Contents of /alx-src/tags/kernel26-2.6.12-alx-r9/mm/mempolicy.c
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Wed Mar 4 11:03:09 2009 UTC (15 years, 6 months ago) by niro
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Wed Mar 4 11:03:09 2009 UTC (15 years, 6 months ago) by niro
File MIME type: text/plain
File size: 29474 byte(s)
Tag kernel26-2.6.12-alx-r9
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 < 0 || 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 & GFP_ZONEMASK) >= 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 | } |