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1da177e4 LT |
1 | /* |
2 | * Simple NUMA memory policy for the Linux kernel. | |
3 | * | |
4 | * Copyright 2003,2004 Andi Kleen, SuSE Labs. | |
5 | * Subject to the GNU Public License, version 2. | |
6 | * | |
7 | * NUMA policy allows the user to give hints in which node(s) memory should | |
8 | * be allocated. | |
9 | * | |
10 | * Support four policies per VMA and per process: | |
11 | * | |
12 | * The VMA policy has priority over the process policy for a page fault. | |
13 | * | |
14 | * interleave Allocate memory interleaved over a set of nodes, | |
15 | * with normal fallback if it fails. | |
16 | * For VMA based allocations this interleaves based on the | |
17 | * offset into the backing object or offset into the mapping | |
18 | * for anonymous memory. For process policy an process counter | |
19 | * is used. | |
20 | * bind Only allocate memory on a specific set of nodes, | |
21 | * no fallback. | |
22 | * preferred Try a specific node first before normal fallback. | |
23 | * As a special case node -1 here means do the allocation | |
24 | * on the local CPU. This is normally identical to default, | |
25 | * but useful to set in a VMA when you have a non default | |
26 | * process policy. | |
27 | * default Allocate on the local node first, or when on a VMA | |
28 | * use the process policy. This is what Linux always did | |
29 | * in a NUMA aware kernel and still does by, ahem, default. | |
30 | * | |
31 | * The process policy is applied for most non interrupt memory allocations | |
32 | * in that process' context. Interrupts ignore the policies and always | |
33 | * try to allocate on the local CPU. The VMA policy is only applied for memory | |
34 | * allocations for a VMA in the VM. | |
35 | * | |
36 | * Currently there are a few corner cases in swapping where the policy | |
37 | * is not applied, but the majority should be handled. When process policy | |
38 | * is used it is not remembered over swap outs/swap ins. | |
39 | * | |
40 | * Only the highest zone in the zone hierarchy gets policied. Allocations | |
41 | * requesting a lower zone just use default policy. This implies that | |
42 | * on systems with highmem kernel lowmem allocation don't get policied. | |
43 | * Same with GFP_DMA allocations. | |
44 | * | |
45 | * For shmfs/tmpfs/hugetlbfs shared memory the policy is shared between | |
46 | * all users and remembered even when nobody has memory mapped. | |
47 | */ | |
48 | ||
49 | /* Notebook: | |
50 | fix mmap readahead to honour policy and enable policy for any page cache | |
51 | object | |
52 | statistics for bigpages | |
53 | global policy for page cache? currently it uses process policy. Requires | |
54 | first item above. | |
55 | handle mremap for shared memory (currently ignored for the policy) | |
56 | grows down? | |
57 | make bind policy root only? It can trigger oom much faster and the | |
58 | kernel is not always grateful with that. | |
59 | could replace all the switch()es with a mempolicy_ops structure. | |
60 | */ | |
61 | ||
62 | #include <linux/mempolicy.h> | |
63 | #include <linux/mm.h> | |
64 | #include <linux/highmem.h> | |
65 | #include <linux/hugetlb.h> | |
66 | #include <linux/kernel.h> | |
67 | #include <linux/sched.h> | |
68 | #include <linux/mm.h> | |
69 | #include <linux/nodemask.h> | |
70 | #include <linux/cpuset.h> | |
71 | #include <linux/gfp.h> | |
72 | #include <linux/slab.h> | |
73 | #include <linux/string.h> | |
74 | #include <linux/module.h> | |
75 | #include <linux/interrupt.h> | |
76 | #include <linux/init.h> | |
77 | #include <linux/compat.h> | |
78 | #include <linux/mempolicy.h> | |
79 | #include <asm/tlbflush.h> | |
80 | #include <asm/uaccess.h> | |
81 | ||
82 | static kmem_cache_t *policy_cache; | |
83 | static kmem_cache_t *sn_cache; | |
84 | ||
85 | #define PDprintk(fmt...) | |
86 | ||
87 | /* Highest zone. An specific allocation for a zone below that is not | |
88 | policied. */ | |
89 | static int policy_zone; | |
90 | ||
91 | static struct mempolicy default_policy = { | |
92 | .refcnt = ATOMIC_INIT(1), /* never free it */ | |
93 | .policy = MPOL_DEFAULT, | |
94 | }; | |
95 | ||
96 | /* Check if all specified nodes are online */ | |
97 | static int nodes_online(unsigned long *nodes) | |
98 | { | |
99 | DECLARE_BITMAP(online2, MAX_NUMNODES); | |
100 | ||
101 | bitmap_copy(online2, nodes_addr(node_online_map), MAX_NUMNODES); | |
102 | if (bitmap_empty(online2, MAX_NUMNODES)) | |
103 | set_bit(0, online2); | |
104 | if (!bitmap_subset(nodes, online2, MAX_NUMNODES)) | |
105 | return -EINVAL; | |
106 | return 0; | |
107 | } | |
108 | ||
109 | /* Do sanity checking on a policy */ | |
110 | static int mpol_check_policy(int mode, unsigned long *nodes) | |
111 | { | |
112 | int empty = bitmap_empty(nodes, MAX_NUMNODES); | |
113 | ||
114 | switch (mode) { | |
115 | case MPOL_DEFAULT: | |
116 | if (!empty) | |
117 | return -EINVAL; | |
118 | break; | |
119 | case MPOL_BIND: | |
120 | case MPOL_INTERLEAVE: | |
121 | /* Preferred will only use the first bit, but allow | |
122 | more for now. */ | |
123 | if (empty) | |
124 | return -EINVAL; | |
125 | break; | |
126 | } | |
127 | return nodes_online(nodes); | |
128 | } | |
129 | ||
130 | /* Copy a node mask from user space. */ | |
131 | static int get_nodes(unsigned long *nodes, unsigned long __user *nmask, | |
132 | unsigned long maxnode, int mode) | |
133 | { | |
134 | unsigned long k; | |
135 | unsigned long nlongs; | |
136 | unsigned long endmask; | |
137 | ||
138 | --maxnode; | |
139 | bitmap_zero(nodes, MAX_NUMNODES); | |
140 | if (maxnode == 0 || !nmask) | |
141 | return 0; | |
142 | ||
143 | nlongs = BITS_TO_LONGS(maxnode); | |
144 | if ((maxnode % BITS_PER_LONG) == 0) | |
145 | endmask = ~0UL; | |
146 | else | |
147 | endmask = (1UL << (maxnode % BITS_PER_LONG)) - 1; | |
148 | ||
149 | /* When the user specified more nodes than supported just check | |
150 | if the non supported part is all zero. */ | |
151 | if (nlongs > BITS_TO_LONGS(MAX_NUMNODES)) { | |
152 | if (nlongs > PAGE_SIZE/sizeof(long)) | |
153 | return -EINVAL; | |
154 | for (k = BITS_TO_LONGS(MAX_NUMNODES); k < nlongs; k++) { | |
155 | unsigned long t; | |
156 | if (get_user(t, nmask + k)) | |
157 | return -EFAULT; | |
158 | if (k == nlongs - 1) { | |
159 | if (t & endmask) | |
160 | return -EINVAL; | |
161 | } else if (t) | |
162 | return -EINVAL; | |
163 | } | |
164 | nlongs = BITS_TO_LONGS(MAX_NUMNODES); | |
165 | endmask = ~0UL; | |
166 | } | |
167 | ||
168 | if (copy_from_user(nodes, nmask, nlongs*sizeof(unsigned long))) | |
169 | return -EFAULT; | |
170 | nodes[nlongs-1] &= endmask; | |
171 | /* Update current mems_allowed */ | |
172 | cpuset_update_current_mems_allowed(); | |
173 | /* Ignore nodes not set in current->mems_allowed */ | |
174 | cpuset_restrict_to_mems_allowed(nodes); | |
175 | return mpol_check_policy(mode, nodes); | |
176 | } | |
177 | ||
178 | /* Generate a custom zonelist for the BIND policy. */ | |
179 | static struct zonelist *bind_zonelist(unsigned long *nodes) | |
180 | { | |
181 | struct zonelist *zl; | |
182 | int num, max, nd; | |
183 | ||
184 | max = 1 + MAX_NR_ZONES * bitmap_weight(nodes, MAX_NUMNODES); | |
185 | zl = kmalloc(sizeof(void *) * max, GFP_KERNEL); | |
186 | if (!zl) | |
187 | return NULL; | |
188 | num = 0; | |
189 | for (nd = find_first_bit(nodes, MAX_NUMNODES); | |
190 | nd < MAX_NUMNODES; | |
191 | nd = find_next_bit(nodes, MAX_NUMNODES, 1+nd)) { | |
192 | int k; | |
193 | for (k = MAX_NR_ZONES-1; k >= 0; k--) { | |
194 | struct zone *z = &NODE_DATA(nd)->node_zones[k]; | |
195 | if (!z->present_pages) | |
196 | continue; | |
197 | zl->zones[num++] = z; | |
198 | if (k > policy_zone) | |
199 | policy_zone = k; | |
200 | } | |
201 | } | |
202 | BUG_ON(num >= max); | |
203 | zl->zones[num] = NULL; | |
204 | return zl; | |
205 | } | |
206 | ||
207 | /* Create a new policy */ | |
208 | static struct mempolicy *mpol_new(int mode, unsigned long *nodes) | |
209 | { | |
210 | struct mempolicy *policy; | |
211 | ||
212 | PDprintk("setting mode %d nodes[0] %lx\n", mode, nodes[0]); | |
213 | if (mode == MPOL_DEFAULT) | |
214 | return NULL; | |
215 | policy = kmem_cache_alloc(policy_cache, GFP_KERNEL); | |
216 | if (!policy) | |
217 | return ERR_PTR(-ENOMEM); | |
218 | atomic_set(&policy->refcnt, 1); | |
219 | switch (mode) { | |
220 | case MPOL_INTERLEAVE: | |
221 | bitmap_copy(policy->v.nodes, nodes, MAX_NUMNODES); | |
222 | break; | |
223 | case MPOL_PREFERRED: | |
224 | policy->v.preferred_node = find_first_bit(nodes, MAX_NUMNODES); | |
225 | if (policy->v.preferred_node >= MAX_NUMNODES) | |
226 | policy->v.preferred_node = -1; | |
227 | break; | |
228 | case MPOL_BIND: | |
229 | policy->v.zonelist = bind_zonelist(nodes); | |
230 | if (policy->v.zonelist == NULL) { | |
231 | kmem_cache_free(policy_cache, policy); | |
232 | return ERR_PTR(-ENOMEM); | |
233 | } | |
234 | break; | |
235 | } | |
236 | policy->policy = mode; | |
237 | return policy; | |
238 | } | |
239 | ||
240 | /* Ensure all existing pages follow the policy. */ | |
241 | static int | |
242 | verify_pages(struct mm_struct *mm, | |
243 | unsigned long addr, unsigned long end, unsigned long *nodes) | |
244 | { | |
245 | while (addr < end) { | |
246 | struct page *p; | |
247 | pte_t *pte; | |
248 | pmd_t *pmd; | |
249 | pud_t *pud; | |
250 | pgd_t *pgd; | |
251 | pgd = pgd_offset(mm, addr); | |
252 | if (pgd_none(*pgd)) { | |
253 | unsigned long next = (addr + PGDIR_SIZE) & PGDIR_MASK; | |
254 | if (next > addr) | |
255 | break; | |
256 | addr = next; | |
257 | continue; | |
258 | } | |
259 | pud = pud_offset(pgd, addr); | |
260 | if (pud_none(*pud)) { | |
261 | addr = (addr + PUD_SIZE) & PUD_MASK; | |
262 | continue; | |
263 | } | |
264 | pmd = pmd_offset(pud, addr); | |
265 | if (pmd_none(*pmd)) { | |
266 | addr = (addr + PMD_SIZE) & PMD_MASK; | |
267 | continue; | |
268 | } | |
269 | p = NULL; | |
270 | pte = pte_offset_map(pmd, addr); | |
271 | if (pte_present(*pte)) | |
272 | p = pte_page(*pte); | |
273 | pte_unmap(pte); | |
274 | if (p) { | |
275 | unsigned nid = page_to_nid(p); | |
276 | if (!test_bit(nid, nodes)) | |
277 | return -EIO; | |
278 | } | |
279 | addr += PAGE_SIZE; | |
280 | } | |
281 | return 0; | |
282 | } | |
283 | ||
284 | /* Step 1: check the range */ | |
285 | static struct vm_area_struct * | |
286 | check_range(struct mm_struct *mm, unsigned long start, unsigned long end, | |
287 | unsigned long *nodes, unsigned long flags) | |
288 | { | |
289 | int err; | |
290 | struct vm_area_struct *first, *vma, *prev; | |
291 | ||
292 | first = find_vma(mm, start); | |
293 | if (!first) | |
294 | return ERR_PTR(-EFAULT); | |
295 | prev = NULL; | |
296 | for (vma = first; vma && vma->vm_start < end; vma = vma->vm_next) { | |
297 | if (!vma->vm_next && vma->vm_end < end) | |
298 | return ERR_PTR(-EFAULT); | |
299 | if (prev && prev->vm_end < vma->vm_start) | |
300 | return ERR_PTR(-EFAULT); | |
301 | if ((flags & MPOL_MF_STRICT) && !is_vm_hugetlb_page(vma)) { | |
302 | err = verify_pages(vma->vm_mm, | |
303 | vma->vm_start, vma->vm_end, nodes); | |
304 | if (err) { | |
305 | first = ERR_PTR(err); | |
306 | break; | |
307 | } | |
308 | } | |
309 | prev = vma; | |
310 | } | |
311 | return first; | |
312 | } | |
313 | ||
314 | /* Apply policy to a single VMA */ | |
315 | static int policy_vma(struct vm_area_struct *vma, struct mempolicy *new) | |
316 | { | |
317 | int err = 0; | |
318 | struct mempolicy *old = vma->vm_policy; | |
319 | ||
320 | PDprintk("vma %lx-%lx/%lx vm_ops %p vm_file %p set_policy %p\n", | |
321 | vma->vm_start, vma->vm_end, vma->vm_pgoff, | |
322 | vma->vm_ops, vma->vm_file, | |
323 | vma->vm_ops ? vma->vm_ops->set_policy : NULL); | |
324 | ||
325 | if (vma->vm_ops && vma->vm_ops->set_policy) | |
326 | err = vma->vm_ops->set_policy(vma, new); | |
327 | if (!err) { | |
328 | mpol_get(new); | |
329 | vma->vm_policy = new; | |
330 | mpol_free(old); | |
331 | } | |
332 | return err; | |
333 | } | |
334 | ||
335 | /* Step 2: apply policy to a range and do splits. */ | |
336 | static int mbind_range(struct vm_area_struct *vma, unsigned long start, | |
337 | unsigned long end, struct mempolicy *new) | |
338 | { | |
339 | struct vm_area_struct *next; | |
340 | int err; | |
341 | ||
342 | err = 0; | |
343 | for (; vma && vma->vm_start < end; vma = next) { | |
344 | next = vma->vm_next; | |
345 | if (vma->vm_start < start) | |
346 | err = split_vma(vma->vm_mm, vma, start, 1); | |
347 | if (!err && vma->vm_end > end) | |
348 | err = split_vma(vma->vm_mm, vma, end, 0); | |
349 | if (!err) | |
350 | err = policy_vma(vma, new); | |
351 | if (err) | |
352 | break; | |
353 | } | |
354 | return err; | |
355 | } | |
356 | ||
357 | /* Change policy for a memory range */ | |
358 | asmlinkage long sys_mbind(unsigned long start, unsigned long len, | |
359 | unsigned long mode, | |
360 | unsigned long __user *nmask, unsigned long maxnode, | |
361 | unsigned flags) | |
362 | { | |
363 | struct vm_area_struct *vma; | |
364 | struct mm_struct *mm = current->mm; | |
365 | struct mempolicy *new; | |
366 | unsigned long end; | |
367 | DECLARE_BITMAP(nodes, MAX_NUMNODES); | |
368 | int err; | |
369 | ||
370 | if ((flags & ~(unsigned long)(MPOL_MF_STRICT)) || mode > MPOL_MAX) | |
371 | return -EINVAL; | |
372 | if (start & ~PAGE_MASK) | |
373 | return -EINVAL; | |
374 | if (mode == MPOL_DEFAULT) | |
375 | flags &= ~MPOL_MF_STRICT; | |
376 | len = (len + PAGE_SIZE - 1) & PAGE_MASK; | |
377 | end = start + len; | |
378 | if (end < start) | |
379 | return -EINVAL; | |
380 | if (end == start) | |
381 | return 0; | |
382 | ||
383 | err = get_nodes(nodes, nmask, maxnode, mode); | |
384 | if (err) | |
385 | return err; | |
386 | ||
387 | new = mpol_new(mode, nodes); | |
388 | if (IS_ERR(new)) | |
389 | return PTR_ERR(new); | |
390 | ||
391 | PDprintk("mbind %lx-%lx mode:%ld nodes:%lx\n",start,start+len, | |
392 | mode,nodes[0]); | |
393 | ||
394 | down_write(&mm->mmap_sem); | |
395 | vma = check_range(mm, start, end, nodes, flags); | |
396 | err = PTR_ERR(vma); | |
397 | if (!IS_ERR(vma)) | |
398 | err = mbind_range(vma, start, end, new); | |
399 | up_write(&mm->mmap_sem); | |
400 | mpol_free(new); | |
401 | return err; | |
402 | } | |
403 | ||
404 | /* Set the process memory policy */ | |
405 | asmlinkage long sys_set_mempolicy(int mode, unsigned long __user *nmask, | |
406 | unsigned long maxnode) | |
407 | { | |
408 | int err; | |
409 | struct mempolicy *new; | |
410 | DECLARE_BITMAP(nodes, MAX_NUMNODES); | |
411 | ||
412 | if (mode > MPOL_MAX) | |
413 | return -EINVAL; | |
414 | err = get_nodes(nodes, nmask, maxnode, mode); | |
415 | if (err) | |
416 | return err; | |
417 | new = mpol_new(mode, nodes); | |
418 | if (IS_ERR(new)) | |
419 | return PTR_ERR(new); | |
420 | mpol_free(current->mempolicy); | |
421 | current->mempolicy = new; | |
422 | if (new && new->policy == MPOL_INTERLEAVE) | |
423 | current->il_next = find_first_bit(new->v.nodes, MAX_NUMNODES); | |
424 | return 0; | |
425 | } | |
426 | ||
427 | /* Fill a zone bitmap for a policy */ | |
428 | static void get_zonemask(struct mempolicy *p, unsigned long *nodes) | |
429 | { | |
430 | int i; | |
431 | ||
432 | bitmap_zero(nodes, MAX_NUMNODES); | |
433 | switch (p->policy) { | |
434 | case MPOL_BIND: | |
435 | for (i = 0; p->v.zonelist->zones[i]; i++) | |
436 | __set_bit(p->v.zonelist->zones[i]->zone_pgdat->node_id, nodes); | |
437 | break; | |
438 | case MPOL_DEFAULT: | |
439 | break; | |
440 | case MPOL_INTERLEAVE: | |
441 | bitmap_copy(nodes, p->v.nodes, MAX_NUMNODES); | |
442 | break; | |
443 | case MPOL_PREFERRED: | |
444 | /* or use current node instead of online map? */ | |
445 | if (p->v.preferred_node < 0) | |
446 | bitmap_copy(nodes, nodes_addr(node_online_map), MAX_NUMNODES); | |
447 | else | |
448 | __set_bit(p->v.preferred_node, nodes); | |
449 | break; | |
450 | default: | |
451 | BUG(); | |
452 | } | |
453 | } | |
454 | ||
455 | static int lookup_node(struct mm_struct *mm, unsigned long addr) | |
456 | { | |
457 | struct page *p; | |
458 | int err; | |
459 | ||
460 | err = get_user_pages(current, mm, addr & PAGE_MASK, 1, 0, 0, &p, NULL); | |
461 | if (err >= 0) { | |
462 | err = page_to_nid(p); | |
463 | put_page(p); | |
464 | } | |
465 | return err; | |
466 | } | |
467 | ||
468 | /* Copy a kernel node mask to user space */ | |
469 | static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode, | |
470 | void *nodes, unsigned nbytes) | |
471 | { | |
472 | unsigned long copy = ALIGN(maxnode-1, 64) / 8; | |
473 | ||
474 | if (copy > nbytes) { | |
475 | if (copy > PAGE_SIZE) | |
476 | return -EINVAL; | |
477 | if (clear_user((char __user *)mask + nbytes, copy - nbytes)) | |
478 | return -EFAULT; | |
479 | copy = nbytes; | |
480 | } | |
481 | return copy_to_user(mask, nodes, copy) ? -EFAULT : 0; | |
482 | } | |
483 | ||
484 | /* Retrieve NUMA policy */ | |
485 | asmlinkage long sys_get_mempolicy(int __user *policy, | |
486 | unsigned long __user *nmask, | |
487 | unsigned long maxnode, | |
488 | unsigned long addr, unsigned long flags) | |
489 | { | |
490 | int err, pval; | |
491 | struct mm_struct *mm = current->mm; | |
492 | struct vm_area_struct *vma = NULL; | |
493 | struct mempolicy *pol = current->mempolicy; | |
494 | ||
495 | if (flags & ~(unsigned long)(MPOL_F_NODE|MPOL_F_ADDR)) | |
496 | return -EINVAL; | |
497 | if (nmask != NULL && maxnode < MAX_NUMNODES) | |
498 | return -EINVAL; | |
499 | if (flags & MPOL_F_ADDR) { | |
500 | down_read(&mm->mmap_sem); | |
501 | vma = find_vma_intersection(mm, addr, addr+1); | |
502 | if (!vma) { | |
503 | up_read(&mm->mmap_sem); | |
504 | return -EFAULT; | |
505 | } | |
506 | if (vma->vm_ops && vma->vm_ops->get_policy) | |
507 | pol = vma->vm_ops->get_policy(vma, addr); | |
508 | else | |
509 | pol = vma->vm_policy; | |
510 | } else if (addr) | |
511 | return -EINVAL; | |
512 | ||
513 | if (!pol) | |
514 | pol = &default_policy; | |
515 | ||
516 | if (flags & MPOL_F_NODE) { | |
517 | if (flags & MPOL_F_ADDR) { | |
518 | err = lookup_node(mm, addr); | |
519 | if (err < 0) | |
520 | goto out; | |
521 | pval = err; | |
522 | } else if (pol == current->mempolicy && | |
523 | pol->policy == MPOL_INTERLEAVE) { | |
524 | pval = current->il_next; | |
525 | } else { | |
526 | err = -EINVAL; | |
527 | goto out; | |
528 | } | |
529 | } else | |
530 | pval = pol->policy; | |
531 | ||
532 | if (vma) { | |
533 | up_read(¤t->mm->mmap_sem); | |
534 | vma = NULL; | |
535 | } | |
536 | ||
537 | if (policy && put_user(pval, policy)) | |
538 | return -EFAULT; | |
539 | ||
540 | err = 0; | |
541 | if (nmask) { | |
542 | DECLARE_BITMAP(nodes, MAX_NUMNODES); | |
543 | get_zonemask(pol, nodes); | |
544 | err = copy_nodes_to_user(nmask, maxnode, nodes, sizeof(nodes)); | |
545 | } | |
546 | ||
547 | out: | |
548 | if (vma) | |
549 | up_read(¤t->mm->mmap_sem); | |
550 | return err; | |
551 | } | |
552 | ||
553 | #ifdef CONFIG_COMPAT | |
554 | ||
555 | asmlinkage long compat_sys_get_mempolicy(int __user *policy, | |
556 | compat_ulong_t __user *nmask, | |
557 | compat_ulong_t maxnode, | |
558 | compat_ulong_t addr, compat_ulong_t flags) | |
559 | { | |
560 | long err; | |
561 | unsigned long __user *nm = NULL; | |
562 | unsigned long nr_bits, alloc_size; | |
563 | DECLARE_BITMAP(bm, MAX_NUMNODES); | |
564 | ||
565 | nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES); | |
566 | alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8; | |
567 | ||
568 | if (nmask) | |
569 | nm = compat_alloc_user_space(alloc_size); | |
570 | ||
571 | err = sys_get_mempolicy(policy, nm, nr_bits+1, addr, flags); | |
572 | ||
573 | if (!err && nmask) { | |
574 | err = copy_from_user(bm, nm, alloc_size); | |
575 | /* ensure entire bitmap is zeroed */ | |
576 | err |= clear_user(nmask, ALIGN(maxnode-1, 8) / 8); | |
577 | err |= compat_put_bitmap(nmask, bm, nr_bits); | |
578 | } | |
579 | ||
580 | return err; | |
581 | } | |
582 | ||
583 | asmlinkage long compat_sys_set_mempolicy(int mode, compat_ulong_t __user *nmask, | |
584 | compat_ulong_t maxnode) | |
585 | { | |
586 | long err = 0; | |
587 | unsigned long __user *nm = NULL; | |
588 | unsigned long nr_bits, alloc_size; | |
589 | DECLARE_BITMAP(bm, MAX_NUMNODES); | |
590 | ||
591 | nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES); | |
592 | alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8; | |
593 | ||
594 | if (nmask) { | |
595 | err = compat_get_bitmap(bm, nmask, nr_bits); | |
596 | nm = compat_alloc_user_space(alloc_size); | |
597 | err |= copy_to_user(nm, bm, alloc_size); | |
598 | } | |
599 | ||
600 | if (err) | |
601 | return -EFAULT; | |
602 | ||
603 | return sys_set_mempolicy(mode, nm, nr_bits+1); | |
604 | } | |
605 | ||
606 | asmlinkage long compat_sys_mbind(compat_ulong_t start, compat_ulong_t len, | |
607 | compat_ulong_t mode, compat_ulong_t __user *nmask, | |
608 | compat_ulong_t maxnode, compat_ulong_t flags) | |
609 | { | |
610 | long err = 0; | |
611 | unsigned long __user *nm = NULL; | |
612 | unsigned long nr_bits, alloc_size; | |
613 | DECLARE_BITMAP(bm, MAX_NUMNODES); | |
614 | ||
615 | nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES); | |
616 | alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8; | |
617 | ||
618 | if (nmask) { | |
619 | err = compat_get_bitmap(bm, nmask, nr_bits); | |
620 | nm = compat_alloc_user_space(alloc_size); | |
621 | err |= copy_to_user(nm, bm, alloc_size); | |
622 | } | |
623 | ||
624 | if (err) | |
625 | return -EFAULT; | |
626 | ||
627 | return sys_mbind(start, len, mode, nm, nr_bits+1, flags); | |
628 | } | |
629 | ||
630 | #endif | |
631 | ||
632 | /* Return effective policy for a VMA */ | |
633 | static struct mempolicy * | |
634 | get_vma_policy(struct vm_area_struct *vma, unsigned long addr) | |
635 | { | |
636 | struct mempolicy *pol = current->mempolicy; | |
637 | ||
638 | if (vma) { | |
639 | if (vma->vm_ops && vma->vm_ops->get_policy) | |
640 | pol = vma->vm_ops->get_policy(vma, addr); | |
641 | else if (vma->vm_policy && | |
642 | vma->vm_policy->policy != MPOL_DEFAULT) | |
643 | pol = vma->vm_policy; | |
644 | } | |
645 | if (!pol) | |
646 | pol = &default_policy; | |
647 | return pol; | |
648 | } | |
649 | ||
650 | /* Return a zonelist representing a mempolicy */ | |
651 | static struct zonelist *zonelist_policy(unsigned int __nocast gfp, struct mempolicy *policy) | |
652 | { | |
653 | int nd; | |
654 | ||
655 | switch (policy->policy) { | |
656 | case MPOL_PREFERRED: | |
657 | nd = policy->v.preferred_node; | |
658 | if (nd < 0) | |
659 | nd = numa_node_id(); | |
660 | break; | |
661 | case MPOL_BIND: | |
662 | /* Lower zones don't get a policy applied */ | |
663 | /* Careful: current->mems_allowed might have moved */ | |
664 | if (gfp >= policy_zone) | |
665 | if (cpuset_zonelist_valid_mems_allowed(policy->v.zonelist)) | |
666 | return policy->v.zonelist; | |
667 | /*FALL THROUGH*/ | |
668 | case MPOL_INTERLEAVE: /* should not happen */ | |
669 | case MPOL_DEFAULT: | |
670 | nd = numa_node_id(); | |
671 | break; | |
672 | default: | |
673 | nd = 0; | |
674 | BUG(); | |
675 | } | |
676 | return NODE_DATA(nd)->node_zonelists + (gfp & GFP_ZONEMASK); | |
677 | } | |
678 | ||
679 | /* Do dynamic interleaving for a process */ | |
680 | static unsigned interleave_nodes(struct mempolicy *policy) | |
681 | { | |
682 | unsigned nid, next; | |
683 | struct task_struct *me = current; | |
684 | ||
685 | nid = me->il_next; | |
686 | BUG_ON(nid >= MAX_NUMNODES); | |
687 | next = find_next_bit(policy->v.nodes, MAX_NUMNODES, 1+nid); | |
688 | if (next >= MAX_NUMNODES) | |
689 | next = find_first_bit(policy->v.nodes, MAX_NUMNODES); | |
690 | me->il_next = next; | |
691 | return nid; | |
692 | } | |
693 | ||
694 | /* Do static interleaving for a VMA with known offset. */ | |
695 | static unsigned offset_il_node(struct mempolicy *pol, | |
696 | struct vm_area_struct *vma, unsigned long off) | |
697 | { | |
698 | unsigned nnodes = bitmap_weight(pol->v.nodes, MAX_NUMNODES); | |
699 | unsigned target = (unsigned)off % nnodes; | |
700 | int c; | |
701 | int nid = -1; | |
702 | ||
703 | c = 0; | |
704 | do { | |
705 | nid = find_next_bit(pol->v.nodes, MAX_NUMNODES, nid+1); | |
706 | c++; | |
707 | } while (c <= target); | |
708 | BUG_ON(nid >= MAX_NUMNODES); | |
709 | BUG_ON(!test_bit(nid, pol->v.nodes)); | |
710 | return nid; | |
711 | } | |
712 | ||
713 | /* Allocate a page in interleaved policy. | |
714 | Own path because it needs to do special accounting. */ | |
715 | static struct page *alloc_page_interleave(unsigned int __nocast gfp, unsigned order, unsigned nid) | |
716 | { | |
717 | struct zonelist *zl; | |
718 | struct page *page; | |
719 | ||
720 | BUG_ON(!node_online(nid)); | |
721 | zl = NODE_DATA(nid)->node_zonelists + (gfp & GFP_ZONEMASK); | |
722 | page = __alloc_pages(gfp, order, zl); | |
723 | if (page && page_zone(page) == zl->zones[0]) { | |
724 | zl->zones[0]->pageset[get_cpu()].interleave_hit++; | |
725 | put_cpu(); | |
726 | } | |
727 | return page; | |
728 | } | |
729 | ||
730 | /** | |
731 | * alloc_page_vma - Allocate a page for a VMA. | |
732 | * | |
733 | * @gfp: | |
734 | * %GFP_USER user allocation. | |
735 | * %GFP_KERNEL kernel allocations, | |
736 | * %GFP_HIGHMEM highmem/user allocations, | |
737 | * %GFP_FS allocation should not call back into a file system. | |
738 | * %GFP_ATOMIC don't sleep. | |
739 | * | |
740 | * @vma: Pointer to VMA or NULL if not available. | |
741 | * @addr: Virtual Address of the allocation. Must be inside the VMA. | |
742 | * | |
743 | * This function allocates a page from the kernel page pool and applies | |
744 | * a NUMA policy associated with the VMA or the current process. | |
745 | * When VMA is not NULL caller must hold down_read on the mmap_sem of the | |
746 | * mm_struct of the VMA to prevent it from going away. Should be used for | |
747 | * all allocations for pages that will be mapped into | |
748 | * user space. Returns NULL when no page can be allocated. | |
749 | * | |
750 | * Should be called with the mm_sem of the vma hold. | |
751 | */ | |
752 | struct page * | |
753 | alloc_page_vma(unsigned int __nocast gfp, struct vm_area_struct *vma, unsigned long addr) | |
754 | { | |
755 | struct mempolicy *pol = get_vma_policy(vma, addr); | |
756 | ||
757 | cpuset_update_current_mems_allowed(); | |
758 | ||
759 | if (unlikely(pol->policy == MPOL_INTERLEAVE)) { | |
760 | unsigned nid; | |
761 | if (vma) { | |
762 | unsigned long off; | |
763 | BUG_ON(addr >= vma->vm_end); | |
764 | BUG_ON(addr < vma->vm_start); | |
765 | off = vma->vm_pgoff; | |
766 | off += (addr - vma->vm_start) >> PAGE_SHIFT; | |
767 | nid = offset_il_node(pol, vma, off); | |
768 | } else { | |
769 | /* fall back to process interleaving */ | |
770 | nid = interleave_nodes(pol); | |
771 | } | |
772 | return alloc_page_interleave(gfp, 0, nid); | |
773 | } | |
774 | return __alloc_pages(gfp, 0, zonelist_policy(gfp, pol)); | |
775 | } | |
776 | ||
777 | /** | |
778 | * alloc_pages_current - Allocate pages. | |
779 | * | |
780 | * @gfp: | |
781 | * %GFP_USER user allocation, | |
782 | * %GFP_KERNEL kernel allocation, | |
783 | * %GFP_HIGHMEM highmem allocation, | |
784 | * %GFP_FS don't call back into a file system. | |
785 | * %GFP_ATOMIC don't sleep. | |
786 | * @order: Power of two of allocation size in pages. 0 is a single page. | |
787 | * | |
788 | * Allocate a page from the kernel page pool. When not in | |
789 | * interrupt context and apply the current process NUMA policy. | |
790 | * Returns NULL when no page can be allocated. | |
791 | * | |
792 | * Don't call cpuset_update_current_mems_allowed() unless | |
793 | * 1) it's ok to take cpuset_sem (can WAIT), and | |
794 | * 2) allocating for current task (not interrupt). | |
795 | */ | |
796 | struct page *alloc_pages_current(unsigned int __nocast gfp, unsigned order) | |
797 | { | |
798 | struct mempolicy *pol = current->mempolicy; | |
799 | ||
800 | if ((gfp & __GFP_WAIT) && !in_interrupt()) | |
801 | cpuset_update_current_mems_allowed(); | |
802 | if (!pol || in_interrupt()) | |
803 | pol = &default_policy; | |
804 | if (pol->policy == MPOL_INTERLEAVE) | |
805 | return alloc_page_interleave(gfp, order, interleave_nodes(pol)); | |
806 | return __alloc_pages(gfp, order, zonelist_policy(gfp, pol)); | |
807 | } | |
808 | EXPORT_SYMBOL(alloc_pages_current); | |
809 | ||
810 | /* Slow path of a mempolicy copy */ | |
811 | struct mempolicy *__mpol_copy(struct mempolicy *old) | |
812 | { | |
813 | struct mempolicy *new = kmem_cache_alloc(policy_cache, GFP_KERNEL); | |
814 | ||
815 | if (!new) | |
816 | return ERR_PTR(-ENOMEM); | |
817 | *new = *old; | |
818 | atomic_set(&new->refcnt, 1); | |
819 | if (new->policy == MPOL_BIND) { | |
820 | int sz = ksize(old->v.zonelist); | |
821 | new->v.zonelist = kmalloc(sz, SLAB_KERNEL); | |
822 | if (!new->v.zonelist) { | |
823 | kmem_cache_free(policy_cache, new); | |
824 | return ERR_PTR(-ENOMEM); | |
825 | } | |
826 | memcpy(new->v.zonelist, old->v.zonelist, sz); | |
827 | } | |
828 | return new; | |
829 | } | |
830 | ||
831 | /* Slow path of a mempolicy comparison */ | |
832 | int __mpol_equal(struct mempolicy *a, struct mempolicy *b) | |
833 | { | |
834 | if (!a || !b) | |
835 | return 0; | |
836 | if (a->policy != b->policy) | |
837 | return 0; | |
838 | switch (a->policy) { | |
839 | case MPOL_DEFAULT: | |
840 | return 1; | |
841 | case MPOL_INTERLEAVE: | |
842 | return bitmap_equal(a->v.nodes, b->v.nodes, MAX_NUMNODES); | |
843 | case MPOL_PREFERRED: | |
844 | return a->v.preferred_node == b->v.preferred_node; | |
845 | case MPOL_BIND: { | |
846 | int i; | |
847 | for (i = 0; a->v.zonelist->zones[i]; i++) | |
848 | if (a->v.zonelist->zones[i] != b->v.zonelist->zones[i]) | |
849 | return 0; | |
850 | return b->v.zonelist->zones[i] == NULL; | |
851 | } | |
852 | default: | |
853 | BUG(); | |
854 | return 0; | |
855 | } | |
856 | } | |
857 | ||
858 | /* Slow path of a mpol destructor. */ | |
859 | void __mpol_free(struct mempolicy *p) | |
860 | { | |
861 | if (!atomic_dec_and_test(&p->refcnt)) | |
862 | return; | |
863 | if (p->policy == MPOL_BIND) | |
864 | kfree(p->v.zonelist); | |
865 | p->policy = MPOL_DEFAULT; | |
866 | kmem_cache_free(policy_cache, p); | |
867 | } | |
868 | ||
869 | /* | |
870 | * Hugetlb policy. Same as above, just works with node numbers instead of | |
871 | * zonelists. | |
872 | */ | |
873 | ||
874 | /* Find first node suitable for an allocation */ | |
875 | int mpol_first_node(struct vm_area_struct *vma, unsigned long addr) | |
876 | { | |
877 | struct mempolicy *pol = get_vma_policy(vma, addr); | |
878 | ||
879 | switch (pol->policy) { | |
880 | case MPOL_DEFAULT: | |
881 | return numa_node_id(); | |
882 | case MPOL_BIND: | |
883 | return pol->v.zonelist->zones[0]->zone_pgdat->node_id; | |
884 | case MPOL_INTERLEAVE: | |
885 | return interleave_nodes(pol); | |
886 | case MPOL_PREFERRED: | |
887 | return pol->v.preferred_node >= 0 ? | |
888 | pol->v.preferred_node : numa_node_id(); | |
889 | } | |
890 | BUG(); | |
891 | return 0; | |
892 | } | |
893 | ||
894 | /* Find secondary valid nodes for an allocation */ | |
895 | int mpol_node_valid(int nid, struct vm_area_struct *vma, unsigned long addr) | |
896 | { | |
897 | struct mempolicy *pol = get_vma_policy(vma, addr); | |
898 | ||
899 | switch (pol->policy) { | |
900 | case MPOL_PREFERRED: | |
901 | case MPOL_DEFAULT: | |
902 | case MPOL_INTERLEAVE: | |
903 | return 1; | |
904 | case MPOL_BIND: { | |
905 | struct zone **z; | |
906 | for (z = pol->v.zonelist->zones; *z; z++) | |
907 | if ((*z)->zone_pgdat->node_id == nid) | |
908 | return 1; | |
909 | return 0; | |
910 | } | |
911 | default: | |
912 | BUG(); | |
913 | return 0; | |
914 | } | |
915 | } | |
916 | ||
917 | /* | |
918 | * Shared memory backing store policy support. | |
919 | * | |
920 | * Remember policies even when nobody has shared memory mapped. | |
921 | * The policies are kept in Red-Black tree linked from the inode. | |
922 | * They are protected by the sp->lock spinlock, which should be held | |
923 | * for any accesses to the tree. | |
924 | */ | |
925 | ||
926 | /* lookup first element intersecting start-end */ | |
927 | /* Caller holds sp->lock */ | |
928 | static struct sp_node * | |
929 | sp_lookup(struct shared_policy *sp, unsigned long start, unsigned long end) | |
930 | { | |
931 | struct rb_node *n = sp->root.rb_node; | |
932 | ||
933 | while (n) { | |
934 | struct sp_node *p = rb_entry(n, struct sp_node, nd); | |
935 | ||
936 | if (start >= p->end) | |
937 | n = n->rb_right; | |
938 | else if (end <= p->start) | |
939 | n = n->rb_left; | |
940 | else | |
941 | break; | |
942 | } | |
943 | if (!n) | |
944 | return NULL; | |
945 | for (;;) { | |
946 | struct sp_node *w = NULL; | |
947 | struct rb_node *prev = rb_prev(n); | |
948 | if (!prev) | |
949 | break; | |
950 | w = rb_entry(prev, struct sp_node, nd); | |
951 | if (w->end <= start) | |
952 | break; | |
953 | n = prev; | |
954 | } | |
955 | return rb_entry(n, struct sp_node, nd); | |
956 | } | |
957 | ||
958 | /* Insert a new shared policy into the list. */ | |
959 | /* Caller holds sp->lock */ | |
960 | static void sp_insert(struct shared_policy *sp, struct sp_node *new) | |
961 | { | |
962 | struct rb_node **p = &sp->root.rb_node; | |
963 | struct rb_node *parent = NULL; | |
964 | struct sp_node *nd; | |
965 | ||
966 | while (*p) { | |
967 | parent = *p; | |
968 | nd = rb_entry(parent, struct sp_node, nd); | |
969 | if (new->start < nd->start) | |
970 | p = &(*p)->rb_left; | |
971 | else if (new->end > nd->end) | |
972 | p = &(*p)->rb_right; | |
973 | else | |
974 | BUG(); | |
975 | } | |
976 | rb_link_node(&new->nd, parent, p); | |
977 | rb_insert_color(&new->nd, &sp->root); | |
978 | PDprintk("inserting %lx-%lx: %d\n", new->start, new->end, | |
979 | new->policy ? new->policy->policy : 0); | |
980 | } | |
981 | ||
982 | /* Find shared policy intersecting idx */ | |
983 | struct mempolicy * | |
984 | mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx) | |
985 | { | |
986 | struct mempolicy *pol = NULL; | |
987 | struct sp_node *sn; | |
988 | ||
989 | if (!sp->root.rb_node) | |
990 | return NULL; | |
991 | spin_lock(&sp->lock); | |
992 | sn = sp_lookup(sp, idx, idx+1); | |
993 | if (sn) { | |
994 | mpol_get(sn->policy); | |
995 | pol = sn->policy; | |
996 | } | |
997 | spin_unlock(&sp->lock); | |
998 | return pol; | |
999 | } | |
1000 | ||
1001 | static void sp_delete(struct shared_policy *sp, struct sp_node *n) | |
1002 | { | |
1003 | PDprintk("deleting %lx-l%x\n", n->start, n->end); | |
1004 | rb_erase(&n->nd, &sp->root); | |
1005 | mpol_free(n->policy); | |
1006 | kmem_cache_free(sn_cache, n); | |
1007 | } | |
1008 | ||
1009 | struct sp_node * | |
1010 | sp_alloc(unsigned long start, unsigned long end, struct mempolicy *pol) | |
1011 | { | |
1012 | struct sp_node *n = kmem_cache_alloc(sn_cache, GFP_KERNEL); | |
1013 | ||
1014 | if (!n) | |
1015 | return NULL; | |
1016 | n->start = start; | |
1017 | n->end = end; | |
1018 | mpol_get(pol); | |
1019 | n->policy = pol; | |
1020 | return n; | |
1021 | } | |
1022 | ||
1023 | /* Replace a policy range. */ | |
1024 | static int shared_policy_replace(struct shared_policy *sp, unsigned long start, | |
1025 | unsigned long end, struct sp_node *new) | |
1026 | { | |
1027 | struct sp_node *n, *new2 = NULL; | |
1028 | ||
1029 | restart: | |
1030 | spin_lock(&sp->lock); | |
1031 | n = sp_lookup(sp, start, end); | |
1032 | /* Take care of old policies in the same range. */ | |
1033 | while (n && n->start < end) { | |
1034 | struct rb_node *next = rb_next(&n->nd); | |
1035 | if (n->start >= start) { | |
1036 | if (n->end <= end) | |
1037 | sp_delete(sp, n); | |
1038 | else | |
1039 | n->start = end; | |
1040 | } else { | |
1041 | /* Old policy spanning whole new range. */ | |
1042 | if (n->end > end) { | |
1043 | if (!new2) { | |
1044 | spin_unlock(&sp->lock); | |
1045 | new2 = sp_alloc(end, n->end, n->policy); | |
1046 | if (!new2) | |
1047 | return -ENOMEM; | |
1048 | goto restart; | |
1049 | } | |
1050 | n->end = start; | |
1051 | sp_insert(sp, new2); | |
1052 | new2 = NULL; | |
1053 | break; | |
1054 | } else | |
1055 | n->end = start; | |
1056 | } | |
1057 | if (!next) | |
1058 | break; | |
1059 | n = rb_entry(next, struct sp_node, nd); | |
1060 | } | |
1061 | if (new) | |
1062 | sp_insert(sp, new); | |
1063 | spin_unlock(&sp->lock); | |
1064 | if (new2) { | |
1065 | mpol_free(new2->policy); | |
1066 | kmem_cache_free(sn_cache, new2); | |
1067 | } | |
1068 | return 0; | |
1069 | } | |
1070 | ||
1071 | int mpol_set_shared_policy(struct shared_policy *info, | |
1072 | struct vm_area_struct *vma, struct mempolicy *npol) | |
1073 | { | |
1074 | int err; | |
1075 | struct sp_node *new = NULL; | |
1076 | unsigned long sz = vma_pages(vma); | |
1077 | ||
1078 | PDprintk("set_shared_policy %lx sz %lu %d %lx\n", | |
1079 | vma->vm_pgoff, | |
1080 | sz, npol? npol->policy : -1, | |
1081 | npol ? npol->v.nodes[0] : -1); | |
1082 | ||
1083 | if (npol) { | |
1084 | new = sp_alloc(vma->vm_pgoff, vma->vm_pgoff + sz, npol); | |
1085 | if (!new) | |
1086 | return -ENOMEM; | |
1087 | } | |
1088 | err = shared_policy_replace(info, vma->vm_pgoff, vma->vm_pgoff+sz, new); | |
1089 | if (err && new) | |
1090 | kmem_cache_free(sn_cache, new); | |
1091 | return err; | |
1092 | } | |
1093 | ||
1094 | /* Free a backing policy store on inode delete. */ | |
1095 | void mpol_free_shared_policy(struct shared_policy *p) | |
1096 | { | |
1097 | struct sp_node *n; | |
1098 | struct rb_node *next; | |
1099 | ||
1100 | if (!p->root.rb_node) | |
1101 | return; | |
1102 | spin_lock(&p->lock); | |
1103 | next = rb_first(&p->root); | |
1104 | while (next) { | |
1105 | n = rb_entry(next, struct sp_node, nd); | |
1106 | next = rb_next(&n->nd); | |
1107 | mpol_free(n->policy); | |
1108 | kmem_cache_free(sn_cache, n); | |
1109 | } | |
1110 | spin_unlock(&p->lock); | |
1111 | p->root = RB_ROOT; | |
1112 | } | |
1113 | ||
1114 | /* assumes fs == KERNEL_DS */ | |
1115 | void __init numa_policy_init(void) | |
1116 | { | |
1117 | policy_cache = kmem_cache_create("numa_policy", | |
1118 | sizeof(struct mempolicy), | |
1119 | 0, SLAB_PANIC, NULL, NULL); | |
1120 | ||
1121 | sn_cache = kmem_cache_create("shared_policy_node", | |
1122 | sizeof(struct sp_node), | |
1123 | 0, SLAB_PANIC, NULL, NULL); | |
1124 | ||
1125 | /* Set interleaving policy for system init. This way not all | |
1126 | the data structures allocated at system boot end up in node zero. */ | |
1127 | ||
1128 | if (sys_set_mempolicy(MPOL_INTERLEAVE, nodes_addr(node_online_map), | |
1129 | MAX_NUMNODES) < 0) | |
1130 | printk("numa_policy_init: interleaving failed\n"); | |
1131 | } | |
1132 | ||
1133 | /* Reset policy of current process to default. | |
1134 | * Assumes fs == KERNEL_DS */ | |
1135 | void numa_default_policy(void) | |
1136 | { | |
1137 | sys_set_mempolicy(MPOL_DEFAULT, NULL, 0); | |
1138 | } |