the task flags of a visible task is not safe.
689 *
690 * The above limitation is why this routine has the funny name
691 * mpol_fix_fork_child_flag().
692 *
693 * It is also safe to call this with a task pointer of current,
694 * which the static wrapper mpol_set_task_struct_flag() does,
695 * for use within this file.
696 */
697
698void mpol_fix_fork_child_flag(struct task_struct *p)
699{
700 if (p->mempolicy)
701 p->flags |= PF_MEMPOLICY;
702 else
703 p->flags &= ~PF_MEMPOLICY;
704}
705
706static void mpol_set_task_struct_flag(void)
707{
708 mpol_fix_fork_child_flag(current);
709}
710
1da177e4 711/* Set the process memory policy */
028fec41
DR
712static long do_set_mempolicy(unsigned short mode, unsigned short flags,
713 nodemask_t *nodes)
1da177e4 714{
58568d2a 715 struct mempolicy *new, *old;
f4e53d91 716 struct mm_struct *mm = current->mm;
4bfc4495 717 NODEMASK_SCRATCH(scratch);
58568d2a 718 int ret;
1da177e4 719
4bfc4495
KH
720 if (!scratch)
721 return -ENOMEM;
f4e53d91 722
4bfc4495
KH
723 new = mpol_new(mode, flags, nodes);
724 if (IS_ERR(new)) {
725 ret = PTR_ERR(new);
726 goto out;
727 }
f4e53d91
LS
728 /*
729 * prevent changing our mempolicy while show_numa_maps()
730 * is using it.
731 * Note: do_set_mempolicy() can be called at init time
732 * with no 'mm'.
733 */
734 if (mm)
735 down_write(&mm->mmap_sem);
58568d2a 736 task_lock(current);
4bfc4495 737 ret = mpol_set_nodemask(new, nodes, scratch);
58568d2a
MX
738 if (ret) {
739 task_unlock(current);
740 if (mm)
741 up_write(&mm->mmap_sem);
742 mpol_put(new);
4bfc4495 743 goto out;
58568d2a
MX
744 }
745 old = current->mempolicy;
1da177e4 746 current->mempolicy = new;
c61afb18 747 mpol_set_task_struct_flag();
45c4745a 748 if (new && new->mode == MPOL_INTERLEAVE &&
f5b087b5 749 nodes_weight(new->v.nodes))
dfcd3c0d 750 current->il_next = first_node(new->v.nodes);
58568d2a 751 task_unlock(current);
f4e53d91
LS
752 if (mm)
753 up_write(&mm->mmap_sem);
754
58568d2a 755 mpol_put(old);
4bfc4495
KH
756 ret = 0;
757out:
758 NODEMASK_SCRATCH_FREE(scratch);
759 return ret;
1da177e4
LT
760}
761
bea904d5
LS
762/*
763 * Return nodemask for policy for get_mempolicy() query
58568d2a
MX
764 *
765 * Called with task's alloc_lock held
bea904d5
LS
766 */
767static void get_policy_nodemask(struct mempolicy *p, nodemask_t *nodes)
1da177e4 768{
dfcd3c0d 769 nodes_clear(*nodes);
bea904d5
LS
770 if (p == &default_policy)
771 return;
772
45c4745a 773 switch (p->mode) {
19770b32
MG
774 case MPOL_BIND:
775 /* Fall through */
1da177e4 776 case MPOL_INTERLEAVE:
dfcd3c0d 777 *nodes = p->v.nodes;
1da177e4
LT
778 break;
779 case MPOL_PREFERRED:
fc36b8d3 780 if (!(p->flags & MPOL_F_LOCAL))
dfcd3c0d 781 node_set(p->v.preferred_node, *nodes);
53f2556b 782 /* else return empty node mask for local allocation */
1da177e4
LT
783 break;
784 default:
785 BUG();
786 }
787}
788
789static int lookup_node(struct mm_struct *mm, unsigned long addr)
790{
791 struct page *p;
792 int err;
793
794 err = get_user_pages(current, mm, addr & PAGE_MASK, 1, 0, 0, &p, NULL);
795 if (err >= 0) {
796 err = page_to_nid(p);
797 put_page(p);
798 }
799 return err;
800}
801
1da177e4 802/* Retrieve NUMA policy */
dbcb0f19
AB
803static long do_get_mempolicy(int *policy, nodemask_t *nmask,
804 unsigned long addr, unsigned long flags)
1da177e4 805{
8bccd85f 806 int err;
1da177e4
LT
807 struct mm_struct *mm = current->mm;
808 struct vm_area_struct *vma = NULL;
809 struct mempolicy *pol = current->mempolicy;
810
754af6f5
LS
811 if (flags &
812 ~(unsigned long)(MPOL_F_NODE|MPOL_F_ADDR|MPOL_F_MEMS_ALLOWED))
1da177e4 813 return -EINVAL;
754af6f5
LS
814
815 if (flags & MPOL_F_MEMS_ALLOWED) {
816 if (flags & (MPOL_F_NODE|MPOL_F_ADDR))
817 return -EINVAL;
818 *policy = 0; /* just so it's initialized */
58568d2a 819 task_lock(current);
754af6f5 820 *nmask = cpuset_current_mems_allowed;
58568d2a 821 task_unlock(current);
754af6f5
LS
822 return 0;
823 }
824
1da177e4 825 if (flags & MPOL_F_ADDR) {
bea904d5
LS
826 /*
827 * Do NOT fall back to task policy if the
828 * vma/shared policy at addr is NULL. We
829 * want to return MPOL_DEFAULT in this case.
830 */
1da177e4
LT
831 down_read(&mm->mmap_sem);
832 vma = find_vma_intersection(mm, addr, addr+1);
833 if (!vma) {
834 up_read(&mm->mmap_sem);
835 return -EFAULT;
836 }
837 if (vma->vm_ops && vma->vm_ops->get_policy)
838 pol = vma->vm_ops->get_policy(vma, addr);
839 else
840 pol = vma->vm_policy;
841 } else if (addr)
842 return -EINVAL;
843
844 if (!pol)
bea904d5 845 pol = &default_policy; /* indicates default behavior */
1da177e4
LT
846
847 if (flags & MPOL_F_NODE) {
848 if (flags & MPOL_F_ADDR) {
849 err = lookup_node(mm, addr);
850 if (err < 0)
851 goto out;
8bccd85f 852 *policy = err;
1da177e4 853 } else if (pol == current->mempolicy &&
45c4745a 854 pol->mode == MPOL_INTERLEAVE) {
8bccd85f 855 *policy = current->il_next;
1da177e4
LT
856 } else {
857 err = -EINVAL;
858 goto out;
859 }
bea904d5
LS
860 } else {
861 *policy = pol == &default_policy ? MPOL_DEFAULT :
862 pol->mode;
d79df630
DR
863 /*
864 * Internal mempolicy flags must be masked off before exposing
865 * the policy to userspace.
866 */
867 *policy |= (pol->flags & MPOL_MODE_FLAGS);
bea904d5 868 }
1da177e4
LT
869
870 if (vma) {
871 up_read(&current->mm->mmap_sem);
872 vma = NULL;
873 }
874
1da177e4 875 err = 0;
58568d2a 876 if (nmask) {
c6b6ef8b
LS
877 if (mpol_store_user_nodemask(pol)) {
878 *nmask = pol->w.user_nodemask;
879 } else {
880 task_lock(current);
881 get_policy_nodemask(pol, nmask);
882 task_unlock(current);
883 }
58568d2a 884 }
1da177e4
LT
885
886 out:
52cd3b07 887 mpol_cond_put(pol);
1da177e4
LT
888 if (vma)
889 up_read(&current->mm->mmap_sem);
890 return err;
891}
892
b20a3503 893#ifdef CONFIG_MIGRATION
6ce3c4c0
CL
894/*
895 * page migration
896 */
fc301289
CL
897static void migrate_page_add(struct page *page, struct list_head *pagelist,
898 unsigned long flags)
6ce3c4c0
CL
899{
900 /*
fc301289 901 * Avoid migrating a page that is shared with others.
6ce3c4c0 902 */
62695a84
NP
903 if ((flags & MPOL_MF_MOVE_ALL) || page_mapcount(page) == 1) {
904 if (!isolate_lru_page(page)) {
905 list_add_tail(&page->lru, pagelist);
6d9c285a
KM
906 inc_zone_page_state(page, NR_ISOLATED_ANON +
907 page_is_file_cache(page));
62695a84
NP
908 }
909 }
7e2ab150 910}
6ce3c4c0 911
742755a1 912static struct page *new_node_page(struct page *page, unsigned long node, int **x)
95a402c3 913{
6484eb3e 914 return alloc_pages_exact_node(node, GFP_HIGHUSER_MOVABLE, 0);
95a402c3
CL
915}
916
7e2ab150
CL
917/*
918 * Migrate pages from one node to a target node.
919 * Returns error or the number of pages not migrated.
920 */
dbcb0f19
AB
921static int migrate_to_node(struct mm_struct *mm, int source, int dest,
922 int flags)
7e2ab150
CL
923{
924 nodemask_t nmask;
925 LIST_HEAD(pagelist);
926 int err = 0;
927
928 nodes_clear(nmask);
929 node_set(source, nmask);
6ce3c4c0 930
6ec3a127 931 check_range(mm, mm->mmap->vm_start, mm->task_size, &nmask,
7e2ab150
CL
932 flags | MPOL_MF_DISCONTIG_OK, &pagelist);
933
aaa994b3 934 if (!list_empty(&pagelist))
62b61f61 935 err = migrate_pages(&pagelist, new_node_page, dest, 0);
95a402c3 936
7e2ab150 937 return err;
6ce3c4c0
CL
938}
939
39743889 940/*
7e2ab150
CL
941 * Move pages between the two nodesets so as to preserve the physical
942 * layout as much as possible.
39743889
CL
943 *
944 * Returns the number of page that could not be moved.
945 */
946int do_migrate_pages(struct mm_struct *mm,
947 const nodemask_t *from_nodes, const nodemask_t *to_nodes, int flags)
948{
7e2ab150 949 int busy = 0;
0aedadf9 950 int err;
7e2ab150 951 nodemask_t tmp;
39743889 952
0aedadf9
CL
953 err = migrate_prep();
954 if (err)
955 return err;
956
53f2556b 957 down_read(&mm->mmap_sem);
39743889 958
7b2259b3
CL
959 err = migrate_vmas(mm, from_nodes, to_nodes, flags);
960 if (err)
961 goto out;
962
da0aa138
KM
963 /*
964 * Find a 'source' bit set in 'tmp' whose corresponding 'dest'
965 * bit in 'to' is not also set in 'tmp'. Clear the found 'source'
966 * bit in 'tmp', and return that <source, dest> pair for migration.
967 * The pair of nodemasks 'to' and 'from' define the map.
968 *
969 * If no pair of bits is found that way, fallback to picking some
970 * pair of 'source' and 'dest' bits that are not the same. If the
971 * 'source' and 'dest' bits are the same, this represents a node
972 * that will be migrating to itself, so no pages need move.
973 *
974 * If no bits are left in 'tmp', or if all remaining bits left
975 * in 'tmp' correspond to the same bit in 'to', return false
976 * (nothing left to migrate).
977 *
978 * This lets us pick a pair of nodes to migrate between, such that
979 * if possible the dest node is not already occupied by some other
980 * source node, minimizing the risk of overloading the memory on a
981 * node that would happen if we migrated incoming memory to a node
982 * before migrating outgoing memory source that same node.
983 *
984 * A single scan of tmp is sufficient. As we go, we remember the
985 * most recent <s, d> pair that moved (s != d). If we find a pair
986 * that not only moved, but what's better, moved to an empty slot
987 * (d is not set in tmp), then we break out then, with that pair.
988 * Otherwise when we finish scannng from_tmp, we at least have the
989 * most recent <s, d> pair that moved. If we get all the way through
990 * the scan of tmp without finding any node that moved, much less
991 * moved to an empty node, then there is nothing left worth migrating.
992 */
d4984711 993
7e2ab150
CL
994 tmp = *from_nodes;
995 while (!nodes_empty(tmp)) {
996 int s,d;
997 int source = -1;
998 int dest = 0;
999
1000 for_each_node_mask(s, tmp) {
1001 d = node_remap(s, *from_nodes, *to_nodes);
1002 if (s == d)
1003 continue;
1004
1005 source = s; /* Node moved. Memorize */
1006 dest = d;
1007
1008 /* dest not in remaining from nodes? */
1009 if (!node_isset(dest, tmp))
1010 break;
1011 }
1012 if (source == -1)
1013 break;
1014
1015 node_clear(source, tmp);
1016 err = migrate_to_node(mm, source, dest, flags);
1017 if (err > 0)
1018 busy += err;
1019 if (err < 0)
1020 break;
39743889 1021 }
7b2259b3 1022out:
39743889 1023 up_read(&mm->mmap_sem);
7e2ab150
CL
1024 if (err < 0)
1025 return err;
1026 return busy;
b20a3503
CL
1027
1028}
1029
3ad33b24
LS
1030/*
1031 * Allocate a new page for page migration based on vma policy.
1032 * Start assuming that page is mapped by vma pointed to by @private.
1033 * Search forward from there, if not. N.B., this assumes that the
1034 * list of pages handed to migrate_pages()--which is how we get here--
1035 * is in virtual address order.
1036 */
742755a1 1037static struct page *new_vma_page(struct page *page, unsigned long private, int **x)
95a402c3
CL
1038{
1039 struct vm_area_struct *vma = (struct vm_area_struct *)private;
3ad33b24 1040 unsigned long uninitialized_var(address);
95a402c3 1041
3ad33b24
LS
1042 while (vma) {
1043 address = page_address_in_vma(page, vma);
1044 if (address != -EFAULT)
1045 break;
1046 vma = vma->vm_next;
1047 }
1048
1049 /*
1050 * if !vma, alloc_page_vma() will use task or system default policy
1051 */
1052 return alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
95a402c3 1053}
b20a3503
CL
1054#else
1055
1056static void migrate_page_add(struct page *page, struct list_head *pagelist,
1057 unsigned long flags)
1058{
39743889
CL
1059}
1060
b20a3503
CL
1061int do_migrate_pages(struct mm_struct *mm,
1062 const nodemask_t *from_nodes, const nodemask_t *to_nodes, int flags)
1063{
1064 return -ENOSYS;
1065}
95a402c3 1066
69939749 1067static struct page *new_vma_page(struct page *page, unsigned long private, int **x)
95a402c3
CL
1068{
1069 return NULL;
1070}
b20a3503
CL
1071#endif
1072
dbcb0f19 1073static long do_mbind(unsigned long start, unsigned long len,
028fec41
DR
1074 unsigned short mode, unsigned short mode_flags,
1075 nodemask_t *nmask, unsigned long flags)
6ce3c4c0
CL
1076{
1077 struct vm_area_struct *vma;
1078 struct mm_struct *mm = current->mm;
1079 struct mempolicy *new;
1080 unsigned long end;
1081 int err;
1082 LIST_HEAD(pagelist);
1083
a3b51e01
DR
1084 if (flags & ~(unsigned long)(MPOL_MF_STRICT |
1085 MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
6ce3c4c0 1086 return -EINVAL;
74c00241 1087 if ((flags & MPOL_MF_MOVE_ALL) && !capable(CAP_SYS_NICE))
6ce3c4c0
CL
1088 return -EPERM;
1089
1090 if (start & ~PAGE_MASK)
1091 return -EINVAL;
1092
1093 if (mode == MPOL_DEFAULT)
1094 flags &= ~MPOL_MF_STRICT;
1095
1096 len = (len + PAGE_SIZE - 1) & PAGE_MASK;
1097 end = start + len;
1098
1099 if (end < start)
1100 return -EINVAL;
1101 if (end == start)
1102 return 0;
1103
028fec41 1104 new = mpol_new(mode, mode_flags, nmask);
6ce3c4c0
CL
1105 if (IS_ERR(new))
1106 return PTR_ERR(new);
1107
1108 /*
1109 * If we are using the default policy then operation
1110 * on discontinuous address spaces is okay after all
1111 */
1112 if (!new)
1113 flags |= MPOL_MF_DISCONTIG_OK;
1114
028fec41
DR
1115 pr_debug("mbind %lx-%lx mode:%d flags:%d nodes:%lx\n",
1116 start, start + len, mode, mode_flags,
1117 nmask ? nodes_addr(*nmask)[0] : -1);
6ce3c4c0 1118
0aedadf9
CL
1119 if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) {
1120
1121 err = migrate_prep();
1122 if (err)
b05ca738 1123 goto mpol_out;
0aedadf9 1124 }
4bfc4495
KH
1125 {
1126 NODEMASK_SCRATCH(scratch);
1127 if (scratch) {
1128 down_write(&mm->mmap_sem);
1129 task_lock(current);
1130 err = mpol_set_nodemask(new, nmask, scratch);
1131 task_unlock(current);
1132 if (err)
1133 up_write(&mm->mmap_sem);
1134 } else
1135 err = -ENOMEM;
1136 NODEMASK_SCRATCH_FREE(scratch);
1137 }
b05ca738
KM
1138 if (err)
1139 goto mpol_out;
1140
6ce3c4c0
CL
1141 vma = check_range(mm, start, end, nmask,
1142 flags | MPOL_MF_INVERT, &pagelist);
1143
1144 err = PTR_ERR(vma);
1145 if (!IS_ERR(vma)) {
1146 int nr_failed = 0;
1147
9d8cebd4 1148 err = mbind_range(mm, start, end, new);
7e2ab150 1149
6ce3c4c0 1150 if (!list_empty(&pagelist))
95a402c3 1151 nr_failed = migrate_pages(&pagelist, new_vma_page,
62b61f61 1152 (unsigned long)vma, 0);
6ce3c4c0
CL
1153
1154 if (!err && nr_failed && (flags & MPOL_MF_STRICT))
1155 err = -EIO;
ab8a3e14
KM
1156 } else
1157 putback_lru_pages(&pagelist);
b20a3503 1158
6ce3c4c0 1159 up_write(&mm->mmap_sem);
b05ca738 1160 mpol_out:
f0be3d32 1161 mpol_put(new);
6ce3c4c0
CL
1162 return err;
1163}
1164
8bccd85f
CL
1165/*
1166 * User space interface with variable sized bitmaps for nodelists.
1167 */
1168
1169/* Copy a node mask from user space. */
39743889 1170static int get_nodes(nodemask_t *nodes, const unsigned long __user *nmask,
8bccd85f
CL
1171 unsigned long maxnode)
1172{
1173 unsigned long k;
1174 unsigned long nlongs;
1175 unsigned long endmask;
1176
1177 --maxnode;
1178 nodes_clear(*nodes);
1179 if (maxnode == 0 || !nmask)
1180 return 0;
a9c930ba 1181 if (maxnode > PAGE_SIZE*BITS_PER_BYTE)
636f13c1 1182 return -EINVAL;
8bccd85f
CL
1183
1184 nlongs = BITS_TO_LONGS(maxnode);
1185 if ((maxnode % BITS_PER_LONG) == 0)
1186 endmask = ~0UL;
1187 else
1188 endmask = (1UL << (maxnode % BITS_PER_LONG)) - 1;
1189
1190 /* When the user specified more nodes than supported just check
1191 if the non supported part is all zero. */
1192 if (nlongs > BITS_TO_LONGS(MAX_NUMNODES)) {
1193 if (nlongs > PAGE_SIZE/sizeof(long))
1194 return -EINVAL;
1195 for (k = BITS_TO_LONGS(MAX_NUMNODES); k < nlongs; k++) {
1196 unsigned long t;
1197 if (get_user(t, nmask + k))
1198 return -EFAULT;
1199 if (k == nlongs - 1) {
1200 if (t & endmask)
1201 return -EINVAL;
1202 } else if (t)
1203 return -EINVAL;
1204 }
1205 nlongs = BITS_TO_LONGS(MAX_NUMNODES);
1206 endmask = ~0UL;
1207 }
1208
1209 if (copy_from_user(nodes_addr(*nodes), nmask, nlongs*sizeof(unsigned long)))
1210 return -EFAULT;
1211 nodes_addr(*nodes)[nlongs-1] &= endmask;
1212 return 0;
1213}
1214
1215/* Copy a kernel node mask to user space */
1216static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode,
1217 nodemask_t *nodes)
1218{
1219 unsigned long copy = ALIGN(maxnode-1, 64) / 8;
1220 const int nbytes = BITS_TO_LONGS(MAX_NUMNODES) * sizeof(long);
1221
1222 if (copy > nbytes) {
1223 if (copy > PAGE_SIZE)
1224 return -EINVAL;
1225 if (clear_user((char __user *)mask + nbytes, copy - nbytes))
1226 return -EFAULT;
1227 copy = nbytes;
1228 }
1229 return copy_to_user(mask, nodes_addr(*nodes), copy) ? -EFAULT : 0;
1230}
1231
938bb9f5
HC
1232SYSCALL_DEFINE6(mbind, unsigned long, start, unsigned long, len,
1233 unsigned long, mode, unsigned long __user *, nmask,
1234 unsigned long, maxnode, unsigned, flags)
8bccd85f
CL
1235{
1236 nodemask_t nodes;
1237 int err;
028fec41 1238 unsigned short mode_flags;
8bccd85f 1239
028fec41
DR
1240 mode_flags = mode & MPOL_MODE_FLAGS;
1241 mode &= ~MPOL_MODE_FLAGS;
a3b51e01
DR
1242 if (mode >= MPOL_MAX)
1243 return -EINVAL;
4c50bc01
DR
1244 if ((mode_flags & MPOL_F_STATIC_NODES) &&
1245 (mode_flags & MPOL_F_RELATIVE_NODES))
1246 return -EINVAL;
8bccd85f
CL
1247 err = get_nodes(&nodes, nmask, maxnode);
1248 if (err)
1249 return err;
028fec41 1250 return do_mbind(start, len, mode, mode_flags, &nodes, flags);
8bccd85f
CL
1251}
1252
1253/* Set the process memory policy */
938bb9f5
HC
1254SYSCALL_DEFINE3(set_mempolicy, int, mode, unsigned long __user *, nmask,
1255 unsigned long, maxnode)
8bccd85f
CL
1256{
1257 int err;
1258 nodemask_t nodes;
028fec41 1259 unsigned short flags;
8bccd85f 1260
028fec41
DR
1261 flags = mode & MPOL_MODE_FLAGS;
1262 mode &= ~MPOL_MODE_FLAGS;
1263 if ((unsigned int)mode >= MPOL_MAX)
8bccd85f 1264 return -EINVAL;
4c50bc01
DR
1265 if ((flags & MPOL_F_STATIC_NODES) && (flags & MPOL_F_RELATIVE_NODES))
1266 return -EINVAL;
8bccd85f
CL
1267 err = get_nodes(&nodes, nmask, maxnode);
1268 if (err)
1269 return err;
028fec41 1270 return do_set_mempolicy(mode, flags, &nodes);
8bccd85f
CL
1271}
1272
938bb9f5
HC
1273SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode,
1274 const unsigned long __user *, old_nodes,
1275 const unsigned long __user *, new_nodes)
39743889 1276{
c69e8d9c 1277 const struct cred *cred = current_cred(), *tcred;
596d7cfa 1278 struct mm_struct *mm = NULL;
39743889 1279 struct task_struct *task;
39743889
CL
1280 nodemask_t task_nodes;
1281 int err;
596d7cfa
KM
1282 nodemask_t *old;
1283 nodemask_t *new;
1284 NODEMASK_SCRATCH(scratch);
1285
1286 if (!scratch)
1287 return -ENOMEM;
39743889 1288
596d7cfa
KM
1289 old = &scratch->mask1;
1290 new = &scratch->mask2;
1291
1292 err = get_nodes(old, old_nodes, maxnode);
39743889 1293 if (err)
596d7cfa 1294 goto out;
39743889 1295
596d7cfa 1296 err = get_nodes(new, new_nodes, maxnode);
39743889 1297 if (err)
596d7cfa 1298 goto out;
39743889
CL
1299
1300 /* Find the mm_struct */
1301 read_lock(&tasklist_lock);
228ebcbe 1302 task = pid ? find_task_by_vpid(pid) : current;
39743889
CL
1303 if (!task) {
1304 read_unlock(&tasklist_lock);
596d7cfa
KM
1305 err = -ESRCH;
1306 goto out;
39743889
CL
1307 }
1308 mm = get_task_mm(task);
1309 read_unlock(&tasklist_lock);
1310
596d7cfa 1311 err = -EINVAL;
39743889 1312 if (!mm)
596d7cfa 1313 goto out;
39743889
CL
1314
1315 /*
1316 * Check if this process has the right to modify the specified
1317 * process. The right exists if the process has administrative
7f927fcc 1318 * capabilities, superuser privileges or the same
39743889
CL
1319 * userid as the target process.
1320 */
c69e8d9c
DH
1321 rcu_read_lock();
1322 tcred = __task_cred(task);
b6dff3ec
DH
1323 if (cred->euid != tcred->suid && cred->euid != tcred->uid &&
1324 cred->uid != tcred->suid && cred->uid != tcred->uid &&
74c00241 1325 !capable(CAP_SYS_NICE)) {
c69e8d9c 1326 rcu_read_unlock();
39743889
CL
1327 err = -EPERM;
1328 goto out;
1329 }
c69e8d9c 1330 rcu_read_unlock();
39743889
CL
1331
1332 task_nodes = cpuset_mems_allowed(task);
1333 /* Is the user allowed to access the target nodes? */
596d7cfa 1334 if (!nodes_subset(*new, task_nodes) && !capable(CAP_SYS_NICE)) {
39743889
CL
1335 err = -EPERM;
1336 goto out;
1337 }
1338
596d7cfa 1339 if (!nodes_subset(*new, node_states[N_HIGH_MEMORY])) {
3b42d28b
CL
1340 err = -EINVAL;
1341 goto out;
1342 }
1343
86c3a764
DQ
1344 err = security_task_movememory(task);
1345 if (err)
1346 goto out;
1347
596d7cfa 1348 err = do_migrate_pages(mm, old, new,
74c00241 1349 capable(CAP_SYS_NICE) ? MPOL_MF_MOVE_ALL : MPOL_MF_MOVE);
39743889 1350out:
596d7cfa
KM
1351 if (mm)
1352 mmput(mm);
1353 NODEMASK_SCRATCH_FREE(scratch);
1354
39743889
CL
1355 return err;
1356}
1357
1358
8bccd85f 1359/* Retrieve NUMA policy */
938bb9f5
HC
1360SYSCALL_DEFINE5(get_mempolicy, int __user *, policy,
1361 unsigned long __user *, nmask, unsigned long, maxnode,
1362 unsigned long, addr, unsigned long, flags)
8bccd85f 1363{
dbcb0f19
AB
1364 int err;
1365 int uninitialized_var(pval);
8bccd85f
CL
1366 nodemask_t nodes;
1367
1368 if (nmask != NULL && maxnode < MAX_NUMNODES)
1369 return -EINVAL;
1370
1371 err = do_get_mempolicy(&pval, &nodes, addr, flags);
1372
1373 if (err)
1374 return err;
1375
1376 if (policy && put_user(pval, policy))
1377 return -EFAULT;
1378
1379 if (nmask)
1380 err = copy_nodes_to_user(nmask, maxnode, &nodes);
1381
1382 return err;
1383}
1384
1da177e4
LT
1385#ifdef CONFIG_COMPAT
1386
1387asmlinkage long compat_sys_get_mempolicy(int __user *policy,
1388 compat_ulong_t __user *nmask,
1389 compat_ulong_t maxnode,
1390 compat_ulong_t addr, compat_ulong_t flags)
1391{
1392 long err;
1393 unsigned long __user *nm = NULL;
1394 unsigned long nr_bits, alloc_size;
1395 DECLARE_BITMAP(bm, MAX_NUMNODES);
1396
1397 nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
1398 alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
1399
1400 if (nmask)
1401 nm = compat_alloc_user_space(alloc_size);
1402
1403 err = sys_get_mempolicy(policy, nm, nr_bits+1, addr, flags);
1404
1405 if (!err && nmask) {
1406 err = copy_from_user(bm, nm, alloc_size);
1407 /* ensure entire bitmap is zeroed */
1408 err |= clear_user(nmask, ALIGN(maxnode-1, 8) / 8);
1409 err |= compat_put_bitmap(nmask, bm, nr_bits);
1410 }
1411
1412 return err;
1413}
1414
1415asmlinkage long compat_sys_set_mempolicy(int mode, compat_ulong_t __user *nmask,
1416 compat_ulong_t maxnode)
1417{
1418 long err = 0;
1419 unsigned long __user *nm = NULL;
1420 unsigned long nr_bits, alloc_size;
1421 DECLARE_BITMAP(bm, MAX_NUMNODES);
1422
1423 nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
1424 alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
1425
1426 if (nmask) {
1427 err = compat_get_bitmap(bm, nmask, nr_bits);
1428 nm = compat_alloc_user_space(alloc_size);
1429 err |= copy_to_user(nm, bm, alloc_size);
1430 }
1431
1432 if (err)
1433 return -EFAULT;
1434
1435 return sys_set_mempolicy(mode, nm, nr_bits+1);
1436}
1437
1438asmlinkage long compat_sys_mbind(compat_ulong_t start, compat_ulong_t len,
1439 compat_ulong_t mode, compat_ulong_t __user *nmask,
1440 compat_ulong_t maxnode, compat_ulong_t flags)
1441{
1442 long err = 0;
1443 unsigned long __user *nm = NULL;
1444 unsigned long nr_bits, alloc_size;
dfcd3c0d 1445 nodemask_t bm;
1da177e4
LT
1446
1447 nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
1448 alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
1449
1450 if (nmask) {
dfcd3c0d 1451 err = compat_get_bitmap(nodes_addr(bm), nmask, nr_bits);
1da177e4 1452 nm = compat_alloc_user_space(alloc_size);
dfcd3c0d 1453 err |= copy_to_user(nm, nodes_addr(bm), alloc_size);
1da177e4
LT
1454 }
1455
1456 if (err)
1457 return -EFAULT;
1458
1459 return sys_mbind(start, len, mode, nm, nr_bits+1, flags);
1460}
1461
1462#endif
1463
480eccf9
LS
1464/*
1465 * get_vma_policy(@task, @vma, @addr)
1466 * @task - task for fallback if vma policy == default
1467 * @vma - virtual memory area whose policy is sought
1468 * @addr - address in @vma for shared policy lookup
1469 *
1470 * Returns effective policy for a VMA at specified address.
1471 * Falls back to @task or system default policy, as necessary.
52cd3b07
LS
1472 * Current or other task's task mempolicy and non-shared vma policies
1473 * are protected by the task's mmap_sem, which must be held for read by
1474 * the caller.
1475 * Shared policies [those marked as MPOL_F_SHARED] require an extra reference
1476 * count--added by the get_policy() vm_op, as appropriate--to protect against
1477 * freeing by another task. It is the caller's responsibility to free the
1478 * extra reference for shared policies.
480eccf9 1479 */
ae4d8c16 1480static struct mempolicy *get_vma_policy(struct task_struct *task,
48fce342 1481 struct vm_area_struct *vma, unsigned long addr)
1da177e4 1482{
6e21c8f1 1483 struct mempolicy *pol = task->mempolicy;
1da177e4
LT
1484
1485 if (vma) {
480eccf9 1486 if (vma->vm_ops && vma->vm_ops->get_policy) {
ae4d8c16
LS
1487 struct mempolicy *vpol = vma->vm_ops->get_policy(vma,
1488 addr);
1489 if (vpol)
1490 pol = vpol;
bea904d5 1491 } else if (vma->vm_policy)
1da177e4
LT
1492 pol = vma->vm_policy;
1493 }
1494 if (!pol)
1495 pol = &default_policy;
1496 return pol;
1497}
1498
52cd3b07
LS
1499/*
1500 * Return a nodemask representing a mempolicy for filtering nodes for
1501 * page allocation
1502 */
1503static nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy)
19770b32
MG
1504{
1505 /* Lower zones don't get a nodemask applied for MPOL_BIND */
45c4745a 1506 if (unlikely(policy->mode == MPOL_BIND) &&
19770b32
MG
1507 gfp_zone(gfp) >= policy_zone &&
1508 cpuset_nodemask_valid_mems_allowed(&policy->v.nodes))
1509 return &policy->v.nodes;
1510
1511 return NULL;
1512}
1513
52cd3b07
LS
1514/* Return a zonelist indicated by gfp for node representing a mempolicy */
1515static struct zonelist *policy_zonelist(gfp_t gfp, struct mempolicy *policy)
1da177e4 1516{
fc36b8d3 1517 int nd = numa_node_id();
1da177e4 1518
45c4745a 1519 switch (policy->mode) {
1da177e4 1520 case MPOL_PREFERRED:
fc36b8d3
LS
1521 if (!(policy->flags & MPOL_F_LOCAL))
1522 nd = policy->v.preferred_node;
1da177e4
LT
1523 break;
1524 case MPOL_BIND:
19770b32 1525 /*
52cd3b07
LS
1526 * Normally, MPOL_BIND allocations are node-local within the
1527 * allowed nodemask. However, if __GFP_THISNODE is set and the
6eb27e1f 1528 * current node isn't part of the mask, we use the zonelist for
52cd3b07 1529 * the first node in the mask instead.
19770b32 1530 */
19770b32
MG
1531 if (unlikely(gfp & __GFP_THISNODE) &&
1532 unlikely(!node_isset(nd, policy->v.nodes)))
1533 nd = first_node(policy->v.nodes);
1534 break;
1da177e4 1535 default:
1da177e4
LT
1536 BUG();
1537 }
0e88460d 1538 return node_zonelist(nd, gfp);
1da177e4
LT
1539}
1540
1541/* Do dynamic interleaving for a process */
1542static unsigned interleave_nodes(struct mempolicy *policy)
1543{
1544 unsigned nid, next;
1545 struct task_struct *me = current;
1546
1547 nid = me->il_next;
dfcd3c0d 1548 next = next_node(nid, policy->v.nodes);
1da177e4 1549 if (next >= MAX_NUMNODES)
dfcd3c0d 1550 next = first_node(policy->v.nodes);
f5b087b5
DR
1551 if (next < MAX_NUMNODES)
1552 me->il_next = next;
1da177e4
LT
1553 return nid;
1554}
1555
dc85da15
CL
1556/*
1557 * Depending on the memory policy provide a node from which to allocate the
1558 * next slab entry.
52cd3b07
LS
1559 * @policy must be protected by freeing by the caller. If @policy is
1560 * the current task's mempolicy, this protection is implicit, as only the
1561 * task can change it's policy. The system default policy requires no
1562 * such protection.
dc85da15
CL
1563 */
1564unsigned slab_node(struct mempolicy *policy)
1565{
fc36b8d3 1566 if (!policy || policy->flags & MPOL_F_LOCAL)
bea904d5
LS
1567 return numa_node_id();
1568
1569 switch (policy->mode) {
1570 case MPOL_PREFERRED:
fc36b8d3
LS
1571 /*
1572 * handled MPOL_F_LOCAL above
1573 */
1574 return policy->v.preferred_node;
765c4507 1575
dc85da15
CL
1576 case MPOL_INTERLEAVE:
1577 return interleave_nodes(policy);
1578
dd1a239f 1579 case MPOL_BIND: {
dc85da15
CL
1580 /*
1581 * Follow bind policy behavior and start allocation at the
1582 * first node.
1583 */
19770b32
MG
1584 struct zonelist *zonelist;
1585 struct zone *zone;
1586 enum zone_type highest_zoneidx = gfp_zone(GFP_KERNEL);
1587 zonelist = &NODE_DATA(numa_node_id())->node_zonelists[0];
1588 (void)first_zones_zonelist(zonelist, highest_zoneidx,
1589 &policy->v.nodes,
1590 &zone);
1591 return zone->node;
dd1a239f 1592 }
dc85da15 1593
dc85da15 1594 default:
bea904d5 1595 BUG();
dc85da15
CL
1596 }
1597}
1598
1da177e4
LT
1599/* Do static interleaving for a VMA with known offset. */
1600static unsigned offset_il_node(struct mempolicy *pol,
1601 struct vm_area_struct *vma, unsigned long off)
1602{
dfcd3c0d 1603 unsigned nnodes = nodes_weight(pol->v.nodes);
f5b087b5 1604 unsigned target;
1da177e4
LT
1605 int c;
1606 int nid = -1;
1607
f5b087b5
DR
1608 if (!nnodes)
1609 return numa_node_id();
1610 target = (unsigned int)off % nnodes;
1da177e4
LT
1611 c = 0;
1612 do {
dfcd3c0d 1613 nid = next_node(nid, pol->v.nodes);
1da177e4
LT
1614 c++;
1615 } while (c <= target);
1da177e4
LT
1616 return nid;
1617}
1618
5da7ca86
CL
1619/* Determine a node number for interleave */
1620static inline unsigned interleave_nid(struct mempolicy *pol,
1621 struct vm_area_struct *vma, unsigned long addr, int shift)
1622{
1623 if (vma) {
1624 unsigned long off;
1625
3b98b087
NA
1626 /*
1627 * for small pages, there is no difference between
1628 * shift and PAGE_SHIFT, so the bit-shift is safe.
1629 * for huge pages, since vm_pgoff is in units of small
1630 * pages, we need to shift off the always 0 bits to get
1631 * a useful offset.
1632 */
1633 BUG_ON(shift < PAGE_SHIFT);
1634 off = vma->vm_pgoff >> (shift - PAGE_SHIFT);
5da7ca86
CL
1635 off += (addr - vma->vm_start) >> shift;
1636 return offset_il_node(pol, vma, off);
1637 } else
1638 return interleave_nodes(pol);
1639}
1640
00ac59ad 1641#ifdef CONFIG_HUGETLBFS
480eccf9
LS
1642/*
1643 * huge_zonelist(@vma, @addr, @gfp_flags, @mpol)
1644 * @vma = virtual memory area whose policy is sought
1645 * @addr = address in @vma for shared policy lookup and interleave policy
1646 * @gfp_flags = for requested zone
19770b32
MG
1647 * @mpol = pointer to mempolicy pointer for reference counted mempolicy
1648 * @nodemask = pointer to nodemask pointer for MPOL_BIND nodemask
480eccf9 1649 *
52cd3b07
LS
1650 * Returns a zonelist suitable for a huge page allocation and a pointer
1651 * to the struct mempolicy for conditional unref after allocation.
1652 * If the effective policy is 'BIND, returns a pointer to the mempolicy's
1653 * @nodemask for filtering the zonelist.
c0ff7453
MX
1654 *
1655 * Must be protected by get_mems_allowed()
480eccf9 1656 */
396faf03 1657struct zonelist *huge_zonelist(struct vm_area_struct *vma, unsigned long addr,
19770b32
MG
1658 gfp_t gfp_flags, struct mempolicy **mpol,
1659 nodemask_t **nodemask)
5da7ca86 1660{
480eccf9 1661 struct zonelist *zl;
5da7ca86 1662
52cd3b07 1663 *mpol = get_vma_policy(current, vma, addr);
19770b32 1664 *nodemask = NULL; /* assume !MPOL_BIND */
5da7ca86 1665
52cd3b07
LS
1666 if (unlikely((*mpol)->mode == MPOL_INTERLEAVE)) {
1667 zl = node_zonelist(interleave_nid(*mpol, vma, addr,
a5516438 1668 huge_page_shift(hstate_vma(vma))), gfp_flags);
52cd3b07
LS
1669 } else {
1670 zl = policy_zonelist(gfp_flags, *mpol);
1671 if ((*mpol)->mode == MPOL_BIND)
1672 *nodemask = &(*mpol)->v.nodes;
480eccf9
LS
1673 }
1674 return zl;
5da7ca86 1675}
06808b08
LS
1676
1677/*
1678 * init_nodemask_of_mempolicy
1679 *
1680 * If the current task's mempolicy is "default" [NULL], return 'false'
1681 * to indicate default policy. Otherwise, extract the policy nodemask
1682 * for 'bind' or 'interleave' policy into the argument nodemask, or
1683 * initialize the argument nodemask to contain the single node for
1684 * 'preferred' or 'local' policy and return 'true' to indicate presence
1685 * of non-default mempolicy.
1686 *
1687 * We don't bother with reference counting the mempolicy [mpol_get/put]
1688 * because the current task is examining it's own mempolicy and a task's
1689 * mempolicy is only ever changed by the task itself.
1690 *
1691 * N.B., it is the caller's responsibility to free a returned nodemask.
1692 */
1693bool init_nodemask_of_mempolicy(nodemask_t *mask)
1694{
1695 struct mempolicy *mempolicy;
1696 int nid;
1697
1698 if (!(mask && current->mempolicy))
1699 return false;
1700
c0ff7453 1701 task_lock(current);
06808b08
LS
1702 mempolicy = current->mempolicy;
1703 switch (mempolicy->mode) {
1704 case MPOL_PREFERRED:
1705 if (mempolicy->flags & MPOL_F_LOCAL)
1706 nid = numa_node_id();
1707 else
1708 nid = mempolicy->v.preferred_node;
1709 init_nodemask_of_node(mask, nid);
1710 break;
1711
1712 case MPOL_BIND:
1713 /* Fall through */
1714 case MPOL_INTERLEAVE:
1715 *mask = mempolicy->v.nodes;
1716 break;
1717
1718 default:
1719 BUG();
1720 }
c0ff7453 1721 task_unlock(current);
06808b08
LS
1722
1723 return true;
1724}
00ac59ad 1725#endif
5da7ca86 1726
6f48d0eb
DR
1727/*
1728 * mempolicy_nodemask_intersects
1729 *
1730 * If tsk's mempolicy is "default" [NULL], return 'true' to indicate default
1731 * policy. Otherwise, check for intersection between mask and the policy
1732 * nodemask for 'bind' or 'interleave' policy. For 'perferred' or 'local'
1733 * policy, always return true since it may allocate elsewhere on fallback.
1734 *
1735 * Takes task_lock(tsk) to prevent freeing of its mempolicy.
1736 */
1737bool mempolicy_nodemask_intersects(struct task_struct *tsk,
1738 const nodemask_t *mask)
1739{
1740 struct mempolicy *mempolicy;
1741 bool ret = true;
1742
1743 if (!mask)
1744 return ret;
1745 task_lock(tsk);
1746 mempolicy = tsk->mempolicy;
1747 if (!mempolicy)
1748 goto out;
1749
1750 switch (mempolicy->mode) {
1751 case MPOL_PREFERRED:
1752 /*
1753 * MPOL_PREFERRED and MPOL_F_LOCAL are only preferred nodes to
1754 * allocate from, they may fallback to other nodes when oom.
1755 * Thus, it's possible for tsk to have allocated memory from
1756 * nodes in mask.
1757 */
1758 break;
1759 case MPOL_BIND:
1760 case MPOL_INTERLEAVE:
1761 ret = nodes_intersects(mempolicy->v.nodes, *mask);
1762 break;
1763 default:
1764 BUG();
1765 }
1766out:
1767 task_unlock(tsk);
1768 return ret;
1769}
1770
1da177e4
LT
1771/* Allocate a page in interleaved policy.
1772 Own path because it needs to do special accounting. */
662f3a0b
AK
1773static struct page *alloc_page_interleave(gfp_t gfp, unsigned order,
1774 unsigned nid)
1da177e4
LT
1775{
1776 struct zonelist *zl;
1777 struct page *page;
1778
0e88460d 1779 zl = node_zonelist(nid, gfp);
1da177e4 1780 page = __alloc_pages(gfp, order, zl);
dd1a239f 1781 if (page && page_zone(page) == zonelist_zone(&zl->_zonerefs[0]))
ca889e6c 1782 inc_zone_page_state(page, NUMA_INTERLEAVE_HIT);
1da177e4
LT
1783 return page;
1784}
1785
1786/**
1787 * alloc_page_vma - Allocate a page for a VMA.
1788 *
1789 * @gfp:
1790 * %GFP_USER user allocation.
1791 * %GFP_KERNEL kernel allocations,
1792 * %GFP_HIGHMEM highmem/user allocations,
1793 * %GFP_FS allocation should not call back into a file system.
1794 * %GFP_ATOMIC don't sleep.
1795 *
1796 * @vma: Pointer to VMA or NULL if not available.
1797 * @addr: Virtual Address of the allocation. Must be inside the VMA.
1798 *
1799 * This function allocates a page from the kernel page pool and applies
1800 * a NUMA policy associated with the VMA or the current process.
1801 * When VMA is not NULL caller must hold down_read on the mmap_sem of the
1802 * mm_struct of the VMA to prevent it from going away. Should be used for
1803 * all allocations for pages that will be mapped into
1804 * user space. Returns NULL when no page can be allocated.
1805 *
1806 * Should be called with the mm_sem of the vma hold.
1807 */
1808struct page *
dd0fc66f 1809alloc_page_vma(gfp_t gfp, struct vm_area_struct *vma, unsigned long addr)
1da177e4 1810{
6e21c8f1 1811 struct mempolicy *pol = get_vma_policy(current, vma, addr);
480eccf9 1812 struct zonelist *zl;
c0ff7453 1813 struct page *page;
1da177e4 1814
c0ff7453 1815 get_mems_allowed();
45c4745a 1816 if (unlikely(pol->mode == MPOL_INTERLEAVE)) {
1da177e4 1817 unsigned nid;
5da7ca86
CL
1818
1819 nid = interleave_nid(pol, vma, addr, PAGE_SHIFT);
52cd3b07 1820 mpol_cond_put(pol);
c0ff7453
MX
1821 page = alloc_page_interleave(gfp, 0, nid);
1822 put_mems_allowed();
1823 return page;
1da177e4 1824 }
52cd3b07
LS
1825 zl = policy_zonelist(gfp, pol);
1826 if (unlikely(mpol_needs_cond_ref(pol))) {
480eccf9 1827 /*
52cd3b07 1828 * slow path: ref counted shared policy
480eccf9 1829 */
19770b32 1830 struct page *page = __alloc_pages_nodemask(gfp, 0,
52cd3b07 1831 zl, policy_nodemask(gfp, pol));
f0be3d32 1832 __mpol_put(pol);
c0ff7453 1833 put_mems_allowed();
480eccf9
LS
1834 return page;
1835 }
1836 /*
1837 * fast path: default or task policy
1838 */
c0ff7453
MX
1839 page = __alloc_pages_nodemask(gfp, 0, zl, policy_nodemask(gfp, pol));
1840 put_mems_allowed();
1841 return page;
1da177e4
LT
1842}
1843
1844/**
1845 * alloc_pages_current - Allocate pages.
1846 *
1847 * @gfp:
1848 * %GFP_USER user allocation,
1849 * %GFP_KERNEL kernel allocation,
1850 * %GFP_HIGHMEM highmem allocation,
1851 * %GFP_FS don't call back into a file system.
1852 * %GFP_ATOMIC don't sleep.
1853 * @order: Power of two of allocation size in pages. 0 is a single page.
1854 *
1855 * Allocate a page from the kernel page pool. When not in
1856 * interrupt context and apply the current process NUMA policy.
1857 * Returns NULL when no page can be allocated.
1858 *
cf2a473c 1859 * Don't call cpuset_update_task_memory_state() unless
1da177e4
LT
1860 * 1) it's ok to take cpuset_sem (can WAIT), and
1861 * 2) allocating for current task (not interrupt).
1862 */
dd0fc66f 1863struct page *alloc_pages_current(gfp_t gfp, unsigned order)
1da177e4
LT
1864{
1865 struct mempolicy *pol = current->mempolicy;
c0ff7453 1866 struct page *page;
1da177e4 1867
9b819d20 1868 if (!pol || in_interrupt() || (gfp & __GFP_THISNODE))
1da177e4 1869 pol = &default_policy;
52cd3b07 1870
c0ff7453 1871 get_mems_allowed();
52cd3b07
LS
1872 /*
1873 * No reference counting needed for current->mempolicy
1874 * nor system default_policy
1875 */
45c4745a 1876 if (pol->mode == MPOL_INTERLEAVE)
c0ff7453
MX
1877 page = alloc_page_interleave(gfp, order, interleave_nodes(pol));
1878 else
1879 page = __alloc_pages_nodemask(gfp, order,
52cd3b07 1880 policy_zonelist(gfp, pol), policy_nodemask(gfp, pol));
c0ff7453
MX
1881 put_mems_allowed();
1882 return page;
1da177e4
LT
1883}
1884EXPORT_SYMBOL(alloc_pages_current);
1885
4225399a 1886/*
846a16bf 1887 * If mpol_dup() sees current->cpuset == cpuset_being_rebound, then it
4225399a
PJ
1888 * rebinds the mempolicy its copying by calling mpol_rebind_policy()
1889 * with the mems_allowed returned by cpuset_mems_allowed(). This
1890 * keeps mempolicies cpuset relative after its cpuset moves. See
1891 * further kernel/cpuset.c update_nodemask().
708c1bbc
MX
1892 *
1893 * current's mempolicy may be rebinded by the other task(the task that changes
1894 * cpuset's mems), so we needn't do rebind work for current task.
4225399a 1895 */
4225399a 1896
846a16bf
LS
1897/* Slow path of a mempolicy duplicate */
1898struct mempolicy *__mpol_dup(struct mempolicy *old)
1da177e4
LT
1899{
1900 struct mempolicy *new = kmem_cache_alloc(policy_cache, GFP_KERNEL);
1901
1902 if (!new)
1903 return ERR_PTR(-ENOMEM);
708c1bbc
MX
1904
1905 /* task's mempolicy is protected by alloc_lock */
1906 if (old == current->mempolicy) {
1907 task_lock(current);
1908 *new = *old;
1909 task_unlock(current);
1910 } else
1911 *new = *old;
1912
99ee4ca7 1913 rcu_read_lock();
4225399a
PJ
1914 if (current_cpuset_is_being_rebound()) {
1915 nodemask_t mems = cpuset_mems_allowed(current);
708c1bbc
MX
1916 if (new->flags & MPOL_F_REBINDING)
1917 mpol_rebind_policy(new, &mems, MPOL_REBIND_STEP2);
1918 else
1919 mpol_rebind_policy(new, &mems, MPOL_REBIND_ONCE);
4225399a 1920 }
99ee4ca7 1921 rcu_read_unlock();
1da177e4 1922 atomic_set(&new->refcnt, 1);
1da177e4
LT
1923 return new;
1924}
1925
52cd3b07
LS
1926/*
1927 * If *frompol needs [has] an extra ref, copy *frompol to *tompol ,
1928 * eliminate the * MPOL_F_* flags that require conditional ref and
1929 * [NOTE!!!] drop the extra ref. Not safe to reference *frompol directly
1930 * after return. Use the returned value.
1931 *
1932 * Allows use of a mempolicy for, e.g., multiple allocations with a single
1933 * policy lookup, even if the policy needs/has extra ref on lookup.
1934 * shmem_readahead needs this.
1935 */
1936struct mempolicy *__mpol_cond_copy(struct mempolicy *tompol,
1937 struct mempolicy *frompol)
1938{
1939 if (!mpol_needs_cond_ref(frompol))
1940 return frompol;
1941
1942 *tompol = *frompol;
1943 tompol->flags &= ~MPOL_F_SHARED; /* copy doesn't need unref */
1944 __mpol_put(frompol);
1945 return tompol;
1946}
1947
1da177e4
LT
1948/* Slow path of a mempolicy comparison */
1949int __mpol_equal(struct mempolicy *a, struct mempolicy *b)
1950{
1951 if (!a || !b)
1952 return 0;
45c4745a 1953 if (a->mode != b->mode)
1da177e4 1954 return 0;
19800502 1955 if (a->flags != b->flags)
f5b087b5 1956 return 0;
19800502
BL
1957 if (mpol_store_user_nodemask(a))
1958 if (!nodes_equal(a->w.user_nodemask, b->w.user_nodemask))
1959 return 0;
1960
45c4745a 1961 switch (a->mode) {
19770b32
MG
1962 case MPOL_BIND:
1963 /* Fall through */
1da177e4 1964 case MPOL_INTERLEAVE:
dfcd3c0d 1965 return nodes_equal(a->v.nodes, b->v.nodes);
1da177e4 1966 case MPOL_PREFERRED:
fc36b8d3
LS
1967 return a->v.preferred_node == b->v.preferred_node &&
1968 a->flags == b->flags;
1da177e4
LT
1969 default:
1970 BUG();
1971 return 0;
1972 }
1973}
1974
1da177e4
LT
1975/*
1976 * Shared memory backing store policy support.
1977 *
1978 * Remember policies even when nobody has shared memory mapped.
1979 * The policies are kept in Red-Black tree linked from the inode.
1980 * They are protected by the sp->lock spinlock, which should be held
1981 * for any accesses to the tree.
1982 */
1983
1984/* lookup first element intersecting start-end */
1985/* Caller holds sp->lock */
1986static struct sp_node *
1987sp_lookup(struct shared_policy *sp, unsigned long start, unsigned long end)
1988{
1989 struct rb_node *n = sp->root.rb_node;
1990
1991 while (n) {
1992 struct sp_node *p = rb_entry(n, struct sp_node, nd);
1993
1994 if (start >= p->end)
1995 n = n->rb_right;
1996 else if (end <= p->start)
1997 n = n->rb_left;
1998 else
1999 break;
2000 }
2001 if (!n)
2002 return NULL;
2003 for (;;) {
2004 struct sp_node *w = NULL;
2005 struct rb_node *prev = rb_prev(n);
2006 if (!prev)
2007 break;
2008 w = rb_entry(prev, struct sp_node, nd);
2009 if (w->end <= start)
2010 break;
2011 n = prev;
2012 }
2013 return rb_entry(n, struct sp_node, nd);
2014}
2015
2016/* Insert a new shared policy into the list. */
2017/* Caller holds sp->lock */
2018static void sp_insert(struct shared_policy *sp, struct sp_node *new)
2019{
2020 struct rb_node **p = &sp->root.rb_node;
2021 struct rb_node *parent = NULL;
2022 struct sp_node *nd;
2023
2024 while (*p) {
2025 parent = *p;
2026 nd = rb_entry(parent, struct sp_node, nd);
2027 if (new->start < nd->start)
2028 p = &(*p)->rb_left;
2029 else if (new->end > nd->end)
2030 p = &(*p)->rb_right;
2031 else
2032 BUG();
2033 }
2034 rb_link_node(&new->nd, parent, p);
2035 rb_insert_color(&new->nd, &sp->root);
140d5a49 2036 pr_debug("inserting %lx-%lx: %d\n", new->start, new->end,
45c4745a 2037 new->policy ? new->policy->mode : 0);
1da177e4
LT
2038}
2039
2040/* Find shared policy intersecting idx */
2041struct mempolicy *
2042mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx)
2043{
2044 struct mempolicy *pol = NULL;
2045 struct sp_node *sn;
2046
2047 if (!sp->root.rb_node)
2048 return NULL;
2049 spin_lock(&sp->lock);
2050 sn = sp_lookup(sp, idx, idx+1);
2051 if (sn) {
2052 mpol_get(sn->policy);
2053 pol = sn->policy;
2054 }
2055 spin_unlock(&sp->lock);
2056 return pol;
2057}
2058
2059static void sp_delete(struct shared_policy *sp, struct sp_node *n)
2060{
140d5a49 2061 pr_debug("deleting %lx-l%lx\n", n->start, n->end);
1da177e4 2062 rb_erase(&n->nd, &sp->root);
f0be3d32 2063 mpol_put(n->policy);
1da177e4
LT
2064 kmem_cache_free(sn_cache, n);
2065}
2066
dbcb0f19
AB
2067static struct sp_node *sp_alloc(unsigned long start, unsigned long end,
2068 struct mempolicy *pol)
1da177e4
LT
2069{
2070 struct sp_node *n = kmem_cache_alloc(sn_cache, GFP_KERNEL);
2071
2072 if (!n)
2073 return NULL;
2074 n->start = start;
2075 n->end = end;
2076 mpol_get(pol);
aab0b102 2077 pol->flags |= MPOL_F_SHARED; /* for unref */
1da177e4
LT
2078 n->policy = pol;
2079 return n;
2080}
2081
2082/* Replace a policy range. */
2083static int shared_policy_replace(struct shared_policy *sp, unsigned long start,
2084 unsigned long end, struct sp_node *new)
2085{
2086 struct sp_node *n, *new2 = NULL;
2087
2088restart:
2089 spin_lock(&sp->lock);
2090 n = sp_lookup(sp, start, end);
2091 /* Take care of old policies in the same range. */
2092 while (n && n->start < end) {
2093 struct rb_node *next = rb_next(&n->nd);
2094 if (n->start >= start) {
2095 if (n->end <= end)
2096 sp_delete(sp, n);
2097 else
2098 n->start = end;
2099 } else {
2100 /* Old policy spanning whole new range. */
2101 if (n->end > end) {
2102 if (!new2) {
2103 spin_unlock(&sp->lock);
2104 new2 = sp_alloc(end, n->end, n->policy);
2105 if (!new2)
2106 return -ENOMEM;
2107 goto restart;
2108 }
2109 n->end = start;
2110 sp_insert(sp, new2);
2111 new2 = NULL;
2112 break;
2113 } else
2114 n->end = start;
2115 }
2116 if (!next)
2117 break;
2118 n = rb_entry(next, struct sp_node, nd);
2119 }
2120 if (new)
2121 sp_insert(sp, new);
2122 spin_unlock(&sp->lock);
2123 if (new2) {
f0be3d32 2124 mpol_put(new2->policy);
1da177e4
LT
2125 kmem_cache_free(sn_cache, new2);
2126 }
2127 return 0;
2128}
2129
71fe804b
LS
2130/**
2131 * mpol_shared_policy_init - initialize shared policy for inode
2132 * @sp: pointer to inode shared policy
2133 * @mpol: struct mempolicy to install
2134 *
2135 * Install non-NULL @mpol in inode's shared policy rb-tree.
2136 * On entry, the current task has a reference on a non-NULL @mpol.
2137 * This must be released on exit.
4bfc4495 2138 * This is called at get_inode() calls and we can use GFP_KERNEL.
71fe804b
LS
2139 */
2140void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol)
2141{
58568d2a
MX
2142 int ret;
2143
71fe804b
LS
2144 sp->root = RB_ROOT; /* empty tree == default mempolicy */
2145 spin_lock_init(&sp->lock);
2146
2147 if (mpol) {
2148 struct vm_area_struct pvma;
2149 struct mempolicy *new;
4bfc4495 2150 NODEMASK_SCRATCH(scratch);
71fe804b 2151
4bfc4495 2152 if (!scratch)
5c0c1654 2153 goto put_mpol;
71fe804b
LS
2154 /* contextualize the tmpfs mount point mempolicy */
2155 new = mpol_new(mpol->mode, mpol->flags, &mpol->w.user_nodemask);
15d77835 2156 if (IS_ERR(new))
0cae3457 2157 goto free_scratch; /* no valid nodemask intersection */
58568d2a
MX
2158
2159 task_lock(current);
4bfc4495 2160 ret = mpol_set_nodemask(new, &mpol->w.user_nodemask, scratch);
58568d2a 2161 task_unlock(current);
15d77835 2162 if (ret)
5c0c1654 2163 goto put_new;
71fe804b
LS
2164
2165 /* Create pseudo-vma that contains just the policy */
2166 memset(&pvma, 0, sizeof(struct vm_area_struct));
2167 pvma.vm_end = TASK_SIZE; /* policy covers entire file */
2168 mpol_set_shared_policy(sp, &pvma, new); /* adds ref */
15d77835 2169
5c0c1654 2170put_new:
71fe804b 2171 mpol_put(new); /* drop initial ref */
0cae3457 2172free_scratch:
4bfc4495 2173 NODEMASK_SCRATCH_FREE(scratch);
5c0c1654
LS
2174put_mpol:
2175 mpol_put(mpol); /* drop our incoming ref on sb mpol */
7339ff83
RH
2176 }
2177}
2178
1da177e4
LT
2179int mpol_set_shared_policy(struct shared_policy *info,
2180 struct vm_area_struct *vma, struct mempolicy *npol)
2181{
2182 int err;
2183 struct sp_node *new = NULL;
2184 unsigned long sz = vma_pages(vma);
2185
028fec41 2186 pr_debug("set_shared_policy %lx sz %lu %d %d %lx\n",
1da177e4 2187 vma->vm_pgoff,
45c4745a 2188 sz, npol ? npol->mode : -1,
028fec41 2189 npol ? npol->flags : -1,
140d5a49 2190 npol ? nodes_addr(npol->v.nodes)[0] : -1);
1da177e4
LT
2191
2192 if (npol) {
2193 new = sp_alloc(vma->vm_pgoff, vma->vm_pgoff + sz, npol);
2194 if (!new)
2195 return -ENOMEM;
2196 }
2197 err = shared_policy_replace(info, vma->vm_pgoff, vma->vm_pgoff+sz, new);
2198 if (err && new)
2199 kmem_cache_free(sn_cache, new);
2200 return err;
2201}
2202
2203/* Free a backing policy store on inode delete. */
2204void mpol_free_shared_policy(struct shared_policy *p)
2205{
2206 struct sp_node *n;
2207 struct rb_node *next;
2208
2209 if (!p->root.rb_node)
2210 return;
2211 spin_lock(&p->lock);
2212 next = rb_first(&p->root);
2213 while (next) {
2214 n = rb_entry(next, struct sp_node, nd);
2215 next = rb_next(&n->nd);
90c5029e 2216 rb_erase(&n->nd, &p->root);
f0be3d32 2217 mpol_put(n->policy);
1da177e4
LT
2218 kmem_cache_free(sn_cache, n);
2219 }
2220 spin_unlock(&p->lock);
1da177e4
LT
2221}
2222
2223/* assumes fs == KERNEL_DS */
2224void __init numa_policy_init(void)
2225{
b71636e2
PM
2226 nodemask_t interleave_nodes;
2227 unsigned long largest = 0;
2228 int nid, prefer = 0;
2229
1da177e4
LT
2230 policy_cache = kmem_cache_create("numa_policy",
2231 sizeof(struct mempolicy),
20c2df83 2232 0, SLAB_PANIC, NULL);
1da177e4
LT
2233
2234 sn_cache = kmem_cache_create("shared_policy_node",
2235 sizeof(struct sp_node),
20c2df83 2236 0, SLAB_PANIC, NULL);
1da177e4 2237
b71636e2
PM
2238 /*
2239 * Set interleaving policy for system init. Interleaving is only
2240 * enabled across suitably sized nodes (default is >= 16MB), or
2241 * fall back to the largest node if they're all smaller.
2242 */
2243 nodes_clear(interleave_nodes);
56bbd65d 2244 for_each_node_state(nid, N_HIGH_MEMORY) {
b71636e2
PM
2245 unsigned long total_pages = node_present_pages(nid);
2246
2247 /* Preserve the largest node */
2248 if (largest < total_pages) {
2249 largest = total_pages;
2250 prefer = nid;
2251 }
2252
2253 /* Interleave this node? */
2254 if ((total_pages << PAGE_SHIFT) >= (16 << 20))
2255 node_set(nid, interleave_nodes);
2256 }
2257
2258 /* All too small, use the largest */
2259 if (unlikely(nodes_empty(interleave_nodes)))
2260 node_set(prefer, interleave_nodes);
1da177e4 2261
028fec41 2262 if (do_set_mempolicy(MPOL_INTERLEAVE, 0, &interleave_nodes))
1da177e4
LT
2263 printk("numa_policy_init: interleaving failed\n");
2264}
2265
8bccd85f 2266/* Reset policy of current process to default */
1da177e4
LT
2267void numa_default_policy(void)
2268{
028fec41 2269 do_set_mempolicy(MPOL_DEFAULT, 0, NULL);
1da177e4 2270}
68860ec1 2271
095f1fc4
LS
2272/*
2273 * Parse and format mempolicy from/to strings
2274 */
2275
1a75a6c8 2276/*
fc36b8d3 2277 * "local" is pseudo-policy: MPOL_PREFERRED with MPOL_F_LOCAL flag
3f226aa1 2278 * Used only for mpol_parse_str() and mpol_to_str()
1a75a6c8 2279 */
345ace9c
LS
2280#define MPOL_LOCAL MPOL_MAX
2281static const char * const policy_modes[] =
2282{
2283 [MPOL_DEFAULT] = "default",
2284 [MPOL_PREFERRED] = "prefer",
2285 [MPOL_BIND] = "bind",
2286 [MPOL_INTERLEAVE] = "interleave",
2287 [MPOL_LOCAL] = "local"
2288};
1a75a6c8 2289
095f1fc4
LS
2290
2291#ifdef CONFIG_TMPFS
2292/**
2293 * mpol_parse_str - parse string to mempolicy
2294 * @str: string containing mempolicy to parse
71fe804b
LS
2295 * @mpol: pointer to struct mempolicy pointer, returned on success.
2296 * @no_context: flag whether to "contextualize" the mempolicy
095f1fc4
LS
2297 *
2298 * Format of input:
2299 * <mode>[=<flags>][:<nodelist>]
2300 *
71fe804b
LS
2301 * if @no_context is true, save the input nodemask in w.user_nodemask in
2302 * the returned mempolicy. This will be used to "clone" the mempolicy in
2303 * a specific context [cpuset] at a later time. Used to parse tmpfs mpol
2304 * mount option. Note that if 'static' or 'relative' mode flags were
2305 * specified, the input nodemask will already have been saved. Saving
2306 * it again is redundant, but safe.
2307 *
2308 * On success, returns 0, else 1
095f1fc4 2309 */
71fe804b 2310int mpol_parse_str(char *str, struct mempolicy **mpol, int no_context)
095f1fc4 2311{
71fe804b 2312 struct mempolicy *new = NULL;
b4652e84 2313 unsigned short mode;
71fe804b
LS
2314 unsigned short uninitialized_var(mode_flags);
2315 nodemask_t nodes;
095f1fc4
LS
2316 char *nodelist = strchr(str, ':');
2317 char *flags = strchr(str, '=');
095f1fc4
LS
2318 int err = 1;
2319
2320 if (nodelist) {
2321 /* NUL-terminate mode or flags string */
2322 *nodelist++ = '\0';
71fe804b 2323 if (nodelist_parse(nodelist, nodes))
095f1fc4 2324 goto out;
71fe804b 2325 if (!nodes_subset(nodes, node_states[N_HIGH_MEMORY]))
095f1fc4 2326 goto out;
71fe804b
LS
2327 } else
2328 nodes_clear(nodes);
2329
095f1fc4
LS
2330 if (flags)
2331 *flags++ = '\0'; /* terminate mode string */
2332
b4652e84 2333 for (mode = 0; mode <= MPOL_LOCAL; mode++) {
345ace9c 2334 if (!strcmp(str, policy_modes[mode])) {
095f1fc4
LS
2335 break;
2336 }
2337 }
b4652e84 2338 if (mode > MPOL_LOCAL)
095f1fc4
LS
2339 goto out;
2340
71fe804b 2341 switch (mode) {
095f1fc4 2342 case MPOL_PREFERRED:
71fe804b
LS
2343 /*
2344 * Insist on a nodelist of one node only
2345 */
095f1fc4
LS
2346 if (nodelist) {
2347 char *rest = nodelist;
2348 while (isdigit(*rest))
2349 rest++;
926f2ae0
KM
2350 if (*rest)
2351 goto out;
095f1fc4
LS
2352 }
2353 break;
095f1fc4
LS
2354 case MPOL_INTERLEAVE:
2355 /*
2356 * Default to online nodes with memory if no nodelist
2357 */
2358 if (!nodelist)
71fe804b 2359 nodes = node_states[N_HIGH_MEMORY];
3f226aa1 2360 break;
71fe804b 2361 case MPOL_LOCAL:
3f226aa1 2362 /*
71fe804b 2363 * Don't allow a nodelist; mpol_new() checks flags
3f226aa1 2364 */
71fe804b 2365 if (nodelist)
3f226aa1 2366 goto out;
71fe804b 2367 mode = MPOL_PREFERRED;
3f226aa1 2368 break;
413b43de
RT
2369 case MPOL_DEFAULT:
2370 /*
2371 * Insist on a empty nodelist
2372 */
2373 if (!nodelist)
2374 err = 0;
2375 goto out;
d69b2e63
KM
2376 case MPOL_BIND:
2377 /*
2378 * Insist on a nodelist
2379 */
2380 if (!nodelist)
2381 goto out;
095f1fc4
LS
2382 }
2383
71fe804b 2384 mode_flags = 0;
095f1fc4
LS
2385 if (flags) {
2386 /*
2387 * Currently, we only support two mutually exclusive
2388 * mode flags.
2389 */
2390 if (!strcmp(flags, "static"))
71fe804b 2391 mode_flags |= MPOL_F_STATIC_NODES;
095f1fc4 2392 else if (!strcmp(flags, "relative"))
71fe804b 2393 mode_flags |= MPOL_F_RELATIVE_NODES;
095f1fc4 2394 else
926f2ae0 2395 goto out;
095f1fc4 2396 }
71fe804b
LS
2397
2398 new = mpol_new(mode, mode_flags, &nodes);
2399 if (IS_ERR(new))
926f2ae0
KM
2400 goto out;
2401
e17f74af
LS
2402 if (no_context) {
2403 /* save for contextualization */
2404 new->w.user_nodemask = nodes;
2405 } else {
58568d2a 2406 int ret;
4bfc4495
KH
2407 NODEMASK_SCRATCH(scratch);
2408 if (scratch) {
2409 task_lock(current);
2410 ret = mpol_set_nodemask(new, &nodes, scratch);
2411 task_unlock(current);
2412 } else
2413 ret = -ENOMEM;
2414 NODEMASK_SCRATCH_FREE(scratch);
2415 if (ret) {
4bfc4495 2416 mpol_put(new);
926f2ae0 2417 goto out;
58568d2a
MX
2418 }
2419 }
926f2ae0 2420 err = 0;
71fe804b 2421
095f1fc4
LS
2422out:
2423 /* Restore string for error message */
2424 if (nodelist)
2425 *--nodelist = ':';
2426 if (flags)
2427 *--flags = '=';
71fe804b
LS
2428 if (!err)
2429 *mpol = new;
095f1fc4
LS
2430 return err;
2431}
2432#endif /* CONFIG_TMPFS */
2433
71fe804b
LS
2434/**
2435 * mpol_to_str - format a mempolicy structure for printing
2436 * @buffer: to contain formatted mempolicy string
2437 * @maxlen: length of @buffer
2438 * @pol: pointer to mempolicy to be formatted
2439 * @no_context: "context free" mempolicy - use nodemask in w.user_nodemask
2440 *
1a75a6c8
CL
2441 * Convert a mempolicy into a string.
2442 * Returns the number of characters in buffer (if positive)
2443 * or an error (negative)
2444 */
71fe804b 2445int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol, int no_context)
1a75a6c8
CL
2446{
2447 char *p = buffer;
2448 int l;
2449 nodemask_t nodes;
bea904d5 2450 unsigned short mode;
f5b087b5 2451 unsigned short flags = pol ? pol->flags : 0;
1a75a6c8 2452
2291990a
LS
2453 /*
2454 * Sanity check: room for longest mode, flag and some nodes
2455 */
2456 VM_BUG_ON(maxlen < strlen("interleave") + strlen("relative") + 16);
2457
bea904d5
LS
2458 if (!pol || pol == &default_policy)
2459 mode = MPOL_DEFAULT;
2460 else
2461 mode = pol->mode;
2462
1a75a6c8
CL
2463 switch (mode) {
2464 case MPOL_DEFAULT:
2465 nodes_clear(nodes);
2466 break;
2467
2468 case MPOL_PREFERRED:
2469 nodes_clear(nodes);
fc36b8d3 2470 if (flags & MPOL_F_LOCAL)
53f2556b
LS
2471 mode = MPOL_LOCAL; /* pseudo-policy */
2472 else
fc36b8d3 2473 node_set(pol->v.preferred_node, nodes);
1a75a6c8
CL
2474 break;
2475
2476 case MPOL_BIND:
19770b32 2477 /* Fall through */
1a75a6c8 2478 case MPOL_INTERLEAVE:
71fe804b
LS
2479 if (no_context)
2480 nodes = pol->w.user_nodemask;
2481 else
2482 nodes = pol->v.nodes;
1a75a6c8
CL
2483 break;
2484
2485 default:
2486 BUG();
1a75a6c8
CL
2487 }
2488
345ace9c 2489 l = strlen(policy_modes[mode]);
53f2556b
LS
2490 if (buffer + maxlen < p + l + 1)
2491 return -ENOSPC;
1a75a6c8 2492
345ace9c 2493 strcpy(p, policy_modes[mode]);
1a75a6c8
CL
2494 p += l;
2495
fc36b8d3 2496 if (flags & MPOL_MODE_FLAGS) {
f5b087b5
DR
2497 if (buffer + maxlen < p + 2)
2498 return -ENOSPC;
2499 *p++ = '=';
2500
2291990a
LS
2501 /*
2502 * Currently, the only defined flags are mutually exclusive
2503 */
f5b087b5 2504 if (flags & MPOL_F_STATIC_NODES)
2291990a
LS
2505 p += snprintf(p, buffer + maxlen - p, "static");
2506 else if (flags & MPOL_F_RELATIVE_NODES)
2507 p += snprintf(p, buffer + maxlen - p, "relative");
f5b087b5
DR
2508 }
2509
1a75a6c8
CL
2510 if (!nodes_empty(nodes)) {
2511 if (buffer + maxlen < p + 2)
2512 return -ENOSPC;
095f1fc4 2513 *p++ = ':';
1a75a6c8
CL
2514 p += nodelist_scnprintf(p, buffer + maxlen - p, nodes);
2515 }
2516 return p - buffer;
2517}
2518
2519struct numa_maps {
2520 unsigned long pages;
2521 unsigned long anon;
397874df
CL
2522 unsigned long active;
2523 unsigned long writeback;
1a75a6c8 2524 unsigned long mapcount_max;
397874df
CL
2525 unsigned long dirty;
2526 unsigned long swapcache;
1a75a6c8
CL
2527 unsigned long node[MAX_NUMNODES];
2528};
2529
397874df 2530static void gather_stats(struct page *page, void *private, int pte_dirty)
1a75a6c8
CL
2531{
2532 struct numa_maps *md = private;
2533 int count = page_mapcount(page);
2534
397874df
CL
2535 md->pages++;
2536 if (pte_dirty || PageDirty(page))
2537 md->dirty++;
1a75a6c8 2538
397874df
CL
2539 if (PageSwapCache(page))
2540 md->swapcache++;
1a75a6c8 2541
894bc310 2542 if (PageActive(page) || PageUnevictable(page))
397874df
CL
2543 md->active++;
2544
2545 if (PageWriteback(page))
2546 md->writeback++;
1a75a6c8
CL
2547
2548 if (PageAnon(page))
2549 md->anon++;
2550
397874df
CL
2551 if (count > md->mapcount_max)
2552 md->mapcount_max = count;
2553
1a75a6c8 2554 md->node[page_to_nid(page)]++;
1a75a6c8
CL
2555}
2556
7f709ed0 2557#ifdef CONFIG_HUGETLB_PAGE
397874df
CL
2558static void check_huge_range(struct vm_area_struct *vma,
2559 unsigned long start, unsigned long end,
2560 struct numa_maps *md)
2561{
2562 unsigned long addr;
2563 struct page *page;
a5516438
AK
2564 struct hstate *h = hstate_vma(vma);
2565 unsigned long sz = huge_page_size(h);
397874df 2566
a5516438
AK
2567 for (addr = start; addr < end; addr += sz) {
2568 pte_t *ptep = huge_pte_offset(vma->vm_mm,
2569 addr & huge_page_mask(h));
397874df
CL
2570 pte_t pte;
2571
2572 if (!ptep)
2573 continue;
2574
2575 pte = *ptep;
2576 if (pte_none(pte))
2577 continue;
2578
2579 page = pte_page(pte);
2580 if (!page)
2581 continue;
2582
2583 gather_stats(page, md, pte_dirty(*ptep));
2584 }
2585}
7f709ed0
AM
2586#else
2587static inline void check_huge_range(struct vm_area_struct *vma,
2588 unsigned long start, unsigned long end,
2589 struct numa_maps *md)
2590{
2591}
2592#endif
397874df 2593
53f2556b
LS
2594/*
2595 * Display pages allocated per node and memory policy via /proc.
2596 */
1a75a6c8
CL
2597int show_numa_map(struct seq_file *m, void *v)
2598{
99f89551 2599 struct proc_maps_private *priv = m->private;
1a75a6c8
CL
2600 struct vm_area_struct *vma = v;
2601 struct numa_maps *md;
397874df
CL
2602 struct file *file = vma->vm_file;
2603 struct mm_struct *mm = vma->vm_mm;
480eccf9 2604 struct mempolicy *pol;
1a75a6c8
CL
2605 int n;
2606 char buffer[50];
2607
397874df 2608 if (!mm)
1a75a6c8
CL
2609 return 0;
2610
2611 md = kzalloc(sizeof(struct numa_maps), GFP_KERNEL);
2612 if (!md)
2613 return 0;
2614
480eccf9 2615 pol = get_vma_policy(priv->task, vma, vma->vm_start);
71fe804b 2616 mpol_to_str(buffer, sizeof(buffer), pol, 0);
52cd3b07 2617 mpol_cond_put(pol);
397874df
CL
2618
2619 seq_printf(m, "%08lx %s", vma->vm_start, buffer);
2620
2621 if (file) {
2622 seq_printf(m, " file=");
c32c2f63 2623 seq_path(m, &file->f_path, "\n\t= ");
397874df
CL
2624 } else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) {
2625 seq_printf(m, " heap");
2626 } else if (vma->vm_start <= mm->start_stack &&
2627 vma->vm_end >= mm->start_stack) {
2628 seq_printf(m, " stack");
2629 }
2630
2631 if (is_vm_hugetlb_page(vma)) {
2632 check_huge_range(vma, vma->vm_start, vma->vm_end, md);
2633 seq_printf(m, " huge");
2634 } else {
a57ebfdb 2635 check_pgd_range(vma, vma->vm_start, vma->vm_end,
56bbd65d 2636 &node_states[N_HIGH_MEMORY], MPOL_MF_STATS, md);
397874df
CL
2637 }
2638
2639 if (!md->pages)
2640 goto out;
1a75a6c8 2641
397874df
CL
2642 if (md->anon)
2643 seq_printf(m," anon=%lu",md->anon);
1a75a6c8 2644
397874df
CL
2645 if (md->dirty)
2646 seq_printf(m," dirty=%lu",md->dirty);
1a75a6c8 2647
397874df
CL
2648 if (md->pages != md->anon && md->pages != md->dirty)
2649 seq_printf(m, " mapped=%lu", md->pages);
1a75a6c8 2650
397874df
CL
2651 if (md->mapcount_max > 1)
2652 seq_printf(m, " mapmax=%lu", md->mapcount_max);
1a75a6c8 2653
397874df
CL
2654 if (md->swapcache)
2655 seq_printf(m," swapcache=%lu", md->swapcache);
2656
2657 if (md->active < md->pages && !is_vm_hugetlb_page(vma))
2658 seq_printf(m," active=%lu", md->active);
2659
2660 if (md->writeback)
2661 seq_printf(m," writeback=%lu", md->writeback);
2662
56bbd65d 2663 for_each_node_state(n, N_HIGH_MEMORY)
397874df
CL
2664 if (md->node[n])
2665 seq_printf(m, " N%d=%lu", n, md->node[n]);
2666out:
2667 seq_putc(m, '\n');
1a75a6c8
CL
2668 kfree(md);
2669
2670 if (m->count < m->size)
99f89551 2671 m->version = (vma != priv->tail_vma) ? vma->vm_start : 0;
1a75a6c8
CL
2672 return 0;
2673}