mempolicy.c 74.8 KB
Newer Older
L
Linus Torvalds 已提交
1 2 3 4
/*
 * Simple NUMA memory policy for the Linux kernel.
 *
 * Copyright 2003,2004 Andi Kleen, SuSE Labs.
5
 * (C) Copyright 2005 Christoph Lameter, Silicon Graphics, Inc.
L
Linus Torvalds 已提交
6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
 * Subject to the GNU Public License, version 2.
 *
 * NUMA policy allows the user to give hints in which node(s) memory should
 * be allocated.
 *
 * Support four policies per VMA and per process:
 *
 * The VMA policy has priority over the process policy for a page fault.
 *
 * interleave     Allocate memory interleaved over a set of nodes,
 *                with normal fallback if it fails.
 *                For VMA based allocations this interleaves based on the
 *                offset into the backing object or offset into the mapping
 *                for anonymous memory. For process policy an process counter
 *                is used.
21
 *
L
Linus Torvalds 已提交
22 23
 * bind           Only allocate memory on a specific set of nodes,
 *                no fallback.
24 25 26 27
 *                FIXME: memory is allocated starting with the first node
 *                to the last. It would be better if bind would truly restrict
 *                the allocation to memory nodes instead
 *
L
Linus Torvalds 已提交
28
 * preferred       Try a specific node first before normal fallback.
D
David Rientjes 已提交
29
 *                As a special case NUMA_NO_NODE here means do the allocation
L
Linus Torvalds 已提交
30 31 32
 *                on the local CPU. This is normally identical to default,
 *                but useful to set in a VMA when you have a non default
 *                process policy.
33
 *
L
Linus Torvalds 已提交
34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77
 * default        Allocate on the local node first, or when on a VMA
 *                use the process policy. This is what Linux always did
 *		  in a NUMA aware kernel and still does by, ahem, default.
 *
 * The process policy is applied for most non interrupt memory allocations
 * in that process' context. Interrupts ignore the policies and always
 * try to allocate on the local CPU. The VMA policy is only applied for memory
 * allocations for a VMA in the VM.
 *
 * Currently there are a few corner cases in swapping where the policy
 * is not applied, but the majority should be handled. When process policy
 * is used it is not remembered over swap outs/swap ins.
 *
 * Only the highest zone in the zone hierarchy gets policied. Allocations
 * requesting a lower zone just use default policy. This implies that
 * on systems with highmem kernel lowmem allocation don't get policied.
 * Same with GFP_DMA allocations.
 *
 * For shmfs/tmpfs/hugetlbfs shared memory the policy is shared between
 * all users and remembered even when nobody has memory mapped.
 */

/* Notebook:
   fix mmap readahead to honour policy and enable policy for any page cache
   object
   statistics for bigpages
   global policy for page cache? currently it uses process policy. Requires
   first item above.
   handle mremap for shared memory (currently ignored for the policy)
   grows down?
   make bind policy root only? It can trigger oom much faster and the
   kernel is not always grateful with that.
*/

#include <linux/mempolicy.h>
#include <linux/mm.h>
#include <linux/highmem.h>
#include <linux/hugetlb.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/nodemask.h>
#include <linux/cpuset.h>
#include <linux/slab.h>
#include <linux/string.h>
78
#include <linux/export.h>
79
#include <linux/nsproxy.h>
L
Linus Torvalds 已提交
80 81 82
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/compat.h>
83
#include <linux/swap.h>
84 85
#include <linux/seq_file.h>
#include <linux/proc_fs.h>
C
Christoph Lameter 已提交
86
#include <linux/migrate.h>
87
#include <linux/ksm.h>
88
#include <linux/rmap.h>
89
#include <linux/security.h>
A
Adrian Bunk 已提交
90
#include <linux/syscalls.h>
91
#include <linux/ctype.h>
92
#include <linux/mm_inline.h>
L
Lee Schermerhorn 已提交
93
#include <linux/mmu_notifier.h>
94

L
Linus Torvalds 已提交
95 96
#include <asm/tlbflush.h>
#include <asm/uaccess.h>
97
#include <linux/random.h>
L
Linus Torvalds 已提交
98

99 100
#include "internal.h"

101
/* Internal flags */
102
#define MPOL_MF_DISCONTIG_OK (MPOL_MF_INTERNAL << 0)	/* Skip checks for continuous vmas */
103
#define MPOL_MF_INVERT (MPOL_MF_INTERNAL << 1)		/* Invert check for nodemask */
104

105 106
static struct kmem_cache *policy_cache;
static struct kmem_cache *sn_cache;
L
Linus Torvalds 已提交
107 108 109

/* Highest zone. An specific allocation for a zone below that is not
   policied. */
110
enum zone_type policy_zone = 0;
L
Linus Torvalds 已提交
111

112 113 114
/*
 * run-time system-wide default policy => local allocation
 */
115
static struct mempolicy default_policy = {
L
Linus Torvalds 已提交
116
	.refcnt = ATOMIC_INIT(1), /* never free it */
117
	.mode = MPOL_PREFERRED,
118
	.flags = MPOL_F_LOCAL,
L
Linus Torvalds 已提交
119 120
};

M
Mel Gorman 已提交
121 122 123 124 125 126 127
static struct mempolicy preferred_node_policy[MAX_NUMNODES];

static struct mempolicy *get_task_policy(struct task_struct *p)
{
	struct mempolicy *pol = p->mempolicy;

	if (!pol) {
128
		int node = numa_node_id();
M
Mel Gorman 已提交
129

130 131 132 133 134 135 136 137 138
		if (node != NUMA_NO_NODE) {
			pol = &preferred_node_policy[node];
			/*
			 * preferred_node_policy is not initialised early in
			 * boot
			 */
			if (!pol->mode)
				pol = NULL;
		}
M
Mel Gorman 已提交
139 140 141 142 143
	}

	return pol;
}

144 145
static const struct mempolicy_operations {
	int (*create)(struct mempolicy *pol, const nodemask_t *nodes);
146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161
	/*
	 * If read-side task has no lock to protect task->mempolicy, write-side
	 * task will rebind the task->mempolicy by two step. The first step is
	 * setting all the newly nodes, and the second step is cleaning all the
	 * disallowed nodes. In this way, we can avoid finding no node to alloc
	 * page.
	 * If we have a lock to protect task->mempolicy in read-side, we do
	 * rebind directly.
	 *
	 * step:
	 * 	MPOL_REBIND_ONCE - do rebind work at once
	 * 	MPOL_REBIND_STEP1 - set all the newly nodes
	 * 	MPOL_REBIND_STEP2 - clean all the disallowed nodes
	 */
	void (*rebind)(struct mempolicy *pol, const nodemask_t *nodes,
			enum mpol_rebind_step step);
162 163
} mpol_ops[MPOL_MAX];

164
/* Check that the nodemask contains at least one populated zone */
165
static int is_valid_nodemask(const nodemask_t *nodemask)
L
Linus Torvalds 已提交
166
{
167
	return nodes_intersects(*nodemask, node_states[N_MEMORY]);
L
Linus Torvalds 已提交
168 169
}

170 171
static inline int mpol_store_user_nodemask(const struct mempolicy *pol)
{
B
Bob Liu 已提交
172
	return pol->flags & MPOL_MODE_FLAGS;
173 174 175 176 177 178 179 180
}

static void mpol_relative_nodemask(nodemask_t *ret, const nodemask_t *orig,
				   const nodemask_t *rel)
{
	nodemask_t tmp;
	nodes_fold(tmp, *orig, nodes_weight(*rel));
	nodes_onto(*ret, tmp, *rel);
181 182
}

183 184 185 186 187 188 189 190 191 192 193
static int mpol_new_interleave(struct mempolicy *pol, const nodemask_t *nodes)
{
	if (nodes_empty(*nodes))
		return -EINVAL;
	pol->v.nodes = *nodes;
	return 0;
}

static int mpol_new_preferred(struct mempolicy *pol, const nodemask_t *nodes)
{
	if (!nodes)
194
		pol->flags |= MPOL_F_LOCAL;	/* local allocation */
195 196 197 198 199 200 201 202 203 204 205 206 207 208 209
	else if (nodes_empty(*nodes))
		return -EINVAL;			/*  no allowed nodes */
	else
		pol->v.preferred_node = first_node(*nodes);
	return 0;
}

static int mpol_new_bind(struct mempolicy *pol, const nodemask_t *nodes)
{
	if (!is_valid_nodemask(nodes))
		return -EINVAL;
	pol->v.nodes = *nodes;
	return 0;
}

210 211 212 213 214 215 216 217 218
/*
 * mpol_set_nodemask is called after mpol_new() to set up the nodemask, if
 * any, for the new policy.  mpol_new() has already validated the nodes
 * parameter with respect to the policy mode and flags.  But, we need to
 * handle an empty nodemask with MPOL_PREFERRED here.
 *
 * Must be called holding task's alloc_lock to protect task's mems_allowed
 * and mempolicy.  May also be called holding the mmap_semaphore for write.
 */
219 220
static int mpol_set_nodemask(struct mempolicy *pol,
		     const nodemask_t *nodes, struct nodemask_scratch *nsc)
221 222 223 224 225 226
{
	int ret;

	/* if mode is MPOL_DEFAULT, pol is NULL. This is right. */
	if (pol == NULL)
		return 0;
227
	/* Check N_MEMORY */
228
	nodes_and(nsc->mask1,
229
		  cpuset_current_mems_allowed, node_states[N_MEMORY]);
230 231 232 233 234 235

	VM_BUG_ON(!nodes);
	if (pol->mode == MPOL_PREFERRED && nodes_empty(*nodes))
		nodes = NULL;	/* explicit local allocation */
	else {
		if (pol->flags & MPOL_F_RELATIVE_NODES)
236
			mpol_relative_nodemask(&nsc->mask2, nodes,&nsc->mask1);
237
		else
238 239
			nodes_and(nsc->mask2, *nodes, nsc->mask1);

240 241 242 243 244 245 246
		if (mpol_store_user_nodemask(pol))
			pol->w.user_nodemask = *nodes;
		else
			pol->w.cpuset_mems_allowed =
						cpuset_current_mems_allowed;
	}

247 248 249 250
	if (nodes)
		ret = mpol_ops[pol->mode].create(pol, &nsc->mask2);
	else
		ret = mpol_ops[pol->mode].create(pol, NULL);
251 252 253 254 255 256 257
	return ret;
}

/*
 * This function just creates a new policy, does some check and simple
 * initialization. You must invoke mpol_set_nodemask() to set nodes.
 */
258 259
static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags,
				  nodemask_t *nodes)
L
Linus Torvalds 已提交
260 261 262
{
	struct mempolicy *policy;

263
	pr_debug("setting mode %d flags %d nodes[0] %lx\n",
D
David Rientjes 已提交
264
		 mode, flags, nodes ? nodes_addr(*nodes)[0] : NUMA_NO_NODE);
265

266 267
	if (mode == MPOL_DEFAULT) {
		if (nodes && !nodes_empty(*nodes))
268
			return ERR_PTR(-EINVAL);
L
Lee Schermerhorn 已提交
269
		return NULL;
270
	}
271 272 273 274 275 276 277 278 279 280 281 282 283
	VM_BUG_ON(!nodes);

	/*
	 * MPOL_PREFERRED cannot be used with MPOL_F_STATIC_NODES or
	 * MPOL_F_RELATIVE_NODES if the nodemask is empty (local allocation).
	 * All other modes require a valid pointer to a non-empty nodemask.
	 */
	if (mode == MPOL_PREFERRED) {
		if (nodes_empty(*nodes)) {
			if (((flags & MPOL_F_STATIC_NODES) ||
			     (flags & MPOL_F_RELATIVE_NODES)))
				return ERR_PTR(-EINVAL);
		}
284 285 286 287
	} else if (mode == MPOL_LOCAL) {
		if (!nodes_empty(*nodes))
			return ERR_PTR(-EINVAL);
		mode = MPOL_PREFERRED;
288 289
	} else if (nodes_empty(*nodes))
		return ERR_PTR(-EINVAL);
L
Linus Torvalds 已提交
290 291 292 293
	policy = kmem_cache_alloc(policy_cache, GFP_KERNEL);
	if (!policy)
		return ERR_PTR(-ENOMEM);
	atomic_set(&policy->refcnt, 1);
294
	policy->mode = mode;
295
	policy->flags = flags;
296

L
Linus Torvalds 已提交
297
	return policy;
298 299
}

300 301 302 303 304 305 306 307
/* Slow path of a mpol destructor. */
void __mpol_put(struct mempolicy *p)
{
	if (!atomic_dec_and_test(&p->refcnt))
		return;
	kmem_cache_free(policy_cache, p);
}

308 309
static void mpol_rebind_default(struct mempolicy *pol, const nodemask_t *nodes,
				enum mpol_rebind_step step)
310 311 312
{
}

313 314 315 316 317 318 319 320
/*
 * step:
 * 	MPOL_REBIND_ONCE  - do rebind work at once
 * 	MPOL_REBIND_STEP1 - set all the newly nodes
 * 	MPOL_REBIND_STEP2 - clean all the disallowed nodes
 */
static void mpol_rebind_nodemask(struct mempolicy *pol, const nodemask_t *nodes,
				 enum mpol_rebind_step step)
321 322 323 324 325 326 327 328
{
	nodemask_t tmp;

	if (pol->flags & MPOL_F_STATIC_NODES)
		nodes_and(tmp, pol->w.user_nodemask, *nodes);
	else if (pol->flags & MPOL_F_RELATIVE_NODES)
		mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes);
	else {
329 330 331 332 333 334 335 336 337 338 339 340 341
		/*
		 * if step == 1, we use ->w.cpuset_mems_allowed to cache the
		 * result
		 */
		if (step == MPOL_REBIND_ONCE || step == MPOL_REBIND_STEP1) {
			nodes_remap(tmp, pol->v.nodes,
					pol->w.cpuset_mems_allowed, *nodes);
			pol->w.cpuset_mems_allowed = step ? tmp : *nodes;
		} else if (step == MPOL_REBIND_STEP2) {
			tmp = pol->w.cpuset_mems_allowed;
			pol->w.cpuset_mems_allowed = *nodes;
		} else
			BUG();
342
	}
343

344 345 346 347 348 349 350 351 352 353
	if (nodes_empty(tmp))
		tmp = *nodes;

	if (step == MPOL_REBIND_STEP1)
		nodes_or(pol->v.nodes, pol->v.nodes, tmp);
	else if (step == MPOL_REBIND_ONCE || step == MPOL_REBIND_STEP2)
		pol->v.nodes = tmp;
	else
		BUG();

354 355 356 357 358 359 360 361 362 363
	if (!node_isset(current->il_next, tmp)) {
		current->il_next = next_node(current->il_next, tmp);
		if (current->il_next >= MAX_NUMNODES)
			current->il_next = first_node(tmp);
		if (current->il_next >= MAX_NUMNODES)
			current->il_next = numa_node_id();
	}
}

static void mpol_rebind_preferred(struct mempolicy *pol,
364 365
				  const nodemask_t *nodes,
				  enum mpol_rebind_step step)
366 367 368 369 370 371
{
	nodemask_t tmp;

	if (pol->flags & MPOL_F_STATIC_NODES) {
		int node = first_node(pol->w.user_nodemask);

372
		if (node_isset(node, *nodes)) {
373
			pol->v.preferred_node = node;
374 375 376
			pol->flags &= ~MPOL_F_LOCAL;
		} else
			pol->flags |= MPOL_F_LOCAL;
377 378 379
	} else if (pol->flags & MPOL_F_RELATIVE_NODES) {
		mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes);
		pol->v.preferred_node = first_node(tmp);
380
	} else if (!(pol->flags & MPOL_F_LOCAL)) {
381 382 383 384 385
		pol->v.preferred_node = node_remap(pol->v.preferred_node,
						   pol->w.cpuset_mems_allowed,
						   *nodes);
		pol->w.cpuset_mems_allowed = *nodes;
	}
L
Linus Torvalds 已提交
386 387
}

388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405
/*
 * mpol_rebind_policy - Migrate a policy to a different set of nodes
 *
 * If read-side task has no lock to protect task->mempolicy, write-side
 * task will rebind the task->mempolicy by two step. The first step is
 * setting all the newly nodes, and the second step is cleaning all the
 * disallowed nodes. In this way, we can avoid finding no node to alloc
 * page.
 * If we have a lock to protect task->mempolicy in read-side, we do
 * rebind directly.
 *
 * step:
 * 	MPOL_REBIND_ONCE  - do rebind work at once
 * 	MPOL_REBIND_STEP1 - set all the newly nodes
 * 	MPOL_REBIND_STEP2 - clean all the disallowed nodes
 */
static void mpol_rebind_policy(struct mempolicy *pol, const nodemask_t *newmask,
				enum mpol_rebind_step step)
406 407 408
{
	if (!pol)
		return;
409
	if (!mpol_store_user_nodemask(pol) && step == MPOL_REBIND_ONCE &&
410 411
	    nodes_equal(pol->w.cpuset_mems_allowed, *newmask))
		return;
412 413 414 415 416 417 418 419 420 421 422 423 424 425 426

	if (step == MPOL_REBIND_STEP1 && (pol->flags & MPOL_F_REBINDING))
		return;

	if (step == MPOL_REBIND_STEP2 && !(pol->flags & MPOL_F_REBINDING))
		BUG();

	if (step == MPOL_REBIND_STEP1)
		pol->flags |= MPOL_F_REBINDING;
	else if (step == MPOL_REBIND_STEP2)
		pol->flags &= ~MPOL_F_REBINDING;
	else if (step >= MPOL_REBIND_NSTEP)
		BUG();

	mpol_ops[pol->mode].rebind(pol, newmask, step);
427 428 429 430 431
}

/*
 * Wrapper for mpol_rebind_policy() that just requires task
 * pointer, and updates task mempolicy.
432 433
 *
 * Called with task's alloc_lock held.
434 435
 */

436 437
void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new,
			enum mpol_rebind_step step)
438
{
439
	mpol_rebind_policy(tsk->mempolicy, new, step);
440 441 442 443 444 445 446 447 448 449 450 451 452 453
}

/*
 * Rebind each vma in mm to new nodemask.
 *
 * Call holding a reference to mm.  Takes mm->mmap_sem during call.
 */

void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new)
{
	struct vm_area_struct *vma;

	down_write(&mm->mmap_sem);
	for (vma = mm->mmap; vma; vma = vma->vm_next)
454
		mpol_rebind_policy(vma->vm_policy, new, MPOL_REBIND_ONCE);
455 456 457
	up_write(&mm->mmap_sem);
}

458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475
static const struct mempolicy_operations mpol_ops[MPOL_MAX] = {
	[MPOL_DEFAULT] = {
		.rebind = mpol_rebind_default,
	},
	[MPOL_INTERLEAVE] = {
		.create = mpol_new_interleave,
		.rebind = mpol_rebind_nodemask,
	},
	[MPOL_PREFERRED] = {
		.create = mpol_new_preferred,
		.rebind = mpol_rebind_preferred,
	},
	[MPOL_BIND] = {
		.create = mpol_new_bind,
		.rebind = mpol_rebind_nodemask,
	},
};

476 477
static void migrate_page_add(struct page *page, struct list_head *pagelist,
				unsigned long flags);
478

479 480 481 482 483
/*
 * Scan through pages checking if pages follow certain conditions,
 * and move them to the pagelist if they do.
 */
static int queue_pages_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
484 485
		unsigned long addr, unsigned long end,
		const nodemask_t *nodes, unsigned long flags,
486
		void *private)
L
Linus Torvalds 已提交
487
{
488 489
	pte_t *orig_pte;
	pte_t *pte;
490
	spinlock_t *ptl;
491

492
	orig_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
493
	do {
494
		struct page *page;
495
		int nid;
496 497

		if (!pte_present(*pte))
L
Linus Torvalds 已提交
498
			continue;
499 500
		page = vm_normal_page(vma, addr, *pte);
		if (!page)
L
Linus Torvalds 已提交
501
			continue;
502
		/*
503 504
		 * vm_normal_page() filters out zero pages, but there might
		 * still be PageReserved pages to skip, perhaps in a VDSO.
505
		 */
H
Hugh Dickins 已提交
506
		if (PageReserved(page))
507
			continue;
508
		nid = page_to_nid(page);
509 510 511
		if (node_isset(nid, *nodes) == !!(flags & MPOL_MF_INVERT))
			continue;

S
Stephen Wilson 已提交
512
		if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
513
			migrate_page_add(page, private, flags);
514 515
		else
			break;
516
	} while (pte++, addr += PAGE_SIZE, addr != end);
517
	pte_unmap_unlock(orig_pte, ptl);
518 519 520
	return addr != end;
}

521 522
static void queue_pages_hugetlb_pmd_range(struct vm_area_struct *vma,
		pmd_t *pmd, const nodemask_t *nodes, unsigned long flags,
523 524 525 526 527
				    void *private)
{
#ifdef CONFIG_HUGETLB_PAGE
	int nid;
	struct page *page;
528
	spinlock_t *ptl;
529

530
	ptl = huge_pte_lock(hstate_vma(vma), vma->vm_mm, (pte_t *)pmd);
531 532 533 534 535 536 537 538 539
	page = pte_page(huge_ptep_get((pte_t *)pmd));
	nid = page_to_nid(page);
	if (node_isset(nid, *nodes) == !!(flags & MPOL_MF_INVERT))
		goto unlock;
	/* With MPOL_MF_MOVE, we migrate only unshared hugepage. */
	if (flags & (MPOL_MF_MOVE_ALL) ||
	    (flags & MPOL_MF_MOVE && page_mapcount(page) == 1))
		isolate_huge_page(page, private);
unlock:
540
	spin_unlock(ptl);
541 542 543 544 545
#else
	BUG();
#endif
}

546
static inline int queue_pages_pmd_range(struct vm_area_struct *vma, pud_t *pud,
547 548
		unsigned long addr, unsigned long end,
		const nodemask_t *nodes, unsigned long flags,
549
		void *private)
550 551 552 553 554 555 556
{
	pmd_t *pmd;
	unsigned long next;

	pmd = pmd_offset(pud, addr);
	do {
		next = pmd_addr_end(addr, end);
557 558 559
		if (!pmd_present(*pmd))
			continue;
		if (pmd_huge(*pmd) && is_vm_hugetlb_page(vma)) {
560
			queue_pages_hugetlb_pmd_range(vma, pmd, nodes,
561 562 563
						flags, private);
			continue;
		}
564
		split_huge_page_pmd(vma, addr, pmd);
565
		if (pmd_none_or_trans_huge_or_clear_bad(pmd))
566
			continue;
567
		if (queue_pages_pte_range(vma, pmd, addr, next, nodes,
568
				    flags, private))
569 570 571 572 573
			return -EIO;
	} while (pmd++, addr = next, addr != end);
	return 0;
}

574
static inline int queue_pages_pud_range(struct vm_area_struct *vma, pgd_t *pgd,
575 576
		unsigned long addr, unsigned long end,
		const nodemask_t *nodes, unsigned long flags,
577
		void *private)
578 579 580 581 582 583 584
{
	pud_t *pud;
	unsigned long next;

	pud = pud_offset(pgd, addr);
	do {
		next = pud_addr_end(addr, end);
585 586
		if (pud_huge(*pud) && is_vm_hugetlb_page(vma))
			continue;
587 588
		if (pud_none_or_clear_bad(pud))
			continue;
589
		if (queue_pages_pmd_range(vma, pud, addr, next, nodes,
590
				    flags, private))
591 592 593 594 595
			return -EIO;
	} while (pud++, addr = next, addr != end);
	return 0;
}

596
static inline int queue_pages_pgd_range(struct vm_area_struct *vma,
597 598
		unsigned long addr, unsigned long end,
		const nodemask_t *nodes, unsigned long flags,
599
		void *private)
600 601 602 603
{
	pgd_t *pgd;
	unsigned long next;

N
Nick Piggin 已提交
604
	pgd = pgd_offset(vma->vm_mm, addr);
605 606 607 608
	do {
		next = pgd_addr_end(addr, end);
		if (pgd_none_or_clear_bad(pgd))
			continue;
609
		if (queue_pages_pud_range(vma, pgd, addr, next, nodes,
610
				    flags, private))
611 612 613
			return -EIO;
	} while (pgd++, addr = next, addr != end);
	return 0;
L
Linus Torvalds 已提交
614 615
}

616
#ifdef CONFIG_NUMA_BALANCING
L
Lee Schermerhorn 已提交
617
/*
618 619 620 621 622 623 624
 * This is used to mark a range of virtual addresses to be inaccessible.
 * These are later cleared by a NUMA hinting fault. Depending on these
 * faults, pages may be migrated for better NUMA placement.
 *
 * This is assuming that NUMA faults are handled using PROT_NONE. If
 * an architecture makes a different choice, it will need further
 * changes to the core.
L
Lee Schermerhorn 已提交
625
 */
626 627
unsigned long change_prot_numa(struct vm_area_struct *vma,
			unsigned long addr, unsigned long end)
L
Lee Schermerhorn 已提交
628
{
629
	int nr_updated;
L
Lee Schermerhorn 已提交
630

631
	nr_updated = change_protection(vma, addr, end, vma->vm_page_prot, 0, 1);
632 633
	if (nr_updated)
		count_vm_numa_events(NUMA_PTE_UPDATES, nr_updated);
L
Lee Schermerhorn 已提交
634

635
	return nr_updated;
L
Lee Schermerhorn 已提交
636 637 638 639 640 641 642
}
#else
static unsigned long change_prot_numa(struct vm_area_struct *vma,
			unsigned long addr, unsigned long end)
{
	return 0;
}
643
#endif /* CONFIG_NUMA_BALANCING */
L
Lee Schermerhorn 已提交
644

645
/*
646 647 648 649 650
 * Walk through page tables and collect pages to be migrated.
 *
 * If pages found in a given range are on a set of nodes (determined by
 * @nodes and @flags,) it's isolated and queued to the pagelist which is
 * passed via @private.)
651
 */
L
Linus Torvalds 已提交
652
static struct vm_area_struct *
653
queue_pages_range(struct mm_struct *mm, unsigned long start, unsigned long end,
654
		const nodemask_t *nodes, unsigned long flags, void *private)
L
Linus Torvalds 已提交
655 656 657 658
{
	int err;
	struct vm_area_struct *first, *vma, *prev;

659

L
Linus Torvalds 已提交
660 661 662 663 664
	first = find_vma(mm, start);
	if (!first)
		return ERR_PTR(-EFAULT);
	prev = NULL;
	for (vma = first; vma && vma->vm_start < end; vma = vma->vm_next) {
L
Lee Schermerhorn 已提交
665 666 667 668 669 670 671
		unsigned long endvma = vma->vm_end;

		if (endvma > end)
			endvma = end;
		if (vma->vm_start > start)
			start = vma->vm_start;

672 673 674 675 676 677
		if (!(flags & MPOL_MF_DISCONTIG_OK)) {
			if (!vma->vm_next && vma->vm_end < end)
				return ERR_PTR(-EFAULT);
			if (prev && prev->vm_end < vma->vm_start)
				return ERR_PTR(-EFAULT);
		}
L
Lee Schermerhorn 已提交
678 679 680 681 682 683 684

		if (flags & MPOL_MF_LAZY) {
			change_prot_numa(vma, start, endvma);
			goto next;
		}

		if ((flags & MPOL_MF_STRICT) ||
685
		     ((flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) &&
L
Lee Schermerhorn 已提交
686
		      vma_migratable(vma))) {
687

688
			err = queue_pages_pgd_range(vma, start, endvma, nodes,
689
						flags, private);
L
Linus Torvalds 已提交
690 691 692 693 694
			if (err) {
				first = ERR_PTR(err);
				break;
			}
		}
L
Lee Schermerhorn 已提交
695
next:
L
Linus Torvalds 已提交
696 697 698 699 700
		prev = vma;
	}
	return first;
}

701 702 703 704 705 706
/*
 * Apply policy to a single VMA
 * This must be called with the mmap_sem held for writing.
 */
static int vma_replace_policy(struct vm_area_struct *vma,
						struct mempolicy *pol)
707
{
708 709 710
	int err;
	struct mempolicy *old;
	struct mempolicy *new;
711 712 713 714 715 716

	pr_debug("vma %lx-%lx/%lx vm_ops %p vm_file %p set_policy %p\n",
		 vma->vm_start, vma->vm_end, vma->vm_pgoff,
		 vma->vm_ops, vma->vm_file,
		 vma->vm_ops ? vma->vm_ops->set_policy : NULL);

717 718 719 720 721
	new = mpol_dup(pol);
	if (IS_ERR(new))
		return PTR_ERR(new);

	if (vma->vm_ops && vma->vm_ops->set_policy) {
722
		err = vma->vm_ops->set_policy(vma, new);
723 724
		if (err)
			goto err_out;
725
	}
726 727 728 729 730 731 732 733

	old = vma->vm_policy;
	vma->vm_policy = new; /* protected by mmap_sem */
	mpol_put(old);

	return 0;
 err_out:
	mpol_put(new);
734 735 736
	return err;
}

L
Linus Torvalds 已提交
737
/* Step 2: apply policy to a range and do splits. */
738 739
static int mbind_range(struct mm_struct *mm, unsigned long start,
		       unsigned long end, struct mempolicy *new_pol)
L
Linus Torvalds 已提交
740 741
{
	struct vm_area_struct *next;
742 743 744
	struct vm_area_struct *prev;
	struct vm_area_struct *vma;
	int err = 0;
745
	pgoff_t pgoff;
746 747
	unsigned long vmstart;
	unsigned long vmend;
L
Linus Torvalds 已提交
748

749
	vma = find_vma(mm, start);
750 751 752
	if (!vma || vma->vm_start > start)
		return -EFAULT;

753
	prev = vma->vm_prev;
754 755 756
	if (start > vma->vm_start)
		prev = vma;

757
	for (; vma && vma->vm_start < end; prev = vma, vma = next) {
L
Linus Torvalds 已提交
758
		next = vma->vm_next;
759 760 761
		vmstart = max(start, vma->vm_start);
		vmend   = min(end, vma->vm_end);

762 763 764 765 766
		if (mpol_equal(vma_policy(vma), new_pol))
			continue;

		pgoff = vma->vm_pgoff +
			((vmstart - vma->vm_start) >> PAGE_SHIFT);
767
		prev = vma_merge(mm, prev, vmstart, vmend, vma->vm_flags,
768
				  vma->anon_vma, vma->vm_file, pgoff,
769
				  new_pol);
770 771 772
		if (prev) {
			vma = prev;
			next = vma->vm_next;
773 774 775 776
			if (mpol_equal(vma_policy(vma), new_pol))
				continue;
			/* vma_merge() joined vma && vma->next, case 8 */
			goto replace;
777 778 779 780 781 782 783 784 785 786 787
		}
		if (vma->vm_start != vmstart) {
			err = split_vma(vma->vm_mm, vma, vmstart, 1);
			if (err)
				goto out;
		}
		if (vma->vm_end != vmend) {
			err = split_vma(vma->vm_mm, vma, vmend, 0);
			if (err)
				goto out;
		}
788
 replace:
789
		err = vma_replace_policy(vma, new_pol);
790 791
		if (err)
			goto out;
L
Linus Torvalds 已提交
792
	}
793 794

 out:
L
Linus Torvalds 已提交
795 796 797
	return err;
}

798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827
/*
 * Update task->flags PF_MEMPOLICY bit: set iff non-default
 * mempolicy.  Allows more rapid checking of this (combined perhaps
 * with other PF_* flag bits) on memory allocation hot code paths.
 *
 * If called from outside this file, the task 'p' should -only- be
 * a newly forked child not yet visible on the task list, because
 * manipulating the task flags of a visible task is not safe.
 *
 * The above limitation is why this routine has the funny name
 * mpol_fix_fork_child_flag().
 *
 * It is also safe to call this with a task pointer of current,
 * which the static wrapper mpol_set_task_struct_flag() does,
 * for use within this file.
 */

void mpol_fix_fork_child_flag(struct task_struct *p)
{
	if (p->mempolicy)
		p->flags |= PF_MEMPOLICY;
	else
		p->flags &= ~PF_MEMPOLICY;
}

static void mpol_set_task_struct_flag(void)
{
	mpol_fix_fork_child_flag(current);
}

L
Linus Torvalds 已提交
828
/* Set the process memory policy */
829 830
static long do_set_mempolicy(unsigned short mode, unsigned short flags,
			     nodemask_t *nodes)
L
Linus Torvalds 已提交
831
{
832
	struct mempolicy *new, *old;
833
	struct mm_struct *mm = current->mm;
834
	NODEMASK_SCRATCH(scratch);
835
	int ret;
L
Linus Torvalds 已提交
836

837 838
	if (!scratch)
		return -ENOMEM;
839

840 841 842 843 844
	new = mpol_new(mode, flags, nodes);
	if (IS_ERR(new)) {
		ret = PTR_ERR(new);
		goto out;
	}
845 846 847 848 849 850 851 852
	/*
	 * prevent changing our mempolicy while show_numa_maps()
	 * is using it.
	 * Note:  do_set_mempolicy() can be called at init time
	 * with no 'mm'.
	 */
	if (mm)
		down_write(&mm->mmap_sem);
853
	task_lock(current);
854
	ret = mpol_set_nodemask(new, nodes, scratch);
855 856 857 858 859
	if (ret) {
		task_unlock(current);
		if (mm)
			up_write(&mm->mmap_sem);
		mpol_put(new);
860
		goto out;
861 862
	}
	old = current->mempolicy;
L
Linus Torvalds 已提交
863
	current->mempolicy = new;
864
	mpol_set_task_struct_flag();
865
	if (new && new->mode == MPOL_INTERLEAVE &&
866
	    nodes_weight(new->v.nodes))
867
		current->il_next = first_node(new->v.nodes);
868
	task_unlock(current);
869 870 871
	if (mm)
		up_write(&mm->mmap_sem);

872
	mpol_put(old);
873 874 875 876
	ret = 0;
out:
	NODEMASK_SCRATCH_FREE(scratch);
	return ret;
L
Linus Torvalds 已提交
877 878
}

879 880
/*
 * Return nodemask for policy for get_mempolicy() query
881 882
 *
 * Called with task's alloc_lock held
883 884
 */
static void get_policy_nodemask(struct mempolicy *p, nodemask_t *nodes)
L
Linus Torvalds 已提交
885
{
886
	nodes_clear(*nodes);
887 888 889
	if (p == &default_policy)
		return;

890
	switch (p->mode) {
891 892
	case MPOL_BIND:
		/* Fall through */
L
Linus Torvalds 已提交
893
	case MPOL_INTERLEAVE:
894
		*nodes = p->v.nodes;
L
Linus Torvalds 已提交
895 896
		break;
	case MPOL_PREFERRED:
897
		if (!(p->flags & MPOL_F_LOCAL))
898
			node_set(p->v.preferred_node, *nodes);
899
		/* else return empty node mask for local allocation */
L
Linus Torvalds 已提交
900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919
		break;
	default:
		BUG();
	}
}

static int lookup_node(struct mm_struct *mm, unsigned long addr)
{
	struct page *p;
	int err;

	err = get_user_pages(current, mm, addr & PAGE_MASK, 1, 0, 0, &p, NULL);
	if (err >= 0) {
		err = page_to_nid(p);
		put_page(p);
	}
	return err;
}

/* Retrieve NUMA policy */
A
Adrian Bunk 已提交
920 921
static long do_get_mempolicy(int *policy, nodemask_t *nmask,
			     unsigned long addr, unsigned long flags)
L
Linus Torvalds 已提交
922
{
923
	int err;
L
Linus Torvalds 已提交
924 925 926 927
	struct mm_struct *mm = current->mm;
	struct vm_area_struct *vma = NULL;
	struct mempolicy *pol = current->mempolicy;

928 929
	if (flags &
		~(unsigned long)(MPOL_F_NODE|MPOL_F_ADDR|MPOL_F_MEMS_ALLOWED))
L
Linus Torvalds 已提交
930
		return -EINVAL;
931 932 933 934 935

	if (flags & MPOL_F_MEMS_ALLOWED) {
		if (flags & (MPOL_F_NODE|MPOL_F_ADDR))
			return -EINVAL;
		*policy = 0;	/* just so it's initialized */
936
		task_lock(current);
937
		*nmask  = cpuset_current_mems_allowed;
938
		task_unlock(current);
939 940 941
		return 0;
	}

L
Linus Torvalds 已提交
942
	if (flags & MPOL_F_ADDR) {
943 944 945 946 947
		/*
		 * Do NOT fall back to task policy if the
		 * vma/shared policy at addr is NULL.  We
		 * want to return MPOL_DEFAULT in this case.
		 */
L
Linus Torvalds 已提交
948 949 950 951 952 953 954 955 956 957 958 959 960 961
		down_read(&mm->mmap_sem);
		vma = find_vma_intersection(mm, addr, addr+1);
		if (!vma) {
			up_read(&mm->mmap_sem);
			return -EFAULT;
		}
		if (vma->vm_ops && vma->vm_ops->get_policy)
			pol = vma->vm_ops->get_policy(vma, addr);
		else
			pol = vma->vm_policy;
	} else if (addr)
		return -EINVAL;

	if (!pol)
962
		pol = &default_policy;	/* indicates default behavior */
L
Linus Torvalds 已提交
963 964 965 966 967 968

	if (flags & MPOL_F_NODE) {
		if (flags & MPOL_F_ADDR) {
			err = lookup_node(mm, addr);
			if (err < 0)
				goto out;
969
			*policy = err;
L
Linus Torvalds 已提交
970
		} else if (pol == current->mempolicy &&
971
				pol->mode == MPOL_INTERLEAVE) {
972
			*policy = current->il_next;
L
Linus Torvalds 已提交
973 974 975 976
		} else {
			err = -EINVAL;
			goto out;
		}
977 978 979
	} else {
		*policy = pol == &default_policy ? MPOL_DEFAULT :
						pol->mode;
980 981 982 983 984
		/*
		 * Internal mempolicy flags must be masked off before exposing
		 * the policy to userspace.
		 */
		*policy |= (pol->flags & MPOL_MODE_FLAGS);
985
	}
L
Linus Torvalds 已提交
986 987 988 989 990 991 992

	if (vma) {
		up_read(&current->mm->mmap_sem);
		vma = NULL;
	}

	err = 0;
993
	if (nmask) {
994 995 996 997 998 999 1000
		if (mpol_store_user_nodemask(pol)) {
			*nmask = pol->w.user_nodemask;
		} else {
			task_lock(current);
			get_policy_nodemask(pol, nmask);
			task_unlock(current);
		}
1001
	}
L
Linus Torvalds 已提交
1002 1003

 out:
1004
	mpol_cond_put(pol);
L
Linus Torvalds 已提交
1005 1006 1007 1008 1009
	if (vma)
		up_read(&current->mm->mmap_sem);
	return err;
}

C
Christoph Lameter 已提交
1010
#ifdef CONFIG_MIGRATION
1011 1012 1013
/*
 * page migration
 */
1014 1015
static void migrate_page_add(struct page *page, struct list_head *pagelist,
				unsigned long flags)
1016 1017
{
	/*
1018
	 * Avoid migrating a page that is shared with others.
1019
	 */
1020 1021 1022
	if ((flags & MPOL_MF_MOVE_ALL) || page_mapcount(page) == 1) {
		if (!isolate_lru_page(page)) {
			list_add_tail(&page->lru, pagelist);
1023 1024
			inc_zone_page_state(page, NR_ISOLATED_ANON +
					    page_is_file_cache(page));
1025 1026
		}
	}
1027
}
1028

1029
static struct page *new_node_page(struct page *page, unsigned long node, int **x)
1030
{
1031 1032 1033 1034 1035
	if (PageHuge(page))
		return alloc_huge_page_node(page_hstate(compound_head(page)),
					node);
	else
		return alloc_pages_exact_node(node, GFP_HIGHUSER_MOVABLE, 0);
1036 1037
}

1038 1039 1040 1041
/*
 * Migrate pages from one node to a target node.
 * Returns error or the number of pages not migrated.
 */
A
Adrian Bunk 已提交
1042 1043
static int migrate_to_node(struct mm_struct *mm, int source, int dest,
			   int flags)
1044 1045 1046 1047 1048 1049 1050
{
	nodemask_t nmask;
	LIST_HEAD(pagelist);
	int err = 0;

	nodes_clear(nmask);
	node_set(source, nmask);
1051

1052 1053 1054 1055 1056 1057
	/*
	 * This does not "check" the range but isolates all pages that
	 * need migration.  Between passing in the full user address
	 * space range and MPOL_MF_DISCONTIG_OK, this call can not fail.
	 */
	VM_BUG_ON(!(flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)));
1058
	queue_pages_range(mm, mm->mmap->vm_start, mm->task_size, &nmask,
1059 1060
			flags | MPOL_MF_DISCONTIG_OK, &pagelist);

1061
	if (!list_empty(&pagelist)) {
1062
		err = migrate_pages(&pagelist, new_node_page, dest,
1063
					MIGRATE_SYNC, MR_SYSCALL);
1064
		if (err)
1065
			putback_movable_pages(&pagelist);
1066
	}
1067

1068
	return err;
1069 1070
}

1071
/*
1072 1073
 * Move pages between the two nodesets so as to preserve the physical
 * layout as much as possible.
1074 1075 1076
 *
 * Returns the number of page that could not be moved.
 */
1077 1078
int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
		     const nodemask_t *to, int flags)
1079
{
1080
	int busy = 0;
1081
	int err;
1082
	nodemask_t tmp;
1083

1084 1085 1086 1087
	err = migrate_prep();
	if (err)
		return err;

1088
	down_read(&mm->mmap_sem);
1089

1090
	err = migrate_vmas(mm, from, to, flags);
1091 1092 1093
	if (err)
		goto out;

1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118
	/*
	 * Find a 'source' bit set in 'tmp' whose corresponding 'dest'
	 * bit in 'to' is not also set in 'tmp'.  Clear the found 'source'
	 * bit in 'tmp', and return that <source, dest> pair for migration.
	 * The pair of nodemasks 'to' and 'from' define the map.
	 *
	 * If no pair of bits is found that way, fallback to picking some
	 * pair of 'source' and 'dest' bits that are not the same.  If the
	 * 'source' and 'dest' bits are the same, this represents a node
	 * that will be migrating to itself, so no pages need move.
	 *
	 * If no bits are left in 'tmp', or if all remaining bits left
	 * in 'tmp' correspond to the same bit in 'to', return false
	 * (nothing left to migrate).
	 *
	 * This lets us pick a pair of nodes to migrate between, such that
	 * if possible the dest node is not already occupied by some other
	 * source node, minimizing the risk of overloading the memory on a
	 * node that would happen if we migrated incoming memory to a node
	 * before migrating outgoing memory source that same node.
	 *
	 * A single scan of tmp is sufficient.  As we go, we remember the
	 * most recent <s, d> pair that moved (s != d).  If we find a pair
	 * that not only moved, but what's better, moved to an empty slot
	 * (d is not set in tmp), then we break out then, with that pair.
1119
	 * Otherwise when we finish scanning from_tmp, we at least have the
1120 1121 1122 1123
	 * most recent <s, d> pair that moved.  If we get all the way through
	 * the scan of tmp without finding any node that moved, much less
	 * moved to an empty node, then there is nothing left worth migrating.
	 */
1124

1125
	tmp = *from;
1126 1127
	while (!nodes_empty(tmp)) {
		int s,d;
J
Jianguo Wu 已提交
1128
		int source = NUMA_NO_NODE;
1129 1130 1131
		int dest = 0;

		for_each_node_mask(s, tmp) {
1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147

			/*
			 * do_migrate_pages() tries to maintain the relative
			 * node relationship of the pages established between
			 * threads and memory areas.
                         *
			 * However if the number of source nodes is not equal to
			 * the number of destination nodes we can not preserve
			 * this node relative relationship.  In that case, skip
			 * copying memory from a node that is in the destination
			 * mask.
			 *
			 * Example: [2,3,4] -> [3,4,5] moves everything.
			 *          [0-7] - > [3,4,5] moves only 0,1,2,6,7.
			 */

1148 1149
			if ((nodes_weight(*from) != nodes_weight(*to)) &&
						(node_isset(s, *to)))
1150 1151
				continue;

1152
			d = node_remap(s, *from, *to);
1153 1154 1155 1156 1157 1158 1159 1160 1161 1162
			if (s == d)
				continue;

			source = s;	/* Node moved. Memorize */
			dest = d;

			/* dest not in remaining from nodes? */
			if (!node_isset(dest, tmp))
				break;
		}
J
Jianguo Wu 已提交
1163
		if (source == NUMA_NO_NODE)
1164 1165 1166 1167 1168 1169 1170 1171
			break;

		node_clear(source, tmp);
		err = migrate_to_node(mm, source, dest, flags);
		if (err > 0)
			busy += err;
		if (err < 0)
			break;
1172
	}
1173
out:
1174
	up_read(&mm->mmap_sem);
1175 1176 1177
	if (err < 0)
		return err;
	return busy;
C
Christoph Lameter 已提交
1178 1179 1180

}

1181 1182 1183 1184 1185 1186 1187
/*
 * Allocate a new page for page migration based on vma policy.
 * Start assuming that page is mapped by vma pointed to by @private.
 * Search forward from there, if not.  N.B., this assumes that the
 * list of pages handed to migrate_pages()--which is how we get here--
 * is in virtual address order.
 */
1188
static struct page *new_vma_page(struct page *page, unsigned long private, int **x)
1189 1190
{
	struct vm_area_struct *vma = (struct vm_area_struct *)private;
1191
	unsigned long uninitialized_var(address);
1192

1193 1194 1195 1196 1197 1198
	while (vma) {
		address = page_address_in_vma(page, vma);
		if (address != -EFAULT)
			break;
		vma = vma->vm_next;
	}
1199 1200

	if (PageHuge(page)) {
1201 1202
		BUG_ON(!vma);
		return alloc_huge_page_noerr(vma, address, 1);
1203
	}
1204
	/*
1205
	 * if !vma, alloc_page_vma() will use task or system default policy
1206
	 */
1207
	return alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
1208
}
C
Christoph Lameter 已提交
1209 1210 1211 1212 1213
#else

static void migrate_page_add(struct page *page, struct list_head *pagelist,
				unsigned long flags)
{
1214 1215
}

1216 1217
int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
		     const nodemask_t *to, int flags)
C
Christoph Lameter 已提交
1218 1219 1220
{
	return -ENOSYS;
}
1221

1222
static struct page *new_vma_page(struct page *page, unsigned long private, int **x)
1223 1224 1225
{
	return NULL;
}
C
Christoph Lameter 已提交
1226 1227
#endif

A
Adrian Bunk 已提交
1228
static long do_mbind(unsigned long start, unsigned long len,
1229 1230
		     unsigned short mode, unsigned short mode_flags,
		     nodemask_t *nmask, unsigned long flags)
1231 1232 1233 1234 1235 1236 1237 1238
{
	struct vm_area_struct *vma;
	struct mm_struct *mm = current->mm;
	struct mempolicy *new;
	unsigned long end;
	int err;
	LIST_HEAD(pagelist);

L
Lee Schermerhorn 已提交
1239
	if (flags & ~(unsigned long)MPOL_MF_VALID)
1240
		return -EINVAL;
1241
	if ((flags & MPOL_MF_MOVE_ALL) && !capable(CAP_SYS_NICE))
1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257
		return -EPERM;

	if (start & ~PAGE_MASK)
		return -EINVAL;

	if (mode == MPOL_DEFAULT)
		flags &= ~MPOL_MF_STRICT;

	len = (len + PAGE_SIZE - 1) & PAGE_MASK;
	end = start + len;

	if (end < start)
		return -EINVAL;
	if (end == start)
		return 0;

1258
	new = mpol_new(mode, mode_flags, nmask);
1259 1260 1261
	if (IS_ERR(new))
		return PTR_ERR(new);

L
Lee Schermerhorn 已提交
1262 1263 1264
	if (flags & MPOL_MF_LAZY)
		new->flags |= MPOL_F_MOF;

1265 1266 1267 1268 1269 1270 1271
	/*
	 * If we are using the default policy then operation
	 * on discontinuous address spaces is okay after all
	 */
	if (!new)
		flags |= MPOL_MF_DISCONTIG_OK;

1272 1273
	pr_debug("mbind %lx-%lx mode:%d flags:%d nodes:%lx\n",
		 start, start + len, mode, mode_flags,
D
David Rientjes 已提交
1274
		 nmask ? nodes_addr(*nmask)[0] : NUMA_NO_NODE);
1275

1276 1277 1278 1279
	if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) {

		err = migrate_prep();
		if (err)
K
KOSAKI Motohiro 已提交
1280
			goto mpol_out;
1281
	}
1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294
	{
		NODEMASK_SCRATCH(scratch);
		if (scratch) {
			down_write(&mm->mmap_sem);
			task_lock(current);
			err = mpol_set_nodemask(new, nmask, scratch);
			task_unlock(current);
			if (err)
				up_write(&mm->mmap_sem);
		} else
			err = -ENOMEM;
		NODEMASK_SCRATCH_FREE(scratch);
	}
K
KOSAKI Motohiro 已提交
1295 1296 1297
	if (err)
		goto mpol_out;

1298
	vma = queue_pages_range(mm, start, end, nmask,
1299 1300
			  flags | MPOL_MF_INVERT, &pagelist);

L
Lee Schermerhorn 已提交
1301
	err = PTR_ERR(vma);	/* maybe ... */
1302
	if (!IS_ERR(vma))
1303
		err = mbind_range(mm, start, end, new);
1304

L
Lee Schermerhorn 已提交
1305 1306 1307
	if (!err) {
		int nr_failed = 0;

1308
		if (!list_empty(&pagelist)) {
L
Lee Schermerhorn 已提交
1309
			WARN_ON_ONCE(flags & MPOL_MF_LAZY);
1310
			nr_failed = migrate_pages(&pagelist, new_vma_page,
1311 1312
					(unsigned long)vma,
					MIGRATE_SYNC, MR_MEMPOLICY_MBIND);
1313
			if (nr_failed)
1314
				putback_movable_pages(&pagelist);
1315
		}
1316

L
Lee Schermerhorn 已提交
1317
		if (nr_failed && (flags & MPOL_MF_STRICT))
1318
			err = -EIO;
1319
	} else
1320
		putback_movable_pages(&pagelist);
C
Christoph Lameter 已提交
1321

1322
	up_write(&mm->mmap_sem);
K
KOSAKI Motohiro 已提交
1323
 mpol_out:
1324
	mpol_put(new);
1325 1326 1327
	return err;
}

1328 1329 1330 1331 1332
/*
 * User space interface with variable sized bitmaps for nodelists.
 */

/* Copy a node mask from user space. */
1333
static int get_nodes(nodemask_t *nodes, const unsigned long __user *nmask,
1334 1335 1336 1337 1338 1339 1340 1341 1342 1343
		     unsigned long maxnode)
{
	unsigned long k;
	unsigned long nlongs;
	unsigned long endmask;

	--maxnode;
	nodes_clear(*nodes);
	if (maxnode == 0 || !nmask)
		return 0;
A
Andi Kleen 已提交
1344
	if (maxnode > PAGE_SIZE*BITS_PER_BYTE)
C
Chris Wright 已提交
1345
		return -EINVAL;
1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394

	nlongs = BITS_TO_LONGS(maxnode);
	if ((maxnode % BITS_PER_LONG) == 0)
		endmask = ~0UL;
	else
		endmask = (1UL << (maxnode % BITS_PER_LONG)) - 1;

	/* When the user specified more nodes than supported just check
	   if the non supported part is all zero. */
	if (nlongs > BITS_TO_LONGS(MAX_NUMNODES)) {
		if (nlongs > PAGE_SIZE/sizeof(long))
			return -EINVAL;
		for (k = BITS_TO_LONGS(MAX_NUMNODES); k < nlongs; k++) {
			unsigned long t;
			if (get_user(t, nmask + k))
				return -EFAULT;
			if (k == nlongs - 1) {
				if (t & endmask)
					return -EINVAL;
			} else if (t)
				return -EINVAL;
		}
		nlongs = BITS_TO_LONGS(MAX_NUMNODES);
		endmask = ~0UL;
	}

	if (copy_from_user(nodes_addr(*nodes), nmask, nlongs*sizeof(unsigned long)))
		return -EFAULT;
	nodes_addr(*nodes)[nlongs-1] &= endmask;
	return 0;
}

/* Copy a kernel node mask to user space */
static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode,
			      nodemask_t *nodes)
{
	unsigned long copy = ALIGN(maxnode-1, 64) / 8;
	const int nbytes = BITS_TO_LONGS(MAX_NUMNODES) * sizeof(long);

	if (copy > nbytes) {
		if (copy > PAGE_SIZE)
			return -EINVAL;
		if (clear_user((char __user *)mask + nbytes, copy - nbytes))
			return -EFAULT;
		copy = nbytes;
	}
	return copy_to_user(mask, nodes_addr(*nodes), copy) ? -EFAULT : 0;
}

1395 1396 1397
SYSCALL_DEFINE6(mbind, unsigned long, start, unsigned long, len,
		unsigned long, mode, unsigned long __user *, nmask,
		unsigned long, maxnode, unsigned, flags)
1398 1399 1400
{
	nodemask_t nodes;
	int err;
1401
	unsigned short mode_flags;
1402

1403 1404
	mode_flags = mode & MPOL_MODE_FLAGS;
	mode &= ~MPOL_MODE_FLAGS;
1405 1406
	if (mode >= MPOL_MAX)
		return -EINVAL;
1407 1408 1409
	if ((mode_flags & MPOL_F_STATIC_NODES) &&
	    (mode_flags & MPOL_F_RELATIVE_NODES))
		return -EINVAL;
1410 1411 1412
	err = get_nodes(&nodes, nmask, maxnode);
	if (err)
		return err;
1413
	return do_mbind(start, len, mode, mode_flags, &nodes, flags);
1414 1415 1416
}

/* Set the process memory policy */
1417 1418
SYSCALL_DEFINE3(set_mempolicy, int, mode, unsigned long __user *, nmask,
		unsigned long, maxnode)
1419 1420 1421
{
	int err;
	nodemask_t nodes;
1422
	unsigned short flags;
1423

1424 1425 1426
	flags = mode & MPOL_MODE_FLAGS;
	mode &= ~MPOL_MODE_FLAGS;
	if ((unsigned int)mode >= MPOL_MAX)
1427
		return -EINVAL;
1428 1429
	if ((flags & MPOL_F_STATIC_NODES) && (flags & MPOL_F_RELATIVE_NODES))
		return -EINVAL;
1430 1431 1432
	err = get_nodes(&nodes, nmask, maxnode);
	if (err)
		return err;
1433
	return do_set_mempolicy(mode, flags, &nodes);
1434 1435
}

1436 1437 1438
SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode,
		const unsigned long __user *, old_nodes,
		const unsigned long __user *, new_nodes)
1439
{
1440
	const struct cred *cred = current_cred(), *tcred;
1441
	struct mm_struct *mm = NULL;
1442 1443 1444
	struct task_struct *task;
	nodemask_t task_nodes;
	int err;
1445 1446 1447 1448 1449 1450
	nodemask_t *old;
	nodemask_t *new;
	NODEMASK_SCRATCH(scratch);

	if (!scratch)
		return -ENOMEM;
1451

1452 1453 1454 1455
	old = &scratch->mask1;
	new = &scratch->mask2;

	err = get_nodes(old, old_nodes, maxnode);
1456
	if (err)
1457
		goto out;
1458

1459
	err = get_nodes(new, new_nodes, maxnode);
1460
	if (err)
1461
		goto out;
1462 1463

	/* Find the mm_struct */
1464
	rcu_read_lock();
1465
	task = pid ? find_task_by_vpid(pid) : current;
1466
	if (!task) {
1467
		rcu_read_unlock();
1468 1469
		err = -ESRCH;
		goto out;
1470
	}
1471
	get_task_struct(task);
1472

1473
	err = -EINVAL;
1474 1475 1476 1477

	/*
	 * Check if this process has the right to modify the specified
	 * process. The right exists if the process has administrative
A
Alexey Dobriyan 已提交
1478
	 * capabilities, superuser privileges or the same
1479 1480
	 * userid as the target process.
	 */
1481
	tcred = __task_cred(task);
1482 1483
	if (!uid_eq(cred->euid, tcred->suid) && !uid_eq(cred->euid, tcred->uid) &&
	    !uid_eq(cred->uid,  tcred->suid) && !uid_eq(cred->uid,  tcred->uid) &&
1484
	    !capable(CAP_SYS_NICE)) {
1485
		rcu_read_unlock();
1486
		err = -EPERM;
1487
		goto out_put;
1488
	}
1489
	rcu_read_unlock();
1490 1491 1492

	task_nodes = cpuset_mems_allowed(task);
	/* Is the user allowed to access the target nodes? */
1493
	if (!nodes_subset(*new, task_nodes) && !capable(CAP_SYS_NICE)) {
1494
		err = -EPERM;
1495
		goto out_put;
1496 1497
	}

1498
	if (!nodes_subset(*new, node_states[N_MEMORY])) {
1499
		err = -EINVAL;
1500
		goto out_put;
1501 1502
	}

1503 1504
	err = security_task_movememory(task);
	if (err)
1505
		goto out_put;
1506

1507 1508
	mm = get_task_mm(task);
	put_task_struct(task);
1509 1510

	if (!mm) {
1511
		err = -EINVAL;
1512 1513 1514 1515 1516
		goto out;
	}

	err = do_migrate_pages(mm, old, new,
		capable(CAP_SYS_NICE) ? MPOL_MF_MOVE_ALL : MPOL_MF_MOVE);
1517 1518 1519

	mmput(mm);
out:
1520 1521
	NODEMASK_SCRATCH_FREE(scratch);

1522
	return err;
1523 1524 1525 1526 1527

out_put:
	put_task_struct(task);
	goto out;

1528 1529 1530
}


1531
/* Retrieve NUMA policy */
1532 1533 1534
SYSCALL_DEFINE5(get_mempolicy, int __user *, policy,
		unsigned long __user *, nmask, unsigned long, maxnode,
		unsigned long, addr, unsigned long, flags)
1535
{
A
Adrian Bunk 已提交
1536 1537
	int err;
	int uninitialized_var(pval);
1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556
	nodemask_t nodes;

	if (nmask != NULL && maxnode < MAX_NUMNODES)
		return -EINVAL;

	err = do_get_mempolicy(&pval, &nodes, addr, flags);

	if (err)
		return err;

	if (policy && put_user(pval, policy))
		return -EFAULT;

	if (nmask)
		err = copy_nodes_to_user(nmask, maxnode, &nodes);

	return err;
}

L
Linus Torvalds 已提交
1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577
#ifdef CONFIG_COMPAT

asmlinkage long compat_sys_get_mempolicy(int __user *policy,
				     compat_ulong_t __user *nmask,
				     compat_ulong_t maxnode,
				     compat_ulong_t addr, compat_ulong_t flags)
{
	long err;
	unsigned long __user *nm = NULL;
	unsigned long nr_bits, alloc_size;
	DECLARE_BITMAP(bm, MAX_NUMNODES);

	nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
	alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;

	if (nmask)
		nm = compat_alloc_user_space(alloc_size);

	err = sys_get_mempolicy(policy, nm, nr_bits+1, addr, flags);

	if (!err && nmask) {
1578 1579 1580
		unsigned long copy_size;
		copy_size = min_t(unsigned long, sizeof(bm), alloc_size);
		err = copy_from_user(bm, nm, copy_size);
L
Linus Torvalds 已提交
1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618
		/* ensure entire bitmap is zeroed */
		err |= clear_user(nmask, ALIGN(maxnode-1, 8) / 8);
		err |= compat_put_bitmap(nmask, bm, nr_bits);
	}

	return err;
}

asmlinkage long compat_sys_set_mempolicy(int mode, compat_ulong_t __user *nmask,
				     compat_ulong_t maxnode)
{
	long err = 0;
	unsigned long __user *nm = NULL;
	unsigned long nr_bits, alloc_size;
	DECLARE_BITMAP(bm, MAX_NUMNODES);

	nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
	alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;

	if (nmask) {
		err = compat_get_bitmap(bm, nmask, nr_bits);
		nm = compat_alloc_user_space(alloc_size);
		err |= copy_to_user(nm, bm, alloc_size);
	}

	if (err)
		return -EFAULT;

	return sys_set_mempolicy(mode, nm, nr_bits+1);
}

asmlinkage long compat_sys_mbind(compat_ulong_t start, compat_ulong_t len,
			     compat_ulong_t mode, compat_ulong_t __user *nmask,
			     compat_ulong_t maxnode, compat_ulong_t flags)
{
	long err = 0;
	unsigned long __user *nm = NULL;
	unsigned long nr_bits, alloc_size;
1619
	nodemask_t bm;
L
Linus Torvalds 已提交
1620 1621 1622 1623 1624

	nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
	alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;

	if (nmask) {
1625
		err = compat_get_bitmap(nodes_addr(bm), nmask, nr_bits);
L
Linus Torvalds 已提交
1626
		nm = compat_alloc_user_space(alloc_size);
1627
		err |= copy_to_user(nm, nodes_addr(bm), alloc_size);
L
Linus Torvalds 已提交
1628 1629 1630 1631 1632 1633 1634 1635 1636 1637
	}

	if (err)
		return -EFAULT;

	return sys_mbind(start, len, mode, nm, nr_bits+1, flags);
}

#endif

1638 1639 1640 1641 1642 1643 1644 1645
/*
 * get_vma_policy(@task, @vma, @addr)
 * @task - task for fallback if vma policy == default
 * @vma   - virtual memory area whose policy is sought
 * @addr  - address in @vma for shared policy lookup
 *
 * Returns effective policy for a VMA at specified address.
 * Falls back to @task or system default policy, as necessary.
1646 1647
 * Current or other task's task mempolicy and non-shared vma policies must be
 * protected by task_lock(task) by the caller.
1648 1649 1650 1651
 * Shared policies [those marked as MPOL_F_SHARED] require an extra reference
 * count--added by the get_policy() vm_op, as appropriate--to protect against
 * freeing by another task.  It is the caller's responsibility to free the
 * extra reference for shared policies.
1652
 */
S
Stephen Wilson 已提交
1653
struct mempolicy *get_vma_policy(struct task_struct *task,
1654
		struct vm_area_struct *vma, unsigned long addr)
L
Linus Torvalds 已提交
1655
{
M
Mel Gorman 已提交
1656
	struct mempolicy *pol = get_task_policy(task);
L
Linus Torvalds 已提交
1657 1658

	if (vma) {
1659
		if (vma->vm_ops && vma->vm_ops->get_policy) {
1660 1661 1662 1663
			struct mempolicy *vpol = vma->vm_ops->get_policy(vma,
									addr);
			if (vpol)
				pol = vpol;
1664
		} else if (vma->vm_policy) {
L
Linus Torvalds 已提交
1665
			pol = vma->vm_policy;
1666 1667 1668 1669 1670 1671 1672 1673 1674 1675

			/*
			 * shmem_alloc_page() passes MPOL_F_SHARED policy with
			 * a pseudo vma whose vma->vm_ops=NULL. Take a reference
			 * count on these policies which will be dropped by
			 * mpol_cond_put() later
			 */
			if (mpol_needs_cond_ref(pol))
				mpol_get(pol);
		}
L
Linus Torvalds 已提交
1676 1677 1678 1679 1680 1681
	}
	if (!pol)
		pol = &default_policy;
	return pol;
}

1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705
bool vma_policy_mof(struct task_struct *task, struct vm_area_struct *vma)
{
	struct mempolicy *pol = get_task_policy(task);
	if (vma) {
		if (vma->vm_ops && vma->vm_ops->get_policy) {
			bool ret = false;

			pol = vma->vm_ops->get_policy(vma, vma->vm_start);
			if (pol && (pol->flags & MPOL_F_MOF))
				ret = true;
			mpol_cond_put(pol);

			return ret;
		} else if (vma->vm_policy) {
			pol = vma->vm_policy;
		}
	}

	if (!pol)
		return default_policy.flags & MPOL_F_MOF;

	return pol->flags & MPOL_F_MOF;
}

1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725
static int apply_policy_zone(struct mempolicy *policy, enum zone_type zone)
{
	enum zone_type dynamic_policy_zone = policy_zone;

	BUG_ON(dynamic_policy_zone == ZONE_MOVABLE);

	/*
	 * if policy->v.nodes has movable memory only,
	 * we apply policy when gfp_zone(gfp) = ZONE_MOVABLE only.
	 *
	 * policy->v.nodes is intersect with node_states[N_MEMORY].
	 * so if the following test faile, it implies
	 * policy->v.nodes has movable memory only.
	 */
	if (!nodes_intersects(policy->v.nodes, node_states[N_HIGH_MEMORY]))
		dynamic_policy_zone = ZONE_MOVABLE;

	return zone >= dynamic_policy_zone;
}

1726 1727 1728 1729 1730
/*
 * Return a nodemask representing a mempolicy for filtering nodes for
 * page allocation
 */
static nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy)
1731 1732
{
	/* Lower zones don't get a nodemask applied for MPOL_BIND */
1733
	if (unlikely(policy->mode == MPOL_BIND) &&
1734
			apply_policy_zone(policy, gfp_zone(gfp)) &&
1735 1736 1737 1738 1739 1740
			cpuset_nodemask_valid_mems_allowed(&policy->v.nodes))
		return &policy->v.nodes;

	return NULL;
}

1741
/* Return a zonelist indicated by gfp for node representing a mempolicy */
1742 1743
static struct zonelist *policy_zonelist(gfp_t gfp, struct mempolicy *policy,
	int nd)
L
Linus Torvalds 已提交
1744
{
1745
	switch (policy->mode) {
L
Linus Torvalds 已提交
1746
	case MPOL_PREFERRED:
1747 1748
		if (!(policy->flags & MPOL_F_LOCAL))
			nd = policy->v.preferred_node;
L
Linus Torvalds 已提交
1749 1750
		break;
	case MPOL_BIND:
1751
		/*
1752 1753
		 * Normally, MPOL_BIND allocations are node-local within the
		 * allowed nodemask.  However, if __GFP_THISNODE is set and the
1754
		 * current node isn't part of the mask, we use the zonelist for
1755
		 * the first node in the mask instead.
1756 1757 1758 1759 1760
		 */
		if (unlikely(gfp & __GFP_THISNODE) &&
				unlikely(!node_isset(nd, policy->v.nodes)))
			nd = first_node(policy->v.nodes);
		break;
L
Linus Torvalds 已提交
1761 1762 1763
	default:
		BUG();
	}
1764
	return node_zonelist(nd, gfp);
L
Linus Torvalds 已提交
1765 1766 1767 1768 1769 1770 1771 1772 1773
}

/* Do dynamic interleaving for a process */
static unsigned interleave_nodes(struct mempolicy *policy)
{
	unsigned nid, next;
	struct task_struct *me = current;

	nid = me->il_next;
1774
	next = next_node(nid, policy->v.nodes);
L
Linus Torvalds 已提交
1775
	if (next >= MAX_NUMNODES)
1776
		next = first_node(policy->v.nodes);
1777 1778
	if (next < MAX_NUMNODES)
		me->il_next = next;
L
Linus Torvalds 已提交
1779 1780 1781
	return nid;
}

1782 1783 1784
/*
 * Depending on the memory policy provide a node from which to allocate the
 * next slab entry.
1785 1786 1787 1788
 * @policy must be protected by freeing by the caller.  If @policy is
 * the current task's mempolicy, this protection is implicit, as only the
 * task can change it's policy.  The system default policy requires no
 * such protection.
1789
 */
1790
unsigned slab_node(void)
1791
{
1792 1793 1794 1795 1796 1797
	struct mempolicy *policy;

	if (in_interrupt())
		return numa_node_id();

	policy = current->mempolicy;
1798
	if (!policy || policy->flags & MPOL_F_LOCAL)
1799 1800 1801 1802
		return numa_node_id();

	switch (policy->mode) {
	case MPOL_PREFERRED:
1803 1804 1805 1806
		/*
		 * handled MPOL_F_LOCAL above
		 */
		return policy->v.preferred_node;
1807

1808 1809 1810
	case MPOL_INTERLEAVE:
		return interleave_nodes(policy);

1811
	case MPOL_BIND: {
1812 1813 1814 1815
		/*
		 * Follow bind policy behavior and start allocation at the
		 * first node.
		 */
1816 1817 1818 1819 1820 1821 1822
		struct zonelist *zonelist;
		struct zone *zone;
		enum zone_type highest_zoneidx = gfp_zone(GFP_KERNEL);
		zonelist = &NODE_DATA(numa_node_id())->node_zonelists[0];
		(void)first_zones_zonelist(zonelist, highest_zoneidx,
							&policy->v.nodes,
							&zone);
E
Eric Dumazet 已提交
1823
		return zone ? zone->node : numa_node_id();
1824
	}
1825 1826

	default:
1827
		BUG();
1828 1829 1830
	}
}

L
Linus Torvalds 已提交
1831 1832 1833 1834
/* Do static interleaving for a VMA with known offset. */
static unsigned offset_il_node(struct mempolicy *pol,
		struct vm_area_struct *vma, unsigned long off)
{
1835
	unsigned nnodes = nodes_weight(pol->v.nodes);
1836
	unsigned target;
L
Linus Torvalds 已提交
1837
	int c;
J
Jianguo Wu 已提交
1838
	int nid = NUMA_NO_NODE;
L
Linus Torvalds 已提交
1839

1840 1841 1842
	if (!nnodes)
		return numa_node_id();
	target = (unsigned int)off % nnodes;
L
Linus Torvalds 已提交
1843 1844
	c = 0;
	do {
1845
		nid = next_node(nid, pol->v.nodes);
L
Linus Torvalds 已提交
1846 1847 1848 1849 1850
		c++;
	} while (c <= target);
	return nid;
}

1851 1852 1853 1854 1855 1856 1857
/* Determine a node number for interleave */
static inline unsigned interleave_nid(struct mempolicy *pol,
		 struct vm_area_struct *vma, unsigned long addr, int shift)
{
	if (vma) {
		unsigned long off;

1858 1859 1860 1861 1862 1863 1864 1865 1866
		/*
		 * for small pages, there is no difference between
		 * shift and PAGE_SHIFT, so the bit-shift is safe.
		 * for huge pages, since vm_pgoff is in units of small
		 * pages, we need to shift off the always 0 bits to get
		 * a useful offset.
		 */
		BUG_ON(shift < PAGE_SHIFT);
		off = vma->vm_pgoff >> (shift - PAGE_SHIFT);
1867 1868 1869 1870 1871 1872
		off += (addr - vma->vm_start) >> shift;
		return offset_il_node(pol, vma, off);
	} else
		return interleave_nodes(pol);
}

1873 1874
/*
 * Return the bit number of a random bit set in the nodemask.
J
Jianguo Wu 已提交
1875
 * (returns NUMA_NO_NODE if nodemask is empty)
1876 1877 1878
 */
int node_random(const nodemask_t *maskp)
{
J
Jianguo Wu 已提交
1879
	int w, bit = NUMA_NO_NODE;
1880 1881 1882 1883 1884 1885 1886 1887

	w = nodes_weight(*maskp);
	if (w)
		bit = bitmap_ord_to_pos(maskp->bits,
			get_random_int() % w, MAX_NUMNODES);
	return bit;
}

1888
#ifdef CONFIG_HUGETLBFS
1889 1890 1891 1892 1893
/*
 * huge_zonelist(@vma, @addr, @gfp_flags, @mpol)
 * @vma = virtual memory area whose policy is sought
 * @addr = address in @vma for shared policy lookup and interleave policy
 * @gfp_flags = for requested zone
1894 1895
 * @mpol = pointer to mempolicy pointer for reference counted mempolicy
 * @nodemask = pointer to nodemask pointer for MPOL_BIND nodemask
1896
 *
1897 1898 1899 1900
 * Returns a zonelist suitable for a huge page allocation and a pointer
 * to the struct mempolicy for conditional unref after allocation.
 * If the effective policy is 'BIND, returns a pointer to the mempolicy's
 * @nodemask for filtering the zonelist.
1901 1902
 *
 * Must be protected by get_mems_allowed()
1903
 */
1904
struct zonelist *huge_zonelist(struct vm_area_struct *vma, unsigned long addr,
1905 1906
				gfp_t gfp_flags, struct mempolicy **mpol,
				nodemask_t **nodemask)
1907
{
1908
	struct zonelist *zl;
1909

1910
	*mpol = get_vma_policy(current, vma, addr);
1911
	*nodemask = NULL;	/* assume !MPOL_BIND */
1912

1913 1914
	if (unlikely((*mpol)->mode == MPOL_INTERLEAVE)) {
		zl = node_zonelist(interleave_nid(*mpol, vma, addr,
1915
				huge_page_shift(hstate_vma(vma))), gfp_flags);
1916
	} else {
1917
		zl = policy_zonelist(gfp_flags, *mpol, numa_node_id());
1918 1919
		if ((*mpol)->mode == MPOL_BIND)
			*nodemask = &(*mpol)->v.nodes;
1920 1921
	}
	return zl;
1922
}
1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947

/*
 * init_nodemask_of_mempolicy
 *
 * If the current task's mempolicy is "default" [NULL], return 'false'
 * to indicate default policy.  Otherwise, extract the policy nodemask
 * for 'bind' or 'interleave' policy into the argument nodemask, or
 * initialize the argument nodemask to contain the single node for
 * 'preferred' or 'local' policy and return 'true' to indicate presence
 * of non-default mempolicy.
 *
 * We don't bother with reference counting the mempolicy [mpol_get/put]
 * because the current task is examining it's own mempolicy and a task's
 * mempolicy is only ever changed by the task itself.
 *
 * N.B., it is the caller's responsibility to free a returned nodemask.
 */
bool init_nodemask_of_mempolicy(nodemask_t *mask)
{
	struct mempolicy *mempolicy;
	int nid;

	if (!(mask && current->mempolicy))
		return false;

1948
	task_lock(current);
1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967
	mempolicy = current->mempolicy;
	switch (mempolicy->mode) {
	case MPOL_PREFERRED:
		if (mempolicy->flags & MPOL_F_LOCAL)
			nid = numa_node_id();
		else
			nid = mempolicy->v.preferred_node;
		init_nodemask_of_node(mask, nid);
		break;

	case MPOL_BIND:
		/* Fall through */
	case MPOL_INTERLEAVE:
		*mask =  mempolicy->v.nodes;
		break;

	default:
		BUG();
	}
1968
	task_unlock(current);
1969 1970 1971

	return true;
}
1972
#endif
1973

1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017
/*
 * mempolicy_nodemask_intersects
 *
 * If tsk's mempolicy is "default" [NULL], return 'true' to indicate default
 * policy.  Otherwise, check for intersection between mask and the policy
 * nodemask for 'bind' or 'interleave' policy.  For 'perferred' or 'local'
 * policy, always return true since it may allocate elsewhere on fallback.
 *
 * Takes task_lock(tsk) to prevent freeing of its mempolicy.
 */
bool mempolicy_nodemask_intersects(struct task_struct *tsk,
					const nodemask_t *mask)
{
	struct mempolicy *mempolicy;
	bool ret = true;

	if (!mask)
		return ret;
	task_lock(tsk);
	mempolicy = tsk->mempolicy;
	if (!mempolicy)
		goto out;

	switch (mempolicy->mode) {
	case MPOL_PREFERRED:
		/*
		 * MPOL_PREFERRED and MPOL_F_LOCAL are only preferred nodes to
		 * allocate from, they may fallback to other nodes when oom.
		 * Thus, it's possible for tsk to have allocated memory from
		 * nodes in mask.
		 */
		break;
	case MPOL_BIND:
	case MPOL_INTERLEAVE:
		ret = nodes_intersects(mempolicy->v.nodes, *mask);
		break;
	default:
		BUG();
	}
out:
	task_unlock(tsk);
	return ret;
}

L
Linus Torvalds 已提交
2018 2019
/* Allocate a page in interleaved policy.
   Own path because it needs to do special accounting. */
2020 2021
static struct page *alloc_page_interleave(gfp_t gfp, unsigned order,
					unsigned nid)
L
Linus Torvalds 已提交
2022 2023 2024 2025
{
	struct zonelist *zl;
	struct page *page;

2026
	zl = node_zonelist(nid, gfp);
L
Linus Torvalds 已提交
2027
	page = __alloc_pages(gfp, order, zl);
2028
	if (page && page_zone(page) == zonelist_zone(&zl->_zonerefs[0]))
2029
		inc_zone_page_state(page, NUMA_INTERLEAVE_HIT);
L
Linus Torvalds 已提交
2030 2031 2032 2033
	return page;
}

/**
2034
 * 	alloc_pages_vma	- Allocate a page for a VMA.
L
Linus Torvalds 已提交
2035 2036 2037 2038 2039 2040 2041 2042
 *
 * 	@gfp:
 *      %GFP_USER    user allocation.
 *      %GFP_KERNEL  kernel allocations,
 *      %GFP_HIGHMEM highmem/user allocations,
 *      %GFP_FS      allocation should not call back into a file system.
 *      %GFP_ATOMIC  don't sleep.
 *
2043
 *	@order:Order of the GFP allocation.
L
Linus Torvalds 已提交
2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056
 * 	@vma:  Pointer to VMA or NULL if not available.
 *	@addr: Virtual Address of the allocation. Must be inside the VMA.
 *
 * 	This function allocates a page from the kernel page pool and applies
 *	a NUMA policy associated with the VMA or the current process.
 *	When VMA is not NULL caller must hold down_read on the mmap_sem of the
 *	mm_struct of the VMA to prevent it from going away. Should be used for
 *	all allocations for pages that will be mapped into
 * 	user space. Returns NULL when no page can be allocated.
 *
 *	Should be called with the mm_sem of the vma hold.
 */
struct page *
2057
alloc_pages_vma(gfp_t gfp, int order, struct vm_area_struct *vma,
2058
		unsigned long addr, int node)
L
Linus Torvalds 已提交
2059
{
2060
	struct mempolicy *pol;
2061
	struct page *page;
2062 2063 2064 2065 2066
	unsigned int cpuset_mems_cookie;

retry_cpuset:
	pol = get_vma_policy(current, vma, addr);
	cpuset_mems_cookie = get_mems_allowed();
L
Linus Torvalds 已提交
2067

2068
	if (unlikely(pol->mode == MPOL_INTERLEAVE)) {
L
Linus Torvalds 已提交
2069
		unsigned nid;
2070

2071
		nid = interleave_nid(pol, vma, addr, PAGE_SHIFT + order);
2072
		mpol_cond_put(pol);
2073
		page = alloc_page_interleave(gfp, order, nid);
2074 2075 2076
		if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page))
			goto retry_cpuset;

2077
		return page;
L
Linus Torvalds 已提交
2078
	}
2079 2080
	page = __alloc_pages_nodemask(gfp, order,
				      policy_zonelist(gfp, pol, node),
2081
				      policy_nodemask(gfp, pol));
2082 2083
	if (unlikely(mpol_needs_cond_ref(pol)))
		__mpol_put(pol);
2084 2085
	if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page))
		goto retry_cpuset;
2086
	return page;
L
Linus Torvalds 已提交
2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103
}

/**
 * 	alloc_pages_current - Allocate pages.
 *
 *	@gfp:
 *		%GFP_USER   user allocation,
 *      	%GFP_KERNEL kernel allocation,
 *      	%GFP_HIGHMEM highmem allocation,
 *      	%GFP_FS     don't call back into a file system.
 *      	%GFP_ATOMIC don't sleep.
 *	@order: Power of two of allocation size in pages. 0 is a single page.
 *
 *	Allocate a page from the kernel page pool.  When not in
 *	interrupt context and apply the current process NUMA policy.
 *	Returns NULL when no page can be allocated.
 *
2104
 *	Don't call cpuset_update_task_memory_state() unless
L
Linus Torvalds 已提交
2105 2106 2107
 *	1) it's ok to take cpuset_sem (can WAIT), and
 *	2) allocating for current task (not interrupt).
 */
A
Al Viro 已提交
2108
struct page *alloc_pages_current(gfp_t gfp, unsigned order)
L
Linus Torvalds 已提交
2109
{
M
Mel Gorman 已提交
2110
	struct mempolicy *pol = get_task_policy(current);
2111
	struct page *page;
2112
	unsigned int cpuset_mems_cookie;
L
Linus Torvalds 已提交
2113

2114
	if (!pol || in_interrupt() || (gfp & __GFP_THISNODE))
L
Linus Torvalds 已提交
2115
		pol = &default_policy;
2116

2117 2118 2119
retry_cpuset:
	cpuset_mems_cookie = get_mems_allowed();

2120 2121 2122 2123
	/*
	 * No reference counting needed for current->mempolicy
	 * nor system default_policy
	 */
2124
	if (pol->mode == MPOL_INTERLEAVE)
2125 2126 2127
		page = alloc_page_interleave(gfp, order, interleave_nodes(pol));
	else
		page = __alloc_pages_nodemask(gfp, order,
2128 2129
				policy_zonelist(gfp, pol, numa_node_id()),
				policy_nodemask(gfp, pol));
2130 2131 2132 2133

	if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page))
		goto retry_cpuset;

2134
	return page;
L
Linus Torvalds 已提交
2135 2136 2137
}
EXPORT_SYMBOL(alloc_pages_current);

2138 2139 2140 2141 2142 2143 2144 2145 2146 2147
int vma_dup_policy(struct vm_area_struct *src, struct vm_area_struct *dst)
{
	struct mempolicy *pol = mpol_dup(vma_policy(src));

	if (IS_ERR(pol))
		return PTR_ERR(pol);
	dst->vm_policy = pol;
	return 0;
}

2148
/*
2149
 * If mpol_dup() sees current->cpuset == cpuset_being_rebound, then it
2150 2151 2152 2153
 * rebinds the mempolicy its copying by calling mpol_rebind_policy()
 * with the mems_allowed returned by cpuset_mems_allowed().  This
 * keeps mempolicies cpuset relative after its cpuset moves.  See
 * further kernel/cpuset.c update_nodemask().
2154 2155 2156
 *
 * current's mempolicy may be rebinded by the other task(the task that changes
 * cpuset's mems), so we needn't do rebind work for current task.
2157 2158
 */

2159 2160
/* Slow path of a mempolicy duplicate */
struct mempolicy *__mpol_dup(struct mempolicy *old)
L
Linus Torvalds 已提交
2161 2162 2163 2164 2165
{
	struct mempolicy *new = kmem_cache_alloc(policy_cache, GFP_KERNEL);

	if (!new)
		return ERR_PTR(-ENOMEM);
2166 2167 2168 2169 2170 2171 2172 2173 2174

	/* task's mempolicy is protected by alloc_lock */
	if (old == current->mempolicy) {
		task_lock(current);
		*new = *old;
		task_unlock(current);
	} else
		*new = *old;

2175
	rcu_read_lock();
2176 2177
	if (current_cpuset_is_being_rebound()) {
		nodemask_t mems = cpuset_mems_allowed(current);
2178 2179 2180 2181
		if (new->flags & MPOL_F_REBINDING)
			mpol_rebind_policy(new, &mems, MPOL_REBIND_STEP2);
		else
			mpol_rebind_policy(new, &mems, MPOL_REBIND_ONCE);
2182
	}
2183
	rcu_read_unlock();
L
Linus Torvalds 已提交
2184 2185 2186 2187 2188
	atomic_set(&new->refcnt, 1);
	return new;
}

/* Slow path of a mempolicy comparison */
2189
bool __mpol_equal(struct mempolicy *a, struct mempolicy *b)
L
Linus Torvalds 已提交
2190 2191
{
	if (!a || !b)
2192
		return false;
2193
	if (a->mode != b->mode)
2194
		return false;
B
Bob Liu 已提交
2195
	if (a->flags != b->flags)
2196
		return false;
B
Bob Liu 已提交
2197 2198
	if (mpol_store_user_nodemask(a))
		if (!nodes_equal(a->w.user_nodemask, b->w.user_nodemask))
2199
			return false;
B
Bob Liu 已提交
2200

2201
	switch (a->mode) {
2202 2203
	case MPOL_BIND:
		/* Fall through */
L
Linus Torvalds 已提交
2204
	case MPOL_INTERLEAVE:
2205
		return !!nodes_equal(a->v.nodes, b->v.nodes);
L
Linus Torvalds 已提交
2206
	case MPOL_PREFERRED:
2207
		return a->v.preferred_node == b->v.preferred_node;
L
Linus Torvalds 已提交
2208 2209
	default:
		BUG();
2210
		return false;
L
Linus Torvalds 已提交
2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223
	}
}

/*
 * Shared memory backing store policy support.
 *
 * Remember policies even when nobody has shared memory mapped.
 * The policies are kept in Red-Black tree linked from the inode.
 * They are protected by the sp->lock spinlock, which should be held
 * for any accesses to the tree.
 */

/* lookup first element intersecting start-end */
2224
/* Caller holds sp->lock */
L
Linus Torvalds 已提交
2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274
static struct sp_node *
sp_lookup(struct shared_policy *sp, unsigned long start, unsigned long end)
{
	struct rb_node *n = sp->root.rb_node;

	while (n) {
		struct sp_node *p = rb_entry(n, struct sp_node, nd);

		if (start >= p->end)
			n = n->rb_right;
		else if (end <= p->start)
			n = n->rb_left;
		else
			break;
	}
	if (!n)
		return NULL;
	for (;;) {
		struct sp_node *w = NULL;
		struct rb_node *prev = rb_prev(n);
		if (!prev)
			break;
		w = rb_entry(prev, struct sp_node, nd);
		if (w->end <= start)
			break;
		n = prev;
	}
	return rb_entry(n, struct sp_node, nd);
}

/* Insert a new shared policy into the list. */
/* Caller holds sp->lock */
static void sp_insert(struct shared_policy *sp, struct sp_node *new)
{
	struct rb_node **p = &sp->root.rb_node;
	struct rb_node *parent = NULL;
	struct sp_node *nd;

	while (*p) {
		parent = *p;
		nd = rb_entry(parent, struct sp_node, nd);
		if (new->start < nd->start)
			p = &(*p)->rb_left;
		else if (new->end > nd->end)
			p = &(*p)->rb_right;
		else
			BUG();
	}
	rb_link_node(&new->nd, parent, p);
	rb_insert_color(&new->nd, &sp->root);
2275
	pr_debug("inserting %lx-%lx: %d\n", new->start, new->end,
2276
		 new->policy ? new->policy->mode : 0);
L
Linus Torvalds 已提交
2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287
}

/* Find shared policy intersecting idx */
struct mempolicy *
mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx)
{
	struct mempolicy *pol = NULL;
	struct sp_node *sn;

	if (!sp->root.rb_node)
		return NULL;
2288
	spin_lock(&sp->lock);
L
Linus Torvalds 已提交
2289 2290 2291 2292 2293
	sn = sp_lookup(sp, idx, idx+1);
	if (sn) {
		mpol_get(sn->policy);
		pol = sn->policy;
	}
2294
	spin_unlock(&sp->lock);
L
Linus Torvalds 已提交
2295 2296 2297
	return pol;
}

2298 2299 2300 2301 2302 2303
static void sp_free(struct sp_node *n)
{
	mpol_put(n->policy);
	kmem_cache_free(sn_cache, n);
}

2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332
#ifdef CONFIG_NUMA_BALANCING
static bool numa_migrate_deferred(struct task_struct *p, int last_cpupid)
{
	/* Never defer a private fault */
	if (cpupid_match_pid(p, last_cpupid))
		return false;

	if (p->numa_migrate_deferred) {
		p->numa_migrate_deferred--;
		return true;
	}
	return false;
}

static inline void defer_numa_migrate(struct task_struct *p)
{
	p->numa_migrate_deferred = sysctl_numa_balancing_migrate_deferred;
}
#else
static inline bool numa_migrate_deferred(struct task_struct *p, int last_cpupid)
{
	return false;
}

static inline void defer_numa_migrate(struct task_struct *p)
{
}
#endif /* CONFIG_NUMA_BALANCING */

2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355
/**
 * mpol_misplaced - check whether current page node is valid in policy
 *
 * @page   - page to be checked
 * @vma    - vm area where page mapped
 * @addr   - virtual address where page mapped
 *
 * Lookup current policy node id for vma,addr and "compare to" page's
 * node id.
 *
 * Returns:
 *	-1	- not misplaced, page is in the right node
 *	node	- node id where the page should be
 *
 * Policy determination "mimics" alloc_page_vma().
 * Called from fault path where we know the vma and faulting address.
 */
int mpol_misplaced(struct page *page, struct vm_area_struct *vma, unsigned long addr)
{
	struct mempolicy *pol;
	struct zone *zone;
	int curnid = page_to_nid(page);
	unsigned long pgoff;
2356 2357
	int thiscpu = raw_smp_processor_id();
	int thisnid = cpu_to_node(thiscpu);
2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402
	int polnid = -1;
	int ret = -1;

	BUG_ON(!vma);

	pol = get_vma_policy(current, vma, addr);
	if (!(pol->flags & MPOL_F_MOF))
		goto out;

	switch (pol->mode) {
	case MPOL_INTERLEAVE:
		BUG_ON(addr >= vma->vm_end);
		BUG_ON(addr < vma->vm_start);

		pgoff = vma->vm_pgoff;
		pgoff += (addr - vma->vm_start) >> PAGE_SHIFT;
		polnid = offset_il_node(pol, vma, pgoff);
		break;

	case MPOL_PREFERRED:
		if (pol->flags & MPOL_F_LOCAL)
			polnid = numa_node_id();
		else
			polnid = pol->v.preferred_node;
		break;

	case MPOL_BIND:
		/*
		 * allows binding to multiple nodes.
		 * use current page if in policy nodemask,
		 * else select nearest allowed node, if any.
		 * If no allowed nodes, use current [!misplaced].
		 */
		if (node_isset(curnid, pol->v.nodes))
			goto out;
		(void)first_zones_zonelist(
				node_zonelist(numa_node_id(), GFP_HIGHUSER),
				gfp_zone(GFP_HIGHUSER),
				&pol->v.nodes, &zone);
		polnid = zone->node;
		break;

	default:
		BUG();
	}
M
Mel Gorman 已提交
2403 2404

	/* Migrate the page towards the node whose CPU is referencing it */
2405
	if (pol->flags & MPOL_F_MORON) {
2406 2407
		int last_cpupid;
		int this_cpupid;
2408

2409 2410
		polnid = thisnid;
		this_cpupid = cpu_pid_to_cpupid(thiscpu, current->pid);
M
Mel Gorman 已提交
2411

2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432
		/*
		 * Multi-stage node selection is used in conjunction
		 * with a periodic migration fault to build a temporal
		 * task<->page relation. By using a two-stage filter we
		 * remove short/unlikely relations.
		 *
		 * Using P(p) ~ n_p / n_t as per frequentist
		 * probability, we can equate a task's usage of a
		 * particular page (n_p) per total usage of this
		 * page (n_t) (in a given time-span) to a probability.
		 *
		 * Our periodic faults will sample this probability and
		 * getting the same result twice in a row, given these
		 * samples are fully independent, is then given by
		 * P(n)^2, provided our sample period is sufficiently
		 * short compared to the usage pattern.
		 *
		 * This quadric squishes small probabilities, making
		 * it less likely we act on an unlikely task<->page
		 * relation.
		 */
2433
		last_cpupid = page_cpupid_xchg_last(page, this_cpupid);
2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451
		if (!cpupid_pid_unset(last_cpupid) && cpupid_to_nid(last_cpupid) != thisnid) {

			/* See sysctl_numa_balancing_migrate_deferred comment */
			if (!cpupid_match_pid(current, last_cpupid))
				defer_numa_migrate(current);

			goto out;
		}

		/*
		 * The quadratic filter above reduces extraneous migration
		 * of shared pages somewhat. This code reduces it even more,
		 * reducing the overhead of page migrations of shared pages.
		 * This makes workloads with shared pages rely more on
		 * "move task near its memory", and less on "move memory
		 * towards its task", which is exactly what we want.
		 */
		if (numa_migrate_deferred(current, last_cpupid))
2452 2453 2454
			goto out;
	}

2455 2456 2457 2458 2459 2460 2461 2462
	if (curnid != polnid)
		ret = polnid;
out:
	mpol_cond_put(pol);

	return ret;
}

L
Linus Torvalds 已提交
2463 2464
static void sp_delete(struct shared_policy *sp, struct sp_node *n)
{
2465
	pr_debug("deleting %lx-l%lx\n", n->start, n->end);
L
Linus Torvalds 已提交
2466
	rb_erase(&n->nd, &sp->root);
2467
	sp_free(n);
L
Linus Torvalds 已提交
2468 2469
}

2470 2471 2472 2473 2474 2475 2476 2477
static void sp_node_init(struct sp_node *node, unsigned long start,
			unsigned long end, struct mempolicy *pol)
{
	node->start = start;
	node->end = end;
	node->policy = pol;
}

A
Adrian Bunk 已提交
2478 2479
static struct sp_node *sp_alloc(unsigned long start, unsigned long end,
				struct mempolicy *pol)
L
Linus Torvalds 已提交
2480
{
2481 2482
	struct sp_node *n;
	struct mempolicy *newpol;
L
Linus Torvalds 已提交
2483

2484
	n = kmem_cache_alloc(sn_cache, GFP_KERNEL);
L
Linus Torvalds 已提交
2485 2486
	if (!n)
		return NULL;
2487 2488 2489 2490 2491 2492 2493

	newpol = mpol_dup(pol);
	if (IS_ERR(newpol)) {
		kmem_cache_free(sn_cache, n);
		return NULL;
	}
	newpol->flags |= MPOL_F_SHARED;
2494
	sp_node_init(n, start, end, newpol);
2495

L
Linus Torvalds 已提交
2496 2497 2498 2499 2500 2501 2502
	return n;
}

/* Replace a policy range. */
static int shared_policy_replace(struct shared_policy *sp, unsigned long start,
				 unsigned long end, struct sp_node *new)
{
2503
	struct sp_node *n;
2504 2505
	struct sp_node *n_new = NULL;
	struct mempolicy *mpol_new = NULL;
2506
	int ret = 0;
L
Linus Torvalds 已提交
2507

2508 2509
restart:
	spin_lock(&sp->lock);
L
Linus Torvalds 已提交
2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521
	n = sp_lookup(sp, start, end);
	/* Take care of old policies in the same range. */
	while (n && n->start < end) {
		struct rb_node *next = rb_next(&n->nd);
		if (n->start >= start) {
			if (n->end <= end)
				sp_delete(sp, n);
			else
				n->start = end;
		} else {
			/* Old policy spanning whole new range. */
			if (n->end > end) {
2522 2523 2524 2525 2526
				if (!n_new)
					goto alloc_new;

				*mpol_new = *n->policy;
				atomic_set(&mpol_new->refcnt, 1);
2527
				sp_node_init(n_new, end, n->end, mpol_new);
L
Linus Torvalds 已提交
2528
				n->end = start;
2529
				sp_insert(sp, n_new);
2530 2531
				n_new = NULL;
				mpol_new = NULL;
L
Linus Torvalds 已提交
2532 2533 2534 2535 2536 2537 2538 2539 2540 2541
				break;
			} else
				n->end = start;
		}
		if (!next)
			break;
		n = rb_entry(next, struct sp_node, nd);
	}
	if (new)
		sp_insert(sp, new);
2542 2543 2544 2545 2546 2547 2548 2549 2550
	spin_unlock(&sp->lock);
	ret = 0;

err_out:
	if (mpol_new)
		mpol_put(mpol_new);
	if (n_new)
		kmem_cache_free(sn_cache, n_new);

2551
	return ret;
2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562

alloc_new:
	spin_unlock(&sp->lock);
	ret = -ENOMEM;
	n_new = kmem_cache_alloc(sn_cache, GFP_KERNEL);
	if (!n_new)
		goto err_out;
	mpol_new = kmem_cache_alloc(policy_cache, GFP_KERNEL);
	if (!mpol_new)
		goto err_out;
	goto restart;
L
Linus Torvalds 已提交
2563 2564
}

2565 2566 2567 2568 2569 2570 2571 2572
/**
 * mpol_shared_policy_init - initialize shared policy for inode
 * @sp: pointer to inode shared policy
 * @mpol:  struct mempolicy to install
 *
 * Install non-NULL @mpol in inode's shared policy rb-tree.
 * On entry, the current task has a reference on a non-NULL @mpol.
 * This must be released on exit.
2573
 * This is called at get_inode() calls and we can use GFP_KERNEL.
2574 2575 2576
 */
void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol)
{
2577 2578
	int ret;

2579
	sp->root = RB_ROOT;		/* empty tree == default mempolicy */
2580
	spin_lock_init(&sp->lock);
2581 2582 2583 2584

	if (mpol) {
		struct vm_area_struct pvma;
		struct mempolicy *new;
2585
		NODEMASK_SCRATCH(scratch);
2586

2587
		if (!scratch)
2588
			goto put_mpol;
2589 2590
		/* contextualize the tmpfs mount point mempolicy */
		new = mpol_new(mpol->mode, mpol->flags, &mpol->w.user_nodemask);
2591
		if (IS_ERR(new))
2592
			goto free_scratch; /* no valid nodemask intersection */
2593 2594

		task_lock(current);
2595
		ret = mpol_set_nodemask(new, &mpol->w.user_nodemask, scratch);
2596
		task_unlock(current);
2597
		if (ret)
2598
			goto put_new;
2599 2600 2601 2602 2603

		/* Create pseudo-vma that contains just the policy */
		memset(&pvma, 0, sizeof(struct vm_area_struct));
		pvma.vm_end = TASK_SIZE;	/* policy covers entire file */
		mpol_set_shared_policy(sp, &pvma, new); /* adds ref */
2604

2605
put_new:
2606
		mpol_put(new);			/* drop initial ref */
2607
free_scratch:
2608
		NODEMASK_SCRATCH_FREE(scratch);
2609 2610
put_mpol:
		mpol_put(mpol);	/* drop our incoming ref on sb mpol */
2611 2612 2613
	}
}

L
Linus Torvalds 已提交
2614 2615 2616 2617 2618 2619 2620
int mpol_set_shared_policy(struct shared_policy *info,
			struct vm_area_struct *vma, struct mempolicy *npol)
{
	int err;
	struct sp_node *new = NULL;
	unsigned long sz = vma_pages(vma);

2621
	pr_debug("set_shared_policy %lx sz %lu %d %d %lx\n",
L
Linus Torvalds 已提交
2622
		 vma->vm_pgoff,
2623
		 sz, npol ? npol->mode : -1,
2624
		 npol ? npol->flags : -1,
D
David Rientjes 已提交
2625
		 npol ? nodes_addr(npol->v.nodes)[0] : NUMA_NO_NODE);
L
Linus Torvalds 已提交
2626 2627 2628 2629 2630 2631 2632 2633

	if (npol) {
		new = sp_alloc(vma->vm_pgoff, vma->vm_pgoff + sz, npol);
		if (!new)
			return -ENOMEM;
	}
	err = shared_policy_replace(info, vma->vm_pgoff, vma->vm_pgoff+sz, new);
	if (err && new)
2634
		sp_free(new);
L
Linus Torvalds 已提交
2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645
	return err;
}

/* Free a backing policy store on inode delete. */
void mpol_free_shared_policy(struct shared_policy *p)
{
	struct sp_node *n;
	struct rb_node *next;

	if (!p->root.rb_node)
		return;
2646
	spin_lock(&p->lock);
L
Linus Torvalds 已提交
2647 2648 2649 2650
	next = rb_first(&p->root);
	while (next) {
		n = rb_entry(next, struct sp_node, nd);
		next = rb_next(&n->nd);
2651
		sp_delete(p, n);
L
Linus Torvalds 已提交
2652
	}
2653
	spin_unlock(&p->lock);
L
Linus Torvalds 已提交
2654 2655
}

2656
#ifdef CONFIG_NUMA_BALANCING
2657
static int __initdata numabalancing_override;
2658 2659 2660 2661 2662 2663 2664 2665

static void __init check_numabalancing_enable(void)
{
	bool numabalancing_default = false;

	if (IS_ENABLED(CONFIG_NUMA_BALANCING_DEFAULT_ENABLED))
		numabalancing_default = true;

2666 2667 2668 2669
	/* Parsed by setup_numabalancing. override == 1 enables, -1 disables */
	if (numabalancing_override)
		set_numabalancing_state(numabalancing_override == 1);

2670
	if (nr_node_ids > 1 && !numabalancing_override) {
2671 2672 2673 2674
		printk(KERN_INFO "%s automatic NUMA balancing. "
			"Configure with numa_balancing= or the "
			"kernel.numa_balancing sysctl",
			numabalancing_default ? "Enabling" : "Disabling");
2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685
		set_numabalancing_state(numabalancing_default);
	}
}

static int __init setup_numabalancing(char *str)
{
	int ret = 0;
	if (!str)
		goto out;

	if (!strcmp(str, "enable")) {
2686
		numabalancing_override = 1;
2687 2688
		ret = 1;
	} else if (!strcmp(str, "disable")) {
2689
		numabalancing_override = -1;
2690 2691 2692 2693 2694 2695 2696 2697 2698 2699 2700 2701 2702 2703 2704
		ret = 1;
	}
out:
	if (!ret)
		printk(KERN_WARNING "Unable to parse numa_balancing=\n");

	return ret;
}
__setup("numa_balancing=", setup_numabalancing);
#else
static inline void __init check_numabalancing_enable(void)
{
}
#endif /* CONFIG_NUMA_BALANCING */

L
Linus Torvalds 已提交
2705 2706 2707
/* assumes fs == KERNEL_DS */
void __init numa_policy_init(void)
{
2708 2709 2710 2711
	nodemask_t interleave_nodes;
	unsigned long largest = 0;
	int nid, prefer = 0;

L
Linus Torvalds 已提交
2712 2713
	policy_cache = kmem_cache_create("numa_policy",
					 sizeof(struct mempolicy),
2714
					 0, SLAB_PANIC, NULL);
L
Linus Torvalds 已提交
2715 2716 2717

	sn_cache = kmem_cache_create("shared_policy_node",
				     sizeof(struct sp_node),
2718
				     0, SLAB_PANIC, NULL);
L
Linus Torvalds 已提交
2719

M
Mel Gorman 已提交
2720 2721 2722 2723 2724 2725 2726 2727 2728
	for_each_node(nid) {
		preferred_node_policy[nid] = (struct mempolicy) {
			.refcnt = ATOMIC_INIT(1),
			.mode = MPOL_PREFERRED,
			.flags = MPOL_F_MOF | MPOL_F_MORON,
			.v = { .preferred_node = nid, },
		};
	}

2729 2730 2731 2732 2733 2734
	/*
	 * Set interleaving policy for system init. Interleaving is only
	 * enabled across suitably sized nodes (default is >= 16MB), or
	 * fall back to the largest node if they're all smaller.
	 */
	nodes_clear(interleave_nodes);
2735
	for_each_node_state(nid, N_MEMORY) {
2736 2737 2738 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748 2749 2750 2751
		unsigned long total_pages = node_present_pages(nid);

		/* Preserve the largest node */
		if (largest < total_pages) {
			largest = total_pages;
			prefer = nid;
		}

		/* Interleave this node? */
		if ((total_pages << PAGE_SHIFT) >= (16 << 20))
			node_set(nid, interleave_nodes);
	}

	/* All too small, use the largest */
	if (unlikely(nodes_empty(interleave_nodes)))
		node_set(prefer, interleave_nodes);
L
Linus Torvalds 已提交
2752

2753
	if (do_set_mempolicy(MPOL_INTERLEAVE, 0, &interleave_nodes))
L
Linus Torvalds 已提交
2754
		printk("numa_policy_init: interleaving failed\n");
2755 2756

	check_numabalancing_enable();
L
Linus Torvalds 已提交
2757 2758
}

2759
/* Reset policy of current process to default */
L
Linus Torvalds 已提交
2760 2761
void numa_default_policy(void)
{
2762
	do_set_mempolicy(MPOL_DEFAULT, 0, NULL);
L
Linus Torvalds 已提交
2763
}
2764

2765 2766 2767 2768
/*
 * Parse and format mempolicy from/to strings
 */

2769
/*
2770
 * "local" is implemented internally by MPOL_PREFERRED with MPOL_F_LOCAL flag.
2771
 */
2772 2773 2774 2775 2776 2777
static const char * const policy_modes[] =
{
	[MPOL_DEFAULT]    = "default",
	[MPOL_PREFERRED]  = "prefer",
	[MPOL_BIND]       = "bind",
	[MPOL_INTERLEAVE] = "interleave",
L
Lee Schermerhorn 已提交
2778
	[MPOL_LOCAL]      = "local",
2779
};
2780

2781 2782 2783

#ifdef CONFIG_TMPFS
/**
2784
 * mpol_parse_str - parse string to mempolicy, for tmpfs mpol mount option.
2785
 * @str:  string containing mempolicy to parse
2786
 * @mpol:  pointer to struct mempolicy pointer, returned on success.
2787 2788 2789 2790
 *
 * Format of input:
 *	<mode>[=<flags>][:<nodelist>]
 *
2791
 * On success, returns 0, else 1
2792
 */
2793
int mpol_parse_str(char *str, struct mempolicy **mpol)
2794
{
2795
	struct mempolicy *new = NULL;
2796
	unsigned short mode;
2797
	unsigned short mode_flags;
2798
	nodemask_t nodes;
2799 2800 2801 2802 2803 2804 2805
	char *nodelist = strchr(str, ':');
	char *flags = strchr(str, '=');
	int err = 1;

	if (nodelist) {
		/* NUL-terminate mode or flags string */
		*nodelist++ = '\0';
2806
		if (nodelist_parse(nodelist, nodes))
2807
			goto out;
2808
		if (!nodes_subset(nodes, node_states[N_MEMORY]))
2809
			goto out;
2810 2811 2812
	} else
		nodes_clear(nodes);

2813 2814 2815
	if (flags)
		*flags++ = '\0';	/* terminate mode string */

2816
	for (mode = 0; mode < MPOL_MAX; mode++) {
2817
		if (!strcmp(str, policy_modes[mode])) {
2818 2819 2820
			break;
		}
	}
2821
	if (mode >= MPOL_MAX)
2822 2823
		goto out;

2824
	switch (mode) {
2825
	case MPOL_PREFERRED:
2826 2827 2828
		/*
		 * Insist on a nodelist of one node only
		 */
2829 2830 2831 2832
		if (nodelist) {
			char *rest = nodelist;
			while (isdigit(*rest))
				rest++;
2833 2834
			if (*rest)
				goto out;
2835 2836 2837 2838 2839 2840 2841
		}
		break;
	case MPOL_INTERLEAVE:
		/*
		 * Default to online nodes with memory if no nodelist
		 */
		if (!nodelist)
2842
			nodes = node_states[N_MEMORY];
2843
		break;
2844
	case MPOL_LOCAL:
2845
		/*
2846
		 * Don't allow a nodelist;  mpol_new() checks flags
2847
		 */
2848
		if (nodelist)
2849
			goto out;
2850
		mode = MPOL_PREFERRED;
2851
		break;
2852 2853 2854 2855 2856 2857 2858
	case MPOL_DEFAULT:
		/*
		 * Insist on a empty nodelist
		 */
		if (!nodelist)
			err = 0;
		goto out;
2859 2860 2861 2862 2863 2864
	case MPOL_BIND:
		/*
		 * Insist on a nodelist
		 */
		if (!nodelist)
			goto out;
2865 2866
	}

2867
	mode_flags = 0;
2868 2869 2870 2871 2872 2873
	if (flags) {
		/*
		 * Currently, we only support two mutually exclusive
		 * mode flags.
		 */
		if (!strcmp(flags, "static"))
2874
			mode_flags |= MPOL_F_STATIC_NODES;
2875
		else if (!strcmp(flags, "relative"))
2876
			mode_flags |= MPOL_F_RELATIVE_NODES;
2877
		else
2878
			goto out;
2879
	}
2880 2881 2882

	new = mpol_new(mode, mode_flags, &nodes);
	if (IS_ERR(new))
2883 2884
		goto out;

2885 2886 2887 2888 2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901
	/*
	 * Save nodes for mpol_to_str() to show the tmpfs mount options
	 * for /proc/mounts, /proc/pid/mounts and /proc/pid/mountinfo.
	 */
	if (mode != MPOL_PREFERRED)
		new->v.nodes = nodes;
	else if (nodelist)
		new->v.preferred_node = first_node(nodes);
	else
		new->flags |= MPOL_F_LOCAL;

	/*
	 * Save nodes for contextualization: this will be used to "clone"
	 * the mempolicy in a specific context [cpuset] at a later time.
	 */
	new->w.user_nodemask = nodes;

2902
	err = 0;
2903

2904 2905 2906 2907 2908 2909
out:
	/* Restore string for error message */
	if (nodelist)
		*--nodelist = ':';
	if (flags)
		*--flags = '=';
2910 2911
	if (!err)
		*mpol = new;
2912 2913 2914 2915
	return err;
}
#endif /* CONFIG_TMPFS */

2916 2917 2918 2919 2920 2921
/**
 * mpol_to_str - format a mempolicy structure for printing
 * @buffer:  to contain formatted mempolicy string
 * @maxlen:  length of @buffer
 * @pol:  pointer to mempolicy to be formatted
 *
2922 2923 2924
 * Convert @pol into a string.  If @buffer is too short, truncate the string.
 * Recommend a @maxlen of at least 32 for the longest mode, "interleave", the
 * longest flag, "relative", and to display at least a few node ids.
2925
 */
2926
void mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol)
2927 2928
{
	char *p = buffer;
2929 2930 2931
	nodemask_t nodes = NODE_MASK_NONE;
	unsigned short mode = MPOL_DEFAULT;
	unsigned short flags = 0;
2932

2933
	if (pol && pol != &default_policy) {
2934
		mode = pol->mode;
2935 2936
		flags = pol->flags;
	}
2937

2938 2939 2940 2941
	switch (mode) {
	case MPOL_DEFAULT:
		break;
	case MPOL_PREFERRED:
2942
		if (flags & MPOL_F_LOCAL)
2943
			mode = MPOL_LOCAL;
2944
		else
2945
			node_set(pol->v.preferred_node, nodes);
2946 2947 2948
		break;
	case MPOL_BIND:
	case MPOL_INTERLEAVE:
2949
		nodes = pol->v.nodes;
2950 2951
		break;
	default:
2952 2953 2954
		WARN_ON_ONCE(1);
		snprintf(p, maxlen, "unknown");
		return;
2955 2956
	}

2957
	p += snprintf(p, maxlen, "%s", policy_modes[mode]);
2958

2959
	if (flags & MPOL_MODE_FLAGS) {
2960
		p += snprintf(p, buffer + maxlen - p, "=");
2961

2962 2963 2964
		/*
		 * Currently, the only defined flags are mutually exclusive
		 */
2965
		if (flags & MPOL_F_STATIC_NODES)
2966 2967 2968
			p += snprintf(p, buffer + maxlen - p, "static");
		else if (flags & MPOL_F_RELATIVE_NODES)
			p += snprintf(p, buffer + maxlen - p, "relative");
2969 2970
	}

2971
	if (!nodes_empty(nodes)) {
2972
		p += snprintf(p, buffer + maxlen - p, ":");
2973 2974 2975
	 	p += nodelist_scnprintf(p, buffer + maxlen - p, nodes);
	}
}