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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Simple NUMA memory policy for the Linux kernel.
3 *
4 * Copyright 2003,2004 Andi Kleen, SuSE Labs.
Christoph Lameter8bccd852005-10-29 18:16:59 -07005 * (C) Copyright 2005 Christoph Lameter, Silicon Graphics, Inc.
Linus Torvalds1da177e2005-04-16 15:20:36 -07006 * Subject to the GNU Public License, version 2.
7 *
8 * NUMA policy allows the user to give hints in which node(s) memory should
9 * be allocated.
10 *
11 * Support four policies per VMA and per process:
12 *
13 * The VMA policy has priority over the process policy for a page fault.
14 *
15 * interleave Allocate memory interleaved over a set of nodes,
16 * with normal fallback if it fails.
17 * For VMA based allocations this interleaves based on the
18 * offset into the backing object or offset into the mapping
19 * for anonymous memory. For process policy an process counter
20 * is used.
Christoph Lameter8bccd852005-10-29 18:16:59 -070021 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070022 * bind Only allocate memory on a specific set of nodes,
23 * no fallback.
Christoph Lameter8bccd852005-10-29 18:16:59 -070024 * FIXME: memory is allocated starting with the first node
25 * to the last. It would be better if bind would truly restrict
26 * the allocation to memory nodes instead
27 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070028 * preferred Try a specific node first before normal fallback.
29 * As a special case node -1 here means do the allocation
30 * on the local CPU. This is normally identical to default,
31 * but useful to set in a VMA when you have a non default
32 * process policy.
Christoph Lameter8bccd852005-10-29 18:16:59 -070033 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070034 * default Allocate on the local node first, or when on a VMA
35 * use the process policy. This is what Linux always did
36 * in a NUMA aware kernel and still does by, ahem, default.
37 *
38 * The process policy is applied for most non interrupt memory allocations
39 * in that process' context. Interrupts ignore the policies and always
40 * try to allocate on the local CPU. The VMA policy is only applied for memory
41 * allocations for a VMA in the VM.
42 *
43 * Currently there are a few corner cases in swapping where the policy
44 * is not applied, but the majority should be handled. When process policy
45 * is used it is not remembered over swap outs/swap ins.
46 *
47 * Only the highest zone in the zone hierarchy gets policied. Allocations
48 * requesting a lower zone just use default policy. This implies that
49 * on systems with highmem kernel lowmem allocation don't get policied.
50 * Same with GFP_DMA allocations.
51 *
52 * For shmfs/tmpfs/hugetlbfs shared memory the policy is shared between
53 * all users and remembered even when nobody has memory mapped.
54 */
55
56/* Notebook:
57 fix mmap readahead to honour policy and enable policy for any page cache
58 object
59 statistics for bigpages
60 global policy for page cache? currently it uses process policy. Requires
61 first item above.
62 handle mremap for shared memory (currently ignored for the policy)
63 grows down?
64 make bind policy root only? It can trigger oom much faster and the
65 kernel is not always grateful with that.
Linus Torvalds1da177e2005-04-16 15:20:36 -070066*/
67
68#include <linux/mempolicy.h>
69#include <linux/mm.h>
70#include <linux/highmem.h>
71#include <linux/hugetlb.h>
72#include <linux/kernel.h>
73#include <linux/sched.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070074#include <linux/nodemask.h>
75#include <linux/cpuset.h>
76#include <linux/gfp.h>
77#include <linux/slab.h>
78#include <linux/string.h>
79#include <linux/module.h>
Pavel Emelyanovb4888932007-10-18 23:40:14 -070080#include <linux/nsproxy.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070081#include <linux/interrupt.h>
82#include <linux/init.h>
83#include <linux/compat.h>
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -080084#include <linux/swap.h>
Christoph Lameter1a75a6c2006-01-08 01:01:02 -080085#include <linux/seq_file.h>
86#include <linux/proc_fs.h>
Christoph Lameterb20a3502006-03-22 00:09:12 -080087#include <linux/migrate.h>
Christoph Lameter95a402c2006-06-23 02:03:53 -070088#include <linux/rmap.h>
David Quigley86c3a762006-06-23 02:04:02 -070089#include <linux/security.h>
Adrian Bunkdbcb0f12007-10-16 01:26:26 -070090#include <linux/syscalls.h>
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -070091#include <linux/ctype.h>
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -080092
Linus Torvalds1da177e2005-04-16 15:20:36 -070093#include <asm/tlbflush.h>
94#include <asm/uaccess.h>
95
Nick Piggin62695a82008-10-18 20:26:09 -070096#include "internal.h"
97
Christoph Lameter38e35862006-01-08 01:01:01 -080098/* Internal flags */
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -080099#define MPOL_MF_DISCONTIG_OK (MPOL_MF_INTERNAL << 0) /* Skip checks for continuous vmas */
Christoph Lameter38e35862006-01-08 01:01:01 -0800100#define MPOL_MF_INVERT (MPOL_MF_INTERNAL << 1) /* Invert check for nodemask */
Christoph Lameter1a75a6c2006-01-08 01:01:02 -0800101#define MPOL_MF_STATS (MPOL_MF_INTERNAL << 2) /* Gather statistics */
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800102
Pekka Enbergfcc234f2006-03-22 00:08:13 -0800103static struct kmem_cache *policy_cache;
104static struct kmem_cache *sn_cache;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106/* Highest zone. An specific allocation for a zone below that is not
107 policied. */
Christoph Lameter62672762007-02-10 01:43:07 -0800108enum zone_type policy_zone = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109
Lee Schermerhornbea904d2008-04-28 02:13:18 -0700110/*
111 * run-time system-wide default policy => local allocation
112 */
Andi Kleend42c6992005-07-06 19:56:03 +0200113struct mempolicy default_policy = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 .refcnt = ATOMIC_INIT(1), /* never free it */
Lee Schermerhornbea904d2008-04-28 02:13:18 -0700115 .mode = MPOL_PREFERRED,
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -0700116 .flags = MPOL_F_LOCAL,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117};
118
David Rientjes37012942008-04-28 02:12:33 -0700119static const struct mempolicy_operations {
120 int (*create)(struct mempolicy *pol, const nodemask_t *nodes);
121 void (*rebind)(struct mempolicy *pol, const nodemask_t *nodes);
122} mpol_ops[MPOL_MAX];
123
Mel Gorman19770b32008-04-28 02:12:18 -0700124/* Check that the nodemask contains at least one populated zone */
David Rientjes37012942008-04-28 02:12:33 -0700125static int is_valid_nodemask(const nodemask_t *nodemask)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126{
Mel Gorman19770b32008-04-28 02:12:18 -0700127 int nd, k;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128
Mel Gorman19770b32008-04-28 02:12:18 -0700129 /* Check that there is something useful in this mask */
130 k = policy_zone;
131
132 for_each_node_mask(nd, *nodemask) {
133 struct zone *z;
134
135 for (k = 0; k <= policy_zone; k++) {
136 z = &NODE_DATA(nd)->node_zones[k];
137 if (z->present_pages > 0)
138 return 1;
Andi Kleendd942ae2006-02-17 01:39:16 +0100139 }
140 }
Mel Gorman19770b32008-04-28 02:12:18 -0700141
142 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143}
144
David Rientjesf5b087b2008-04-28 02:12:27 -0700145static inline int mpol_store_user_nodemask(const struct mempolicy *pol)
146{
David Rientjes4c50bc02008-04-28 02:12:30 -0700147 return pol->flags & (MPOL_F_STATIC_NODES | MPOL_F_RELATIVE_NODES);
148}
149
150static void mpol_relative_nodemask(nodemask_t *ret, const nodemask_t *orig,
151 const nodemask_t *rel)
152{
153 nodemask_t tmp;
154 nodes_fold(tmp, *orig, nodes_weight(*rel));
155 nodes_onto(*ret, tmp, *rel);
David Rientjesf5b087b2008-04-28 02:12:27 -0700156}
157
David Rientjes37012942008-04-28 02:12:33 -0700158static int mpol_new_interleave(struct mempolicy *pol, const nodemask_t *nodes)
159{
160 if (nodes_empty(*nodes))
161 return -EINVAL;
162 pol->v.nodes = *nodes;
163 return 0;
164}
165
166static int mpol_new_preferred(struct mempolicy *pol, const nodemask_t *nodes)
167{
168 if (!nodes)
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -0700169 pol->flags |= MPOL_F_LOCAL; /* local allocation */
David Rientjes37012942008-04-28 02:12:33 -0700170 else if (nodes_empty(*nodes))
171 return -EINVAL; /* no allowed nodes */
172 else
173 pol->v.preferred_node = first_node(*nodes);
174 return 0;
175}
176
177static int mpol_new_bind(struct mempolicy *pol, const nodemask_t *nodes)
178{
179 if (!is_valid_nodemask(nodes))
180 return -EINVAL;
181 pol->v.nodes = *nodes;
182 return 0;
183}
184
Miao Xie58568d22009-06-16 15:31:49 -0700185/*
186 * mpol_set_nodemask is called after mpol_new() to set up the nodemask, if
187 * any, for the new policy. mpol_new() has already validated the nodes
188 * parameter with respect to the policy mode and flags. But, we need to
189 * handle an empty nodemask with MPOL_PREFERRED here.
190 *
191 * Must be called holding task's alloc_lock to protect task's mems_allowed
192 * and mempolicy. May also be called holding the mmap_semaphore for write.
193 */
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -0700194static int mpol_set_nodemask(struct mempolicy *pol,
195 const nodemask_t *nodes, struct nodemask_scratch *nsc)
Miao Xie58568d22009-06-16 15:31:49 -0700196{
Miao Xie58568d22009-06-16 15:31:49 -0700197 int ret;
198
199 /* if mode is MPOL_DEFAULT, pol is NULL. This is right. */
200 if (pol == NULL)
201 return 0;
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -0700202 /* Check N_HIGH_MEMORY */
203 nodes_and(nsc->mask1,
204 cpuset_current_mems_allowed, node_states[N_HIGH_MEMORY]);
Miao Xie58568d22009-06-16 15:31:49 -0700205
206 VM_BUG_ON(!nodes);
207 if (pol->mode == MPOL_PREFERRED && nodes_empty(*nodes))
208 nodes = NULL; /* explicit local allocation */
209 else {
210 if (pol->flags & MPOL_F_RELATIVE_NODES)
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -0700211 mpol_relative_nodemask(&nsc->mask2, nodes,&nsc->mask1);
Miao Xie58568d22009-06-16 15:31:49 -0700212 else
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -0700213 nodes_and(nsc->mask2, *nodes, nsc->mask1);
214
Miao Xie58568d22009-06-16 15:31:49 -0700215 if (mpol_store_user_nodemask(pol))
216 pol->w.user_nodemask = *nodes;
217 else
218 pol->w.cpuset_mems_allowed =
219 cpuset_current_mems_allowed;
220 }
221
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -0700222 if (nodes)
223 ret = mpol_ops[pol->mode].create(pol, &nsc->mask2);
224 else
225 ret = mpol_ops[pol->mode].create(pol, NULL);
Miao Xie58568d22009-06-16 15:31:49 -0700226 return ret;
227}
228
229/*
230 * This function just creates a new policy, does some check and simple
231 * initialization. You must invoke mpol_set_nodemask() to set nodes.
232 */
David Rientjes028fec42008-04-28 02:12:25 -0700233static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags,
234 nodemask_t *nodes)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235{
236 struct mempolicy *policy;
237
David Rientjes028fec42008-04-28 02:12:25 -0700238 pr_debug("setting mode %d flags %d nodes[0] %lx\n",
239 mode, flags, nodes ? nodes_addr(*nodes)[0] : -1);
Paul Mundt140d5a42007-07-15 23:38:16 -0700240
David Rientjes3e1f0642008-04-28 02:12:34 -0700241 if (mode == MPOL_DEFAULT) {
242 if (nodes && !nodes_empty(*nodes))
David Rientjes37012942008-04-28 02:12:33 -0700243 return ERR_PTR(-EINVAL);
Lee Schermerhornbea904d2008-04-28 02:13:18 -0700244 return NULL; /* simply delete any existing policy */
David Rientjes37012942008-04-28 02:12:33 -0700245 }
David Rientjes3e1f0642008-04-28 02:12:34 -0700246 VM_BUG_ON(!nodes);
247
248 /*
249 * MPOL_PREFERRED cannot be used with MPOL_F_STATIC_NODES or
250 * MPOL_F_RELATIVE_NODES if the nodemask is empty (local allocation).
251 * All other modes require a valid pointer to a non-empty nodemask.
252 */
253 if (mode == MPOL_PREFERRED) {
254 if (nodes_empty(*nodes)) {
255 if (((flags & MPOL_F_STATIC_NODES) ||
256 (flags & MPOL_F_RELATIVE_NODES)))
257 return ERR_PTR(-EINVAL);
David Rientjes3e1f0642008-04-28 02:12:34 -0700258 }
259 } else if (nodes_empty(*nodes))
260 return ERR_PTR(-EINVAL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261 policy = kmem_cache_alloc(policy_cache, GFP_KERNEL);
262 if (!policy)
263 return ERR_PTR(-ENOMEM);
264 atomic_set(&policy->refcnt, 1);
Lee Schermerhorn45c47452008-04-28 02:13:12 -0700265 policy->mode = mode;
David Rientjes3e1f0642008-04-28 02:12:34 -0700266 policy->flags = flags;
David Rientjesf5b087b2008-04-28 02:12:27 -0700267
David Rientjes37012942008-04-28 02:12:33 -0700268 return policy;
269}
270
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -0700271/* Slow path of a mpol destructor. */
272void __mpol_put(struct mempolicy *p)
273{
274 if (!atomic_dec_and_test(&p->refcnt))
275 return;
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -0700276 kmem_cache_free(policy_cache, p);
277}
278
David Rientjes37012942008-04-28 02:12:33 -0700279static void mpol_rebind_default(struct mempolicy *pol, const nodemask_t *nodes)
280{
281}
282
283static void mpol_rebind_nodemask(struct mempolicy *pol,
284 const nodemask_t *nodes)
285{
286 nodemask_t tmp;
287
288 if (pol->flags & MPOL_F_STATIC_NODES)
289 nodes_and(tmp, pol->w.user_nodemask, *nodes);
290 else if (pol->flags & MPOL_F_RELATIVE_NODES)
291 mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes);
292 else {
293 nodes_remap(tmp, pol->v.nodes, pol->w.cpuset_mems_allowed,
294 *nodes);
295 pol->w.cpuset_mems_allowed = *nodes;
296 }
297
298 pol->v.nodes = tmp;
299 if (!node_isset(current->il_next, tmp)) {
300 current->il_next = next_node(current->il_next, tmp);
301 if (current->il_next >= MAX_NUMNODES)
302 current->il_next = first_node(tmp);
303 if (current->il_next >= MAX_NUMNODES)
304 current->il_next = numa_node_id();
305 }
306}
307
308static void mpol_rebind_preferred(struct mempolicy *pol,
309 const nodemask_t *nodes)
310{
311 nodemask_t tmp;
312
David Rientjes37012942008-04-28 02:12:33 -0700313 if (pol->flags & MPOL_F_STATIC_NODES) {
314 int node = first_node(pol->w.user_nodemask);
315
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -0700316 if (node_isset(node, *nodes)) {
David Rientjes37012942008-04-28 02:12:33 -0700317 pol->v.preferred_node = node;
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -0700318 pol->flags &= ~MPOL_F_LOCAL;
319 } else
320 pol->flags |= MPOL_F_LOCAL;
David Rientjes37012942008-04-28 02:12:33 -0700321 } else if (pol->flags & MPOL_F_RELATIVE_NODES) {
322 mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes);
323 pol->v.preferred_node = first_node(tmp);
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -0700324 } else if (!(pol->flags & MPOL_F_LOCAL)) {
David Rientjes37012942008-04-28 02:12:33 -0700325 pol->v.preferred_node = node_remap(pol->v.preferred_node,
326 pol->w.cpuset_mems_allowed,
327 *nodes);
328 pol->w.cpuset_mems_allowed = *nodes;
329 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330}
331
David Rientjes1d0d2682008-04-28 02:12:32 -0700332/* Migrate a policy to a different set of nodes */
333static void mpol_rebind_policy(struct mempolicy *pol,
334 const nodemask_t *newmask)
335{
David Rientjes1d0d2682008-04-28 02:12:32 -0700336 if (!pol)
337 return;
David Rientjes1d0d2682008-04-28 02:12:32 -0700338 if (!mpol_store_user_nodemask(pol) &&
339 nodes_equal(pol->w.cpuset_mems_allowed, *newmask))
340 return;
Lee Schermerhorn45c47452008-04-28 02:13:12 -0700341 mpol_ops[pol->mode].rebind(pol, newmask);
David Rientjes1d0d2682008-04-28 02:12:32 -0700342}
343
344/*
345 * Wrapper for mpol_rebind_policy() that just requires task
346 * pointer, and updates task mempolicy.
Miao Xie58568d22009-06-16 15:31:49 -0700347 *
348 * Called with task's alloc_lock held.
David Rientjes1d0d2682008-04-28 02:12:32 -0700349 */
350
351void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new)
352{
353 mpol_rebind_policy(tsk->mempolicy, new);
354}
355
356/*
357 * Rebind each vma in mm to new nodemask.
358 *
359 * Call holding a reference to mm. Takes mm->mmap_sem during call.
360 */
361
362void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new)
363{
364 struct vm_area_struct *vma;
365
366 down_write(&mm->mmap_sem);
367 for (vma = mm->mmap; vma; vma = vma->vm_next)
368 mpol_rebind_policy(vma->vm_policy, new);
369 up_write(&mm->mmap_sem);
370}
371
David Rientjes37012942008-04-28 02:12:33 -0700372static const struct mempolicy_operations mpol_ops[MPOL_MAX] = {
373 [MPOL_DEFAULT] = {
374 .rebind = mpol_rebind_default,
375 },
376 [MPOL_INTERLEAVE] = {
377 .create = mpol_new_interleave,
378 .rebind = mpol_rebind_nodemask,
379 },
380 [MPOL_PREFERRED] = {
381 .create = mpol_new_preferred,
382 .rebind = mpol_rebind_preferred,
383 },
384 [MPOL_BIND] = {
385 .create = mpol_new_bind,
386 .rebind = mpol_rebind_nodemask,
387 },
388};
389
Christoph Lameter397874d2006-03-06 15:42:53 -0800390static void gather_stats(struct page *, void *, int pte_dirty);
Christoph Lameterfc301282006-01-18 17:42:29 -0800391static void migrate_page_add(struct page *page, struct list_head *pagelist,
392 unsigned long flags);
Christoph Lameter1a75a6c2006-01-08 01:01:02 -0800393
Christoph Lameter38e35862006-01-08 01:01:01 -0800394/* Scan through pages checking if pages follow certain conditions. */
Nick Pigginb5810032005-10-29 18:16:12 -0700395static int check_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800396 unsigned long addr, unsigned long end,
397 const nodemask_t *nodes, unsigned long flags,
Christoph Lameter38e35862006-01-08 01:01:01 -0800398 void *private)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399{
Hugh Dickins91612e02005-06-21 17:15:07 -0700400 pte_t *orig_pte;
401 pte_t *pte;
Hugh Dickins705e87c2005-10-29 18:16:27 -0700402 spinlock_t *ptl;
Hugh Dickins941150a2005-06-21 17:15:06 -0700403
Hugh Dickins705e87c2005-10-29 18:16:27 -0700404 orig_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
Hugh Dickins91612e02005-06-21 17:15:07 -0700405 do {
Linus Torvalds6aab3412005-11-28 14:34:23 -0800406 struct page *page;
Andy Whitcroft25ba77c2006-12-06 20:33:03 -0800407 int nid;
Hugh Dickins91612e02005-06-21 17:15:07 -0700408
409 if (!pte_present(*pte))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700410 continue;
Linus Torvalds6aab3412005-11-28 14:34:23 -0800411 page = vm_normal_page(vma, addr, *pte);
412 if (!page)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700413 continue;
Nick Piggin053837f2006-01-18 17:42:27 -0800414 /*
415 * The check for PageReserved here is important to avoid
416 * handling zero pages and other pages that may have been
417 * marked special by the system.
418 *
419 * If the PageReserved would not be checked here then f.e.
420 * the location of the zero page could have an influence
421 * on MPOL_MF_STRICT, zero pages would be counted for
422 * the per node stats, and there would be useless attempts
423 * to put zero pages on the migration list.
424 */
Christoph Lameterf4598c82006-01-12 01:05:20 -0800425 if (PageReserved(page))
426 continue;
Linus Torvalds6aab3412005-11-28 14:34:23 -0800427 nid = page_to_nid(page);
Christoph Lameter38e35862006-01-08 01:01:01 -0800428 if (node_isset(nid, *nodes) == !!(flags & MPOL_MF_INVERT))
429 continue;
430
Christoph Lameter1a75a6c2006-01-08 01:01:02 -0800431 if (flags & MPOL_MF_STATS)
Christoph Lameter397874d2006-03-06 15:42:53 -0800432 gather_stats(page, private, pte_dirty(*pte));
Nick Piggin053837f2006-01-18 17:42:27 -0800433 else if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
Christoph Lameterfc301282006-01-18 17:42:29 -0800434 migrate_page_add(page, private, flags);
Christoph Lameter38e35862006-01-08 01:01:01 -0800435 else
436 break;
Hugh Dickins91612e02005-06-21 17:15:07 -0700437 } while (pte++, addr += PAGE_SIZE, addr != end);
Hugh Dickins705e87c2005-10-29 18:16:27 -0700438 pte_unmap_unlock(orig_pte, ptl);
Hugh Dickins91612e02005-06-21 17:15:07 -0700439 return addr != end;
440}
441
Nick Pigginb5810032005-10-29 18:16:12 -0700442static inline int check_pmd_range(struct vm_area_struct *vma, pud_t *pud,
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800443 unsigned long addr, unsigned long end,
444 const nodemask_t *nodes, unsigned long flags,
Christoph Lameter38e35862006-01-08 01:01:01 -0800445 void *private)
Hugh Dickins91612e02005-06-21 17:15:07 -0700446{
447 pmd_t *pmd;
448 unsigned long next;
449
450 pmd = pmd_offset(pud, addr);
451 do {
452 next = pmd_addr_end(addr, end);
453 if (pmd_none_or_clear_bad(pmd))
454 continue;
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800455 if (check_pte_range(vma, pmd, addr, next, nodes,
Christoph Lameter38e35862006-01-08 01:01:01 -0800456 flags, private))
Hugh Dickins91612e02005-06-21 17:15:07 -0700457 return -EIO;
458 } while (pmd++, addr = next, addr != end);
459 return 0;
460}
461
Nick Pigginb5810032005-10-29 18:16:12 -0700462static inline int check_pud_range(struct vm_area_struct *vma, pgd_t *pgd,
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800463 unsigned long addr, unsigned long end,
464 const nodemask_t *nodes, unsigned long flags,
Christoph Lameter38e35862006-01-08 01:01:01 -0800465 void *private)
Hugh Dickins91612e02005-06-21 17:15:07 -0700466{
467 pud_t *pud;
468 unsigned long next;
469
470 pud = pud_offset(pgd, addr);
471 do {
472 next = pud_addr_end(addr, end);
473 if (pud_none_or_clear_bad(pud))
474 continue;
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800475 if (check_pmd_range(vma, pud, addr, next, nodes,
Christoph Lameter38e35862006-01-08 01:01:01 -0800476 flags, private))
Hugh Dickins91612e02005-06-21 17:15:07 -0700477 return -EIO;
478 } while (pud++, addr = next, addr != end);
479 return 0;
480}
481
Nick Pigginb5810032005-10-29 18:16:12 -0700482static inline int check_pgd_range(struct vm_area_struct *vma,
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800483 unsigned long addr, unsigned long end,
484 const nodemask_t *nodes, unsigned long flags,
Christoph Lameter38e35862006-01-08 01:01:01 -0800485 void *private)
Hugh Dickins91612e02005-06-21 17:15:07 -0700486{
487 pgd_t *pgd;
488 unsigned long next;
489
Nick Pigginb5810032005-10-29 18:16:12 -0700490 pgd = pgd_offset(vma->vm_mm, addr);
Hugh Dickins91612e02005-06-21 17:15:07 -0700491 do {
492 next = pgd_addr_end(addr, end);
493 if (pgd_none_or_clear_bad(pgd))
494 continue;
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800495 if (check_pud_range(vma, pgd, addr, next, nodes,
Christoph Lameter38e35862006-01-08 01:01:01 -0800496 flags, private))
Hugh Dickins91612e02005-06-21 17:15:07 -0700497 return -EIO;
498 } while (pgd++, addr = next, addr != end);
499 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500}
501
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800502/*
503 * Check if all pages in a range are on a set of nodes.
504 * If pagelist != NULL then isolate pages from the LRU and
505 * put them on the pagelist.
506 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507static struct vm_area_struct *
508check_range(struct mm_struct *mm, unsigned long start, unsigned long end,
Christoph Lameter38e35862006-01-08 01:01:01 -0800509 const nodemask_t *nodes, unsigned long flags, void *private)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510{
511 int err;
512 struct vm_area_struct *first, *vma, *prev;
513
Nick Piggin053837f2006-01-18 17:42:27 -0800514
Linus Torvalds1da177e2005-04-16 15:20:36 -0700515 first = find_vma(mm, start);
516 if (!first)
517 return ERR_PTR(-EFAULT);
518 prev = NULL;
519 for (vma = first; vma && vma->vm_start < end; vma = vma->vm_next) {
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800520 if (!(flags & MPOL_MF_DISCONTIG_OK)) {
521 if (!vma->vm_next && vma->vm_end < end)
522 return ERR_PTR(-EFAULT);
523 if (prev && prev->vm_end < vma->vm_start)
524 return ERR_PTR(-EFAULT);
525 }
526 if (!is_vm_hugetlb_page(vma) &&
527 ((flags & MPOL_MF_STRICT) ||
528 ((flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) &&
529 vma_migratable(vma)))) {
Andi Kleen5b952b32005-09-13 01:25:08 -0700530 unsigned long endvma = vma->vm_end;
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800531
Andi Kleen5b952b32005-09-13 01:25:08 -0700532 if (endvma > end)
533 endvma = end;
534 if (vma->vm_start > start)
535 start = vma->vm_start;
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800536 err = check_pgd_range(vma, start, endvma, nodes,
Christoph Lameter38e35862006-01-08 01:01:01 -0800537 flags, private);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700538 if (err) {
539 first = ERR_PTR(err);
540 break;
541 }
542 }
543 prev = vma;
544 }
545 return first;
546}
547
548/* Apply policy to a single VMA */
549static int policy_vma(struct vm_area_struct *vma, struct mempolicy *new)
550{
551 int err = 0;
552 struct mempolicy *old = vma->vm_policy;
553
Paul Mundt140d5a42007-07-15 23:38:16 -0700554 pr_debug("vma %lx-%lx/%lx vm_ops %p vm_file %p set_policy %p\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555 vma->vm_start, vma->vm_end, vma->vm_pgoff,
556 vma->vm_ops, vma->vm_file,
557 vma->vm_ops ? vma->vm_ops->set_policy : NULL);
558
559 if (vma->vm_ops && vma->vm_ops->set_policy)
560 err = vma->vm_ops->set_policy(vma, new);
561 if (!err) {
562 mpol_get(new);
563 vma->vm_policy = new;
Lee Schermerhornf0be3d32008-04-28 02:13:08 -0700564 mpol_put(old);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565 }
566 return err;
567}
568
569/* Step 2: apply policy to a range and do splits. */
570static int mbind_range(struct vm_area_struct *vma, unsigned long start,
571 unsigned long end, struct mempolicy *new)
572{
573 struct vm_area_struct *next;
574 int err;
575
576 err = 0;
577 for (; vma && vma->vm_start < end; vma = next) {
578 next = vma->vm_next;
579 if (vma->vm_start < start)
580 err = split_vma(vma->vm_mm, vma, start, 1);
581 if (!err && vma->vm_end > end)
582 err = split_vma(vma->vm_mm, vma, end, 0);
583 if (!err)
584 err = policy_vma(vma, new);
585 if (err)
586 break;
587 }
588 return err;
589}
590
Paul Jacksonc61afb12006-03-24 03:16:08 -0800591/*
592 * Update task->flags PF_MEMPOLICY bit: set iff non-default
593 * mempolicy. Allows more rapid checking of this (combined perhaps
594 * with other PF_* flag bits) on memory allocation hot code paths.
595 *
596 * If called from outside this file, the task 'p' should -only- be
597 * a newly forked child not yet visible on the task list, because
598 * manipulating the task flags of a visible task is not safe.
599 *
600 * The above limitation is why this routine has the funny name
601 * mpol_fix_fork_child_flag().
602 *
603 * It is also safe to call this with a task pointer of current,
604 * which the static wrapper mpol_set_task_struct_flag() does,
605 * for use within this file.
606 */
607
608void mpol_fix_fork_child_flag(struct task_struct *p)
609{
610 if (p->mempolicy)
611 p->flags |= PF_MEMPOLICY;
612 else
613 p->flags &= ~PF_MEMPOLICY;
614}
615
616static void mpol_set_task_struct_flag(void)
617{
618 mpol_fix_fork_child_flag(current);
619}
620
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621/* Set the process memory policy */
David Rientjes028fec42008-04-28 02:12:25 -0700622static long do_set_mempolicy(unsigned short mode, unsigned short flags,
623 nodemask_t *nodes)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624{
Miao Xie58568d22009-06-16 15:31:49 -0700625 struct mempolicy *new, *old;
Lee Schermerhornf4e53d92008-04-28 02:13:10 -0700626 struct mm_struct *mm = current->mm;
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -0700627 NODEMASK_SCRATCH(scratch);
Miao Xie58568d22009-06-16 15:31:49 -0700628 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -0700630 if (!scratch)
631 return -ENOMEM;
Lee Schermerhornf4e53d92008-04-28 02:13:10 -0700632
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -0700633 new = mpol_new(mode, flags, nodes);
634 if (IS_ERR(new)) {
635 ret = PTR_ERR(new);
636 goto out;
637 }
Lee Schermerhornf4e53d92008-04-28 02:13:10 -0700638 /*
639 * prevent changing our mempolicy while show_numa_maps()
640 * is using it.
641 * Note: do_set_mempolicy() can be called at init time
642 * with no 'mm'.
643 */
644 if (mm)
645 down_write(&mm->mmap_sem);
Miao Xie58568d22009-06-16 15:31:49 -0700646 task_lock(current);
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -0700647 ret = mpol_set_nodemask(new, nodes, scratch);
Miao Xie58568d22009-06-16 15:31:49 -0700648 if (ret) {
649 task_unlock(current);
650 if (mm)
651 up_write(&mm->mmap_sem);
652 mpol_put(new);
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -0700653 goto out;
Miao Xie58568d22009-06-16 15:31:49 -0700654 }
655 old = current->mempolicy;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700656 current->mempolicy = new;
Paul Jacksonc61afb12006-03-24 03:16:08 -0800657 mpol_set_task_struct_flag();
Lee Schermerhorn45c47452008-04-28 02:13:12 -0700658 if (new && new->mode == MPOL_INTERLEAVE &&
David Rientjesf5b087b2008-04-28 02:12:27 -0700659 nodes_weight(new->v.nodes))
Andi Kleendfcd3c02005-10-29 18:15:48 -0700660 current->il_next = first_node(new->v.nodes);
Miao Xie58568d22009-06-16 15:31:49 -0700661 task_unlock(current);
Lee Schermerhornf4e53d92008-04-28 02:13:10 -0700662 if (mm)
663 up_write(&mm->mmap_sem);
664
Miao Xie58568d22009-06-16 15:31:49 -0700665 mpol_put(old);
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -0700666 ret = 0;
667out:
668 NODEMASK_SCRATCH_FREE(scratch);
669 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670}
671
Lee Schermerhornbea904d2008-04-28 02:13:18 -0700672/*
673 * Return nodemask for policy for get_mempolicy() query
Miao Xie58568d22009-06-16 15:31:49 -0700674 *
675 * Called with task's alloc_lock held
Lee Schermerhornbea904d2008-04-28 02:13:18 -0700676 */
677static void get_policy_nodemask(struct mempolicy *p, nodemask_t *nodes)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678{
Andi Kleendfcd3c02005-10-29 18:15:48 -0700679 nodes_clear(*nodes);
Lee Schermerhornbea904d2008-04-28 02:13:18 -0700680 if (p == &default_policy)
681 return;
682
Lee Schermerhorn45c47452008-04-28 02:13:12 -0700683 switch (p->mode) {
Mel Gorman19770b32008-04-28 02:12:18 -0700684 case MPOL_BIND:
685 /* Fall through */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700686 case MPOL_INTERLEAVE:
Andi Kleendfcd3c02005-10-29 18:15:48 -0700687 *nodes = p->v.nodes;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700688 break;
689 case MPOL_PREFERRED:
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -0700690 if (!(p->flags & MPOL_F_LOCAL))
Andi Kleendfcd3c02005-10-29 18:15:48 -0700691 node_set(p->v.preferred_node, *nodes);
Lee Schermerhorn53f25562008-04-28 02:13:20 -0700692 /* else return empty node mask for local allocation */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693 break;
694 default:
695 BUG();
696 }
697}
698
699static int lookup_node(struct mm_struct *mm, unsigned long addr)
700{
701 struct page *p;
702 int err;
703
704 err = get_user_pages(current, mm, addr & PAGE_MASK, 1, 0, 0, &p, NULL);
705 if (err >= 0) {
706 err = page_to_nid(p);
707 put_page(p);
708 }
709 return err;
710}
711
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712/* Retrieve NUMA policy */
Adrian Bunkdbcb0f12007-10-16 01:26:26 -0700713static long do_get_mempolicy(int *policy, nodemask_t *nmask,
714 unsigned long addr, unsigned long flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715{
Christoph Lameter8bccd852005-10-29 18:16:59 -0700716 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700717 struct mm_struct *mm = current->mm;
718 struct vm_area_struct *vma = NULL;
719 struct mempolicy *pol = current->mempolicy;
720
Lee Schermerhorn754af6f2007-10-16 01:24:51 -0700721 if (flags &
722 ~(unsigned long)(MPOL_F_NODE|MPOL_F_ADDR|MPOL_F_MEMS_ALLOWED))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700723 return -EINVAL;
Lee Schermerhorn754af6f2007-10-16 01:24:51 -0700724
725 if (flags & MPOL_F_MEMS_ALLOWED) {
726 if (flags & (MPOL_F_NODE|MPOL_F_ADDR))
727 return -EINVAL;
728 *policy = 0; /* just so it's initialized */
Miao Xie58568d22009-06-16 15:31:49 -0700729 task_lock(current);
Lee Schermerhorn754af6f2007-10-16 01:24:51 -0700730 *nmask = cpuset_current_mems_allowed;
Miao Xie58568d22009-06-16 15:31:49 -0700731 task_unlock(current);
Lee Schermerhorn754af6f2007-10-16 01:24:51 -0700732 return 0;
733 }
734
Linus Torvalds1da177e2005-04-16 15:20:36 -0700735 if (flags & MPOL_F_ADDR) {
Lee Schermerhornbea904d2008-04-28 02:13:18 -0700736 /*
737 * Do NOT fall back to task policy if the
738 * vma/shared policy at addr is NULL. We
739 * want to return MPOL_DEFAULT in this case.
740 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700741 down_read(&mm->mmap_sem);
742 vma = find_vma_intersection(mm, addr, addr+1);
743 if (!vma) {
744 up_read(&mm->mmap_sem);
745 return -EFAULT;
746 }
747 if (vma->vm_ops && vma->vm_ops->get_policy)
748 pol = vma->vm_ops->get_policy(vma, addr);
749 else
750 pol = vma->vm_policy;
751 } else if (addr)
752 return -EINVAL;
753
754 if (!pol)
Lee Schermerhornbea904d2008-04-28 02:13:18 -0700755 pol = &default_policy; /* indicates default behavior */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700756
757 if (flags & MPOL_F_NODE) {
758 if (flags & MPOL_F_ADDR) {
759 err = lookup_node(mm, addr);
760 if (err < 0)
761 goto out;
Christoph Lameter8bccd852005-10-29 18:16:59 -0700762 *policy = err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763 } else if (pol == current->mempolicy &&
Lee Schermerhorn45c47452008-04-28 02:13:12 -0700764 pol->mode == MPOL_INTERLEAVE) {
Christoph Lameter8bccd852005-10-29 18:16:59 -0700765 *policy = current->il_next;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700766 } else {
767 err = -EINVAL;
768 goto out;
769 }
Lee Schermerhornbea904d2008-04-28 02:13:18 -0700770 } else {
771 *policy = pol == &default_policy ? MPOL_DEFAULT :
772 pol->mode;
David Rientjesd79df632008-07-04 12:24:13 -0700773 /*
774 * Internal mempolicy flags must be masked off before exposing
775 * the policy to userspace.
776 */
777 *policy |= (pol->flags & MPOL_MODE_FLAGS);
Lee Schermerhornbea904d2008-04-28 02:13:18 -0700778 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700779
780 if (vma) {
781 up_read(&current->mm->mmap_sem);
782 vma = NULL;
783 }
784
Linus Torvalds1da177e2005-04-16 15:20:36 -0700785 err = 0;
Miao Xie58568d22009-06-16 15:31:49 -0700786 if (nmask) {
787 task_lock(current);
Lee Schermerhornbea904d2008-04-28 02:13:18 -0700788 get_policy_nodemask(pol, nmask);
Miao Xie58568d22009-06-16 15:31:49 -0700789 task_unlock(current);
790 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700791
792 out:
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -0700793 mpol_cond_put(pol);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700794 if (vma)
795 up_read(&current->mm->mmap_sem);
796 return err;
797}
798
Christoph Lameterb20a3502006-03-22 00:09:12 -0800799#ifdef CONFIG_MIGRATION
Christoph Lameter8bccd852005-10-29 18:16:59 -0700800/*
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -0800801 * page migration
802 */
Christoph Lameterfc301282006-01-18 17:42:29 -0800803static void migrate_page_add(struct page *page, struct list_head *pagelist,
804 unsigned long flags)
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -0800805{
806 /*
Christoph Lameterfc301282006-01-18 17:42:29 -0800807 * Avoid migrating a page that is shared with others.
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -0800808 */
Nick Piggin62695a82008-10-18 20:26:09 -0700809 if ((flags & MPOL_MF_MOVE_ALL) || page_mapcount(page) == 1) {
810 if (!isolate_lru_page(page)) {
811 list_add_tail(&page->lru, pagelist);
812 }
813 }
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -0800814}
815
Christoph Lameter742755a2006-06-23 02:03:55 -0700816static struct page *new_node_page(struct page *page, unsigned long node, int **x)
Christoph Lameter95a402c2006-06-23 02:03:53 -0700817{
Mel Gorman6484eb32009-06-16 15:31:54 -0700818 return alloc_pages_exact_node(node, GFP_HIGHUSER_MOVABLE, 0);
Christoph Lameter95a402c2006-06-23 02:03:53 -0700819}
820
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -0800821/*
Christoph Lameter7e2ab152006-02-01 03:05:40 -0800822 * Migrate pages from one node to a target node.
823 * Returns error or the number of pages not migrated.
824 */
Adrian Bunkdbcb0f12007-10-16 01:26:26 -0700825static int migrate_to_node(struct mm_struct *mm, int source, int dest,
826 int flags)
Christoph Lameter7e2ab152006-02-01 03:05:40 -0800827{
828 nodemask_t nmask;
829 LIST_HEAD(pagelist);
830 int err = 0;
831
832 nodes_clear(nmask);
833 node_set(source, nmask);
834
835 check_range(mm, mm->mmap->vm_start, TASK_SIZE, &nmask,
836 flags | MPOL_MF_DISCONTIG_OK, &pagelist);
837
Christoph Lameteraaa994b2006-06-23 02:03:52 -0700838 if (!list_empty(&pagelist))
Christoph Lameter95a402c2006-06-23 02:03:53 -0700839 err = migrate_pages(&pagelist, new_node_page, dest);
840
Christoph Lameter7e2ab152006-02-01 03:05:40 -0800841 return err;
842}
843
844/*
845 * Move pages between the two nodesets so as to preserve the physical
846 * layout as much as possible.
Christoph Lameter39743882006-01-08 01:00:51 -0800847 *
848 * Returns the number of page that could not be moved.
849 */
850int do_migrate_pages(struct mm_struct *mm,
851 const nodemask_t *from_nodes, const nodemask_t *to_nodes, int flags)
852{
Christoph Lameter7e2ab152006-02-01 03:05:40 -0800853 int busy = 0;
Christoph Lameter0aedadf2008-11-06 12:53:30 -0800854 int err;
Christoph Lameter7e2ab152006-02-01 03:05:40 -0800855 nodemask_t tmp;
Christoph Lameter39743882006-01-08 01:00:51 -0800856
Christoph Lameter0aedadf2008-11-06 12:53:30 -0800857 err = migrate_prep();
858 if (err)
859 return err;
860
Lee Schermerhorn53f25562008-04-28 02:13:20 -0700861 down_read(&mm->mmap_sem);
Christoph Lameter39743882006-01-08 01:00:51 -0800862
Christoph Lameter7b2259b2006-06-25 05:46:48 -0700863 err = migrate_vmas(mm, from_nodes, to_nodes, flags);
864 if (err)
865 goto out;
866
Christoph Lameter7e2ab152006-02-01 03:05:40 -0800867/*
868 * Find a 'source' bit set in 'tmp' whose corresponding 'dest'
869 * bit in 'to' is not also set in 'tmp'. Clear the found 'source'
870 * bit in 'tmp', and return that <source, dest> pair for migration.
871 * The pair of nodemasks 'to' and 'from' define the map.
872 *
873 * If no pair of bits is found that way, fallback to picking some
874 * pair of 'source' and 'dest' bits that are not the same. If the
875 * 'source' and 'dest' bits are the same, this represents a node
876 * that will be migrating to itself, so no pages need move.
877 *
878 * If no bits are left in 'tmp', or if all remaining bits left
879 * in 'tmp' correspond to the same bit in 'to', return false
880 * (nothing left to migrate).
881 *
882 * This lets us pick a pair of nodes to migrate between, such that
883 * if possible the dest node is not already occupied by some other
884 * source node, minimizing the risk of overloading the memory on a
885 * node that would happen if we migrated incoming memory to a node
886 * before migrating outgoing memory source that same node.
887 *
888 * A single scan of tmp is sufficient. As we go, we remember the
889 * most recent <s, d> pair that moved (s != d). If we find a pair
890 * that not only moved, but what's better, moved to an empty slot
891 * (d is not set in tmp), then we break out then, with that pair.
892 * Otherwise when we finish scannng from_tmp, we at least have the
893 * most recent <s, d> pair that moved. If we get all the way through
894 * the scan of tmp without finding any node that moved, much less
895 * moved to an empty node, then there is nothing left worth migrating.
896 */
Christoph Lameterd4984712006-01-08 01:00:55 -0800897
Christoph Lameter7e2ab152006-02-01 03:05:40 -0800898 tmp = *from_nodes;
899 while (!nodes_empty(tmp)) {
900 int s,d;
901 int source = -1;
902 int dest = 0;
903
904 for_each_node_mask(s, tmp) {
905 d = node_remap(s, *from_nodes, *to_nodes);
906 if (s == d)
907 continue;
908
909 source = s; /* Node moved. Memorize */
910 dest = d;
911
912 /* dest not in remaining from nodes? */
913 if (!node_isset(dest, tmp))
914 break;
915 }
916 if (source == -1)
917 break;
918
919 node_clear(source, tmp);
920 err = migrate_to_node(mm, source, dest, flags);
921 if (err > 0)
922 busy += err;
923 if (err < 0)
924 break;
Christoph Lameter39743882006-01-08 01:00:51 -0800925 }
Christoph Lameter7b2259b2006-06-25 05:46:48 -0700926out:
Christoph Lameter39743882006-01-08 01:00:51 -0800927 up_read(&mm->mmap_sem);
Christoph Lameter7e2ab152006-02-01 03:05:40 -0800928 if (err < 0)
929 return err;
930 return busy;
Christoph Lameterb20a3502006-03-22 00:09:12 -0800931
Christoph Lameter39743882006-01-08 01:00:51 -0800932}
933
Lee Schermerhorn3ad33b22007-11-14 16:59:10 -0800934/*
935 * Allocate a new page for page migration based on vma policy.
936 * Start assuming that page is mapped by vma pointed to by @private.
937 * Search forward from there, if not. N.B., this assumes that the
938 * list of pages handed to migrate_pages()--which is how we get here--
939 * is in virtual address order.
940 */
Christoph Lameter742755a2006-06-23 02:03:55 -0700941static struct page *new_vma_page(struct page *page, unsigned long private, int **x)
Christoph Lameter95a402c2006-06-23 02:03:53 -0700942{
943 struct vm_area_struct *vma = (struct vm_area_struct *)private;
Lee Schermerhorn3ad33b22007-11-14 16:59:10 -0800944 unsigned long uninitialized_var(address);
Christoph Lameter95a402c2006-06-23 02:03:53 -0700945
Lee Schermerhorn3ad33b22007-11-14 16:59:10 -0800946 while (vma) {
947 address = page_address_in_vma(page, vma);
948 if (address != -EFAULT)
949 break;
950 vma = vma->vm_next;
951 }
952
953 /*
954 * if !vma, alloc_page_vma() will use task or system default policy
955 */
956 return alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
Christoph Lameter95a402c2006-06-23 02:03:53 -0700957}
Christoph Lameterb20a3502006-03-22 00:09:12 -0800958#else
959
960static void migrate_page_add(struct page *page, struct list_head *pagelist,
961 unsigned long flags)
962{
963}
964
965int do_migrate_pages(struct mm_struct *mm,
966 const nodemask_t *from_nodes, const nodemask_t *to_nodes, int flags)
967{
968 return -ENOSYS;
969}
Christoph Lameter95a402c2006-06-23 02:03:53 -0700970
Keith Owens69939742006-10-11 01:21:28 -0700971static struct page *new_vma_page(struct page *page, unsigned long private, int **x)
Christoph Lameter95a402c2006-06-23 02:03:53 -0700972{
973 return NULL;
974}
Christoph Lameterb20a3502006-03-22 00:09:12 -0800975#endif
976
Adrian Bunkdbcb0f12007-10-16 01:26:26 -0700977static long do_mbind(unsigned long start, unsigned long len,
David Rientjes028fec42008-04-28 02:12:25 -0700978 unsigned short mode, unsigned short mode_flags,
979 nodemask_t *nmask, unsigned long flags)
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -0800980{
981 struct vm_area_struct *vma;
982 struct mm_struct *mm = current->mm;
983 struct mempolicy *new;
984 unsigned long end;
985 int err;
986 LIST_HEAD(pagelist);
987
David Rientjesa3b51e02008-04-28 02:12:23 -0700988 if (flags & ~(unsigned long)(MPOL_MF_STRICT |
989 MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -0800990 return -EINVAL;
Christoph Lameter74c00242006-03-14 19:50:21 -0800991 if ((flags & MPOL_MF_MOVE_ALL) && !capable(CAP_SYS_NICE))
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -0800992 return -EPERM;
993
994 if (start & ~PAGE_MASK)
995 return -EINVAL;
996
997 if (mode == MPOL_DEFAULT)
998 flags &= ~MPOL_MF_STRICT;
999
1000 len = (len + PAGE_SIZE - 1) & PAGE_MASK;
1001 end = start + len;
1002
1003 if (end < start)
1004 return -EINVAL;
1005 if (end == start)
1006 return 0;
1007
David Rientjes028fec42008-04-28 02:12:25 -07001008 new = mpol_new(mode, mode_flags, nmask);
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -08001009 if (IS_ERR(new))
1010 return PTR_ERR(new);
1011
1012 /*
1013 * If we are using the default policy then operation
1014 * on discontinuous address spaces is okay after all
1015 */
1016 if (!new)
1017 flags |= MPOL_MF_DISCONTIG_OK;
1018
David Rientjes028fec42008-04-28 02:12:25 -07001019 pr_debug("mbind %lx-%lx mode:%d flags:%d nodes:%lx\n",
1020 start, start + len, mode, mode_flags,
1021 nmask ? nodes_addr(*nmask)[0] : -1);
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -08001022
Christoph Lameter0aedadf2008-11-06 12:53:30 -08001023 if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) {
1024
1025 err = migrate_prep();
1026 if (err)
KOSAKI Motohirob05ca732009-10-26 16:49:59 -07001027 goto mpol_out;
Christoph Lameter0aedadf2008-11-06 12:53:30 -08001028 }
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -07001029 {
1030 NODEMASK_SCRATCH(scratch);
1031 if (scratch) {
1032 down_write(&mm->mmap_sem);
1033 task_lock(current);
1034 err = mpol_set_nodemask(new, nmask, scratch);
1035 task_unlock(current);
1036 if (err)
1037 up_write(&mm->mmap_sem);
1038 } else
1039 err = -ENOMEM;
1040 NODEMASK_SCRATCH_FREE(scratch);
1041 }
KOSAKI Motohirob05ca732009-10-26 16:49:59 -07001042 if (err)
1043 goto mpol_out;
1044
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -08001045 vma = check_range(mm, start, end, nmask,
1046 flags | MPOL_MF_INVERT, &pagelist);
1047
1048 err = PTR_ERR(vma);
1049 if (!IS_ERR(vma)) {
1050 int nr_failed = 0;
1051
1052 err = mbind_range(vma, start, end, new);
Christoph Lameter7e2ab152006-02-01 03:05:40 -08001053
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -08001054 if (!list_empty(&pagelist))
Christoph Lameter95a402c2006-06-23 02:03:53 -07001055 nr_failed = migrate_pages(&pagelist, new_vma_page,
1056 (unsigned long)vma);
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -08001057
1058 if (!err && nr_failed && (flags & MPOL_MF_STRICT))
1059 err = -EIO;
KOSAKI Motohiroab8a3e12009-10-26 16:49:58 -07001060 } else
1061 putback_lru_pages(&pagelist);
Christoph Lameterb20a3502006-03-22 00:09:12 -08001062
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -08001063 up_write(&mm->mmap_sem);
KOSAKI Motohirob05ca732009-10-26 16:49:59 -07001064 mpol_out:
Lee Schermerhornf0be3d32008-04-28 02:13:08 -07001065 mpol_put(new);
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -08001066 return err;
1067}
1068
Christoph Lameter39743882006-01-08 01:00:51 -08001069/*
Christoph Lameter8bccd852005-10-29 18:16:59 -07001070 * User space interface with variable sized bitmaps for nodelists.
1071 */
1072
1073/* Copy a node mask from user space. */
Christoph Lameter39743882006-01-08 01:00:51 -08001074static int get_nodes(nodemask_t *nodes, const unsigned long __user *nmask,
Christoph Lameter8bccd852005-10-29 18:16:59 -07001075 unsigned long maxnode)
1076{
1077 unsigned long k;
1078 unsigned long nlongs;
1079 unsigned long endmask;
1080
1081 --maxnode;
1082 nodes_clear(*nodes);
1083 if (maxnode == 0 || !nmask)
1084 return 0;
Andi Kleena9c930b2006-02-20 18:27:59 -08001085 if (maxnode > PAGE_SIZE*BITS_PER_BYTE)
Chris Wright636f13c2006-02-17 13:59:36 -08001086 return -EINVAL;
Christoph Lameter8bccd852005-10-29 18:16:59 -07001087
1088 nlongs = BITS_TO_LONGS(maxnode);
1089 if ((maxnode % BITS_PER_LONG) == 0)
1090 endmask = ~0UL;
1091 else
1092 endmask = (1UL << (maxnode % BITS_PER_LONG)) - 1;
1093
1094 /* When the user specified more nodes than supported just check
1095 if the non supported part is all zero. */
1096 if (nlongs > BITS_TO_LONGS(MAX_NUMNODES)) {
1097 if (nlongs > PAGE_SIZE/sizeof(long))
1098 return -EINVAL;
1099 for (k = BITS_TO_LONGS(MAX_NUMNODES); k < nlongs; k++) {
1100 unsigned long t;
1101 if (get_user(t, nmask + k))
1102 return -EFAULT;
1103 if (k == nlongs - 1) {
1104 if (t & endmask)
1105 return -EINVAL;
1106 } else if (t)
1107 return -EINVAL;
1108 }
1109 nlongs = BITS_TO_LONGS(MAX_NUMNODES);
1110 endmask = ~0UL;
1111 }
1112
1113 if (copy_from_user(nodes_addr(*nodes), nmask, nlongs*sizeof(unsigned long)))
1114 return -EFAULT;
1115 nodes_addr(*nodes)[nlongs-1] &= endmask;
1116 return 0;
1117}
1118
1119/* Copy a kernel node mask to user space */
1120static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode,
1121 nodemask_t *nodes)
1122{
1123 unsigned long copy = ALIGN(maxnode-1, 64) / 8;
1124 const int nbytes = BITS_TO_LONGS(MAX_NUMNODES) * sizeof(long);
1125
1126 if (copy > nbytes) {
1127 if (copy > PAGE_SIZE)
1128 return -EINVAL;
1129 if (clear_user((char __user *)mask + nbytes, copy - nbytes))
1130 return -EFAULT;
1131 copy = nbytes;
1132 }
1133 return copy_to_user(mask, nodes_addr(*nodes), copy) ? -EFAULT : 0;
1134}
1135
Heiko Carstens938bb9f2009-01-14 14:14:30 +01001136SYSCALL_DEFINE6(mbind, unsigned long, start, unsigned long, len,
1137 unsigned long, mode, unsigned long __user *, nmask,
1138 unsigned long, maxnode, unsigned, flags)
Christoph Lameter8bccd852005-10-29 18:16:59 -07001139{
1140 nodemask_t nodes;
1141 int err;
David Rientjes028fec42008-04-28 02:12:25 -07001142 unsigned short mode_flags;
Christoph Lameter8bccd852005-10-29 18:16:59 -07001143
David Rientjes028fec42008-04-28 02:12:25 -07001144 mode_flags = mode & MPOL_MODE_FLAGS;
1145 mode &= ~MPOL_MODE_FLAGS;
David Rientjesa3b51e02008-04-28 02:12:23 -07001146 if (mode >= MPOL_MAX)
1147 return -EINVAL;
David Rientjes4c50bc02008-04-28 02:12:30 -07001148 if ((mode_flags & MPOL_F_STATIC_NODES) &&
1149 (mode_flags & MPOL_F_RELATIVE_NODES))
1150 return -EINVAL;
Christoph Lameter8bccd852005-10-29 18:16:59 -07001151 err = get_nodes(&nodes, nmask, maxnode);
1152 if (err)
1153 return err;
David Rientjes028fec42008-04-28 02:12:25 -07001154 return do_mbind(start, len, mode, mode_flags, &nodes, flags);
Christoph Lameter8bccd852005-10-29 18:16:59 -07001155}
1156
1157/* Set the process memory policy */
Heiko Carstens938bb9f2009-01-14 14:14:30 +01001158SYSCALL_DEFINE3(set_mempolicy, int, mode, unsigned long __user *, nmask,
1159 unsigned long, maxnode)
Christoph Lameter8bccd852005-10-29 18:16:59 -07001160{
1161 int err;
1162 nodemask_t nodes;
David Rientjes028fec42008-04-28 02:12:25 -07001163 unsigned short flags;
Christoph Lameter8bccd852005-10-29 18:16:59 -07001164
David Rientjes028fec42008-04-28 02:12:25 -07001165 flags = mode & MPOL_MODE_FLAGS;
1166 mode &= ~MPOL_MODE_FLAGS;
1167 if ((unsigned int)mode >= MPOL_MAX)
Christoph Lameter8bccd852005-10-29 18:16:59 -07001168 return -EINVAL;
David Rientjes4c50bc02008-04-28 02:12:30 -07001169 if ((flags & MPOL_F_STATIC_NODES) && (flags & MPOL_F_RELATIVE_NODES))
1170 return -EINVAL;
Christoph Lameter8bccd852005-10-29 18:16:59 -07001171 err = get_nodes(&nodes, nmask, maxnode);
1172 if (err)
1173 return err;
David Rientjes028fec42008-04-28 02:12:25 -07001174 return do_set_mempolicy(mode, flags, &nodes);
Christoph Lameter8bccd852005-10-29 18:16:59 -07001175}
1176
Heiko Carstens938bb9f2009-01-14 14:14:30 +01001177SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode,
1178 const unsigned long __user *, old_nodes,
1179 const unsigned long __user *, new_nodes)
Christoph Lameter39743882006-01-08 01:00:51 -08001180{
David Howellsc69e8d92008-11-14 10:39:19 +11001181 const struct cred *cred = current_cred(), *tcred;
Christoph Lameter39743882006-01-08 01:00:51 -08001182 struct mm_struct *mm;
1183 struct task_struct *task;
1184 nodemask_t old;
1185 nodemask_t new;
1186 nodemask_t task_nodes;
1187 int err;
1188
1189 err = get_nodes(&old, old_nodes, maxnode);
1190 if (err)
1191 return err;
1192
1193 err = get_nodes(&new, new_nodes, maxnode);
1194 if (err)
1195 return err;
1196
1197 /* Find the mm_struct */
1198 read_lock(&tasklist_lock);
Pavel Emelyanov228ebcb2007-10-18 23:40:16 -07001199 task = pid ? find_task_by_vpid(pid) : current;
Christoph Lameter39743882006-01-08 01:00:51 -08001200 if (!task) {
1201 read_unlock(&tasklist_lock);
1202 return -ESRCH;
1203 }
1204 mm = get_task_mm(task);
1205 read_unlock(&tasklist_lock);
1206
1207 if (!mm)
1208 return -EINVAL;
1209
1210 /*
1211 * Check if this process has the right to modify the specified
1212 * process. The right exists if the process has administrative
Alexey Dobriyan7f927fc2006-03-28 01:56:53 -08001213 * capabilities, superuser privileges or the same
Christoph Lameter39743882006-01-08 01:00:51 -08001214 * userid as the target process.
1215 */
David Howellsc69e8d92008-11-14 10:39:19 +11001216 rcu_read_lock();
1217 tcred = __task_cred(task);
David Howellsb6dff3e2008-11-14 10:39:16 +11001218 if (cred->euid != tcred->suid && cred->euid != tcred->uid &&
1219 cred->uid != tcred->suid && cred->uid != tcred->uid &&
Christoph Lameter74c00242006-03-14 19:50:21 -08001220 !capable(CAP_SYS_NICE)) {
David Howellsc69e8d92008-11-14 10:39:19 +11001221 rcu_read_unlock();
Christoph Lameter39743882006-01-08 01:00:51 -08001222 err = -EPERM;
1223 goto out;
1224 }
David Howellsc69e8d92008-11-14 10:39:19 +11001225 rcu_read_unlock();
Christoph Lameter39743882006-01-08 01:00:51 -08001226
1227 task_nodes = cpuset_mems_allowed(task);
1228 /* Is the user allowed to access the target nodes? */
Christoph Lameter74c00242006-03-14 19:50:21 -08001229 if (!nodes_subset(new, task_nodes) && !capable(CAP_SYS_NICE)) {
Christoph Lameter39743882006-01-08 01:00:51 -08001230 err = -EPERM;
1231 goto out;
1232 }
1233
Lee Schermerhorn37b07e42007-10-16 01:25:39 -07001234 if (!nodes_subset(new, node_states[N_HIGH_MEMORY])) {
Christoph Lameter3b42d282007-08-31 00:12:08 -07001235 err = -EINVAL;
1236 goto out;
1237 }
1238
David Quigley86c3a762006-06-23 02:04:02 -07001239 err = security_task_movememory(task);
1240 if (err)
1241 goto out;
1242
Christoph Lameter511030b2006-02-28 16:58:57 -08001243 err = do_migrate_pages(mm, &old, &new,
Christoph Lameter74c00242006-03-14 19:50:21 -08001244 capable(CAP_SYS_NICE) ? MPOL_MF_MOVE_ALL : MPOL_MF_MOVE);
Christoph Lameter39743882006-01-08 01:00:51 -08001245out:
1246 mmput(mm);
1247 return err;
1248}
1249
1250
Christoph Lameter8bccd852005-10-29 18:16:59 -07001251/* Retrieve NUMA policy */
Heiko Carstens938bb9f2009-01-14 14:14:30 +01001252SYSCALL_DEFINE5(get_mempolicy, int __user *, policy,
1253 unsigned long __user *, nmask, unsigned long, maxnode,
1254 unsigned long, addr, unsigned long, flags)
Christoph Lameter8bccd852005-10-29 18:16:59 -07001255{
Adrian Bunkdbcb0f12007-10-16 01:26:26 -07001256 int err;
1257 int uninitialized_var(pval);
Christoph Lameter8bccd852005-10-29 18:16:59 -07001258 nodemask_t nodes;
1259
1260 if (nmask != NULL && maxnode < MAX_NUMNODES)
1261 return -EINVAL;
1262
1263 err = do_get_mempolicy(&pval, &nodes, addr, flags);
1264
1265 if (err)
1266 return err;
1267
1268 if (policy && put_user(pval, policy))
1269 return -EFAULT;
1270
1271 if (nmask)
1272 err = copy_nodes_to_user(nmask, maxnode, &nodes);
1273
1274 return err;
1275}
1276
Linus Torvalds1da177e2005-04-16 15:20:36 -07001277#ifdef CONFIG_COMPAT
1278
1279asmlinkage long compat_sys_get_mempolicy(int __user *policy,
1280 compat_ulong_t __user *nmask,
1281 compat_ulong_t maxnode,
1282 compat_ulong_t addr, compat_ulong_t flags)
1283{
1284 long err;
1285 unsigned long __user *nm = NULL;
1286 unsigned long nr_bits, alloc_size;
1287 DECLARE_BITMAP(bm, MAX_NUMNODES);
1288
1289 nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
1290 alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
1291
1292 if (nmask)
1293 nm = compat_alloc_user_space(alloc_size);
1294
1295 err = sys_get_mempolicy(policy, nm, nr_bits+1, addr, flags);
1296
1297 if (!err && nmask) {
1298 err = copy_from_user(bm, nm, alloc_size);
1299 /* ensure entire bitmap is zeroed */
1300 err |= clear_user(nmask, ALIGN(maxnode-1, 8) / 8);
1301 err |= compat_put_bitmap(nmask, bm, nr_bits);
1302 }
1303
1304 return err;
1305}
1306
1307asmlinkage long compat_sys_set_mempolicy(int mode, compat_ulong_t __user *nmask,
1308 compat_ulong_t maxnode)
1309{
1310 long err = 0;
1311 unsigned long __user *nm = NULL;
1312 unsigned long nr_bits, alloc_size;
1313 DECLARE_BITMAP(bm, MAX_NUMNODES);
1314
1315 nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
1316 alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
1317
1318 if (nmask) {
1319 err = compat_get_bitmap(bm, nmask, nr_bits);
1320 nm = compat_alloc_user_space(alloc_size);
1321 err |= copy_to_user(nm, bm, alloc_size);
1322 }
1323
1324 if (err)
1325 return -EFAULT;
1326
1327 return sys_set_mempolicy(mode, nm, nr_bits+1);
1328}
1329
1330asmlinkage long compat_sys_mbind(compat_ulong_t start, compat_ulong_t len,
1331 compat_ulong_t mode, compat_ulong_t __user *nmask,
1332 compat_ulong_t maxnode, compat_ulong_t flags)
1333{
1334 long err = 0;
1335 unsigned long __user *nm = NULL;
1336 unsigned long nr_bits, alloc_size;
Andi Kleendfcd3c02005-10-29 18:15:48 -07001337 nodemask_t bm;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001338
1339 nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
1340 alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
1341
1342 if (nmask) {
Andi Kleendfcd3c02005-10-29 18:15:48 -07001343 err = compat_get_bitmap(nodes_addr(bm), nmask, nr_bits);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001344 nm = compat_alloc_user_space(alloc_size);
Andi Kleendfcd3c02005-10-29 18:15:48 -07001345 err |= copy_to_user(nm, nodes_addr(bm), alloc_size);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001346 }
1347
1348 if (err)
1349 return -EFAULT;
1350
1351 return sys_mbind(start, len, mode, nm, nr_bits+1, flags);
1352}
1353
1354#endif
1355
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001356/*
1357 * get_vma_policy(@task, @vma, @addr)
1358 * @task - task for fallback if vma policy == default
1359 * @vma - virtual memory area whose policy is sought
1360 * @addr - address in @vma for shared policy lookup
1361 *
1362 * Returns effective policy for a VMA at specified address.
1363 * Falls back to @task or system default policy, as necessary.
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001364 * Current or other task's task mempolicy and non-shared vma policies
1365 * are protected by the task's mmap_sem, which must be held for read by
1366 * the caller.
1367 * Shared policies [those marked as MPOL_F_SHARED] require an extra reference
1368 * count--added by the get_policy() vm_op, as appropriate--to protect against
1369 * freeing by another task. It is the caller's responsibility to free the
1370 * extra reference for shared policies.
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001371 */
Lee Schermerhornae4d8c12008-04-28 02:13:11 -07001372static struct mempolicy *get_vma_policy(struct task_struct *task,
Christoph Lameter48fce342006-01-08 01:01:03 -08001373 struct vm_area_struct *vma, unsigned long addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001374{
Christoph Lameter6e21c8f2005-09-03 15:54:45 -07001375 struct mempolicy *pol = task->mempolicy;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001376
1377 if (vma) {
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001378 if (vma->vm_ops && vma->vm_ops->get_policy) {
Lee Schermerhornae4d8c12008-04-28 02:13:11 -07001379 struct mempolicy *vpol = vma->vm_ops->get_policy(vma,
1380 addr);
1381 if (vpol)
1382 pol = vpol;
Lee Schermerhornbea904d2008-04-28 02:13:18 -07001383 } else if (vma->vm_policy)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001384 pol = vma->vm_policy;
1385 }
1386 if (!pol)
1387 pol = &default_policy;
1388 return pol;
1389}
1390
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001391/*
1392 * Return a nodemask representing a mempolicy for filtering nodes for
1393 * page allocation
1394 */
1395static nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy)
Mel Gorman19770b32008-04-28 02:12:18 -07001396{
1397 /* Lower zones don't get a nodemask applied for MPOL_BIND */
Lee Schermerhorn45c47452008-04-28 02:13:12 -07001398 if (unlikely(policy->mode == MPOL_BIND) &&
Mel Gorman19770b32008-04-28 02:12:18 -07001399 gfp_zone(gfp) >= policy_zone &&
1400 cpuset_nodemask_valid_mems_allowed(&policy->v.nodes))
1401 return &policy->v.nodes;
1402
1403 return NULL;
1404}
1405
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001406/* Return a zonelist indicated by gfp for node representing a mempolicy */
1407static struct zonelist *policy_zonelist(gfp_t gfp, struct mempolicy *policy)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001408{
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -07001409 int nd = numa_node_id();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001410
Lee Schermerhorn45c47452008-04-28 02:13:12 -07001411 switch (policy->mode) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001412 case MPOL_PREFERRED:
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -07001413 if (!(policy->flags & MPOL_F_LOCAL))
1414 nd = policy->v.preferred_node;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001415 break;
1416 case MPOL_BIND:
Mel Gorman19770b32008-04-28 02:12:18 -07001417 /*
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001418 * Normally, MPOL_BIND allocations are node-local within the
1419 * allowed nodemask. However, if __GFP_THISNODE is set and the
1420 * current node is part of the mask, we use the zonelist for
1421 * the first node in the mask instead.
Mel Gorman19770b32008-04-28 02:12:18 -07001422 */
Mel Gorman19770b32008-04-28 02:12:18 -07001423 if (unlikely(gfp & __GFP_THISNODE) &&
1424 unlikely(!node_isset(nd, policy->v.nodes)))
1425 nd = first_node(policy->v.nodes);
1426 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001427 case MPOL_INTERLEAVE: /* should not happen */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001428 break;
1429 default:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001430 BUG();
1431 }
Mel Gorman0e884602008-04-28 02:12:14 -07001432 return node_zonelist(nd, gfp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001433}
1434
1435/* Do dynamic interleaving for a process */
1436static unsigned interleave_nodes(struct mempolicy *policy)
1437{
1438 unsigned nid, next;
1439 struct task_struct *me = current;
1440
1441 nid = me->il_next;
Andi Kleendfcd3c02005-10-29 18:15:48 -07001442 next = next_node(nid, policy->v.nodes);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001443 if (next >= MAX_NUMNODES)
Andi Kleendfcd3c02005-10-29 18:15:48 -07001444 next = first_node(policy->v.nodes);
David Rientjesf5b087b2008-04-28 02:12:27 -07001445 if (next < MAX_NUMNODES)
1446 me->il_next = next;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001447 return nid;
1448}
1449
Christoph Lameterdc85da12006-01-18 17:42:36 -08001450/*
1451 * Depending on the memory policy provide a node from which to allocate the
1452 * next slab entry.
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001453 * @policy must be protected by freeing by the caller. If @policy is
1454 * the current task's mempolicy, this protection is implicit, as only the
1455 * task can change it's policy. The system default policy requires no
1456 * such protection.
Christoph Lameterdc85da12006-01-18 17:42:36 -08001457 */
1458unsigned slab_node(struct mempolicy *policy)
1459{
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -07001460 if (!policy || policy->flags & MPOL_F_LOCAL)
Lee Schermerhornbea904d2008-04-28 02:13:18 -07001461 return numa_node_id();
Christoph Lameter765c4502006-09-27 01:50:08 -07001462
Lee Schermerhornbea904d2008-04-28 02:13:18 -07001463 switch (policy->mode) {
1464 case MPOL_PREFERRED:
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -07001465 /*
1466 * handled MPOL_F_LOCAL above
1467 */
1468 return policy->v.preferred_node;
Lee Schermerhornbea904d2008-04-28 02:13:18 -07001469
Christoph Lameterdc85da12006-01-18 17:42:36 -08001470 case MPOL_INTERLEAVE:
1471 return interleave_nodes(policy);
1472
Mel Gormandd1a2392008-04-28 02:12:17 -07001473 case MPOL_BIND: {
Christoph Lameterdc85da12006-01-18 17:42:36 -08001474 /*
1475 * Follow bind policy behavior and start allocation at the
1476 * first node.
1477 */
Mel Gorman19770b32008-04-28 02:12:18 -07001478 struct zonelist *zonelist;
1479 struct zone *zone;
1480 enum zone_type highest_zoneidx = gfp_zone(GFP_KERNEL);
1481 zonelist = &NODE_DATA(numa_node_id())->node_zonelists[0];
1482 (void)first_zones_zonelist(zonelist, highest_zoneidx,
1483 &policy->v.nodes,
1484 &zone);
1485 return zone->node;
Mel Gormandd1a2392008-04-28 02:12:17 -07001486 }
Christoph Lameterdc85da12006-01-18 17:42:36 -08001487
Christoph Lameterdc85da12006-01-18 17:42:36 -08001488 default:
Lee Schermerhornbea904d2008-04-28 02:13:18 -07001489 BUG();
Christoph Lameterdc85da12006-01-18 17:42:36 -08001490 }
1491}
1492
Linus Torvalds1da177e2005-04-16 15:20:36 -07001493/* Do static interleaving for a VMA with known offset. */
1494static unsigned offset_il_node(struct mempolicy *pol,
1495 struct vm_area_struct *vma, unsigned long off)
1496{
Andi Kleendfcd3c02005-10-29 18:15:48 -07001497 unsigned nnodes = nodes_weight(pol->v.nodes);
David Rientjesf5b087b2008-04-28 02:12:27 -07001498 unsigned target;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001499 int c;
1500 int nid = -1;
1501
David Rientjesf5b087b2008-04-28 02:12:27 -07001502 if (!nnodes)
1503 return numa_node_id();
1504 target = (unsigned int)off % nnodes;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001505 c = 0;
1506 do {
Andi Kleendfcd3c02005-10-29 18:15:48 -07001507 nid = next_node(nid, pol->v.nodes);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001508 c++;
1509 } while (c <= target);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001510 return nid;
1511}
1512
Christoph Lameter5da7ca82006-01-06 00:10:46 -08001513/* Determine a node number for interleave */
1514static inline unsigned interleave_nid(struct mempolicy *pol,
1515 struct vm_area_struct *vma, unsigned long addr, int shift)
1516{
1517 if (vma) {
1518 unsigned long off;
1519
Nishanth Aravamudan3b98b082006-08-31 21:27:53 -07001520 /*
1521 * for small pages, there is no difference between
1522 * shift and PAGE_SHIFT, so the bit-shift is safe.
1523 * for huge pages, since vm_pgoff is in units of small
1524 * pages, we need to shift off the always 0 bits to get
1525 * a useful offset.
1526 */
1527 BUG_ON(shift < PAGE_SHIFT);
1528 off = vma->vm_pgoff >> (shift - PAGE_SHIFT);
Christoph Lameter5da7ca82006-01-06 00:10:46 -08001529 off += (addr - vma->vm_start) >> shift;
1530 return offset_il_node(pol, vma, off);
1531 } else
1532 return interleave_nodes(pol);
1533}
1534
Chen, Kenneth W00ac59a2006-02-03 21:51:14 +01001535#ifdef CONFIG_HUGETLBFS
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001536/*
1537 * huge_zonelist(@vma, @addr, @gfp_flags, @mpol)
1538 * @vma = virtual memory area whose policy is sought
1539 * @addr = address in @vma for shared policy lookup and interleave policy
1540 * @gfp_flags = for requested zone
Mel Gorman19770b32008-04-28 02:12:18 -07001541 * @mpol = pointer to mempolicy pointer for reference counted mempolicy
1542 * @nodemask = pointer to nodemask pointer for MPOL_BIND nodemask
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001543 *
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001544 * Returns a zonelist suitable for a huge page allocation and a pointer
1545 * to the struct mempolicy for conditional unref after allocation.
1546 * If the effective policy is 'BIND, returns a pointer to the mempolicy's
1547 * @nodemask for filtering the zonelist.
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001548 */
Mel Gorman396faf02007-07-17 04:03:13 -07001549struct zonelist *huge_zonelist(struct vm_area_struct *vma, unsigned long addr,
Mel Gorman19770b32008-04-28 02:12:18 -07001550 gfp_t gfp_flags, struct mempolicy **mpol,
1551 nodemask_t **nodemask)
Christoph Lameter5da7ca82006-01-06 00:10:46 -08001552{
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001553 struct zonelist *zl;
Christoph Lameter5da7ca82006-01-06 00:10:46 -08001554
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001555 *mpol = get_vma_policy(current, vma, addr);
Mel Gorman19770b32008-04-28 02:12:18 -07001556 *nodemask = NULL; /* assume !MPOL_BIND */
Christoph Lameter5da7ca82006-01-06 00:10:46 -08001557
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001558 if (unlikely((*mpol)->mode == MPOL_INTERLEAVE)) {
1559 zl = node_zonelist(interleave_nid(*mpol, vma, addr,
Andi Kleena5516432008-07-23 21:27:41 -07001560 huge_page_shift(hstate_vma(vma))), gfp_flags);
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001561 } else {
1562 zl = policy_zonelist(gfp_flags, *mpol);
1563 if ((*mpol)->mode == MPOL_BIND)
1564 *nodemask = &(*mpol)->v.nodes;
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001565 }
1566 return zl;
Christoph Lameter5da7ca82006-01-06 00:10:46 -08001567}
Chen, Kenneth W00ac59a2006-02-03 21:51:14 +01001568#endif
Christoph Lameter5da7ca82006-01-06 00:10:46 -08001569
Linus Torvalds1da177e2005-04-16 15:20:36 -07001570/* Allocate a page in interleaved policy.
1571 Own path because it needs to do special accounting. */
Andi Kleen662f3a02005-10-29 18:15:49 -07001572static struct page *alloc_page_interleave(gfp_t gfp, unsigned order,
1573 unsigned nid)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001574{
1575 struct zonelist *zl;
1576 struct page *page;
1577
Mel Gorman0e884602008-04-28 02:12:14 -07001578 zl = node_zonelist(nid, gfp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001579 page = __alloc_pages(gfp, order, zl);
Mel Gormandd1a2392008-04-28 02:12:17 -07001580 if (page && page_zone(page) == zonelist_zone(&zl->_zonerefs[0]))
Christoph Lameterca889e62006-06-30 01:55:44 -07001581 inc_zone_page_state(page, NUMA_INTERLEAVE_HIT);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001582 return page;
1583}
1584
1585/**
1586 * alloc_page_vma - Allocate a page for a VMA.
1587 *
1588 * @gfp:
1589 * %GFP_USER user allocation.
1590 * %GFP_KERNEL kernel allocations,
1591 * %GFP_HIGHMEM highmem/user allocations,
1592 * %GFP_FS allocation should not call back into a file system.
1593 * %GFP_ATOMIC don't sleep.
1594 *
1595 * @vma: Pointer to VMA or NULL if not available.
1596 * @addr: Virtual Address of the allocation. Must be inside the VMA.
1597 *
1598 * This function allocates a page from the kernel page pool and applies
1599 * a NUMA policy associated with the VMA or the current process.
1600 * When VMA is not NULL caller must hold down_read on the mmap_sem of the
1601 * mm_struct of the VMA to prevent it from going away. Should be used for
1602 * all allocations for pages that will be mapped into
1603 * user space. Returns NULL when no page can be allocated.
1604 *
1605 * Should be called with the mm_sem of the vma hold.
1606 */
1607struct page *
Al Virodd0fc662005-10-07 07:46:04 +01001608alloc_page_vma(gfp_t gfp, struct vm_area_struct *vma, unsigned long addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001609{
Christoph Lameter6e21c8f2005-09-03 15:54:45 -07001610 struct mempolicy *pol = get_vma_policy(current, vma, addr);
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001611 struct zonelist *zl;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001612
Lee Schermerhorn45c47452008-04-28 02:13:12 -07001613 if (unlikely(pol->mode == MPOL_INTERLEAVE)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001614 unsigned nid;
Christoph Lameter5da7ca82006-01-06 00:10:46 -08001615
1616 nid = interleave_nid(pol, vma, addr, PAGE_SHIFT);
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001617 mpol_cond_put(pol);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001618 return alloc_page_interleave(gfp, 0, nid);
1619 }
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001620 zl = policy_zonelist(gfp, pol);
1621 if (unlikely(mpol_needs_cond_ref(pol))) {
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001622 /*
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001623 * slow path: ref counted shared policy
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001624 */
Mel Gorman19770b32008-04-28 02:12:18 -07001625 struct page *page = __alloc_pages_nodemask(gfp, 0,
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001626 zl, policy_nodemask(gfp, pol));
Lee Schermerhornf0be3d32008-04-28 02:13:08 -07001627 __mpol_put(pol);
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001628 return page;
1629 }
1630 /*
1631 * fast path: default or task policy
1632 */
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001633 return __alloc_pages_nodemask(gfp, 0, zl, policy_nodemask(gfp, pol));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001634}
1635
1636/**
1637 * alloc_pages_current - Allocate pages.
1638 *
1639 * @gfp:
1640 * %GFP_USER user allocation,
1641 * %GFP_KERNEL kernel allocation,
1642 * %GFP_HIGHMEM highmem allocation,
1643 * %GFP_FS don't call back into a file system.
1644 * %GFP_ATOMIC don't sleep.
1645 * @order: Power of two of allocation size in pages. 0 is a single page.
1646 *
1647 * Allocate a page from the kernel page pool. When not in
1648 * interrupt context and apply the current process NUMA policy.
1649 * Returns NULL when no page can be allocated.
1650 *
Paul Jacksoncf2a4732006-01-08 01:01:54 -08001651 * Don't call cpuset_update_task_memory_state() unless
Linus Torvalds1da177e2005-04-16 15:20:36 -07001652 * 1) it's ok to take cpuset_sem (can WAIT), and
1653 * 2) allocating for current task (not interrupt).
1654 */
Al Virodd0fc662005-10-07 07:46:04 +01001655struct page *alloc_pages_current(gfp_t gfp, unsigned order)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001656{
1657 struct mempolicy *pol = current->mempolicy;
1658
Christoph Lameter9b819d22006-09-25 23:31:40 -07001659 if (!pol || in_interrupt() || (gfp & __GFP_THISNODE))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001660 pol = &default_policy;
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001661
1662 /*
1663 * No reference counting needed for current->mempolicy
1664 * nor system default_policy
1665 */
Lee Schermerhorn45c47452008-04-28 02:13:12 -07001666 if (pol->mode == MPOL_INTERLEAVE)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001667 return alloc_page_interleave(gfp, order, interleave_nodes(pol));
Mel Gorman19770b32008-04-28 02:12:18 -07001668 return __alloc_pages_nodemask(gfp, order,
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001669 policy_zonelist(gfp, pol), policy_nodemask(gfp, pol));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001670}
1671EXPORT_SYMBOL(alloc_pages_current);
1672
Paul Jackson42253992006-01-08 01:01:59 -08001673/*
Lee Schermerhorn846a16b2008-04-28 02:13:09 -07001674 * If mpol_dup() sees current->cpuset == cpuset_being_rebound, then it
Paul Jackson42253992006-01-08 01:01:59 -08001675 * rebinds the mempolicy its copying by calling mpol_rebind_policy()
1676 * with the mems_allowed returned by cpuset_mems_allowed(). This
1677 * keeps mempolicies cpuset relative after its cpuset moves. See
1678 * further kernel/cpuset.c update_nodemask().
1679 */
Paul Jackson42253992006-01-08 01:01:59 -08001680
Lee Schermerhorn846a16b2008-04-28 02:13:09 -07001681/* Slow path of a mempolicy duplicate */
1682struct mempolicy *__mpol_dup(struct mempolicy *old)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001683{
1684 struct mempolicy *new = kmem_cache_alloc(policy_cache, GFP_KERNEL);
1685
1686 if (!new)
1687 return ERR_PTR(-ENOMEM);
Paul Jackson42253992006-01-08 01:01:59 -08001688 if (current_cpuset_is_being_rebound()) {
1689 nodemask_t mems = cpuset_mems_allowed(current);
1690 mpol_rebind_policy(old, &mems);
1691 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001692 *new = *old;
1693 atomic_set(&new->refcnt, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001694 return new;
1695}
1696
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001697/*
1698 * If *frompol needs [has] an extra ref, copy *frompol to *tompol ,
1699 * eliminate the * MPOL_F_* flags that require conditional ref and
1700 * [NOTE!!!] drop the extra ref. Not safe to reference *frompol directly
1701 * after return. Use the returned value.
1702 *
1703 * Allows use of a mempolicy for, e.g., multiple allocations with a single
1704 * policy lookup, even if the policy needs/has extra ref on lookup.
1705 * shmem_readahead needs this.
1706 */
1707struct mempolicy *__mpol_cond_copy(struct mempolicy *tompol,
1708 struct mempolicy *frompol)
1709{
1710 if (!mpol_needs_cond_ref(frompol))
1711 return frompol;
1712
1713 *tompol = *frompol;
1714 tompol->flags &= ~MPOL_F_SHARED; /* copy doesn't need unref */
1715 __mpol_put(frompol);
1716 return tompol;
1717}
1718
David Rientjesf5b087b2008-04-28 02:12:27 -07001719static int mpol_match_intent(const struct mempolicy *a,
1720 const struct mempolicy *b)
1721{
1722 if (a->flags != b->flags)
1723 return 0;
1724 if (!mpol_store_user_nodemask(a))
1725 return 1;
1726 return nodes_equal(a->w.user_nodemask, b->w.user_nodemask);
1727}
1728
Linus Torvalds1da177e2005-04-16 15:20:36 -07001729/* Slow path of a mempolicy comparison */
1730int __mpol_equal(struct mempolicy *a, struct mempolicy *b)
1731{
1732 if (!a || !b)
1733 return 0;
Lee Schermerhorn45c47452008-04-28 02:13:12 -07001734 if (a->mode != b->mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001735 return 0;
Lee Schermerhorn45c47452008-04-28 02:13:12 -07001736 if (a->mode != MPOL_DEFAULT && !mpol_match_intent(a, b))
David Rientjesf5b087b2008-04-28 02:12:27 -07001737 return 0;
Lee Schermerhorn45c47452008-04-28 02:13:12 -07001738 switch (a->mode) {
Mel Gorman19770b32008-04-28 02:12:18 -07001739 case MPOL_BIND:
1740 /* Fall through */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001741 case MPOL_INTERLEAVE:
Andi Kleendfcd3c02005-10-29 18:15:48 -07001742 return nodes_equal(a->v.nodes, b->v.nodes);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001743 case MPOL_PREFERRED:
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -07001744 return a->v.preferred_node == b->v.preferred_node &&
1745 a->flags == b->flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001746 default:
1747 BUG();
1748 return 0;
1749 }
1750}
1751
Linus Torvalds1da177e2005-04-16 15:20:36 -07001752/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07001753 * Shared memory backing store policy support.
1754 *
1755 * Remember policies even when nobody has shared memory mapped.
1756 * The policies are kept in Red-Black tree linked from the inode.
1757 * They are protected by the sp->lock spinlock, which should be held
1758 * for any accesses to the tree.
1759 */
1760
1761/* lookup first element intersecting start-end */
1762/* Caller holds sp->lock */
1763static struct sp_node *
1764sp_lookup(struct shared_policy *sp, unsigned long start, unsigned long end)
1765{
1766 struct rb_node *n = sp->root.rb_node;
1767
1768 while (n) {
1769 struct sp_node *p = rb_entry(n, struct sp_node, nd);
1770
1771 if (start >= p->end)
1772 n = n->rb_right;
1773 else if (end <= p->start)
1774 n = n->rb_left;
1775 else
1776 break;
1777 }
1778 if (!n)
1779 return NULL;
1780 for (;;) {
1781 struct sp_node *w = NULL;
1782 struct rb_node *prev = rb_prev(n);
1783 if (!prev)
1784 break;
1785 w = rb_entry(prev, struct sp_node, nd);
1786 if (w->end <= start)
1787 break;
1788 n = prev;
1789 }
1790 return rb_entry(n, struct sp_node, nd);
1791}
1792
1793/* Insert a new shared policy into the list. */
1794/* Caller holds sp->lock */
1795static void sp_insert(struct shared_policy *sp, struct sp_node *new)
1796{
1797 struct rb_node **p = &sp->root.rb_node;
1798 struct rb_node *parent = NULL;
1799 struct sp_node *nd;
1800
1801 while (*p) {
1802 parent = *p;
1803 nd = rb_entry(parent, struct sp_node, nd);
1804 if (new->start < nd->start)
1805 p = &(*p)->rb_left;
1806 else if (new->end > nd->end)
1807 p = &(*p)->rb_right;
1808 else
1809 BUG();
1810 }
1811 rb_link_node(&new->nd, parent, p);
1812 rb_insert_color(&new->nd, &sp->root);
Paul Mundt140d5a42007-07-15 23:38:16 -07001813 pr_debug("inserting %lx-%lx: %d\n", new->start, new->end,
Lee Schermerhorn45c47452008-04-28 02:13:12 -07001814 new->policy ? new->policy->mode : 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001815}
1816
1817/* Find shared policy intersecting idx */
1818struct mempolicy *
1819mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx)
1820{
1821 struct mempolicy *pol = NULL;
1822 struct sp_node *sn;
1823
1824 if (!sp->root.rb_node)
1825 return NULL;
1826 spin_lock(&sp->lock);
1827 sn = sp_lookup(sp, idx, idx+1);
1828 if (sn) {
1829 mpol_get(sn->policy);
1830 pol = sn->policy;
1831 }
1832 spin_unlock(&sp->lock);
1833 return pol;
1834}
1835
1836static void sp_delete(struct shared_policy *sp, struct sp_node *n)
1837{
Paul Mundt140d5a42007-07-15 23:38:16 -07001838 pr_debug("deleting %lx-l%lx\n", n->start, n->end);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001839 rb_erase(&n->nd, &sp->root);
Lee Schermerhornf0be3d32008-04-28 02:13:08 -07001840 mpol_put(n->policy);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001841 kmem_cache_free(sn_cache, n);
1842}
1843
Adrian Bunkdbcb0f12007-10-16 01:26:26 -07001844static struct sp_node *sp_alloc(unsigned long start, unsigned long end,
1845 struct mempolicy *pol)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001846{
1847 struct sp_node *n = kmem_cache_alloc(sn_cache, GFP_KERNEL);
1848
1849 if (!n)
1850 return NULL;
1851 n->start = start;
1852 n->end = end;
1853 mpol_get(pol);
Lee Schermerhornaab0b102008-04-28 02:13:13 -07001854 pol->flags |= MPOL_F_SHARED; /* for unref */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001855 n->policy = pol;
1856 return n;
1857}
1858
1859/* Replace a policy range. */
1860static int shared_policy_replace(struct shared_policy *sp, unsigned long start,
1861 unsigned long end, struct sp_node *new)
1862{
1863 struct sp_node *n, *new2 = NULL;
1864
1865restart:
1866 spin_lock(&sp->lock);
1867 n = sp_lookup(sp, start, end);
1868 /* Take care of old policies in the same range. */
1869 while (n && n->start < end) {
1870 struct rb_node *next = rb_next(&n->nd);
1871 if (n->start >= start) {
1872 if (n->end <= end)
1873 sp_delete(sp, n);
1874 else
1875 n->start = end;
1876 } else {
1877 /* Old policy spanning whole new range. */
1878 if (n->end > end) {
1879 if (!new2) {
1880 spin_unlock(&sp->lock);
1881 new2 = sp_alloc(end, n->end, n->policy);
1882 if (!new2)
1883 return -ENOMEM;
1884 goto restart;
1885 }
1886 n->end = start;
1887 sp_insert(sp, new2);
1888 new2 = NULL;
1889 break;
1890 } else
1891 n->end = start;
1892 }
1893 if (!next)
1894 break;
1895 n = rb_entry(next, struct sp_node, nd);
1896 }
1897 if (new)
1898 sp_insert(sp, new);
1899 spin_unlock(&sp->lock);
1900 if (new2) {
Lee Schermerhornf0be3d32008-04-28 02:13:08 -07001901 mpol_put(new2->policy);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001902 kmem_cache_free(sn_cache, new2);
1903 }
1904 return 0;
1905}
1906
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07001907/**
1908 * mpol_shared_policy_init - initialize shared policy for inode
1909 * @sp: pointer to inode shared policy
1910 * @mpol: struct mempolicy to install
1911 *
1912 * Install non-NULL @mpol in inode's shared policy rb-tree.
1913 * On entry, the current task has a reference on a non-NULL @mpol.
1914 * This must be released on exit.
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -07001915 * This is called at get_inode() calls and we can use GFP_KERNEL.
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07001916 */
1917void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol)
Robin Holt7339ff82006-01-14 13:20:48 -08001918{
Miao Xie58568d22009-06-16 15:31:49 -07001919 int ret;
1920
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07001921 sp->root = RB_ROOT; /* empty tree == default mempolicy */
1922 spin_lock_init(&sp->lock);
Robin Holt7339ff82006-01-14 13:20:48 -08001923
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07001924 if (mpol) {
1925 struct vm_area_struct pvma;
1926 struct mempolicy *new;
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -07001927 NODEMASK_SCRATCH(scratch);
Robin Holt7339ff82006-01-14 13:20:48 -08001928
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -07001929 if (!scratch)
1930 return;
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07001931 /* contextualize the tmpfs mount point mempolicy */
1932 new = mpol_new(mpol->mode, mpol->flags, &mpol->w.user_nodemask);
Miao Xie58568d22009-06-16 15:31:49 -07001933 if (IS_ERR(new)) {
1934 mpol_put(mpol); /* drop our ref on sb mpol */
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -07001935 NODEMASK_SCRATCH_FREE(scratch);
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07001936 return; /* no valid nodemask intersection */
Miao Xie58568d22009-06-16 15:31:49 -07001937 }
1938
1939 task_lock(current);
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -07001940 ret = mpol_set_nodemask(new, &mpol->w.user_nodemask, scratch);
Miao Xie58568d22009-06-16 15:31:49 -07001941 task_unlock(current);
1942 mpol_put(mpol); /* drop our ref on sb mpol */
1943 if (ret) {
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -07001944 NODEMASK_SCRATCH_FREE(scratch);
Miao Xie58568d22009-06-16 15:31:49 -07001945 mpol_put(new);
1946 return;
1947 }
Robin Holt7339ff82006-01-14 13:20:48 -08001948
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07001949 /* Create pseudo-vma that contains just the policy */
1950 memset(&pvma, 0, sizeof(struct vm_area_struct));
1951 pvma.vm_end = TASK_SIZE; /* policy covers entire file */
1952 mpol_set_shared_policy(sp, &pvma, new); /* adds ref */
1953 mpol_put(new); /* drop initial ref */
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -07001954 NODEMASK_SCRATCH_FREE(scratch);
Robin Holt7339ff82006-01-14 13:20:48 -08001955 }
1956}
1957
Linus Torvalds1da177e2005-04-16 15:20:36 -07001958int mpol_set_shared_policy(struct shared_policy *info,
1959 struct vm_area_struct *vma, struct mempolicy *npol)
1960{
1961 int err;
1962 struct sp_node *new = NULL;
1963 unsigned long sz = vma_pages(vma);
1964
David Rientjes028fec42008-04-28 02:12:25 -07001965 pr_debug("set_shared_policy %lx sz %lu %d %d %lx\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001966 vma->vm_pgoff,
Lee Schermerhorn45c47452008-04-28 02:13:12 -07001967 sz, npol ? npol->mode : -1,
David Rientjes028fec42008-04-28 02:12:25 -07001968 npol ? npol->flags : -1,
Paul Mundt140d5a42007-07-15 23:38:16 -07001969 npol ? nodes_addr(npol->v.nodes)[0] : -1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001970
1971 if (npol) {
1972 new = sp_alloc(vma->vm_pgoff, vma->vm_pgoff + sz, npol);
1973 if (!new)
1974 return -ENOMEM;
1975 }
1976 err = shared_policy_replace(info, vma->vm_pgoff, vma->vm_pgoff+sz, new);
1977 if (err && new)
1978 kmem_cache_free(sn_cache, new);
1979 return err;
1980}
1981
1982/* Free a backing policy store on inode delete. */
1983void mpol_free_shared_policy(struct shared_policy *p)
1984{
1985 struct sp_node *n;
1986 struct rb_node *next;
1987
1988 if (!p->root.rb_node)
1989 return;
1990 spin_lock(&p->lock);
1991 next = rb_first(&p->root);
1992 while (next) {
1993 n = rb_entry(next, struct sp_node, nd);
1994 next = rb_next(&n->nd);
Andi Kleen90c50292005-07-27 11:43:50 -07001995 rb_erase(&n->nd, &p->root);
Lee Schermerhornf0be3d32008-04-28 02:13:08 -07001996 mpol_put(n->policy);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001997 kmem_cache_free(sn_cache, n);
1998 }
1999 spin_unlock(&p->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002000}
2001
2002/* assumes fs == KERNEL_DS */
2003void __init numa_policy_init(void)
2004{
Paul Mundtb71636e2007-07-15 23:38:15 -07002005 nodemask_t interleave_nodes;
2006 unsigned long largest = 0;
2007 int nid, prefer = 0;
2008
Linus Torvalds1da177e2005-04-16 15:20:36 -07002009 policy_cache = kmem_cache_create("numa_policy",
2010 sizeof(struct mempolicy),
Paul Mundt20c2df82007-07-20 10:11:58 +09002011 0, SLAB_PANIC, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002012
2013 sn_cache = kmem_cache_create("shared_policy_node",
2014 sizeof(struct sp_node),
Paul Mundt20c2df82007-07-20 10:11:58 +09002015 0, SLAB_PANIC, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002016
Paul Mundtb71636e2007-07-15 23:38:15 -07002017 /*
2018 * Set interleaving policy for system init. Interleaving is only
2019 * enabled across suitably sized nodes (default is >= 16MB), or
2020 * fall back to the largest node if they're all smaller.
2021 */
2022 nodes_clear(interleave_nodes);
Christoph Lameter56bbd652007-10-16 01:25:35 -07002023 for_each_node_state(nid, N_HIGH_MEMORY) {
Paul Mundtb71636e2007-07-15 23:38:15 -07002024 unsigned long total_pages = node_present_pages(nid);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002025
Paul Mundtb71636e2007-07-15 23:38:15 -07002026 /* Preserve the largest node */
2027 if (largest < total_pages) {
2028 largest = total_pages;
2029 prefer = nid;
2030 }
2031
2032 /* Interleave this node? */
2033 if ((total_pages << PAGE_SHIFT) >= (16 << 20))
2034 node_set(nid, interleave_nodes);
2035 }
2036
2037 /* All too small, use the largest */
2038 if (unlikely(nodes_empty(interleave_nodes)))
2039 node_set(prefer, interleave_nodes);
2040
David Rientjes028fec42008-04-28 02:12:25 -07002041 if (do_set_mempolicy(MPOL_INTERLEAVE, 0, &interleave_nodes))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002042 printk("numa_policy_init: interleaving failed\n");
2043}
2044
Christoph Lameter8bccd852005-10-29 18:16:59 -07002045/* Reset policy of current process to default */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002046void numa_default_policy(void)
2047{
David Rientjes028fec42008-04-28 02:12:25 -07002048 do_set_mempolicy(MPOL_DEFAULT, 0, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002049}
Paul Jackson68860ec2005-10-30 15:02:36 -08002050
Paul Jackson42253992006-01-08 01:01:59 -08002051/*
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002052 * Parse and format mempolicy from/to strings
2053 */
2054
2055/*
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -07002056 * "local" is pseudo-policy: MPOL_PREFERRED with MPOL_F_LOCAL flag
Lee Schermerhorn3f226aa2008-04-28 02:13:24 -07002057 * Used only for mpol_parse_str() and mpol_to_str()
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002058 */
Lee Schermerhorn53f25562008-04-28 02:13:20 -07002059#define MPOL_LOCAL (MPOL_INTERLEAVE + 1)
Helge Deller15ad7cd2006-12-06 20:40:36 -08002060static const char * const policy_types[] =
Lee Schermerhorn53f25562008-04-28 02:13:20 -07002061 { "default", "prefer", "bind", "interleave", "local" };
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002062
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002063
2064#ifdef CONFIG_TMPFS
2065/**
2066 * mpol_parse_str - parse string to mempolicy
2067 * @str: string containing mempolicy to parse
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002068 * @mpol: pointer to struct mempolicy pointer, returned on success.
2069 * @no_context: flag whether to "contextualize" the mempolicy
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002070 *
2071 * Format of input:
2072 * <mode>[=<flags>][:<nodelist>]
2073 *
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002074 * if @no_context is true, save the input nodemask in w.user_nodemask in
2075 * the returned mempolicy. This will be used to "clone" the mempolicy in
2076 * a specific context [cpuset] at a later time. Used to parse tmpfs mpol
2077 * mount option. Note that if 'static' or 'relative' mode flags were
2078 * specified, the input nodemask will already have been saved. Saving
2079 * it again is redundant, but safe.
2080 *
2081 * On success, returns 0, else 1
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002082 */
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002083int mpol_parse_str(char *str, struct mempolicy **mpol, int no_context)
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002084{
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002085 struct mempolicy *new = NULL;
2086 unsigned short uninitialized_var(mode);
2087 unsigned short uninitialized_var(mode_flags);
2088 nodemask_t nodes;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002089 char *nodelist = strchr(str, ':');
2090 char *flags = strchr(str, '=');
2091 int i;
2092 int err = 1;
2093
2094 if (nodelist) {
2095 /* NUL-terminate mode or flags string */
2096 *nodelist++ = '\0';
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002097 if (nodelist_parse(nodelist, nodes))
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002098 goto out;
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002099 if (!nodes_subset(nodes, node_states[N_HIGH_MEMORY]))
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002100 goto out;
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002101 } else
2102 nodes_clear(nodes);
2103
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002104 if (flags)
2105 *flags++ = '\0'; /* terminate mode string */
2106
Lee Schermerhorn3f226aa2008-04-28 02:13:24 -07002107 for (i = 0; i <= MPOL_LOCAL; i++) {
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002108 if (!strcmp(str, policy_types[i])) {
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002109 mode = i;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002110 break;
2111 }
2112 }
Lee Schermerhorn3f226aa2008-04-28 02:13:24 -07002113 if (i > MPOL_LOCAL)
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002114 goto out;
2115
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002116 switch (mode) {
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002117 case MPOL_PREFERRED:
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002118 /*
2119 * Insist on a nodelist of one node only
2120 */
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002121 if (nodelist) {
2122 char *rest = nodelist;
2123 while (isdigit(*rest))
2124 rest++;
2125 if (!*rest)
2126 err = 0;
2127 }
2128 break;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002129 case MPOL_INTERLEAVE:
2130 /*
2131 * Default to online nodes with memory if no nodelist
2132 */
2133 if (!nodelist)
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002134 nodes = node_states[N_HIGH_MEMORY];
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002135 err = 0;
Lee Schermerhorn3f226aa2008-04-28 02:13:24 -07002136 break;
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002137 case MPOL_LOCAL:
Lee Schermerhorn3f226aa2008-04-28 02:13:24 -07002138 /*
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002139 * Don't allow a nodelist; mpol_new() checks flags
Lee Schermerhorn3f226aa2008-04-28 02:13:24 -07002140 */
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002141 if (nodelist)
Lee Schermerhorn3f226aa2008-04-28 02:13:24 -07002142 goto out;
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002143 mode = MPOL_PREFERRED;
Lee Schermerhorn3f226aa2008-04-28 02:13:24 -07002144 break;
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002145
2146 /*
2147 * case MPOL_BIND: mpol_new() enforces non-empty nodemask.
2148 * case MPOL_DEFAULT: mpol_new() enforces empty nodemask, ignores flags.
2149 */
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002150 }
2151
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002152 mode_flags = 0;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002153 if (flags) {
2154 /*
2155 * Currently, we only support two mutually exclusive
2156 * mode flags.
2157 */
2158 if (!strcmp(flags, "static"))
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002159 mode_flags |= MPOL_F_STATIC_NODES;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002160 else if (!strcmp(flags, "relative"))
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002161 mode_flags |= MPOL_F_RELATIVE_NODES;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002162 else
2163 err = 1;
2164 }
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002165
2166 new = mpol_new(mode, mode_flags, &nodes);
2167 if (IS_ERR(new))
2168 err = 1;
Miao Xie58568d22009-06-16 15:31:49 -07002169 else {
2170 int ret;
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -07002171 NODEMASK_SCRATCH(scratch);
2172 if (scratch) {
2173 task_lock(current);
2174 ret = mpol_set_nodemask(new, &nodes, scratch);
2175 task_unlock(current);
2176 } else
2177 ret = -ENOMEM;
2178 NODEMASK_SCRATCH_FREE(scratch);
2179 if (ret) {
Miao Xie58568d22009-06-16 15:31:49 -07002180 err = 1;
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -07002181 mpol_put(new);
2182 } else if (no_context) {
Miao Xie58568d22009-06-16 15:31:49 -07002183 /* save for contextualization */
2184 new->w.user_nodemask = nodes;
2185 }
2186 }
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002187
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002188out:
2189 /* Restore string for error message */
2190 if (nodelist)
2191 *--nodelist = ':';
2192 if (flags)
2193 *--flags = '=';
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002194 if (!err)
2195 *mpol = new;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002196 return err;
2197}
2198#endif /* CONFIG_TMPFS */
2199
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002200/**
2201 * mpol_to_str - format a mempolicy structure for printing
2202 * @buffer: to contain formatted mempolicy string
2203 * @maxlen: length of @buffer
2204 * @pol: pointer to mempolicy to be formatted
2205 * @no_context: "context free" mempolicy - use nodemask in w.user_nodemask
2206 *
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002207 * Convert a mempolicy into a string.
2208 * Returns the number of characters in buffer (if positive)
2209 * or an error (negative)
2210 */
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002211int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol, int no_context)
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002212{
2213 char *p = buffer;
2214 int l;
2215 nodemask_t nodes;
Lee Schermerhornbea904d2008-04-28 02:13:18 -07002216 unsigned short mode;
David Rientjesf5b087b2008-04-28 02:12:27 -07002217 unsigned short flags = pol ? pol->flags : 0;
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002218
Lee Schermerhorn22919902008-04-28 02:13:22 -07002219 /*
2220 * Sanity check: room for longest mode, flag and some nodes
2221 */
2222 VM_BUG_ON(maxlen < strlen("interleave") + strlen("relative") + 16);
2223
Lee Schermerhornbea904d2008-04-28 02:13:18 -07002224 if (!pol || pol == &default_policy)
2225 mode = MPOL_DEFAULT;
2226 else
2227 mode = pol->mode;
2228
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002229 switch (mode) {
2230 case MPOL_DEFAULT:
2231 nodes_clear(nodes);
2232 break;
2233
2234 case MPOL_PREFERRED:
2235 nodes_clear(nodes);
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -07002236 if (flags & MPOL_F_LOCAL)
Lee Schermerhorn53f25562008-04-28 02:13:20 -07002237 mode = MPOL_LOCAL; /* pseudo-policy */
2238 else
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -07002239 node_set(pol->v.preferred_node, nodes);
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002240 break;
2241
2242 case MPOL_BIND:
Mel Gorman19770b32008-04-28 02:12:18 -07002243 /* Fall through */
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002244 case MPOL_INTERLEAVE:
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002245 if (no_context)
2246 nodes = pol->w.user_nodemask;
2247 else
2248 nodes = pol->v.nodes;
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002249 break;
2250
2251 default:
2252 BUG();
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002253 }
2254
2255 l = strlen(policy_types[mode]);
Lee Schermerhorn53f25562008-04-28 02:13:20 -07002256 if (buffer + maxlen < p + l + 1)
2257 return -ENOSPC;
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002258
2259 strcpy(p, policy_types[mode]);
2260 p += l;
2261
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -07002262 if (flags & MPOL_MODE_FLAGS) {
David Rientjesf5b087b2008-04-28 02:12:27 -07002263 if (buffer + maxlen < p + 2)
2264 return -ENOSPC;
2265 *p++ = '=';
2266
Lee Schermerhorn22919902008-04-28 02:13:22 -07002267 /*
2268 * Currently, the only defined flags are mutually exclusive
2269 */
David Rientjesf5b087b2008-04-28 02:12:27 -07002270 if (flags & MPOL_F_STATIC_NODES)
Lee Schermerhorn22919902008-04-28 02:13:22 -07002271 p += snprintf(p, buffer + maxlen - p, "static");
2272 else if (flags & MPOL_F_RELATIVE_NODES)
2273 p += snprintf(p, buffer + maxlen - p, "relative");
David Rientjesf5b087b2008-04-28 02:12:27 -07002274 }
2275
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002276 if (!nodes_empty(nodes)) {
2277 if (buffer + maxlen < p + 2)
2278 return -ENOSPC;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002279 *p++ = ':';
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002280 p += nodelist_scnprintf(p, buffer + maxlen - p, nodes);
2281 }
2282 return p - buffer;
2283}
2284
2285struct numa_maps {
2286 unsigned long pages;
2287 unsigned long anon;
Christoph Lameter397874d2006-03-06 15:42:53 -08002288 unsigned long active;
2289 unsigned long writeback;
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002290 unsigned long mapcount_max;
Christoph Lameter397874d2006-03-06 15:42:53 -08002291 unsigned long dirty;
2292 unsigned long swapcache;
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002293 unsigned long node[MAX_NUMNODES];
2294};
2295
Christoph Lameter397874d2006-03-06 15:42:53 -08002296static void gather_stats(struct page *page, void *private, int pte_dirty)
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002297{
2298 struct numa_maps *md = private;
2299 int count = page_mapcount(page);
2300
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002301 md->pages++;
Christoph Lameter397874d2006-03-06 15:42:53 -08002302 if (pte_dirty || PageDirty(page))
2303 md->dirty++;
2304
2305 if (PageSwapCache(page))
2306 md->swapcache++;
2307
Lee Schermerhorn894bc312008-10-18 20:26:39 -07002308 if (PageActive(page) || PageUnevictable(page))
Christoph Lameter397874d2006-03-06 15:42:53 -08002309 md->active++;
2310
2311 if (PageWriteback(page))
2312 md->writeback++;
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002313
2314 if (PageAnon(page))
2315 md->anon++;
2316
Christoph Lameter397874d2006-03-06 15:42:53 -08002317 if (count > md->mapcount_max)
2318 md->mapcount_max = count;
2319
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002320 md->node[page_to_nid(page)]++;
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002321}
2322
Andrew Morton7f709ed2006-03-07 21:55:22 -08002323#ifdef CONFIG_HUGETLB_PAGE
Christoph Lameter397874d2006-03-06 15:42:53 -08002324static void check_huge_range(struct vm_area_struct *vma,
2325 unsigned long start, unsigned long end,
2326 struct numa_maps *md)
2327{
2328 unsigned long addr;
2329 struct page *page;
Andi Kleena5516432008-07-23 21:27:41 -07002330 struct hstate *h = hstate_vma(vma);
2331 unsigned long sz = huge_page_size(h);
Christoph Lameter397874d2006-03-06 15:42:53 -08002332
Andi Kleena5516432008-07-23 21:27:41 -07002333 for (addr = start; addr < end; addr += sz) {
2334 pte_t *ptep = huge_pte_offset(vma->vm_mm,
2335 addr & huge_page_mask(h));
Christoph Lameter397874d2006-03-06 15:42:53 -08002336 pte_t pte;
2337
2338 if (!ptep)
2339 continue;
2340
2341 pte = *ptep;
2342 if (pte_none(pte))
2343 continue;
2344
2345 page = pte_page(pte);
2346 if (!page)
2347 continue;
2348
2349 gather_stats(page, md, pte_dirty(*ptep));
2350 }
2351}
Andrew Morton7f709ed2006-03-07 21:55:22 -08002352#else
2353static inline void check_huge_range(struct vm_area_struct *vma,
2354 unsigned long start, unsigned long end,
2355 struct numa_maps *md)
2356{
2357}
2358#endif
Christoph Lameter397874d2006-03-06 15:42:53 -08002359
Lee Schermerhorn53f25562008-04-28 02:13:20 -07002360/*
2361 * Display pages allocated per node and memory policy via /proc.
2362 */
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002363int show_numa_map(struct seq_file *m, void *v)
2364{
Eric W. Biederman99f89552006-06-26 00:25:55 -07002365 struct proc_maps_private *priv = m->private;
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002366 struct vm_area_struct *vma = v;
2367 struct numa_maps *md;
Christoph Lameter397874d2006-03-06 15:42:53 -08002368 struct file *file = vma->vm_file;
2369 struct mm_struct *mm = vma->vm_mm;
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07002370 struct mempolicy *pol;
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002371 int n;
2372 char buffer[50];
2373
Christoph Lameter397874d2006-03-06 15:42:53 -08002374 if (!mm)
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002375 return 0;
2376
2377 md = kzalloc(sizeof(struct numa_maps), GFP_KERNEL);
2378 if (!md)
2379 return 0;
2380
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07002381 pol = get_vma_policy(priv->task, vma, vma->vm_start);
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002382 mpol_to_str(buffer, sizeof(buffer), pol, 0);
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07002383 mpol_cond_put(pol);
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002384
Christoph Lameter397874d2006-03-06 15:42:53 -08002385 seq_printf(m, "%08lx %s", vma->vm_start, buffer);
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002386
Christoph Lameter397874d2006-03-06 15:42:53 -08002387 if (file) {
2388 seq_printf(m, " file=");
Jan Blunckc32c2f62008-02-14 19:38:43 -08002389 seq_path(m, &file->f_path, "\n\t= ");
Christoph Lameter397874d2006-03-06 15:42:53 -08002390 } else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) {
2391 seq_printf(m, " heap");
2392 } else if (vma->vm_start <= mm->start_stack &&
2393 vma->vm_end >= mm->start_stack) {
2394 seq_printf(m, " stack");
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002395 }
Christoph Lameter397874d2006-03-06 15:42:53 -08002396
2397 if (is_vm_hugetlb_page(vma)) {
2398 check_huge_range(vma, vma->vm_start, vma->vm_end, md);
2399 seq_printf(m, " huge");
2400 } else {
2401 check_pgd_range(vma, vma->vm_start, vma->vm_end,
Christoph Lameter56bbd652007-10-16 01:25:35 -07002402 &node_states[N_HIGH_MEMORY], MPOL_MF_STATS, md);
Christoph Lameter397874d2006-03-06 15:42:53 -08002403 }
2404
2405 if (!md->pages)
2406 goto out;
2407
2408 if (md->anon)
2409 seq_printf(m," anon=%lu",md->anon);
2410
2411 if (md->dirty)
2412 seq_printf(m," dirty=%lu",md->dirty);
2413
2414 if (md->pages != md->anon && md->pages != md->dirty)
2415 seq_printf(m, " mapped=%lu", md->pages);
2416
2417 if (md->mapcount_max > 1)
2418 seq_printf(m, " mapmax=%lu", md->mapcount_max);
2419
2420 if (md->swapcache)
2421 seq_printf(m," swapcache=%lu", md->swapcache);
2422
2423 if (md->active < md->pages && !is_vm_hugetlb_page(vma))
2424 seq_printf(m," active=%lu", md->active);
2425
2426 if (md->writeback)
2427 seq_printf(m," writeback=%lu", md->writeback);
2428
Christoph Lameter56bbd652007-10-16 01:25:35 -07002429 for_each_node_state(n, N_HIGH_MEMORY)
Christoph Lameter397874d2006-03-06 15:42:53 -08002430 if (md->node[n])
2431 seq_printf(m, " N%d=%lu", n, md->node[n]);
2432out:
2433 seq_putc(m, '\n');
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002434 kfree(md);
2435
2436 if (m->count < m->size)
Eric W. Biederman99f89552006-06-26 00:25:55 -07002437 m->version = (vma != priv->tail_vma) ? vma->vm_start : 0;
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002438 return 0;
2439}