mempolicy.c 31.6 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 29 30 31 32
 * preferred       Try a specific node first before normal fallback.
 *                As a special case node -1 here means do the allocation
 *                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 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97
 * 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.
   could replace all the switch()es with a mempolicy_ops structure.
*/

#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/mm.h>
#include <linux/nodemask.h>
#include <linux/cpuset.h>
#include <linux/gfp.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/compat.h>
#include <linux/mempolicy.h>
#include <asm/tlbflush.h>
#include <asm/uaccess.h>

static kmem_cache_t *policy_cache;
static kmem_cache_t *sn_cache;

#define PDprintk(fmt...)

/* Highest zone. An specific allocation for a zone below that is not
   policied. */
static int policy_zone;

98
struct mempolicy default_policy = {
L
Linus Torvalds 已提交
99 100 101 102 103
	.refcnt = ATOMIC_INIT(1), /* never free it */
	.policy = MPOL_DEFAULT,
};

/* Do sanity checking on a policy */
104
static int mpol_check_policy(int mode, nodemask_t *nodes)
L
Linus Torvalds 已提交
105
{
106
	int empty = nodes_empty(*nodes);
L
Linus Torvalds 已提交
107 108 109 110 111 112 113 114 115 116 117 118 119 120

	switch (mode) {
	case MPOL_DEFAULT:
		if (!empty)
			return -EINVAL;
		break;
	case MPOL_BIND:
	case MPOL_INTERLEAVE:
		/* Preferred will only use the first bit, but allow
		   more for now. */
		if (empty)
			return -EINVAL;
		break;
	}
121
	return nodes_subset(*nodes, node_online_map) ? 0 : -EINVAL;
L
Linus Torvalds 已提交
122 123
}
/* Generate a custom zonelist for the BIND policy. */
124
static struct zonelist *bind_zonelist(nodemask_t *nodes)
L
Linus Torvalds 已提交
125 126 127 128
{
	struct zonelist *zl;
	int num, max, nd;

129
	max = 1 + MAX_NR_ZONES * nodes_weight(*nodes);
L
Linus Torvalds 已提交
130 131 132 133
	zl = kmalloc(sizeof(void *) * max, GFP_KERNEL);
	if (!zl)
		return NULL;
	num = 0;
134
	for_each_node_mask(nd, *nodes) {
L
Linus Torvalds 已提交
135 136 137 138 139 140 141 142 143 144 145 146 147 148 149
		int k;
		for (k = MAX_NR_ZONES-1; k >= 0; k--) {
			struct zone *z = &NODE_DATA(nd)->node_zones[k];
			if (!z->present_pages)
				continue;
			zl->zones[num++] = z;
			if (k > policy_zone)
				policy_zone = k;
		}
	}
	zl->zones[num] = NULL;
	return zl;
}

/* Create a new policy */
150
static struct mempolicy *mpol_new(int mode, nodemask_t *nodes)
L
Linus Torvalds 已提交
151 152 153
{
	struct mempolicy *policy;

154
	PDprintk("setting mode %d nodes[0] %lx\n", mode, nodes_addr(*nodes)[0]);
L
Linus Torvalds 已提交
155 156 157 158 159 160 161 162
	if (mode == MPOL_DEFAULT)
		return NULL;
	policy = kmem_cache_alloc(policy_cache, GFP_KERNEL);
	if (!policy)
		return ERR_PTR(-ENOMEM);
	atomic_set(&policy->refcnt, 1);
	switch (mode) {
	case MPOL_INTERLEAVE:
163
		policy->v.nodes = *nodes;
L
Linus Torvalds 已提交
164 165
		break;
	case MPOL_PREFERRED:
166
		policy->v.preferred_node = first_node(*nodes);
L
Linus Torvalds 已提交
167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182
		if (policy->v.preferred_node >= MAX_NUMNODES)
			policy->v.preferred_node = -1;
		break;
	case MPOL_BIND:
		policy->v.zonelist = bind_zonelist(nodes);
		if (policy->v.zonelist == NULL) {
			kmem_cache_free(policy_cache, policy);
			return ERR_PTR(-ENOMEM);
		}
		break;
	}
	policy->policy = mode;
	return policy;
}

/* Ensure all existing pages follow the policy. */
N
Nick Piggin 已提交
183
static int check_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
184
		unsigned long addr, unsigned long end, nodemask_t *nodes)
L
Linus Torvalds 已提交
185
{
186 187
	pte_t *orig_pte;
	pte_t *pte;
188
	spinlock_t *ptl;
189

190
	orig_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
191 192 193 194 195
	do {
		unsigned long pfn;
		unsigned int nid;

		if (!pte_present(*pte))
L
Linus Torvalds 已提交
196
			continue;
197
		pfn = pte_pfn(*pte);
N
Nick Piggin 已提交
198 199
		if (!pfn_valid(pfn)) {
			print_bad_pte(vma, *pte, addr);
L
Linus Torvalds 已提交
200
			continue;
N
Nick Piggin 已提交
201
		}
202
		nid = pfn_to_nid(pfn);
203
		if (!node_isset(nid, *nodes))
204 205
			break;
	} while (pte++, addr += PAGE_SIZE, addr != end);
206
	pte_unmap_unlock(orig_pte, ptl);
207 208 209
	return addr != end;
}

N
Nick Piggin 已提交
210
static inline int check_pmd_range(struct vm_area_struct *vma, pud_t *pud,
211
		unsigned long addr, unsigned long end, nodemask_t *nodes)
212 213 214 215 216 217 218 219 220
{
	pmd_t *pmd;
	unsigned long next;

	pmd = pmd_offset(pud, addr);
	do {
		next = pmd_addr_end(addr, end);
		if (pmd_none_or_clear_bad(pmd))
			continue;
N
Nick Piggin 已提交
221
		if (check_pte_range(vma, pmd, addr, next, nodes))
222 223 224 225 226
			return -EIO;
	} while (pmd++, addr = next, addr != end);
	return 0;
}

N
Nick Piggin 已提交
227
static inline int check_pud_range(struct vm_area_struct *vma, pgd_t *pgd,
228
		unsigned long addr, unsigned long end, nodemask_t *nodes)
229 230 231 232 233 234 235 236 237
{
	pud_t *pud;
	unsigned long next;

	pud = pud_offset(pgd, addr);
	do {
		next = pud_addr_end(addr, end);
		if (pud_none_or_clear_bad(pud))
			continue;
N
Nick Piggin 已提交
238
		if (check_pmd_range(vma, pud, addr, next, nodes))
239 240 241 242 243
			return -EIO;
	} while (pud++, addr = next, addr != end);
	return 0;
}

N
Nick Piggin 已提交
244
static inline int check_pgd_range(struct vm_area_struct *vma,
245
		unsigned long addr, unsigned long end, nodemask_t *nodes)
246 247 248 249
{
	pgd_t *pgd;
	unsigned long next;

N
Nick Piggin 已提交
250
	pgd = pgd_offset(vma->vm_mm, addr);
251 252 253 254
	do {
		next = pgd_addr_end(addr, end);
		if (pgd_none_or_clear_bad(pgd))
			continue;
N
Nick Piggin 已提交
255
		if (check_pud_range(vma, pgd, addr, next, nodes))
256 257 258
			return -EIO;
	} while (pgd++, addr = next, addr != end);
	return 0;
L
Linus Torvalds 已提交
259 260 261 262 263
}

/* Step 1: check the range */
static struct vm_area_struct *
check_range(struct mm_struct *mm, unsigned long start, unsigned long end,
264
	    nodemask_t *nodes, unsigned long flags)
L
Linus Torvalds 已提交
265 266 267 268 269 270 271
{
	int err;
	struct vm_area_struct *first, *vma, *prev;

	first = find_vma(mm, start);
	if (!first)
		return ERR_PTR(-EFAULT);
N
Nick Piggin 已提交
272 273
	if (first->vm_flags & VM_RESERVED)
		return ERR_PTR(-EACCES);
L
Linus Torvalds 已提交
274 275 276 277 278 279 280
	prev = NULL;
	for (vma = first; vma && vma->vm_start < end; vma = vma->vm_next) {
		if (!vma->vm_next && vma->vm_end < end)
			return ERR_PTR(-EFAULT);
		if (prev && prev->vm_end < vma->vm_start)
			return ERR_PTR(-EFAULT);
		if ((flags & MPOL_MF_STRICT) && !is_vm_hugetlb_page(vma)) {
A
Andi Kleen 已提交
281 282 283 284 285
			unsigned long endvma = vma->vm_end;
			if (endvma > end)
				endvma = end;
			if (vma->vm_start > start)
				start = vma->vm_start;
N
Nick Piggin 已提交
286
			err = check_pgd_range(vma, start, endvma, nodes);
L
Linus Torvalds 已提交
287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339
			if (err) {
				first = ERR_PTR(err);
				break;
			}
		}
		prev = vma;
	}
	return first;
}

/* Apply policy to a single VMA */
static int policy_vma(struct vm_area_struct *vma, struct mempolicy *new)
{
	int err = 0;
	struct mempolicy *old = vma->vm_policy;

	PDprintk("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);

	if (vma->vm_ops && vma->vm_ops->set_policy)
		err = vma->vm_ops->set_policy(vma, new);
	if (!err) {
		mpol_get(new);
		vma->vm_policy = new;
		mpol_free(old);
	}
	return err;
}

/* Step 2: apply policy to a range and do splits. */
static int mbind_range(struct vm_area_struct *vma, unsigned long start,
		       unsigned long end, struct mempolicy *new)
{
	struct vm_area_struct *next;
	int err;

	err = 0;
	for (; vma && vma->vm_start < end; vma = next) {
		next = vma->vm_next;
		if (vma->vm_start < start)
			err = split_vma(vma->vm_mm, vma, start, 1);
		if (!err && vma->vm_end > end)
			err = split_vma(vma->vm_mm, vma, end, 0);
		if (!err)
			err = policy_vma(vma, new);
		if (err)
			break;
	}
	return err;
}

340 341 342 343 344 345 346 347 348 349 350 351 352 353
static int contextualize_policy(int mode, nodemask_t *nodes)
{
	if (!nodes)
		return 0;

	/* Update current mems_allowed */
	cpuset_update_current_mems_allowed();
	/* Ignore nodes not set in current->mems_allowed */
	cpuset_restrict_to_mems_allowed(nodes->bits);
	return mpol_check_policy(mode, nodes);
}

long do_mbind(unsigned long start, unsigned long len,
		unsigned long mode, nodemask_t *nmask, unsigned long flags)
L
Linus Torvalds 已提交
354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372
{
	struct vm_area_struct *vma;
	struct mm_struct *mm = current->mm;
	struct mempolicy *new;
	unsigned long end;
	int err;

	if ((flags & ~(unsigned long)(MPOL_MF_STRICT)) || mode > MPOL_MAX)
		return -EINVAL;
	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;
373
	if (mpol_check_policy(mode, nmask))
374 375
		return -EINVAL;
	new = mpol_new(mode, nmask);
L
Linus Torvalds 已提交
376 377 378 379
	if (IS_ERR(new))
		return PTR_ERR(new);

	PDprintk("mbind %lx-%lx mode:%ld nodes:%lx\n",start,start+len,
380
			mode,nodes_addr(nodes)[0]);
L
Linus Torvalds 已提交
381 382

	down_write(&mm->mmap_sem);
383
	vma = check_range(mm, start, end, nmask, flags);
L
Linus Torvalds 已提交
384 385 386 387 388 389 390 391 392
	err = PTR_ERR(vma);
	if (!IS_ERR(vma))
		err = mbind_range(vma, start, end, new);
	up_write(&mm->mmap_sem);
	mpol_free(new);
	return err;
}

/* Set the process memory policy */
393
long do_set_mempolicy(int mode, nodemask_t *nodes)
L
Linus Torvalds 已提交
394 395 396
{
	struct mempolicy *new;

397
	if (contextualize_policy(mode, nodes))
L
Linus Torvalds 已提交
398
		return -EINVAL;
399
	new = mpol_new(mode, nodes);
L
Linus Torvalds 已提交
400 401 402 403 404
	if (IS_ERR(new))
		return PTR_ERR(new);
	mpol_free(current->mempolicy);
	current->mempolicy = new;
	if (new && new->policy == MPOL_INTERLEAVE)
405
		current->il_next = first_node(new->v.nodes);
L
Linus Torvalds 已提交
406 407 408 409
	return 0;
}

/* Fill a zone bitmap for a policy */
410
static void get_zonemask(struct mempolicy *p, nodemask_t *nodes)
L
Linus Torvalds 已提交
411 412 413
{
	int i;

414
	nodes_clear(*nodes);
L
Linus Torvalds 已提交
415 416 417
	switch (p->policy) {
	case MPOL_BIND:
		for (i = 0; p->v.zonelist->zones[i]; i++)
418 419
			node_set(p->v.zonelist->zones[i]->zone_pgdat->node_id,
				*nodes);
L
Linus Torvalds 已提交
420 421 422 423
		break;
	case MPOL_DEFAULT:
		break;
	case MPOL_INTERLEAVE:
424
		*nodes = p->v.nodes;
L
Linus Torvalds 已提交
425 426 427 428
		break;
	case MPOL_PREFERRED:
		/* or use current node instead of online map? */
		if (p->v.preferred_node < 0)
429
			*nodes = node_online_map;
L
Linus Torvalds 已提交
430
		else
431
			node_set(p->v.preferred_node, *nodes);
L
Linus Torvalds 已提交
432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451
		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 */
452 453
long do_get_mempolicy(int *policy, nodemask_t *nmask,
			unsigned long addr, unsigned long flags)
L
Linus Torvalds 已提交
454
{
455
	int err;
L
Linus Torvalds 已提交
456 457 458 459
	struct mm_struct *mm = current->mm;
	struct vm_area_struct *vma = NULL;
	struct mempolicy *pol = current->mempolicy;

460
	cpuset_update_current_mems_allowed();
L
Linus Torvalds 已提交
461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484
	if (flags & ~(unsigned long)(MPOL_F_NODE|MPOL_F_ADDR))
		return -EINVAL;
	if (flags & MPOL_F_ADDR) {
		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)
		pol = &default_policy;

	if (flags & MPOL_F_NODE) {
		if (flags & MPOL_F_ADDR) {
			err = lookup_node(mm, addr);
			if (err < 0)
				goto out;
485
			*policy = err;
L
Linus Torvalds 已提交
486 487
		} else if (pol == current->mempolicy &&
				pol->policy == MPOL_INTERLEAVE) {
488
			*policy = current->il_next;
L
Linus Torvalds 已提交
489 490 491 492 493
		} else {
			err = -EINVAL;
			goto out;
		}
	} else
494
		*policy = pol->policy;
L
Linus Torvalds 已提交
495 496 497 498 499 500 501

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

	err = 0;
502 503
	if (nmask)
		get_zonemask(pol, nmask);
L
Linus Torvalds 已提交
504 505 506 507 508 509 510

 out:
	if (vma)
		up_read(&current->mm->mmap_sem);
	return err;
}

511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630
/*
 * User space interface with variable sized bitmaps for nodelists.
 */

/* Copy a node mask from user space. */
static int get_nodes(nodemask_t *nodes, unsigned long __user *nmask,
		     unsigned long maxnode)
{
	unsigned long k;
	unsigned long nlongs;
	unsigned long endmask;

	--maxnode;
	nodes_clear(*nodes);
	if (maxnode == 0 || !nmask)
		return 0;

	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;
}

asmlinkage long sys_mbind(unsigned long start, unsigned long len,
			unsigned long mode,
			unsigned long __user *nmask, unsigned long maxnode,
			unsigned flags)
{
	nodemask_t nodes;
	int err;

	err = get_nodes(&nodes, nmask, maxnode);
	if (err)
		return err;
	return do_mbind(start, len, mode, &nodes, flags);
}

/* Set the process memory policy */
asmlinkage long sys_set_mempolicy(int mode, unsigned long __user *nmask,
		unsigned long maxnode)
{
	int err;
	nodemask_t nodes;

	if (mode < 0 || mode > MPOL_MAX)
		return -EINVAL;
	err = get_nodes(&nodes, nmask, maxnode);
	if (err)
		return err;
	return do_set_mempolicy(mode, &nodes);
}

/* Retrieve NUMA policy */
asmlinkage long sys_get_mempolicy(int __user *policy,
				unsigned long __user *nmask,
				unsigned long maxnode,
				unsigned long addr, unsigned long flags)
{
	int err, pval;
	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
631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690
#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) {
		err = copy_from_user(bm, nm, alloc_size);
		/* 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;
691
	nodemask_t bm;
L
Linus Torvalds 已提交
692 693 694 695 696

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

	if (nmask) {
697
		err = compat_get_bitmap(nodes_addr(bm), nmask, nr_bits);
L
Linus Torvalds 已提交
698
		nm = compat_alloc_user_space(alloc_size);
699
		err |= copy_to_user(nm, nodes_addr(bm), alloc_size);
L
Linus Torvalds 已提交
700 701 702 703 704 705 706 707 708 709 710
	}

	if (err)
		return -EFAULT;

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

#endif

/* Return effective policy for a VMA */
711 712
struct mempolicy *
get_vma_policy(struct task_struct *task, struct vm_area_struct *vma, unsigned long addr)
L
Linus Torvalds 已提交
713
{
714
	struct mempolicy *pol = task->mempolicy;
L
Linus Torvalds 已提交
715 716 717

	if (vma) {
		if (vma->vm_ops && vma->vm_ops->get_policy)
718
			pol = vma->vm_ops->get_policy(vma, addr);
L
Linus Torvalds 已提交
719 720 721 722 723 724 725 726 727 728
		else if (vma->vm_policy &&
				vma->vm_policy->policy != MPOL_DEFAULT)
			pol = vma->vm_policy;
	}
	if (!pol)
		pol = &default_policy;
	return pol;
}

/* Return a zonelist representing a mempolicy */
A
Al Viro 已提交
729
static struct zonelist *zonelist_policy(gfp_t gfp, struct mempolicy *policy)
L
Linus Torvalds 已提交
730 731 732 733 734 735 736 737 738 739 740 741
{
	int nd;

	switch (policy->policy) {
	case MPOL_PREFERRED:
		nd = policy->v.preferred_node;
		if (nd < 0)
			nd = numa_node_id();
		break;
	case MPOL_BIND:
		/* Lower zones don't get a policy applied */
		/* Careful: current->mems_allowed might have moved */
A
Al Viro 已提交
742
		if (gfp_zone(gfp) >= policy_zone)
L
Linus Torvalds 已提交
743 744 745 746 747 748 749 750 751 752 753
			if (cpuset_zonelist_valid_mems_allowed(policy->v.zonelist))
				return policy->v.zonelist;
		/*FALL THROUGH*/
	case MPOL_INTERLEAVE: /* should not happen */
	case MPOL_DEFAULT:
		nd = numa_node_id();
		break;
	default:
		nd = 0;
		BUG();
	}
A
Al Viro 已提交
754
	return NODE_DATA(nd)->node_zonelists + gfp_zone(gfp);
L
Linus Torvalds 已提交
755 756 757 758 759 760 761 762 763
}

/* 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;
764
	next = next_node(nid, policy->v.nodes);
L
Linus Torvalds 已提交
765
	if (next >= MAX_NUMNODES)
766
		next = first_node(policy->v.nodes);
L
Linus Torvalds 已提交
767 768 769 770 771 772 773 774
	me->il_next = next;
	return nid;
}

/* 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)
{
775
	unsigned nnodes = nodes_weight(pol->v.nodes);
L
Linus Torvalds 已提交
776 777 778 779 780 781
	unsigned target = (unsigned)off % nnodes;
	int c;
	int nid = -1;

	c = 0;
	do {
782
		nid = next_node(nid, pol->v.nodes);
L
Linus Torvalds 已提交
783 784 785 786 787 788 789
		c++;
	} while (c <= target);
	return nid;
}

/* Allocate a page in interleaved policy.
   Own path because it needs to do special accounting. */
790 791
static struct page *alloc_page_interleave(gfp_t gfp, unsigned order,
					unsigned nid)
L
Linus Torvalds 已提交
792 793 794 795
{
	struct zonelist *zl;
	struct page *page;

A
Al Viro 已提交
796
	zl = NODE_DATA(nid)->node_zonelists + gfp_zone(gfp);
L
Linus Torvalds 已提交
797 798
	page = __alloc_pages(gfp, order, zl);
	if (page && page_zone(page) == zl->zones[0]) {
799
		zone_pcp(zl->zones[0],get_cpu())->interleave_hit++;
L
Linus Torvalds 已提交
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
		put_cpu();
	}
	return page;
}

/**
 * 	alloc_page_vma	- Allocate a page for a VMA.
 *
 * 	@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.
 *
 * 	@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 *
A
Al Viro 已提交
828
alloc_page_vma(gfp_t gfp, struct vm_area_struct *vma, unsigned long addr)
L
Linus Torvalds 已提交
829
{
830
	struct mempolicy *pol = get_vma_policy(current, vma, addr);
L
Linus Torvalds 已提交
831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868

	cpuset_update_current_mems_allowed();

	if (unlikely(pol->policy == MPOL_INTERLEAVE)) {
		unsigned nid;
		if (vma) {
			unsigned long off;
			off = vma->vm_pgoff;
			off += (addr - vma->vm_start) >> PAGE_SHIFT;
			nid = offset_il_node(pol, vma, off);
		} else {
			/* fall back to process interleaving */
			nid = interleave_nodes(pol);
		}
		return alloc_page_interleave(gfp, 0, nid);
	}
	return __alloc_pages(gfp, 0, zonelist_policy(gfp, pol));
}

/**
 * 	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.
 *
 *	Don't call cpuset_update_current_mems_allowed() unless
 *	1) it's ok to take cpuset_sem (can WAIT), and
 *	2) allocating for current task (not interrupt).
 */
A
Al Viro 已提交
869
struct page *alloc_pages_current(gfp_t gfp, unsigned order)
L
Linus Torvalds 已提交
870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914
{
	struct mempolicy *pol = current->mempolicy;

	if ((gfp & __GFP_WAIT) && !in_interrupt())
		cpuset_update_current_mems_allowed();
	if (!pol || in_interrupt())
		pol = &default_policy;
	if (pol->policy == MPOL_INTERLEAVE)
		return alloc_page_interleave(gfp, order, interleave_nodes(pol));
	return __alloc_pages(gfp, order, zonelist_policy(gfp, pol));
}
EXPORT_SYMBOL(alloc_pages_current);

/* Slow path of a mempolicy copy */
struct mempolicy *__mpol_copy(struct mempolicy *old)
{
	struct mempolicy *new = kmem_cache_alloc(policy_cache, GFP_KERNEL);

	if (!new)
		return ERR_PTR(-ENOMEM);
	*new = *old;
	atomic_set(&new->refcnt, 1);
	if (new->policy == MPOL_BIND) {
		int sz = ksize(old->v.zonelist);
		new->v.zonelist = kmalloc(sz, SLAB_KERNEL);
		if (!new->v.zonelist) {
			kmem_cache_free(policy_cache, new);
			return ERR_PTR(-ENOMEM);
		}
		memcpy(new->v.zonelist, old->v.zonelist, sz);
	}
	return new;
}

/* Slow path of a mempolicy comparison */
int __mpol_equal(struct mempolicy *a, struct mempolicy *b)
{
	if (!a || !b)
		return 0;
	if (a->policy != b->policy)
		return 0;
	switch (a->policy) {
	case MPOL_DEFAULT:
		return 1;
	case MPOL_INTERLEAVE:
915
		return nodes_equal(a->v.nodes, b->v.nodes);
L
Linus Torvalds 已提交
916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949
	case MPOL_PREFERRED:
		return a->v.preferred_node == b->v.preferred_node;
	case MPOL_BIND: {
		int i;
		for (i = 0; a->v.zonelist->zones[i]; i++)
			if (a->v.zonelist->zones[i] != b->v.zonelist->zones[i])
				return 0;
		return b->v.zonelist->zones[i] == NULL;
	}
	default:
		BUG();
		return 0;
	}
}

/* Slow path of a mpol destructor. */
void __mpol_free(struct mempolicy *p)
{
	if (!atomic_dec_and_test(&p->refcnt))
		return;
	if (p->policy == MPOL_BIND)
		kfree(p->v.zonelist);
	p->policy = MPOL_DEFAULT;
	kmem_cache_free(policy_cache, p);
}

/*
 * Hugetlb policy. Same as above, just works with node numbers instead of
 * zonelists.
 */

/* Find first node suitable for an allocation */
int mpol_first_node(struct vm_area_struct *vma, unsigned long addr)
{
950
	struct mempolicy *pol = get_vma_policy(current, vma, addr);
L
Linus Torvalds 已提交
951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969

	switch (pol->policy) {
	case MPOL_DEFAULT:
		return numa_node_id();
	case MPOL_BIND:
		return pol->v.zonelist->zones[0]->zone_pgdat->node_id;
	case MPOL_INTERLEAVE:
		return interleave_nodes(pol);
	case MPOL_PREFERRED:
		return pol->v.preferred_node >= 0 ?
				pol->v.preferred_node : numa_node_id();
	}
	BUG();
	return 0;
}

/* Find secondary valid nodes for an allocation */
int mpol_node_valid(int nid, struct vm_area_struct *vma, unsigned long addr)
{
970
	struct mempolicy *pol = get_vma_policy(current, vma, addr);
L
Linus Torvalds 已提交
971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 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 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153

	switch (pol->policy) {
	case MPOL_PREFERRED:
	case MPOL_DEFAULT:
	case MPOL_INTERLEAVE:
		return 1;
	case MPOL_BIND: {
		struct zone **z;
		for (z = pol->v.zonelist->zones; *z; z++)
			if ((*z)->zone_pgdat->node_id == nid)
				return 1;
		return 0;
	}
	default:
		BUG();
		return 0;
	}
}

/*
 * 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 */
/* Caller holds sp->lock */
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);
	PDprintk("inserting %lx-%lx: %d\n", new->start, new->end,
		 new->policy ? new->policy->policy : 0);
}

/* 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;
	spin_lock(&sp->lock);
	sn = sp_lookup(sp, idx, idx+1);
	if (sn) {
		mpol_get(sn->policy);
		pol = sn->policy;
	}
	spin_unlock(&sp->lock);
	return pol;
}

static void sp_delete(struct shared_policy *sp, struct sp_node *n)
{
	PDprintk("deleting %lx-l%x\n", n->start, n->end);
	rb_erase(&n->nd, &sp->root);
	mpol_free(n->policy);
	kmem_cache_free(sn_cache, n);
}

struct sp_node *
sp_alloc(unsigned long start, unsigned long end, struct mempolicy *pol)
{
	struct sp_node *n = kmem_cache_alloc(sn_cache, GFP_KERNEL);

	if (!n)
		return NULL;
	n->start = start;
	n->end = end;
	mpol_get(pol);
	n->policy = pol;
	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)
{
	struct sp_node *n, *new2 = NULL;

restart:
	spin_lock(&sp->lock);
	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) {
				if (!new2) {
					spin_unlock(&sp->lock);
					new2 = sp_alloc(end, n->end, n->policy);
					if (!new2)
						return -ENOMEM;
					goto restart;
				}
				n->end = start;
				sp_insert(sp, new2);
				new2 = NULL;
				break;
			} else
				n->end = start;
		}
		if (!next)
			break;
		n = rb_entry(next, struct sp_node, nd);
	}
	if (new)
		sp_insert(sp, new);
	spin_unlock(&sp->lock);
	if (new2) {
		mpol_free(new2->policy);
		kmem_cache_free(sn_cache, new2);
	}
	return 0;
}

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);

	PDprintk("set_shared_policy %lx sz %lu %d %lx\n",
		 vma->vm_pgoff,
		 sz, npol? npol->policy : -1,
1154
		npol ? nodes_addr(npol->v.nodes)[0] : -1);
L
Linus Torvalds 已提交
1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179

	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)
		kmem_cache_free(sn_cache, new);
	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;
	spin_lock(&p->lock);
	next = rb_first(&p->root);
	while (next) {
		n = rb_entry(next, struct sp_node, nd);
		next = rb_next(&n->nd);
1180
		rb_erase(&n->nd, &p->root);
L
Linus Torvalds 已提交
1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200
		mpol_free(n->policy);
		kmem_cache_free(sn_cache, n);
	}
	spin_unlock(&p->lock);
}

/* assumes fs == KERNEL_DS */
void __init numa_policy_init(void)
{
	policy_cache = kmem_cache_create("numa_policy",
					 sizeof(struct mempolicy),
					 0, SLAB_PANIC, NULL, NULL);

	sn_cache = kmem_cache_create("shared_policy_node",
				     sizeof(struct sp_node),
				     0, SLAB_PANIC, NULL, NULL);

	/* Set interleaving policy for system init. This way not all
	   the data structures allocated at system boot end up in node zero. */

1201
	if (do_set_mempolicy(MPOL_INTERLEAVE, &node_online_map))
L
Linus Torvalds 已提交
1202 1203 1204
		printk("numa_policy_init: interleaving failed\n");
}

1205
/* Reset policy of current process to default */
L
Linus Torvalds 已提交
1206 1207
void numa_default_policy(void)
{
1208
	do_set_mempolicy(MPOL_DEFAULT, NULL);
L
Linus Torvalds 已提交
1209
}
1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272

/* Migrate a policy to a different set of nodes */
static void rebind_policy(struct mempolicy *pol, const nodemask_t *old,
							const nodemask_t *new)
{
	nodemask_t tmp;

	if (!pol)
		return;

	switch (pol->policy) {
	case MPOL_DEFAULT:
		break;
	case MPOL_INTERLEAVE:
		nodes_remap(tmp, pol->v.nodes, *old, *new);
		pol->v.nodes = tmp;
		current->il_next = node_remap(current->il_next, *old, *new);
		break;
	case MPOL_PREFERRED:
		pol->v.preferred_node = node_remap(pol->v.preferred_node,
								*old, *new);
		break;
	case MPOL_BIND: {
		nodemask_t nodes;
		struct zone **z;
		struct zonelist *zonelist;

		nodes_clear(nodes);
		for (z = pol->v.zonelist->zones; *z; z++)
			node_set((*z)->zone_pgdat->node_id, nodes);
		nodes_remap(tmp, nodes, *old, *new);
		nodes = tmp;

		zonelist = bind_zonelist(&nodes);

		/* If no mem, then zonelist is NULL and we keep old zonelist.
		 * If that old zonelist has no remaining mems_allowed nodes,
		 * then zonelist_policy() will "FALL THROUGH" to MPOL_DEFAULT.
		 */

		if (zonelist) {
			/* Good - got mem - substitute new zonelist */
			kfree(pol->v.zonelist);
			pol->v.zonelist = zonelist;
		}
		break;
	}
	default:
		BUG();
		break;
	}
}

/*
 * Someone moved this task to different nodes.  Fixup mempolicies.
 *
 * TODO - fixup current->mm->vma and shmfs/tmpfs/hugetlbfs policies as well,
 * once we have a cpuset mechanism to mark which cpuset subtree is migrating.
 */
void numa_policy_rebind(const nodemask_t *old, const nodemask_t *new)
{
	rebind_policy(current->mempolicy, old, new);
}