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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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070076#include <linux/slab.h>
77#include <linux/string.h>
78#include <linux/module.h>
Pavel Emelyanovb4888932007-10-18 23:40:14 -070079#include <linux/nsproxy.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070080#include <linux/interrupt.h>
81#include <linux/init.h>
82#include <linux/compat.h>
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -080083#include <linux/swap.h>
Christoph Lameter1a75a6c2006-01-08 01:01:02 -080084#include <linux/seq_file.h>
85#include <linux/proc_fs.h>
Christoph Lameterb20a3502006-03-22 00:09:12 -080086#include <linux/migrate.h>
Hugh Dickins62b61f62009-12-14 17:59:33 -080087#include <linux/ksm.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>
KOSAKI Motohiro6d9c2852009-12-14 17:58:11 -080092#include <linux/mm_inline.h>
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -080093
Linus Torvalds1da177e2005-04-16 15:20:36 -070094#include <asm/tlbflush.h>
95#include <asm/uaccess.h>
96
Nick Piggin62695a82008-10-18 20:26:09 -070097#include "internal.h"
98
Christoph Lameter38e35862006-01-08 01:01:01 -080099/* Internal flags */
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800100#define MPOL_MF_DISCONTIG_OK (MPOL_MF_INTERNAL << 0) /* Skip checks for continuous vmas */
Christoph Lameter38e35862006-01-08 01:01:01 -0800101#define MPOL_MF_INVERT (MPOL_MF_INTERNAL << 1) /* Invert check for nodemask */
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);
Miao Xie708c1bb2010-05-24 14:32:07 -0700121 /*
122 * If read-side task has no lock to protect task->mempolicy, write-side
123 * task will rebind the task->mempolicy by two step. The first step is
124 * setting all the newly nodes, and the second step is cleaning all the
125 * disallowed nodes. In this way, we can avoid finding no node to alloc
126 * page.
127 * If we have a lock to protect task->mempolicy in read-side, we do
128 * rebind directly.
129 *
130 * step:
131 * MPOL_REBIND_ONCE - do rebind work at once
132 * MPOL_REBIND_STEP1 - set all the newly nodes
133 * MPOL_REBIND_STEP2 - clean all the disallowed nodes
134 */
135 void (*rebind)(struct mempolicy *pol, const nodemask_t *nodes,
136 enum mpol_rebind_step step);
David Rientjes37012942008-04-28 02:12:33 -0700137} mpol_ops[MPOL_MAX];
138
Mel Gorman19770b32008-04-28 02:12:18 -0700139/* Check that the nodemask contains at least one populated zone */
David Rientjes37012942008-04-28 02:12:33 -0700140static int is_valid_nodemask(const nodemask_t *nodemask)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141{
Mel Gorman19770b32008-04-28 02:12:18 -0700142 int nd, k;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143
Mel Gorman19770b32008-04-28 02:12:18 -0700144 for_each_node_mask(nd, *nodemask) {
145 struct zone *z;
146
147 for (k = 0; k <= policy_zone; k++) {
148 z = &NODE_DATA(nd)->node_zones[k];
149 if (z->present_pages > 0)
150 return 1;
Andi Kleendd942ae2006-02-17 01:39:16 +0100151 }
152 }
Mel Gorman19770b32008-04-28 02:12:18 -0700153
154 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155}
156
David Rientjesf5b087b2008-04-28 02:12:27 -0700157static inline int mpol_store_user_nodemask(const struct mempolicy *pol)
158{
Bob Liu6d556292010-05-24 14:31:59 -0700159 return pol->flags & MPOL_MODE_FLAGS;
David Rientjes4c50bc02008-04-28 02:12:30 -0700160}
161
162static void mpol_relative_nodemask(nodemask_t *ret, const nodemask_t *orig,
163 const nodemask_t *rel)
164{
165 nodemask_t tmp;
166 nodes_fold(tmp, *orig, nodes_weight(*rel));
167 nodes_onto(*ret, tmp, *rel);
David Rientjesf5b087b2008-04-28 02:12:27 -0700168}
169
David Rientjes37012942008-04-28 02:12:33 -0700170static int mpol_new_interleave(struct mempolicy *pol, const nodemask_t *nodes)
171{
172 if (nodes_empty(*nodes))
173 return -EINVAL;
174 pol->v.nodes = *nodes;
175 return 0;
176}
177
178static int mpol_new_preferred(struct mempolicy *pol, const nodemask_t *nodes)
179{
180 if (!nodes)
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -0700181 pol->flags |= MPOL_F_LOCAL; /* local allocation */
David Rientjes37012942008-04-28 02:12:33 -0700182 else if (nodes_empty(*nodes))
183 return -EINVAL; /* no allowed nodes */
184 else
185 pol->v.preferred_node = first_node(*nodes);
186 return 0;
187}
188
189static int mpol_new_bind(struct mempolicy *pol, const nodemask_t *nodes)
190{
191 if (!is_valid_nodemask(nodes))
192 return -EINVAL;
193 pol->v.nodes = *nodes;
194 return 0;
195}
196
Miao Xie58568d22009-06-16 15:31:49 -0700197/*
198 * mpol_set_nodemask is called after mpol_new() to set up the nodemask, if
199 * any, for the new policy. mpol_new() has already validated the nodes
200 * parameter with respect to the policy mode and flags. But, we need to
201 * handle an empty nodemask with MPOL_PREFERRED here.
202 *
203 * Must be called holding task's alloc_lock to protect task's mems_allowed
204 * and mempolicy. May also be called holding the mmap_semaphore for write.
205 */
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -0700206static int mpol_set_nodemask(struct mempolicy *pol,
207 const nodemask_t *nodes, struct nodemask_scratch *nsc)
Miao Xie58568d22009-06-16 15:31:49 -0700208{
Miao Xie58568d22009-06-16 15:31:49 -0700209 int ret;
210
211 /* if mode is MPOL_DEFAULT, pol is NULL. This is right. */
212 if (pol == NULL)
213 return 0;
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -0700214 /* Check N_HIGH_MEMORY */
215 nodes_and(nsc->mask1,
216 cpuset_current_mems_allowed, node_states[N_HIGH_MEMORY]);
Miao Xie58568d22009-06-16 15:31:49 -0700217
218 VM_BUG_ON(!nodes);
219 if (pol->mode == MPOL_PREFERRED && nodes_empty(*nodes))
220 nodes = NULL; /* explicit local allocation */
221 else {
222 if (pol->flags & MPOL_F_RELATIVE_NODES)
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -0700223 mpol_relative_nodemask(&nsc->mask2, nodes,&nsc->mask1);
Miao Xie58568d22009-06-16 15:31:49 -0700224 else
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -0700225 nodes_and(nsc->mask2, *nodes, nsc->mask1);
226
Miao Xie58568d22009-06-16 15:31:49 -0700227 if (mpol_store_user_nodemask(pol))
228 pol->w.user_nodemask = *nodes;
229 else
230 pol->w.cpuset_mems_allowed =
231 cpuset_current_mems_allowed;
232 }
233
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -0700234 if (nodes)
235 ret = mpol_ops[pol->mode].create(pol, &nsc->mask2);
236 else
237 ret = mpol_ops[pol->mode].create(pol, NULL);
Miao Xie58568d22009-06-16 15:31:49 -0700238 return ret;
239}
240
241/*
242 * This function just creates a new policy, does some check and simple
243 * initialization. You must invoke mpol_set_nodemask() to set nodes.
244 */
David Rientjes028fec42008-04-28 02:12:25 -0700245static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags,
246 nodemask_t *nodes)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247{
248 struct mempolicy *policy;
249
David Rientjes028fec42008-04-28 02:12:25 -0700250 pr_debug("setting mode %d flags %d nodes[0] %lx\n",
251 mode, flags, nodes ? nodes_addr(*nodes)[0] : -1);
Paul Mundt140d5a42007-07-15 23:38:16 -0700252
David Rientjes3e1f0642008-04-28 02:12:34 -0700253 if (mode == MPOL_DEFAULT) {
254 if (nodes && !nodes_empty(*nodes))
David Rientjes37012942008-04-28 02:12:33 -0700255 return ERR_PTR(-EINVAL);
Lee Schermerhornbea904d2008-04-28 02:13:18 -0700256 return NULL; /* simply delete any existing policy */
David Rientjes37012942008-04-28 02:12:33 -0700257 }
David Rientjes3e1f0642008-04-28 02:12:34 -0700258 VM_BUG_ON(!nodes);
259
260 /*
261 * MPOL_PREFERRED cannot be used with MPOL_F_STATIC_NODES or
262 * MPOL_F_RELATIVE_NODES if the nodemask is empty (local allocation).
263 * All other modes require a valid pointer to a non-empty nodemask.
264 */
265 if (mode == MPOL_PREFERRED) {
266 if (nodes_empty(*nodes)) {
267 if (((flags & MPOL_F_STATIC_NODES) ||
268 (flags & MPOL_F_RELATIVE_NODES)))
269 return ERR_PTR(-EINVAL);
David Rientjes3e1f0642008-04-28 02:12:34 -0700270 }
271 } else if (nodes_empty(*nodes))
272 return ERR_PTR(-EINVAL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273 policy = kmem_cache_alloc(policy_cache, GFP_KERNEL);
274 if (!policy)
275 return ERR_PTR(-ENOMEM);
276 atomic_set(&policy->refcnt, 1);
Lee Schermerhorn45c47452008-04-28 02:13:12 -0700277 policy->mode = mode;
David Rientjes3e1f0642008-04-28 02:12:34 -0700278 policy->flags = flags;
David Rientjesf5b087b2008-04-28 02:12:27 -0700279
David Rientjes37012942008-04-28 02:12:33 -0700280 return policy;
281}
282
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -0700283/* Slow path of a mpol destructor. */
284void __mpol_put(struct mempolicy *p)
285{
286 if (!atomic_dec_and_test(&p->refcnt))
287 return;
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -0700288 kmem_cache_free(policy_cache, p);
289}
290
Miao Xie708c1bb2010-05-24 14:32:07 -0700291static void mpol_rebind_default(struct mempolicy *pol, const nodemask_t *nodes,
292 enum mpol_rebind_step step)
David Rientjes37012942008-04-28 02:12:33 -0700293{
294}
295
Miao Xie708c1bb2010-05-24 14:32:07 -0700296/*
297 * step:
298 * MPOL_REBIND_ONCE - do rebind work at once
299 * MPOL_REBIND_STEP1 - set all the newly nodes
300 * MPOL_REBIND_STEP2 - clean all the disallowed nodes
301 */
302static void mpol_rebind_nodemask(struct mempolicy *pol, const nodemask_t *nodes,
303 enum mpol_rebind_step step)
David Rientjes37012942008-04-28 02:12:33 -0700304{
305 nodemask_t tmp;
306
307 if (pol->flags & MPOL_F_STATIC_NODES)
308 nodes_and(tmp, pol->w.user_nodemask, *nodes);
309 else if (pol->flags & MPOL_F_RELATIVE_NODES)
310 mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes);
311 else {
Miao Xie708c1bb2010-05-24 14:32:07 -0700312 /*
313 * if step == 1, we use ->w.cpuset_mems_allowed to cache the
314 * result
315 */
316 if (step == MPOL_REBIND_ONCE || step == MPOL_REBIND_STEP1) {
317 nodes_remap(tmp, pol->v.nodes,
318 pol->w.cpuset_mems_allowed, *nodes);
319 pol->w.cpuset_mems_allowed = step ? tmp : *nodes;
320 } else if (step == MPOL_REBIND_STEP2) {
321 tmp = pol->w.cpuset_mems_allowed;
322 pol->w.cpuset_mems_allowed = *nodes;
323 } else
324 BUG();
David Rientjes37012942008-04-28 02:12:33 -0700325 }
326
Miao Xie708c1bb2010-05-24 14:32:07 -0700327 if (nodes_empty(tmp))
328 tmp = *nodes;
329
330 if (step == MPOL_REBIND_STEP1)
331 nodes_or(pol->v.nodes, pol->v.nodes, tmp);
332 else if (step == MPOL_REBIND_ONCE || step == MPOL_REBIND_STEP2)
333 pol->v.nodes = tmp;
334 else
335 BUG();
336
David Rientjes37012942008-04-28 02:12:33 -0700337 if (!node_isset(current->il_next, tmp)) {
338 current->il_next = next_node(current->il_next, tmp);
339 if (current->il_next >= MAX_NUMNODES)
340 current->il_next = first_node(tmp);
341 if (current->il_next >= MAX_NUMNODES)
342 current->il_next = numa_node_id();
343 }
344}
345
346static void mpol_rebind_preferred(struct mempolicy *pol,
Miao Xie708c1bb2010-05-24 14:32:07 -0700347 const nodemask_t *nodes,
348 enum mpol_rebind_step step)
David Rientjes37012942008-04-28 02:12:33 -0700349{
350 nodemask_t tmp;
351
David Rientjes37012942008-04-28 02:12:33 -0700352 if (pol->flags & MPOL_F_STATIC_NODES) {
353 int node = first_node(pol->w.user_nodemask);
354
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -0700355 if (node_isset(node, *nodes)) {
David Rientjes37012942008-04-28 02:12:33 -0700356 pol->v.preferred_node = node;
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -0700357 pol->flags &= ~MPOL_F_LOCAL;
358 } else
359 pol->flags |= MPOL_F_LOCAL;
David Rientjes37012942008-04-28 02:12:33 -0700360 } else if (pol->flags & MPOL_F_RELATIVE_NODES) {
361 mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes);
362 pol->v.preferred_node = first_node(tmp);
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -0700363 } else if (!(pol->flags & MPOL_F_LOCAL)) {
David Rientjes37012942008-04-28 02:12:33 -0700364 pol->v.preferred_node = node_remap(pol->v.preferred_node,
365 pol->w.cpuset_mems_allowed,
366 *nodes);
367 pol->w.cpuset_mems_allowed = *nodes;
368 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369}
370
Miao Xie708c1bb2010-05-24 14:32:07 -0700371/*
372 * mpol_rebind_policy - Migrate a policy to a different set of nodes
373 *
374 * If read-side task has no lock to protect task->mempolicy, write-side
375 * task will rebind the task->mempolicy by two step. The first step is
376 * setting all the newly nodes, and the second step is cleaning all the
377 * disallowed nodes. In this way, we can avoid finding no node to alloc
378 * page.
379 * If we have a lock to protect task->mempolicy in read-side, we do
380 * rebind directly.
381 *
382 * step:
383 * MPOL_REBIND_ONCE - do rebind work at once
384 * MPOL_REBIND_STEP1 - set all the newly nodes
385 * MPOL_REBIND_STEP2 - clean all the disallowed nodes
386 */
387static void mpol_rebind_policy(struct mempolicy *pol, const nodemask_t *newmask,
388 enum mpol_rebind_step step)
David Rientjes1d0d2682008-04-28 02:12:32 -0700389{
David Rientjes1d0d2682008-04-28 02:12:32 -0700390 if (!pol)
391 return;
Miao Xie708c1bb2010-05-24 14:32:07 -0700392 if (!mpol_store_user_nodemask(pol) && step == 0 &&
David Rientjes1d0d2682008-04-28 02:12:32 -0700393 nodes_equal(pol->w.cpuset_mems_allowed, *newmask))
394 return;
Miao Xie708c1bb2010-05-24 14:32:07 -0700395
396 if (step == MPOL_REBIND_STEP1 && (pol->flags & MPOL_F_REBINDING))
397 return;
398
399 if (step == MPOL_REBIND_STEP2 && !(pol->flags & MPOL_F_REBINDING))
400 BUG();
401
402 if (step == MPOL_REBIND_STEP1)
403 pol->flags |= MPOL_F_REBINDING;
404 else if (step == MPOL_REBIND_STEP2)
405 pol->flags &= ~MPOL_F_REBINDING;
406 else if (step >= MPOL_REBIND_NSTEP)
407 BUG();
408
409 mpol_ops[pol->mode].rebind(pol, newmask, step);
David Rientjes1d0d2682008-04-28 02:12:32 -0700410}
411
412/*
413 * Wrapper for mpol_rebind_policy() that just requires task
414 * pointer, and updates task mempolicy.
Miao Xie58568d22009-06-16 15:31:49 -0700415 *
416 * Called with task's alloc_lock held.
David Rientjes1d0d2682008-04-28 02:12:32 -0700417 */
418
Miao Xie708c1bb2010-05-24 14:32:07 -0700419void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new,
420 enum mpol_rebind_step step)
David Rientjes1d0d2682008-04-28 02:12:32 -0700421{
Miao Xie708c1bb2010-05-24 14:32:07 -0700422 mpol_rebind_policy(tsk->mempolicy, new, step);
David Rientjes1d0d2682008-04-28 02:12:32 -0700423}
424
425/*
426 * Rebind each vma in mm to new nodemask.
427 *
428 * Call holding a reference to mm. Takes mm->mmap_sem during call.
429 */
430
431void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new)
432{
433 struct vm_area_struct *vma;
434
435 down_write(&mm->mmap_sem);
436 for (vma = mm->mmap; vma; vma = vma->vm_next)
Miao Xie708c1bb2010-05-24 14:32:07 -0700437 mpol_rebind_policy(vma->vm_policy, new, MPOL_REBIND_ONCE);
David Rientjes1d0d2682008-04-28 02:12:32 -0700438 up_write(&mm->mmap_sem);
439}
440
David Rientjes37012942008-04-28 02:12:33 -0700441static const struct mempolicy_operations mpol_ops[MPOL_MAX] = {
442 [MPOL_DEFAULT] = {
443 .rebind = mpol_rebind_default,
444 },
445 [MPOL_INTERLEAVE] = {
446 .create = mpol_new_interleave,
447 .rebind = mpol_rebind_nodemask,
448 },
449 [MPOL_PREFERRED] = {
450 .create = mpol_new_preferred,
451 .rebind = mpol_rebind_preferred,
452 },
453 [MPOL_BIND] = {
454 .create = mpol_new_bind,
455 .rebind = mpol_rebind_nodemask,
456 },
457};
458
Christoph Lameterfc301282006-01-18 17:42:29 -0800459static void migrate_page_add(struct page *page, struct list_head *pagelist,
460 unsigned long flags);
Christoph Lameter1a75a6c2006-01-08 01:01:02 -0800461
Christoph Lameter38e35862006-01-08 01:01:01 -0800462/* Scan through pages checking if pages follow certain conditions. */
Nick Pigginb5810032005-10-29 18:16:12 -0700463static int check_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800464 unsigned long addr, unsigned long end,
465 const nodemask_t *nodes, unsigned long flags,
Christoph Lameter38e35862006-01-08 01:01:01 -0800466 void *private)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467{
Hugh Dickins91612e02005-06-21 17:15:07 -0700468 pte_t *orig_pte;
469 pte_t *pte;
Hugh Dickins705e87c2005-10-29 18:16:27 -0700470 spinlock_t *ptl;
Hugh Dickins941150a2005-06-21 17:15:06 -0700471
Hugh Dickins705e87c2005-10-29 18:16:27 -0700472 orig_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
Hugh Dickins91612e02005-06-21 17:15:07 -0700473 do {
Linus Torvalds6aab3412005-11-28 14:34:23 -0800474 struct page *page;
Andy Whitcroft25ba77c2006-12-06 20:33:03 -0800475 int nid;
Hugh Dickins91612e02005-06-21 17:15:07 -0700476
477 if (!pte_present(*pte))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478 continue;
Linus Torvalds6aab3412005-11-28 14:34:23 -0800479 page = vm_normal_page(vma, addr, *pte);
480 if (!page)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481 continue;
Nick Piggin053837f2006-01-18 17:42:27 -0800482 /*
Hugh Dickins62b61f62009-12-14 17:59:33 -0800483 * vm_normal_page() filters out zero pages, but there might
484 * still be PageReserved pages to skip, perhaps in a VDSO.
485 * And we cannot move PageKsm pages sensibly or safely yet.
Nick Piggin053837f2006-01-18 17:42:27 -0800486 */
Hugh Dickins62b61f62009-12-14 17:59:33 -0800487 if (PageReserved(page) || PageKsm(page))
Christoph Lameterf4598c82006-01-12 01:05:20 -0800488 continue;
Linus Torvalds6aab3412005-11-28 14:34:23 -0800489 nid = page_to_nid(page);
Christoph Lameter38e35862006-01-08 01:01:01 -0800490 if (node_isset(nid, *nodes) == !!(flags & MPOL_MF_INVERT))
491 continue;
492
Stephen Wilsonb1f72d12011-05-24 17:12:43 -0700493 if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
Christoph Lameterfc301282006-01-18 17:42:29 -0800494 migrate_page_add(page, private, flags);
Christoph Lameter38e35862006-01-08 01:01:01 -0800495 else
496 break;
Hugh Dickins91612e02005-06-21 17:15:07 -0700497 } while (pte++, addr += PAGE_SIZE, addr != end);
Hugh Dickins705e87c2005-10-29 18:16:27 -0700498 pte_unmap_unlock(orig_pte, ptl);
Hugh Dickins91612e02005-06-21 17:15:07 -0700499 return addr != end;
500}
501
Nick Pigginb5810032005-10-29 18:16:12 -0700502static inline int check_pmd_range(struct vm_area_struct *vma, pud_t *pud,
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800503 unsigned long addr, unsigned long end,
504 const nodemask_t *nodes, unsigned long flags,
Christoph Lameter38e35862006-01-08 01:01:01 -0800505 void *private)
Hugh Dickins91612e02005-06-21 17:15:07 -0700506{
507 pmd_t *pmd;
508 unsigned long next;
509
510 pmd = pmd_offset(pud, addr);
511 do {
512 next = pmd_addr_end(addr, end);
Andrea Arcangelibae9c192011-01-13 15:46:46 -0800513 split_huge_page_pmd(vma->vm_mm, pmd);
Hugh Dickins91612e02005-06-21 17:15:07 -0700514 if (pmd_none_or_clear_bad(pmd))
515 continue;
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800516 if (check_pte_range(vma, pmd, addr, next, nodes,
Christoph Lameter38e35862006-01-08 01:01:01 -0800517 flags, private))
Hugh Dickins91612e02005-06-21 17:15:07 -0700518 return -EIO;
519 } while (pmd++, addr = next, addr != end);
520 return 0;
521}
522
Nick Pigginb5810032005-10-29 18:16:12 -0700523static inline int check_pud_range(struct vm_area_struct *vma, pgd_t *pgd,
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800524 unsigned long addr, unsigned long end,
525 const nodemask_t *nodes, unsigned long flags,
Christoph Lameter38e35862006-01-08 01:01:01 -0800526 void *private)
Hugh Dickins91612e02005-06-21 17:15:07 -0700527{
528 pud_t *pud;
529 unsigned long next;
530
531 pud = pud_offset(pgd, addr);
532 do {
533 next = pud_addr_end(addr, end);
534 if (pud_none_or_clear_bad(pud))
535 continue;
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800536 if (check_pmd_range(vma, pud, addr, next, nodes,
Christoph Lameter38e35862006-01-08 01:01:01 -0800537 flags, private))
Hugh Dickins91612e02005-06-21 17:15:07 -0700538 return -EIO;
539 } while (pud++, addr = next, addr != end);
540 return 0;
541}
542
Nick Pigginb5810032005-10-29 18:16:12 -0700543static inline int check_pgd_range(struct vm_area_struct *vma,
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800544 unsigned long addr, unsigned long end,
545 const nodemask_t *nodes, unsigned long flags,
Christoph Lameter38e35862006-01-08 01:01:01 -0800546 void *private)
Hugh Dickins91612e02005-06-21 17:15:07 -0700547{
548 pgd_t *pgd;
549 unsigned long next;
550
Nick Pigginb5810032005-10-29 18:16:12 -0700551 pgd = pgd_offset(vma->vm_mm, addr);
Hugh Dickins91612e02005-06-21 17:15:07 -0700552 do {
553 next = pgd_addr_end(addr, end);
554 if (pgd_none_or_clear_bad(pgd))
555 continue;
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800556 if (check_pud_range(vma, pgd, addr, next, nodes,
Christoph Lameter38e35862006-01-08 01:01:01 -0800557 flags, private))
Hugh Dickins91612e02005-06-21 17:15:07 -0700558 return -EIO;
559 } while (pgd++, addr = next, addr != end);
560 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561}
562
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800563/*
564 * Check if all pages in a range are on a set of nodes.
565 * If pagelist != NULL then isolate pages from the LRU and
566 * put them on the pagelist.
567 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568static struct vm_area_struct *
569check_range(struct mm_struct *mm, unsigned long start, unsigned long end,
Christoph Lameter38e35862006-01-08 01:01:01 -0800570 const nodemask_t *nodes, unsigned long flags, void *private)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700571{
572 int err;
573 struct vm_area_struct *first, *vma, *prev;
574
Nick Piggin053837f2006-01-18 17:42:27 -0800575
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576 first = find_vma(mm, start);
577 if (!first)
578 return ERR_PTR(-EFAULT);
579 prev = NULL;
580 for (vma = first; vma && vma->vm_start < end; vma = vma->vm_next) {
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800581 if (!(flags & MPOL_MF_DISCONTIG_OK)) {
582 if (!vma->vm_next && vma->vm_end < end)
583 return ERR_PTR(-EFAULT);
584 if (prev && prev->vm_end < vma->vm_start)
585 return ERR_PTR(-EFAULT);
586 }
587 if (!is_vm_hugetlb_page(vma) &&
588 ((flags & MPOL_MF_STRICT) ||
589 ((flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) &&
590 vma_migratable(vma)))) {
Andi Kleen5b952b32005-09-13 01:25:08 -0700591 unsigned long endvma = vma->vm_end;
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800592
Andi Kleen5b952b32005-09-13 01:25:08 -0700593 if (endvma > end)
594 endvma = end;
595 if (vma->vm_start > start)
596 start = vma->vm_start;
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800597 err = check_pgd_range(vma, start, endvma, nodes,
Christoph Lameter38e35862006-01-08 01:01:01 -0800598 flags, private);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599 if (err) {
600 first = ERR_PTR(err);
601 break;
602 }
603 }
604 prev = vma;
605 }
606 return first;
607}
608
609/* Apply policy to a single VMA */
610static int policy_vma(struct vm_area_struct *vma, struct mempolicy *new)
611{
612 int err = 0;
613 struct mempolicy *old = vma->vm_policy;
614
Paul Mundt140d5a42007-07-15 23:38:16 -0700615 pr_debug("vma %lx-%lx/%lx vm_ops %p vm_file %p set_policy %p\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616 vma->vm_start, vma->vm_end, vma->vm_pgoff,
617 vma->vm_ops, vma->vm_file,
618 vma->vm_ops ? vma->vm_ops->set_policy : NULL);
619
620 if (vma->vm_ops && vma->vm_ops->set_policy)
621 err = vma->vm_ops->set_policy(vma, new);
622 if (!err) {
623 mpol_get(new);
624 vma->vm_policy = new;
Lee Schermerhornf0be3d32008-04-28 02:13:08 -0700625 mpol_put(old);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700626 }
627 return err;
628}
629
630/* Step 2: apply policy to a range and do splits. */
KOSAKI Motohiro9d8cebd2010-03-05 13:41:57 -0800631static int mbind_range(struct mm_struct *mm, unsigned long start,
632 unsigned long end, struct mempolicy *new_pol)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633{
634 struct vm_area_struct *next;
KOSAKI Motohiro9d8cebd2010-03-05 13:41:57 -0800635 struct vm_area_struct *prev;
636 struct vm_area_struct *vma;
637 int err = 0;
638 pgoff_t pgoff;
639 unsigned long vmstart;
640 unsigned long vmend;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700641
KOSAKI Motohiro9d8cebd2010-03-05 13:41:57 -0800642 vma = find_vma_prev(mm, start, &prev);
643 if (!vma || vma->vm_start > start)
644 return -EFAULT;
645
646 for (; vma && vma->vm_start < end; prev = vma, vma = next) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647 next = vma->vm_next;
KOSAKI Motohiro9d8cebd2010-03-05 13:41:57 -0800648 vmstart = max(start, vma->vm_start);
649 vmend = min(end, vma->vm_end);
650
651 pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
652 prev = vma_merge(mm, prev, vmstart, vmend, vma->vm_flags,
653 vma->anon_vma, vma->vm_file, pgoff, new_pol);
654 if (prev) {
655 vma = prev;
656 next = vma->vm_next;
657 continue;
658 }
659 if (vma->vm_start != vmstart) {
660 err = split_vma(vma->vm_mm, vma, vmstart, 1);
661 if (err)
662 goto out;
663 }
664 if (vma->vm_end != vmend) {
665 err = split_vma(vma->vm_mm, vma, vmend, 0);
666 if (err)
667 goto out;
668 }
669 err = policy_vma(vma, new_pol);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670 if (err)
KOSAKI Motohiro9d8cebd2010-03-05 13:41:57 -0800671 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672 }
KOSAKI Motohiro9d8cebd2010-03-05 13:41:57 -0800673
674 out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675 return err;
676}
677
Paul Jacksonc61afb12006-03-24 03:16:08 -0800678/*
679 * Update task->flags PF_MEMPOLICY bit: set iff non-default
680 * mempolicy. Allows more rapid checking of this (combined perhaps
681 * with other PF_* flag bits) on memory allocation hot code paths.
682 *
683 * If called from outside this file, the task 'p' should -only- be
684 * a newly forked child not yet visible on the task list, because
685 * manipulating the task flags of a visible task is not safe.
686 *
687 * The above limitation is why this routine has the funny name
688 * mpol_fix_fork_child_flag().
689 *
690 * It is also safe to call this with a task pointer of current,
691 * which the static wrapper mpol_set_task_struct_flag() does,
692 * for use within this file.
693 */
694
695void mpol_fix_fork_child_flag(struct task_struct *p)
696{
697 if (p->mempolicy)
698 p->flags |= PF_MEMPOLICY;
699 else
700 p->flags &= ~PF_MEMPOLICY;
701}
702
703static void mpol_set_task_struct_flag(void)
704{
705 mpol_fix_fork_child_flag(current);
706}
707
Linus Torvalds1da177e2005-04-16 15:20:36 -0700708/* Set the process memory policy */
David Rientjes028fec42008-04-28 02:12:25 -0700709static long do_set_mempolicy(unsigned short mode, unsigned short flags,
710 nodemask_t *nodes)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700711{
Miao Xie58568d22009-06-16 15:31:49 -0700712 struct mempolicy *new, *old;
Lee Schermerhornf4e53d92008-04-28 02:13:10 -0700713 struct mm_struct *mm = current->mm;
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -0700714 NODEMASK_SCRATCH(scratch);
Miao Xie58568d22009-06-16 15:31:49 -0700715 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700716
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -0700717 if (!scratch)
718 return -ENOMEM;
Lee Schermerhornf4e53d92008-04-28 02:13:10 -0700719
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -0700720 new = mpol_new(mode, flags, nodes);
721 if (IS_ERR(new)) {
722 ret = PTR_ERR(new);
723 goto out;
724 }
Lee Schermerhornf4e53d92008-04-28 02:13:10 -0700725 /*
726 * prevent changing our mempolicy while show_numa_maps()
727 * is using it.
728 * Note: do_set_mempolicy() can be called at init time
729 * with no 'mm'.
730 */
731 if (mm)
732 down_write(&mm->mmap_sem);
Miao Xie58568d22009-06-16 15:31:49 -0700733 task_lock(current);
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -0700734 ret = mpol_set_nodemask(new, nodes, scratch);
Miao Xie58568d22009-06-16 15:31:49 -0700735 if (ret) {
736 task_unlock(current);
737 if (mm)
738 up_write(&mm->mmap_sem);
739 mpol_put(new);
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -0700740 goto out;
Miao Xie58568d22009-06-16 15:31:49 -0700741 }
742 old = current->mempolicy;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700743 current->mempolicy = new;
Paul Jacksonc61afb12006-03-24 03:16:08 -0800744 mpol_set_task_struct_flag();
Lee Schermerhorn45c47452008-04-28 02:13:12 -0700745 if (new && new->mode == MPOL_INTERLEAVE &&
David Rientjesf5b087b2008-04-28 02:12:27 -0700746 nodes_weight(new->v.nodes))
Andi Kleendfcd3c02005-10-29 18:15:48 -0700747 current->il_next = first_node(new->v.nodes);
Miao Xie58568d22009-06-16 15:31:49 -0700748 task_unlock(current);
Lee Schermerhornf4e53d92008-04-28 02:13:10 -0700749 if (mm)
750 up_write(&mm->mmap_sem);
751
Miao Xie58568d22009-06-16 15:31:49 -0700752 mpol_put(old);
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -0700753 ret = 0;
754out:
755 NODEMASK_SCRATCH_FREE(scratch);
756 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700757}
758
Lee Schermerhornbea904d2008-04-28 02:13:18 -0700759/*
760 * Return nodemask for policy for get_mempolicy() query
Miao Xie58568d22009-06-16 15:31:49 -0700761 *
762 * Called with task's alloc_lock held
Lee Schermerhornbea904d2008-04-28 02:13:18 -0700763 */
764static void get_policy_nodemask(struct mempolicy *p, nodemask_t *nodes)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765{
Andi Kleendfcd3c02005-10-29 18:15:48 -0700766 nodes_clear(*nodes);
Lee Schermerhornbea904d2008-04-28 02:13:18 -0700767 if (p == &default_policy)
768 return;
769
Lee Schermerhorn45c47452008-04-28 02:13:12 -0700770 switch (p->mode) {
Mel Gorman19770b32008-04-28 02:12:18 -0700771 case MPOL_BIND:
772 /* Fall through */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700773 case MPOL_INTERLEAVE:
Andi Kleendfcd3c02005-10-29 18:15:48 -0700774 *nodes = p->v.nodes;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700775 break;
776 case MPOL_PREFERRED:
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -0700777 if (!(p->flags & MPOL_F_LOCAL))
Andi Kleendfcd3c02005-10-29 18:15:48 -0700778 node_set(p->v.preferred_node, *nodes);
Lee Schermerhorn53f25562008-04-28 02:13:20 -0700779 /* else return empty node mask for local allocation */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700780 break;
781 default:
782 BUG();
783 }
784}
785
786static int lookup_node(struct mm_struct *mm, unsigned long addr)
787{
788 struct page *p;
789 int err;
790
791 err = get_user_pages(current, mm, addr & PAGE_MASK, 1, 0, 0, &p, NULL);
792 if (err >= 0) {
793 err = page_to_nid(p);
794 put_page(p);
795 }
796 return err;
797}
798
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799/* Retrieve NUMA policy */
Adrian Bunkdbcb0f12007-10-16 01:26:26 -0700800static long do_get_mempolicy(int *policy, nodemask_t *nmask,
801 unsigned long addr, unsigned long flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700802{
Christoph Lameter8bccd852005-10-29 18:16:59 -0700803 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700804 struct mm_struct *mm = current->mm;
805 struct vm_area_struct *vma = NULL;
806 struct mempolicy *pol = current->mempolicy;
807
Lee Schermerhorn754af6f2007-10-16 01:24:51 -0700808 if (flags &
809 ~(unsigned long)(MPOL_F_NODE|MPOL_F_ADDR|MPOL_F_MEMS_ALLOWED))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700810 return -EINVAL;
Lee Schermerhorn754af6f2007-10-16 01:24:51 -0700811
812 if (flags & MPOL_F_MEMS_ALLOWED) {
813 if (flags & (MPOL_F_NODE|MPOL_F_ADDR))
814 return -EINVAL;
815 *policy = 0; /* just so it's initialized */
Miao Xie58568d22009-06-16 15:31:49 -0700816 task_lock(current);
Lee Schermerhorn754af6f2007-10-16 01:24:51 -0700817 *nmask = cpuset_current_mems_allowed;
Miao Xie58568d22009-06-16 15:31:49 -0700818 task_unlock(current);
Lee Schermerhorn754af6f2007-10-16 01:24:51 -0700819 return 0;
820 }
821
Linus Torvalds1da177e2005-04-16 15:20:36 -0700822 if (flags & MPOL_F_ADDR) {
Lee Schermerhornbea904d2008-04-28 02:13:18 -0700823 /*
824 * Do NOT fall back to task policy if the
825 * vma/shared policy at addr is NULL. We
826 * want to return MPOL_DEFAULT in this case.
827 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700828 down_read(&mm->mmap_sem);
829 vma = find_vma_intersection(mm, addr, addr+1);
830 if (!vma) {
831 up_read(&mm->mmap_sem);
832 return -EFAULT;
833 }
834 if (vma->vm_ops && vma->vm_ops->get_policy)
835 pol = vma->vm_ops->get_policy(vma, addr);
836 else
837 pol = vma->vm_policy;
838 } else if (addr)
839 return -EINVAL;
840
841 if (!pol)
Lee Schermerhornbea904d2008-04-28 02:13:18 -0700842 pol = &default_policy; /* indicates default behavior */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700843
844 if (flags & MPOL_F_NODE) {
845 if (flags & MPOL_F_ADDR) {
846 err = lookup_node(mm, addr);
847 if (err < 0)
848 goto out;
Christoph Lameter8bccd852005-10-29 18:16:59 -0700849 *policy = err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700850 } else if (pol == current->mempolicy &&
Lee Schermerhorn45c47452008-04-28 02:13:12 -0700851 pol->mode == MPOL_INTERLEAVE) {
Christoph Lameter8bccd852005-10-29 18:16:59 -0700852 *policy = current->il_next;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700853 } else {
854 err = -EINVAL;
855 goto out;
856 }
Lee Schermerhornbea904d2008-04-28 02:13:18 -0700857 } else {
858 *policy = pol == &default_policy ? MPOL_DEFAULT :
859 pol->mode;
David Rientjesd79df632008-07-04 12:24:13 -0700860 /*
861 * Internal mempolicy flags must be masked off before exposing
862 * the policy to userspace.
863 */
864 *policy |= (pol->flags & MPOL_MODE_FLAGS);
Lee Schermerhornbea904d2008-04-28 02:13:18 -0700865 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700866
867 if (vma) {
868 up_read(&current->mm->mmap_sem);
869 vma = NULL;
870 }
871
Linus Torvalds1da177e2005-04-16 15:20:36 -0700872 err = 0;
Miao Xie58568d22009-06-16 15:31:49 -0700873 if (nmask) {
Lee Schermerhornc6b6ef82010-03-23 13:35:41 -0700874 if (mpol_store_user_nodemask(pol)) {
875 *nmask = pol->w.user_nodemask;
876 } else {
877 task_lock(current);
878 get_policy_nodemask(pol, nmask);
879 task_unlock(current);
880 }
Miao Xie58568d22009-06-16 15:31:49 -0700881 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700882
883 out:
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -0700884 mpol_cond_put(pol);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700885 if (vma)
886 up_read(&current->mm->mmap_sem);
887 return err;
888}
889
Christoph Lameterb20a3502006-03-22 00:09:12 -0800890#ifdef CONFIG_MIGRATION
Christoph Lameter8bccd852005-10-29 18:16:59 -0700891/*
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -0800892 * page migration
893 */
Christoph Lameterfc301282006-01-18 17:42:29 -0800894static void migrate_page_add(struct page *page, struct list_head *pagelist,
895 unsigned long flags)
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -0800896{
897 /*
Christoph Lameterfc301282006-01-18 17:42:29 -0800898 * Avoid migrating a page that is shared with others.
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -0800899 */
Nick Piggin62695a82008-10-18 20:26:09 -0700900 if ((flags & MPOL_MF_MOVE_ALL) || page_mapcount(page) == 1) {
901 if (!isolate_lru_page(page)) {
902 list_add_tail(&page->lru, pagelist);
KOSAKI Motohiro6d9c2852009-12-14 17:58:11 -0800903 inc_zone_page_state(page, NR_ISOLATED_ANON +
904 page_is_file_cache(page));
Nick Piggin62695a82008-10-18 20:26:09 -0700905 }
906 }
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -0800907}
908
Christoph Lameter742755a2006-06-23 02:03:55 -0700909static struct page *new_node_page(struct page *page, unsigned long node, int **x)
Christoph Lameter95a402c2006-06-23 02:03:53 -0700910{
Mel Gorman6484eb32009-06-16 15:31:54 -0700911 return alloc_pages_exact_node(node, GFP_HIGHUSER_MOVABLE, 0);
Christoph Lameter95a402c2006-06-23 02:03:53 -0700912}
913
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -0800914/*
Christoph Lameter7e2ab152006-02-01 03:05:40 -0800915 * Migrate pages from one node to a target node.
916 * Returns error or the number of pages not migrated.
917 */
Adrian Bunkdbcb0f12007-10-16 01:26:26 -0700918static int migrate_to_node(struct mm_struct *mm, int source, int dest,
919 int flags)
Christoph Lameter7e2ab152006-02-01 03:05:40 -0800920{
921 nodemask_t nmask;
922 LIST_HEAD(pagelist);
923 int err = 0;
Vasiliy Kulikov0def08e2010-10-26 14:21:32 -0700924 struct vm_area_struct *vma;
Christoph Lameter7e2ab152006-02-01 03:05:40 -0800925
926 nodes_clear(nmask);
927 node_set(source, nmask);
928
Vasiliy Kulikov0def08e2010-10-26 14:21:32 -0700929 vma = check_range(mm, mm->mmap->vm_start, mm->task_size, &nmask,
Christoph Lameter7e2ab152006-02-01 03:05:40 -0800930 flags | MPOL_MF_DISCONTIG_OK, &pagelist);
Vasiliy Kulikov0def08e2010-10-26 14:21:32 -0700931 if (IS_ERR(vma))
932 return PTR_ERR(vma);
Christoph Lameter7e2ab152006-02-01 03:05:40 -0800933
Minchan Kimcf608ac2010-10-26 14:21:29 -0700934 if (!list_empty(&pagelist)) {
Mel Gorman7f0f2492011-01-13 15:45:58 -0800935 err = migrate_pages(&pagelist, new_node_page, dest,
936 false, true);
Minchan Kimcf608ac2010-10-26 14:21:29 -0700937 if (err)
938 putback_lru_pages(&pagelist);
939 }
Christoph Lameter95a402c2006-06-23 02:03:53 -0700940
Christoph Lameter7e2ab152006-02-01 03:05:40 -0800941 return err;
942}
943
944/*
945 * Move pages between the two nodesets so as to preserve the physical
946 * layout as much as possible.
Christoph Lameter39743882006-01-08 01:00:51 -0800947 *
948 * Returns the number of page that could not be moved.
949 */
950int do_migrate_pages(struct mm_struct *mm,
951 const nodemask_t *from_nodes, const nodemask_t *to_nodes, int flags)
952{
Christoph Lameter7e2ab152006-02-01 03:05:40 -0800953 int busy = 0;
Christoph Lameter0aedadf2008-11-06 12:53:30 -0800954 int err;
Christoph Lameter7e2ab152006-02-01 03:05:40 -0800955 nodemask_t tmp;
Christoph Lameter39743882006-01-08 01:00:51 -0800956
Christoph Lameter0aedadf2008-11-06 12:53:30 -0800957 err = migrate_prep();
958 if (err)
959 return err;
960
Lee Schermerhorn53f25562008-04-28 02:13:20 -0700961 down_read(&mm->mmap_sem);
Christoph Lameter39743882006-01-08 01:00:51 -0800962
Christoph Lameter7b2259b2006-06-25 05:46:48 -0700963 err = migrate_vmas(mm, from_nodes, to_nodes, flags);
964 if (err)
965 goto out;
966
KOSAKI Motohiroda0aa132010-03-05 13:41:59 -0800967 /*
968 * Find a 'source' bit set in 'tmp' whose corresponding 'dest'
969 * bit in 'to' is not also set in 'tmp'. Clear the found 'source'
970 * bit in 'tmp', and return that <source, dest> pair for migration.
971 * The pair of nodemasks 'to' and 'from' define the map.
972 *
973 * If no pair of bits is found that way, fallback to picking some
974 * pair of 'source' and 'dest' bits that are not the same. If the
975 * 'source' and 'dest' bits are the same, this represents a node
976 * that will be migrating to itself, so no pages need move.
977 *
978 * If no bits are left in 'tmp', or if all remaining bits left
979 * in 'tmp' correspond to the same bit in 'to', return false
980 * (nothing left to migrate).
981 *
982 * This lets us pick a pair of nodes to migrate between, such that
983 * if possible the dest node is not already occupied by some other
984 * source node, minimizing the risk of overloading the memory on a
985 * node that would happen if we migrated incoming memory to a node
986 * before migrating outgoing memory source that same node.
987 *
988 * A single scan of tmp is sufficient. As we go, we remember the
989 * most recent <s, d> pair that moved (s != d). If we find a pair
990 * that not only moved, but what's better, moved to an empty slot
991 * (d is not set in tmp), then we break out then, with that pair.
Justin P. Mattockae0e47f2011-03-01 15:06:02 +0100992 * Otherwise when we finish scanning from_tmp, we at least have the
KOSAKI Motohiroda0aa132010-03-05 13:41:59 -0800993 * most recent <s, d> pair that moved. If we get all the way through
994 * the scan of tmp without finding any node that moved, much less
995 * moved to an empty node, then there is nothing left worth migrating.
996 */
Christoph Lameterd4984712006-01-08 01:00:55 -0800997
Christoph Lameter7e2ab152006-02-01 03:05:40 -0800998 tmp = *from_nodes;
999 while (!nodes_empty(tmp)) {
1000 int s,d;
1001 int source = -1;
1002 int dest = 0;
1003
1004 for_each_node_mask(s, tmp) {
1005 d = node_remap(s, *from_nodes, *to_nodes);
1006 if (s == d)
1007 continue;
1008
1009 source = s; /* Node moved. Memorize */
1010 dest = d;
1011
1012 /* dest not in remaining from nodes? */
1013 if (!node_isset(dest, tmp))
1014 break;
1015 }
1016 if (source == -1)
1017 break;
1018
1019 node_clear(source, tmp);
1020 err = migrate_to_node(mm, source, dest, flags);
1021 if (err > 0)
1022 busy += err;
1023 if (err < 0)
1024 break;
Christoph Lameter39743882006-01-08 01:00:51 -08001025 }
Christoph Lameter7b2259b2006-06-25 05:46:48 -07001026out:
Christoph Lameter39743882006-01-08 01:00:51 -08001027 up_read(&mm->mmap_sem);
Christoph Lameter7e2ab152006-02-01 03:05:40 -08001028 if (err < 0)
1029 return err;
1030 return busy;
Christoph Lameterb20a3502006-03-22 00:09:12 -08001031
Christoph Lameter39743882006-01-08 01:00:51 -08001032}
1033
Lee Schermerhorn3ad33b22007-11-14 16:59:10 -08001034/*
1035 * Allocate a new page for page migration based on vma policy.
1036 * Start assuming that page is mapped by vma pointed to by @private.
1037 * Search forward from there, if not. N.B., this assumes that the
1038 * list of pages handed to migrate_pages()--which is how we get here--
1039 * is in virtual address order.
1040 */
Christoph Lameter742755a2006-06-23 02:03:55 -07001041static struct page *new_vma_page(struct page *page, unsigned long private, int **x)
Christoph Lameter95a402c2006-06-23 02:03:53 -07001042{
1043 struct vm_area_struct *vma = (struct vm_area_struct *)private;
Lee Schermerhorn3ad33b22007-11-14 16:59:10 -08001044 unsigned long uninitialized_var(address);
Christoph Lameter95a402c2006-06-23 02:03:53 -07001045
Lee Schermerhorn3ad33b22007-11-14 16:59:10 -08001046 while (vma) {
1047 address = page_address_in_vma(page, vma);
1048 if (address != -EFAULT)
1049 break;
1050 vma = vma->vm_next;
1051 }
1052
1053 /*
1054 * if !vma, alloc_page_vma() will use task or system default policy
1055 */
1056 return alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
Christoph Lameter95a402c2006-06-23 02:03:53 -07001057}
Christoph Lameterb20a3502006-03-22 00:09:12 -08001058#else
1059
1060static void migrate_page_add(struct page *page, struct list_head *pagelist,
1061 unsigned long flags)
1062{
1063}
1064
1065int do_migrate_pages(struct mm_struct *mm,
1066 const nodemask_t *from_nodes, const nodemask_t *to_nodes, int flags)
1067{
1068 return -ENOSYS;
1069}
Christoph Lameter95a402c2006-06-23 02:03:53 -07001070
Keith Owens69939742006-10-11 01:21:28 -07001071static struct page *new_vma_page(struct page *page, unsigned long private, int **x)
Christoph Lameter95a402c2006-06-23 02:03:53 -07001072{
1073 return NULL;
1074}
Christoph Lameterb20a3502006-03-22 00:09:12 -08001075#endif
1076
Adrian Bunkdbcb0f12007-10-16 01:26:26 -07001077static long do_mbind(unsigned long start, unsigned long len,
David Rientjes028fec42008-04-28 02:12:25 -07001078 unsigned short mode, unsigned short mode_flags,
1079 nodemask_t *nmask, unsigned long flags)
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -08001080{
1081 struct vm_area_struct *vma;
1082 struct mm_struct *mm = current->mm;
1083 struct mempolicy *new;
1084 unsigned long end;
1085 int err;
1086 LIST_HEAD(pagelist);
1087
David Rientjesa3b51e02008-04-28 02:12:23 -07001088 if (flags & ~(unsigned long)(MPOL_MF_STRICT |
1089 MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -08001090 return -EINVAL;
Christoph Lameter74c00242006-03-14 19:50:21 -08001091 if ((flags & MPOL_MF_MOVE_ALL) && !capable(CAP_SYS_NICE))
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -08001092 return -EPERM;
1093
1094 if (start & ~PAGE_MASK)
1095 return -EINVAL;
1096
1097 if (mode == MPOL_DEFAULT)
1098 flags &= ~MPOL_MF_STRICT;
1099
1100 len = (len + PAGE_SIZE - 1) & PAGE_MASK;
1101 end = start + len;
1102
1103 if (end < start)
1104 return -EINVAL;
1105 if (end == start)
1106 return 0;
1107
David Rientjes028fec42008-04-28 02:12:25 -07001108 new = mpol_new(mode, mode_flags, nmask);
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -08001109 if (IS_ERR(new))
1110 return PTR_ERR(new);
1111
1112 /*
1113 * If we are using the default policy then operation
1114 * on discontinuous address spaces is okay after all
1115 */
1116 if (!new)
1117 flags |= MPOL_MF_DISCONTIG_OK;
1118
David Rientjes028fec42008-04-28 02:12:25 -07001119 pr_debug("mbind %lx-%lx mode:%d flags:%d nodes:%lx\n",
1120 start, start + len, mode, mode_flags,
1121 nmask ? nodes_addr(*nmask)[0] : -1);
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -08001122
Christoph Lameter0aedadf2008-11-06 12:53:30 -08001123 if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) {
1124
1125 err = migrate_prep();
1126 if (err)
KOSAKI Motohirob05ca732009-10-26 16:49:59 -07001127 goto mpol_out;
Christoph Lameter0aedadf2008-11-06 12:53:30 -08001128 }
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -07001129 {
1130 NODEMASK_SCRATCH(scratch);
1131 if (scratch) {
1132 down_write(&mm->mmap_sem);
1133 task_lock(current);
1134 err = mpol_set_nodemask(new, nmask, scratch);
1135 task_unlock(current);
1136 if (err)
1137 up_write(&mm->mmap_sem);
1138 } else
1139 err = -ENOMEM;
1140 NODEMASK_SCRATCH_FREE(scratch);
1141 }
KOSAKI Motohirob05ca732009-10-26 16:49:59 -07001142 if (err)
1143 goto mpol_out;
1144
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -08001145 vma = check_range(mm, start, end, nmask,
1146 flags | MPOL_MF_INVERT, &pagelist);
1147
1148 err = PTR_ERR(vma);
1149 if (!IS_ERR(vma)) {
1150 int nr_failed = 0;
1151
KOSAKI Motohiro9d8cebd2010-03-05 13:41:57 -08001152 err = mbind_range(mm, start, end, new);
Christoph Lameter7e2ab152006-02-01 03:05:40 -08001153
Minchan Kimcf608ac2010-10-26 14:21:29 -07001154 if (!list_empty(&pagelist)) {
Christoph Lameter95a402c2006-06-23 02:03:53 -07001155 nr_failed = migrate_pages(&pagelist, new_vma_page,
Mel Gorman7f0f2492011-01-13 15:45:58 -08001156 (unsigned long)vma,
1157 false, true);
Minchan Kimcf608ac2010-10-26 14:21:29 -07001158 if (nr_failed)
1159 putback_lru_pages(&pagelist);
1160 }
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -08001161
1162 if (!err && nr_failed && (flags & MPOL_MF_STRICT))
1163 err = -EIO;
KOSAKI Motohiroab8a3e12009-10-26 16:49:58 -07001164 } else
1165 putback_lru_pages(&pagelist);
Christoph Lameterb20a3502006-03-22 00:09:12 -08001166
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -08001167 up_write(&mm->mmap_sem);
KOSAKI Motohirob05ca732009-10-26 16:49:59 -07001168 mpol_out:
Lee Schermerhornf0be3d32008-04-28 02:13:08 -07001169 mpol_put(new);
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -08001170 return err;
1171}
1172
Christoph Lameter39743882006-01-08 01:00:51 -08001173/*
Christoph Lameter8bccd852005-10-29 18:16:59 -07001174 * User space interface with variable sized bitmaps for nodelists.
1175 */
1176
1177/* Copy a node mask from user space. */
Christoph Lameter39743882006-01-08 01:00:51 -08001178static int get_nodes(nodemask_t *nodes, const unsigned long __user *nmask,
Christoph Lameter8bccd852005-10-29 18:16:59 -07001179 unsigned long maxnode)
1180{
1181 unsigned long k;
1182 unsigned long nlongs;
1183 unsigned long endmask;
1184
1185 --maxnode;
1186 nodes_clear(*nodes);
1187 if (maxnode == 0 || !nmask)
1188 return 0;
Andi Kleena9c930b2006-02-20 18:27:59 -08001189 if (maxnode > PAGE_SIZE*BITS_PER_BYTE)
Chris Wright636f13c2006-02-17 13:59:36 -08001190 return -EINVAL;
Christoph Lameter8bccd852005-10-29 18:16:59 -07001191
1192 nlongs = BITS_TO_LONGS(maxnode);
1193 if ((maxnode % BITS_PER_LONG) == 0)
1194 endmask = ~0UL;
1195 else
1196 endmask = (1UL << (maxnode % BITS_PER_LONG)) - 1;
1197
1198 /* When the user specified more nodes than supported just check
1199 if the non supported part is all zero. */
1200 if (nlongs > BITS_TO_LONGS(MAX_NUMNODES)) {
1201 if (nlongs > PAGE_SIZE/sizeof(long))
1202 return -EINVAL;
1203 for (k = BITS_TO_LONGS(MAX_NUMNODES); k < nlongs; k++) {
1204 unsigned long t;
1205 if (get_user(t, nmask + k))
1206 return -EFAULT;
1207 if (k == nlongs - 1) {
1208 if (t & endmask)
1209 return -EINVAL;
1210 } else if (t)
1211 return -EINVAL;
1212 }
1213 nlongs = BITS_TO_LONGS(MAX_NUMNODES);
1214 endmask = ~0UL;
1215 }
1216
1217 if (copy_from_user(nodes_addr(*nodes), nmask, nlongs*sizeof(unsigned long)))
1218 return -EFAULT;
1219 nodes_addr(*nodes)[nlongs-1] &= endmask;
1220 return 0;
1221}
1222
1223/* Copy a kernel node mask to user space */
1224static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode,
1225 nodemask_t *nodes)
1226{
1227 unsigned long copy = ALIGN(maxnode-1, 64) / 8;
1228 const int nbytes = BITS_TO_LONGS(MAX_NUMNODES) * sizeof(long);
1229
1230 if (copy > nbytes) {
1231 if (copy > PAGE_SIZE)
1232 return -EINVAL;
1233 if (clear_user((char __user *)mask + nbytes, copy - nbytes))
1234 return -EFAULT;
1235 copy = nbytes;
1236 }
1237 return copy_to_user(mask, nodes_addr(*nodes), copy) ? -EFAULT : 0;
1238}
1239
Heiko Carstens938bb9f2009-01-14 14:14:30 +01001240SYSCALL_DEFINE6(mbind, unsigned long, start, unsigned long, len,
1241 unsigned long, mode, unsigned long __user *, nmask,
1242 unsigned long, maxnode, unsigned, flags)
Christoph Lameter8bccd852005-10-29 18:16:59 -07001243{
1244 nodemask_t nodes;
1245 int err;
David Rientjes028fec42008-04-28 02:12:25 -07001246 unsigned short mode_flags;
Christoph Lameter8bccd852005-10-29 18:16:59 -07001247
David Rientjes028fec42008-04-28 02:12:25 -07001248 mode_flags = mode & MPOL_MODE_FLAGS;
1249 mode &= ~MPOL_MODE_FLAGS;
David Rientjesa3b51e02008-04-28 02:12:23 -07001250 if (mode >= MPOL_MAX)
1251 return -EINVAL;
David Rientjes4c50bc02008-04-28 02:12:30 -07001252 if ((mode_flags & MPOL_F_STATIC_NODES) &&
1253 (mode_flags & MPOL_F_RELATIVE_NODES))
1254 return -EINVAL;
Christoph Lameter8bccd852005-10-29 18:16:59 -07001255 err = get_nodes(&nodes, nmask, maxnode);
1256 if (err)
1257 return err;
David Rientjes028fec42008-04-28 02:12:25 -07001258 return do_mbind(start, len, mode, mode_flags, &nodes, flags);
Christoph Lameter8bccd852005-10-29 18:16:59 -07001259}
1260
1261/* Set the process memory policy */
Heiko Carstens938bb9f2009-01-14 14:14:30 +01001262SYSCALL_DEFINE3(set_mempolicy, int, mode, unsigned long __user *, nmask,
1263 unsigned long, maxnode)
Christoph Lameter8bccd852005-10-29 18:16:59 -07001264{
1265 int err;
1266 nodemask_t nodes;
David Rientjes028fec42008-04-28 02:12:25 -07001267 unsigned short flags;
Christoph Lameter8bccd852005-10-29 18:16:59 -07001268
David Rientjes028fec42008-04-28 02:12:25 -07001269 flags = mode & MPOL_MODE_FLAGS;
1270 mode &= ~MPOL_MODE_FLAGS;
1271 if ((unsigned int)mode >= MPOL_MAX)
Christoph Lameter8bccd852005-10-29 18:16:59 -07001272 return -EINVAL;
David Rientjes4c50bc02008-04-28 02:12:30 -07001273 if ((flags & MPOL_F_STATIC_NODES) && (flags & MPOL_F_RELATIVE_NODES))
1274 return -EINVAL;
Christoph Lameter8bccd852005-10-29 18:16:59 -07001275 err = get_nodes(&nodes, nmask, maxnode);
1276 if (err)
1277 return err;
David Rientjes028fec42008-04-28 02:12:25 -07001278 return do_set_mempolicy(mode, flags, &nodes);
Christoph Lameter8bccd852005-10-29 18:16:59 -07001279}
1280
Heiko Carstens938bb9f2009-01-14 14:14:30 +01001281SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode,
1282 const unsigned long __user *, old_nodes,
1283 const unsigned long __user *, new_nodes)
Christoph Lameter39743882006-01-08 01:00:51 -08001284{
David Howellsc69e8d92008-11-14 10:39:19 +11001285 const struct cred *cred = current_cred(), *tcred;
KOSAKI Motohiro596d7cf2010-08-09 17:19:01 -07001286 struct mm_struct *mm = NULL;
Christoph Lameter39743882006-01-08 01:00:51 -08001287 struct task_struct *task;
Christoph Lameter39743882006-01-08 01:00:51 -08001288 nodemask_t task_nodes;
1289 int err;
KOSAKI Motohiro596d7cf2010-08-09 17:19:01 -07001290 nodemask_t *old;
1291 nodemask_t *new;
1292 NODEMASK_SCRATCH(scratch);
Christoph Lameter39743882006-01-08 01:00:51 -08001293
KOSAKI Motohiro596d7cf2010-08-09 17:19:01 -07001294 if (!scratch)
1295 return -ENOMEM;
Christoph Lameter39743882006-01-08 01:00:51 -08001296
KOSAKI Motohiro596d7cf2010-08-09 17:19:01 -07001297 old = &scratch->mask1;
1298 new = &scratch->mask2;
1299
1300 err = get_nodes(old, old_nodes, maxnode);
Christoph Lameter39743882006-01-08 01:00:51 -08001301 if (err)
KOSAKI Motohiro596d7cf2010-08-09 17:19:01 -07001302 goto out;
1303
1304 err = get_nodes(new, new_nodes, maxnode);
1305 if (err)
1306 goto out;
Christoph Lameter39743882006-01-08 01:00:51 -08001307
1308 /* Find the mm_struct */
Zeng Zhaoming55cfaa32010-12-02 14:31:13 -08001309 rcu_read_lock();
Pavel Emelyanov228ebcb2007-10-18 23:40:16 -07001310 task = pid ? find_task_by_vpid(pid) : current;
Christoph Lameter39743882006-01-08 01:00:51 -08001311 if (!task) {
Zeng Zhaoming55cfaa32010-12-02 14:31:13 -08001312 rcu_read_unlock();
KOSAKI Motohiro596d7cf2010-08-09 17:19:01 -07001313 err = -ESRCH;
1314 goto out;
Christoph Lameter39743882006-01-08 01:00:51 -08001315 }
1316 mm = get_task_mm(task);
Zeng Zhaoming55cfaa32010-12-02 14:31:13 -08001317 rcu_read_unlock();
Christoph Lameter39743882006-01-08 01:00:51 -08001318
KOSAKI Motohiro596d7cf2010-08-09 17:19:01 -07001319 err = -EINVAL;
Christoph Lameter39743882006-01-08 01:00:51 -08001320 if (!mm)
KOSAKI Motohiro596d7cf2010-08-09 17:19:01 -07001321 goto out;
Christoph Lameter39743882006-01-08 01:00:51 -08001322
1323 /*
1324 * Check if this process has the right to modify the specified
1325 * process. The right exists if the process has administrative
Alexey Dobriyan7f927fc2006-03-28 01:56:53 -08001326 * capabilities, superuser privileges or the same
Christoph Lameter39743882006-01-08 01:00:51 -08001327 * userid as the target process.
1328 */
David Howellsc69e8d92008-11-14 10:39:19 +11001329 rcu_read_lock();
1330 tcred = __task_cred(task);
David Howellsb6dff3e2008-11-14 10:39:16 +11001331 if (cred->euid != tcred->suid && cred->euid != tcred->uid &&
1332 cred->uid != tcred->suid && cred->uid != tcred->uid &&
Christoph Lameter74c00242006-03-14 19:50:21 -08001333 !capable(CAP_SYS_NICE)) {
David Howellsc69e8d92008-11-14 10:39:19 +11001334 rcu_read_unlock();
Christoph Lameter39743882006-01-08 01:00:51 -08001335 err = -EPERM;
1336 goto out;
1337 }
David Howellsc69e8d92008-11-14 10:39:19 +11001338 rcu_read_unlock();
Christoph Lameter39743882006-01-08 01:00:51 -08001339
1340 task_nodes = cpuset_mems_allowed(task);
1341 /* Is the user allowed to access the target nodes? */
KOSAKI Motohiro596d7cf2010-08-09 17:19:01 -07001342 if (!nodes_subset(*new, task_nodes) && !capable(CAP_SYS_NICE)) {
Christoph Lameter39743882006-01-08 01:00:51 -08001343 err = -EPERM;
1344 goto out;
1345 }
1346
KOSAKI Motohiro596d7cf2010-08-09 17:19:01 -07001347 if (!nodes_subset(*new, node_states[N_HIGH_MEMORY])) {
Christoph Lameter3b42d282007-08-31 00:12:08 -07001348 err = -EINVAL;
1349 goto out;
1350 }
1351
David Quigley86c3a762006-06-23 02:04:02 -07001352 err = security_task_movememory(task);
1353 if (err)
1354 goto out;
1355
KOSAKI Motohiro596d7cf2010-08-09 17:19:01 -07001356 err = do_migrate_pages(mm, old, new,
Christoph Lameter74c00242006-03-14 19:50:21 -08001357 capable(CAP_SYS_NICE) ? MPOL_MF_MOVE_ALL : MPOL_MF_MOVE);
Christoph Lameter39743882006-01-08 01:00:51 -08001358out:
KOSAKI Motohiro596d7cf2010-08-09 17:19:01 -07001359 if (mm)
1360 mmput(mm);
1361 NODEMASK_SCRATCH_FREE(scratch);
1362
Christoph Lameter39743882006-01-08 01:00:51 -08001363 return err;
1364}
1365
1366
Christoph Lameter8bccd852005-10-29 18:16:59 -07001367/* Retrieve NUMA policy */
Heiko Carstens938bb9f2009-01-14 14:14:30 +01001368SYSCALL_DEFINE5(get_mempolicy, int __user *, policy,
1369 unsigned long __user *, nmask, unsigned long, maxnode,
1370 unsigned long, addr, unsigned long, flags)
Christoph Lameter8bccd852005-10-29 18:16:59 -07001371{
Adrian Bunkdbcb0f12007-10-16 01:26:26 -07001372 int err;
1373 int uninitialized_var(pval);
Christoph Lameter8bccd852005-10-29 18:16:59 -07001374 nodemask_t nodes;
1375
1376 if (nmask != NULL && maxnode < MAX_NUMNODES)
1377 return -EINVAL;
1378
1379 err = do_get_mempolicy(&pval, &nodes, addr, flags);
1380
1381 if (err)
1382 return err;
1383
1384 if (policy && put_user(pval, policy))
1385 return -EFAULT;
1386
1387 if (nmask)
1388 err = copy_nodes_to_user(nmask, maxnode, &nodes);
1389
1390 return err;
1391}
1392
Linus Torvalds1da177e2005-04-16 15:20:36 -07001393#ifdef CONFIG_COMPAT
1394
1395asmlinkage long compat_sys_get_mempolicy(int __user *policy,
1396 compat_ulong_t __user *nmask,
1397 compat_ulong_t maxnode,
1398 compat_ulong_t addr, compat_ulong_t flags)
1399{
1400 long err;
1401 unsigned long __user *nm = NULL;
1402 unsigned long nr_bits, alloc_size;
1403 DECLARE_BITMAP(bm, MAX_NUMNODES);
1404
1405 nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
1406 alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
1407
1408 if (nmask)
1409 nm = compat_alloc_user_space(alloc_size);
1410
1411 err = sys_get_mempolicy(policy, nm, nr_bits+1, addr, flags);
1412
1413 if (!err && nmask) {
1414 err = copy_from_user(bm, nm, alloc_size);
1415 /* ensure entire bitmap is zeroed */
1416 err |= clear_user(nmask, ALIGN(maxnode-1, 8) / 8);
1417 err |= compat_put_bitmap(nmask, bm, nr_bits);
1418 }
1419
1420 return err;
1421}
1422
1423asmlinkage long compat_sys_set_mempolicy(int mode, compat_ulong_t __user *nmask,
1424 compat_ulong_t maxnode)
1425{
1426 long err = 0;
1427 unsigned long __user *nm = NULL;
1428 unsigned long nr_bits, alloc_size;
1429 DECLARE_BITMAP(bm, MAX_NUMNODES);
1430
1431 nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
1432 alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
1433
1434 if (nmask) {
1435 err = compat_get_bitmap(bm, nmask, nr_bits);
1436 nm = compat_alloc_user_space(alloc_size);
1437 err |= copy_to_user(nm, bm, alloc_size);
1438 }
1439
1440 if (err)
1441 return -EFAULT;
1442
1443 return sys_set_mempolicy(mode, nm, nr_bits+1);
1444}
1445
1446asmlinkage long compat_sys_mbind(compat_ulong_t start, compat_ulong_t len,
1447 compat_ulong_t mode, compat_ulong_t __user *nmask,
1448 compat_ulong_t maxnode, compat_ulong_t flags)
1449{
1450 long err = 0;
1451 unsigned long __user *nm = NULL;
1452 unsigned long nr_bits, alloc_size;
Andi Kleendfcd3c02005-10-29 18:15:48 -07001453 nodemask_t bm;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001454
1455 nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
1456 alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
1457
1458 if (nmask) {
Andi Kleendfcd3c02005-10-29 18:15:48 -07001459 err = compat_get_bitmap(nodes_addr(bm), nmask, nr_bits);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001460 nm = compat_alloc_user_space(alloc_size);
Andi Kleendfcd3c02005-10-29 18:15:48 -07001461 err |= copy_to_user(nm, nodes_addr(bm), alloc_size);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001462 }
1463
1464 if (err)
1465 return -EFAULT;
1466
1467 return sys_mbind(start, len, mode, nm, nr_bits+1, flags);
1468}
1469
1470#endif
1471
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001472/*
1473 * get_vma_policy(@task, @vma, @addr)
1474 * @task - task for fallback if vma policy == default
1475 * @vma - virtual memory area whose policy is sought
1476 * @addr - address in @vma for shared policy lookup
1477 *
1478 * Returns effective policy for a VMA at specified address.
1479 * Falls back to @task or system default policy, as necessary.
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001480 * Current or other task's task mempolicy and non-shared vma policies
1481 * are protected by the task's mmap_sem, which must be held for read by
1482 * the caller.
1483 * Shared policies [those marked as MPOL_F_SHARED] require an extra reference
1484 * count--added by the get_policy() vm_op, as appropriate--to protect against
1485 * freeing by another task. It is the caller's responsibility to free the
1486 * extra reference for shared policies.
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001487 */
Stephen Wilsond98f6cb2011-05-24 17:12:41 -07001488struct mempolicy *get_vma_policy(struct task_struct *task,
Christoph Lameter48fce342006-01-08 01:01:03 -08001489 struct vm_area_struct *vma, unsigned long addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001490{
Christoph Lameter6e21c8f2005-09-03 15:54:45 -07001491 struct mempolicy *pol = task->mempolicy;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001492
1493 if (vma) {
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001494 if (vma->vm_ops && vma->vm_ops->get_policy) {
Lee Schermerhornae4d8c12008-04-28 02:13:11 -07001495 struct mempolicy *vpol = vma->vm_ops->get_policy(vma,
1496 addr);
1497 if (vpol)
1498 pol = vpol;
Lee Schermerhornbea904d2008-04-28 02:13:18 -07001499 } else if (vma->vm_policy)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001500 pol = vma->vm_policy;
1501 }
1502 if (!pol)
1503 pol = &default_policy;
1504 return pol;
1505}
1506
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001507/*
1508 * Return a nodemask representing a mempolicy for filtering nodes for
1509 * page allocation
1510 */
1511static nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy)
Mel Gorman19770b32008-04-28 02:12:18 -07001512{
1513 /* Lower zones don't get a nodemask applied for MPOL_BIND */
Lee Schermerhorn45c47452008-04-28 02:13:12 -07001514 if (unlikely(policy->mode == MPOL_BIND) &&
Mel Gorman19770b32008-04-28 02:12:18 -07001515 gfp_zone(gfp) >= policy_zone &&
1516 cpuset_nodemask_valid_mems_allowed(&policy->v.nodes))
1517 return &policy->v.nodes;
1518
1519 return NULL;
1520}
1521
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001522/* Return a zonelist indicated by gfp for node representing a mempolicy */
Andi Kleen2f5f9482011-03-04 17:36:29 -08001523static struct zonelist *policy_zonelist(gfp_t gfp, struct mempolicy *policy,
1524 int nd)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001525{
Lee Schermerhorn45c47452008-04-28 02:13:12 -07001526 switch (policy->mode) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001527 case MPOL_PREFERRED:
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -07001528 if (!(policy->flags & MPOL_F_LOCAL))
1529 nd = policy->v.preferred_node;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001530 break;
1531 case MPOL_BIND:
Mel Gorman19770b32008-04-28 02:12:18 -07001532 /*
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001533 * Normally, MPOL_BIND allocations are node-local within the
1534 * allowed nodemask. However, if __GFP_THISNODE is set and the
Bob Liu6eb27e12010-05-24 14:32:00 -07001535 * current node isn't part of the mask, we use the zonelist for
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001536 * the first node in the mask instead.
Mel Gorman19770b32008-04-28 02:12:18 -07001537 */
Mel Gorman19770b32008-04-28 02:12:18 -07001538 if (unlikely(gfp & __GFP_THISNODE) &&
1539 unlikely(!node_isset(nd, policy->v.nodes)))
1540 nd = first_node(policy->v.nodes);
1541 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001542 default:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001543 BUG();
1544 }
Mel Gorman0e884602008-04-28 02:12:14 -07001545 return node_zonelist(nd, gfp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001546}
1547
1548/* Do dynamic interleaving for a process */
1549static unsigned interleave_nodes(struct mempolicy *policy)
1550{
1551 unsigned nid, next;
1552 struct task_struct *me = current;
1553
1554 nid = me->il_next;
Andi Kleendfcd3c02005-10-29 18:15:48 -07001555 next = next_node(nid, policy->v.nodes);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001556 if (next >= MAX_NUMNODES)
Andi Kleendfcd3c02005-10-29 18:15:48 -07001557 next = first_node(policy->v.nodes);
David Rientjesf5b087b2008-04-28 02:12:27 -07001558 if (next < MAX_NUMNODES)
1559 me->il_next = next;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001560 return nid;
1561}
1562
Christoph Lameterdc85da12006-01-18 17:42:36 -08001563/*
1564 * Depending on the memory policy provide a node from which to allocate the
1565 * next slab entry.
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001566 * @policy must be protected by freeing by the caller. If @policy is
1567 * the current task's mempolicy, this protection is implicit, as only the
1568 * task can change it's policy. The system default policy requires no
1569 * such protection.
Christoph Lameterdc85da12006-01-18 17:42:36 -08001570 */
1571unsigned slab_node(struct mempolicy *policy)
1572{
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -07001573 if (!policy || policy->flags & MPOL_F_LOCAL)
Lee Schermerhornbea904d2008-04-28 02:13:18 -07001574 return numa_node_id();
Christoph Lameter765c4502006-09-27 01:50:08 -07001575
Lee Schermerhornbea904d2008-04-28 02:13:18 -07001576 switch (policy->mode) {
1577 case MPOL_PREFERRED:
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -07001578 /*
1579 * handled MPOL_F_LOCAL above
1580 */
1581 return policy->v.preferred_node;
Lee Schermerhornbea904d2008-04-28 02:13:18 -07001582
Christoph Lameterdc85da12006-01-18 17:42:36 -08001583 case MPOL_INTERLEAVE:
1584 return interleave_nodes(policy);
1585
Mel Gormandd1a2392008-04-28 02:12:17 -07001586 case MPOL_BIND: {
Christoph Lameterdc85da12006-01-18 17:42:36 -08001587 /*
1588 * Follow bind policy behavior and start allocation at the
1589 * first node.
1590 */
Mel Gorman19770b32008-04-28 02:12:18 -07001591 struct zonelist *zonelist;
1592 struct zone *zone;
1593 enum zone_type highest_zoneidx = gfp_zone(GFP_KERNEL);
1594 zonelist = &NODE_DATA(numa_node_id())->node_zonelists[0];
1595 (void)first_zones_zonelist(zonelist, highest_zoneidx,
1596 &policy->v.nodes,
1597 &zone);
Eric Dumazet800416f2010-10-27 19:33:43 +02001598 return zone ? zone->node : numa_node_id();
Mel Gormandd1a2392008-04-28 02:12:17 -07001599 }
Christoph Lameterdc85da12006-01-18 17:42:36 -08001600
Christoph Lameterdc85da12006-01-18 17:42:36 -08001601 default:
Lee Schermerhornbea904d2008-04-28 02:13:18 -07001602 BUG();
Christoph Lameterdc85da12006-01-18 17:42:36 -08001603 }
1604}
1605
Linus Torvalds1da177e2005-04-16 15:20:36 -07001606/* Do static interleaving for a VMA with known offset. */
1607static unsigned offset_il_node(struct mempolicy *pol,
1608 struct vm_area_struct *vma, unsigned long off)
1609{
Andi Kleendfcd3c02005-10-29 18:15:48 -07001610 unsigned nnodes = nodes_weight(pol->v.nodes);
David Rientjesf5b087b2008-04-28 02:12:27 -07001611 unsigned target;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001612 int c;
1613 int nid = -1;
1614
David Rientjesf5b087b2008-04-28 02:12:27 -07001615 if (!nnodes)
1616 return numa_node_id();
1617 target = (unsigned int)off % nnodes;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001618 c = 0;
1619 do {
Andi Kleendfcd3c02005-10-29 18:15:48 -07001620 nid = next_node(nid, pol->v.nodes);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001621 c++;
1622 } while (c <= target);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001623 return nid;
1624}
1625
Christoph Lameter5da7ca82006-01-06 00:10:46 -08001626/* Determine a node number for interleave */
1627static inline unsigned interleave_nid(struct mempolicy *pol,
1628 struct vm_area_struct *vma, unsigned long addr, int shift)
1629{
1630 if (vma) {
1631 unsigned long off;
1632
Nishanth Aravamudan3b98b082006-08-31 21:27:53 -07001633 /*
1634 * for small pages, there is no difference between
1635 * shift and PAGE_SHIFT, so the bit-shift is safe.
1636 * for huge pages, since vm_pgoff is in units of small
1637 * pages, we need to shift off the always 0 bits to get
1638 * a useful offset.
1639 */
1640 BUG_ON(shift < PAGE_SHIFT);
1641 off = vma->vm_pgoff >> (shift - PAGE_SHIFT);
Christoph Lameter5da7ca82006-01-06 00:10:46 -08001642 off += (addr - vma->vm_start) >> shift;
1643 return offset_il_node(pol, vma, off);
1644 } else
1645 return interleave_nodes(pol);
1646}
1647
Chen, Kenneth W00ac59a2006-02-03 21:51:14 +01001648#ifdef CONFIG_HUGETLBFS
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001649/*
1650 * huge_zonelist(@vma, @addr, @gfp_flags, @mpol)
1651 * @vma = virtual memory area whose policy is sought
1652 * @addr = address in @vma for shared policy lookup and interleave policy
1653 * @gfp_flags = for requested zone
Mel Gorman19770b32008-04-28 02:12:18 -07001654 * @mpol = pointer to mempolicy pointer for reference counted mempolicy
1655 * @nodemask = pointer to nodemask pointer for MPOL_BIND nodemask
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001656 *
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001657 * Returns a zonelist suitable for a huge page allocation and a pointer
1658 * to the struct mempolicy for conditional unref after allocation.
1659 * If the effective policy is 'BIND, returns a pointer to the mempolicy's
1660 * @nodemask for filtering the zonelist.
Miao Xiec0ff7452010-05-24 14:32:08 -07001661 *
1662 * Must be protected by get_mems_allowed()
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001663 */
Mel Gorman396faf02007-07-17 04:03:13 -07001664struct zonelist *huge_zonelist(struct vm_area_struct *vma, unsigned long addr,
Mel Gorman19770b32008-04-28 02:12:18 -07001665 gfp_t gfp_flags, struct mempolicy **mpol,
1666 nodemask_t **nodemask)
Christoph Lameter5da7ca82006-01-06 00:10:46 -08001667{
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001668 struct zonelist *zl;
Christoph Lameter5da7ca82006-01-06 00:10:46 -08001669
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001670 *mpol = get_vma_policy(current, vma, addr);
Mel Gorman19770b32008-04-28 02:12:18 -07001671 *nodemask = NULL; /* assume !MPOL_BIND */
Christoph Lameter5da7ca82006-01-06 00:10:46 -08001672
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001673 if (unlikely((*mpol)->mode == MPOL_INTERLEAVE)) {
1674 zl = node_zonelist(interleave_nid(*mpol, vma, addr,
Andi Kleena5516432008-07-23 21:27:41 -07001675 huge_page_shift(hstate_vma(vma))), gfp_flags);
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001676 } else {
Andi Kleen2f5f9482011-03-04 17:36:29 -08001677 zl = policy_zonelist(gfp_flags, *mpol, numa_node_id());
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001678 if ((*mpol)->mode == MPOL_BIND)
1679 *nodemask = &(*mpol)->v.nodes;
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001680 }
1681 return zl;
Christoph Lameter5da7ca82006-01-06 00:10:46 -08001682}
Lee Schermerhorn06808b02009-12-14 17:58:21 -08001683
1684/*
1685 * init_nodemask_of_mempolicy
1686 *
1687 * If the current task's mempolicy is "default" [NULL], return 'false'
1688 * to indicate default policy. Otherwise, extract the policy nodemask
1689 * for 'bind' or 'interleave' policy into the argument nodemask, or
1690 * initialize the argument nodemask to contain the single node for
1691 * 'preferred' or 'local' policy and return 'true' to indicate presence
1692 * of non-default mempolicy.
1693 *
1694 * We don't bother with reference counting the mempolicy [mpol_get/put]
1695 * because the current task is examining it's own mempolicy and a task's
1696 * mempolicy is only ever changed by the task itself.
1697 *
1698 * N.B., it is the caller's responsibility to free a returned nodemask.
1699 */
1700bool init_nodemask_of_mempolicy(nodemask_t *mask)
1701{
1702 struct mempolicy *mempolicy;
1703 int nid;
1704
1705 if (!(mask && current->mempolicy))
1706 return false;
1707
Miao Xiec0ff7452010-05-24 14:32:08 -07001708 task_lock(current);
Lee Schermerhorn06808b02009-12-14 17:58:21 -08001709 mempolicy = current->mempolicy;
1710 switch (mempolicy->mode) {
1711 case MPOL_PREFERRED:
1712 if (mempolicy->flags & MPOL_F_LOCAL)
1713 nid = numa_node_id();
1714 else
1715 nid = mempolicy->v.preferred_node;
1716 init_nodemask_of_node(mask, nid);
1717 break;
1718
1719 case MPOL_BIND:
1720 /* Fall through */
1721 case MPOL_INTERLEAVE:
1722 *mask = mempolicy->v.nodes;
1723 break;
1724
1725 default:
1726 BUG();
1727 }
Miao Xiec0ff7452010-05-24 14:32:08 -07001728 task_unlock(current);
Lee Schermerhorn06808b02009-12-14 17:58:21 -08001729
1730 return true;
1731}
Chen, Kenneth W00ac59a2006-02-03 21:51:14 +01001732#endif
Christoph Lameter5da7ca82006-01-06 00:10:46 -08001733
David Rientjes6f48d0eb2010-08-09 17:18:52 -07001734/*
1735 * mempolicy_nodemask_intersects
1736 *
1737 * If tsk's mempolicy is "default" [NULL], return 'true' to indicate default
1738 * policy. Otherwise, check for intersection between mask and the policy
1739 * nodemask for 'bind' or 'interleave' policy. For 'perferred' or 'local'
1740 * policy, always return true since it may allocate elsewhere on fallback.
1741 *
1742 * Takes task_lock(tsk) to prevent freeing of its mempolicy.
1743 */
1744bool mempolicy_nodemask_intersects(struct task_struct *tsk,
1745 const nodemask_t *mask)
1746{
1747 struct mempolicy *mempolicy;
1748 bool ret = true;
1749
1750 if (!mask)
1751 return ret;
1752 task_lock(tsk);
1753 mempolicy = tsk->mempolicy;
1754 if (!mempolicy)
1755 goto out;
1756
1757 switch (mempolicy->mode) {
1758 case MPOL_PREFERRED:
1759 /*
1760 * MPOL_PREFERRED and MPOL_F_LOCAL are only preferred nodes to
1761 * allocate from, they may fallback to other nodes when oom.
1762 * Thus, it's possible for tsk to have allocated memory from
1763 * nodes in mask.
1764 */
1765 break;
1766 case MPOL_BIND:
1767 case MPOL_INTERLEAVE:
1768 ret = nodes_intersects(mempolicy->v.nodes, *mask);
1769 break;
1770 default:
1771 BUG();
1772 }
1773out:
1774 task_unlock(tsk);
1775 return ret;
1776}
1777
Linus Torvalds1da177e2005-04-16 15:20:36 -07001778/* Allocate a page in interleaved policy.
1779 Own path because it needs to do special accounting. */
Andi Kleen662f3a02005-10-29 18:15:49 -07001780static struct page *alloc_page_interleave(gfp_t gfp, unsigned order,
1781 unsigned nid)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001782{
1783 struct zonelist *zl;
1784 struct page *page;
1785
Mel Gorman0e884602008-04-28 02:12:14 -07001786 zl = node_zonelist(nid, gfp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001787 page = __alloc_pages(gfp, order, zl);
Mel Gormandd1a2392008-04-28 02:12:17 -07001788 if (page && page_zone(page) == zonelist_zone(&zl->_zonerefs[0]))
Christoph Lameterca889e62006-06-30 01:55:44 -07001789 inc_zone_page_state(page, NUMA_INTERLEAVE_HIT);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001790 return page;
1791}
1792
1793/**
Andrea Arcangeli0bbbc0b2011-01-13 15:47:05 -08001794 * alloc_pages_vma - Allocate a page for a VMA.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001795 *
1796 * @gfp:
1797 * %GFP_USER user allocation.
1798 * %GFP_KERNEL kernel allocations,
1799 * %GFP_HIGHMEM highmem/user allocations,
1800 * %GFP_FS allocation should not call back into a file system.
1801 * %GFP_ATOMIC don't sleep.
1802 *
Andrea Arcangeli0bbbc0b2011-01-13 15:47:05 -08001803 * @order:Order of the GFP allocation.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001804 * @vma: Pointer to VMA or NULL if not available.
1805 * @addr: Virtual Address of the allocation. Must be inside the VMA.
1806 *
1807 * This function allocates a page from the kernel page pool and applies
1808 * a NUMA policy associated with the VMA or the current process.
1809 * When VMA is not NULL caller must hold down_read on the mmap_sem of the
1810 * mm_struct of the VMA to prevent it from going away. Should be used for
1811 * all allocations for pages that will be mapped into
1812 * user space. Returns NULL when no page can be allocated.
1813 *
1814 * Should be called with the mm_sem of the vma hold.
1815 */
1816struct page *
Andrea Arcangeli0bbbc0b2011-01-13 15:47:05 -08001817alloc_pages_vma(gfp_t gfp, int order, struct vm_area_struct *vma,
Andi Kleen2f5f9482011-03-04 17:36:29 -08001818 unsigned long addr, int node)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001819{
Christoph Lameter6e21c8f2005-09-03 15:54:45 -07001820 struct mempolicy *pol = get_vma_policy(current, vma, addr);
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001821 struct zonelist *zl;
Miao Xiec0ff7452010-05-24 14:32:08 -07001822 struct page *page;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001823
Miao Xiec0ff7452010-05-24 14:32:08 -07001824 get_mems_allowed();
Lee Schermerhorn45c47452008-04-28 02:13:12 -07001825 if (unlikely(pol->mode == MPOL_INTERLEAVE)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001826 unsigned nid;
Christoph Lameter5da7ca82006-01-06 00:10:46 -08001827
Andi Kleen8eac5632011-02-25 14:44:28 -08001828 nid = interleave_nid(pol, vma, addr, PAGE_SHIFT + order);
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001829 mpol_cond_put(pol);
Andrea Arcangeli0bbbc0b2011-01-13 15:47:05 -08001830 page = alloc_page_interleave(gfp, order, nid);
Miao Xiec0ff7452010-05-24 14:32:08 -07001831 put_mems_allowed();
1832 return page;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001833 }
Andi Kleen2f5f9482011-03-04 17:36:29 -08001834 zl = policy_zonelist(gfp, pol, node);
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001835 if (unlikely(mpol_needs_cond_ref(pol))) {
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001836 /*
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001837 * slow path: ref counted shared policy
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001838 */
Andrea Arcangeli0bbbc0b2011-01-13 15:47:05 -08001839 struct page *page = __alloc_pages_nodemask(gfp, order,
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001840 zl, policy_nodemask(gfp, pol));
Lee Schermerhornf0be3d32008-04-28 02:13:08 -07001841 __mpol_put(pol);
Miao Xiec0ff7452010-05-24 14:32:08 -07001842 put_mems_allowed();
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001843 return page;
1844 }
1845 /*
1846 * fast path: default or task policy
1847 */
Andrea Arcangeli0bbbc0b2011-01-13 15:47:05 -08001848 page = __alloc_pages_nodemask(gfp, order, zl,
1849 policy_nodemask(gfp, pol));
Miao Xiec0ff7452010-05-24 14:32:08 -07001850 put_mems_allowed();
1851 return page;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001852}
1853
1854/**
1855 * alloc_pages_current - Allocate pages.
1856 *
1857 * @gfp:
1858 * %GFP_USER user allocation,
1859 * %GFP_KERNEL kernel allocation,
1860 * %GFP_HIGHMEM highmem allocation,
1861 * %GFP_FS don't call back into a file system.
1862 * %GFP_ATOMIC don't sleep.
1863 * @order: Power of two of allocation size in pages. 0 is a single page.
1864 *
1865 * Allocate a page from the kernel page pool. When not in
1866 * interrupt context and apply the current process NUMA policy.
1867 * Returns NULL when no page can be allocated.
1868 *
Paul Jacksoncf2a4732006-01-08 01:01:54 -08001869 * Don't call cpuset_update_task_memory_state() unless
Linus Torvalds1da177e2005-04-16 15:20:36 -07001870 * 1) it's ok to take cpuset_sem (can WAIT), and
1871 * 2) allocating for current task (not interrupt).
1872 */
Al Virodd0fc662005-10-07 07:46:04 +01001873struct page *alloc_pages_current(gfp_t gfp, unsigned order)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001874{
1875 struct mempolicy *pol = current->mempolicy;
Miao Xiec0ff7452010-05-24 14:32:08 -07001876 struct page *page;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001877
Christoph Lameter9b819d22006-09-25 23:31:40 -07001878 if (!pol || in_interrupt() || (gfp & __GFP_THISNODE))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001879 pol = &default_policy;
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001880
Miao Xiec0ff7452010-05-24 14:32:08 -07001881 get_mems_allowed();
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001882 /*
1883 * No reference counting needed for current->mempolicy
1884 * nor system default_policy
1885 */
Lee Schermerhorn45c47452008-04-28 02:13:12 -07001886 if (pol->mode == MPOL_INTERLEAVE)
Miao Xiec0ff7452010-05-24 14:32:08 -07001887 page = alloc_page_interleave(gfp, order, interleave_nodes(pol));
1888 else
1889 page = __alloc_pages_nodemask(gfp, order,
Andi Kleen5c4b4be2011-03-04 17:36:32 -08001890 policy_zonelist(gfp, pol, numa_node_id()),
1891 policy_nodemask(gfp, pol));
Miao Xiec0ff7452010-05-24 14:32:08 -07001892 put_mems_allowed();
1893 return page;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001894}
1895EXPORT_SYMBOL(alloc_pages_current);
1896
Paul Jackson42253992006-01-08 01:01:59 -08001897/*
Lee Schermerhorn846a16b2008-04-28 02:13:09 -07001898 * If mpol_dup() sees current->cpuset == cpuset_being_rebound, then it
Paul Jackson42253992006-01-08 01:01:59 -08001899 * rebinds the mempolicy its copying by calling mpol_rebind_policy()
1900 * with the mems_allowed returned by cpuset_mems_allowed(). This
1901 * keeps mempolicies cpuset relative after its cpuset moves. See
1902 * further kernel/cpuset.c update_nodemask().
Miao Xie708c1bb2010-05-24 14:32:07 -07001903 *
1904 * current's mempolicy may be rebinded by the other task(the task that changes
1905 * cpuset's mems), so we needn't do rebind work for current task.
Paul Jackson42253992006-01-08 01:01:59 -08001906 */
Paul Jackson42253992006-01-08 01:01:59 -08001907
Lee Schermerhorn846a16b2008-04-28 02:13:09 -07001908/* Slow path of a mempolicy duplicate */
1909struct mempolicy *__mpol_dup(struct mempolicy *old)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001910{
1911 struct mempolicy *new = kmem_cache_alloc(policy_cache, GFP_KERNEL);
1912
1913 if (!new)
1914 return ERR_PTR(-ENOMEM);
Miao Xie708c1bb2010-05-24 14:32:07 -07001915
1916 /* task's mempolicy is protected by alloc_lock */
1917 if (old == current->mempolicy) {
1918 task_lock(current);
1919 *new = *old;
1920 task_unlock(current);
1921 } else
1922 *new = *old;
1923
Paul E. McKenney99ee4ca2010-03-03 17:50:17 -08001924 rcu_read_lock();
Paul Jackson42253992006-01-08 01:01:59 -08001925 if (current_cpuset_is_being_rebound()) {
1926 nodemask_t mems = cpuset_mems_allowed(current);
Miao Xie708c1bb2010-05-24 14:32:07 -07001927 if (new->flags & MPOL_F_REBINDING)
1928 mpol_rebind_policy(new, &mems, MPOL_REBIND_STEP2);
1929 else
1930 mpol_rebind_policy(new, &mems, MPOL_REBIND_ONCE);
Paul Jackson42253992006-01-08 01:01:59 -08001931 }
Paul E. McKenney99ee4ca2010-03-03 17:50:17 -08001932 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001933 atomic_set(&new->refcnt, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001934 return new;
1935}
1936
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001937/*
1938 * If *frompol needs [has] an extra ref, copy *frompol to *tompol ,
1939 * eliminate the * MPOL_F_* flags that require conditional ref and
1940 * [NOTE!!!] drop the extra ref. Not safe to reference *frompol directly
1941 * after return. Use the returned value.
1942 *
1943 * Allows use of a mempolicy for, e.g., multiple allocations with a single
1944 * policy lookup, even if the policy needs/has extra ref on lookup.
1945 * shmem_readahead needs this.
1946 */
1947struct mempolicy *__mpol_cond_copy(struct mempolicy *tompol,
1948 struct mempolicy *frompol)
1949{
1950 if (!mpol_needs_cond_ref(frompol))
1951 return frompol;
1952
1953 *tompol = *frompol;
1954 tompol->flags &= ~MPOL_F_SHARED; /* copy doesn't need unref */
1955 __mpol_put(frompol);
1956 return tompol;
1957}
1958
Linus Torvalds1da177e2005-04-16 15:20:36 -07001959/* Slow path of a mempolicy comparison */
1960int __mpol_equal(struct mempolicy *a, struct mempolicy *b)
1961{
1962 if (!a || !b)
1963 return 0;
Lee Schermerhorn45c47452008-04-28 02:13:12 -07001964 if (a->mode != b->mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001965 return 0;
Bob Liu19800502010-05-24 14:32:01 -07001966 if (a->flags != b->flags)
David Rientjesf5b087b2008-04-28 02:12:27 -07001967 return 0;
Bob Liu19800502010-05-24 14:32:01 -07001968 if (mpol_store_user_nodemask(a))
1969 if (!nodes_equal(a->w.user_nodemask, b->w.user_nodemask))
1970 return 0;
1971
Lee Schermerhorn45c47452008-04-28 02:13:12 -07001972 switch (a->mode) {
Mel Gorman19770b32008-04-28 02:12:18 -07001973 case MPOL_BIND:
1974 /* Fall through */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001975 case MPOL_INTERLEAVE:
Andi Kleendfcd3c02005-10-29 18:15:48 -07001976 return nodes_equal(a->v.nodes, b->v.nodes);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001977 case MPOL_PREFERRED:
Namhyung Kim75719662011-03-22 16:33:02 -07001978 return a->v.preferred_node == b->v.preferred_node;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001979 default:
1980 BUG();
1981 return 0;
1982 }
1983}
1984
Linus Torvalds1da177e2005-04-16 15:20:36 -07001985/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07001986 * Shared memory backing store policy support.
1987 *
1988 * Remember policies even when nobody has shared memory mapped.
1989 * The policies are kept in Red-Black tree linked from the inode.
1990 * They are protected by the sp->lock spinlock, which should be held
1991 * for any accesses to the tree.
1992 */
1993
1994/* lookup first element intersecting start-end */
1995/* Caller holds sp->lock */
1996static struct sp_node *
1997sp_lookup(struct shared_policy *sp, unsigned long start, unsigned long end)
1998{
1999 struct rb_node *n = sp->root.rb_node;
2000
2001 while (n) {
2002 struct sp_node *p = rb_entry(n, struct sp_node, nd);
2003
2004 if (start >= p->end)
2005 n = n->rb_right;
2006 else if (end <= p->start)
2007 n = n->rb_left;
2008 else
2009 break;
2010 }
2011 if (!n)
2012 return NULL;
2013 for (;;) {
2014 struct sp_node *w = NULL;
2015 struct rb_node *prev = rb_prev(n);
2016 if (!prev)
2017 break;
2018 w = rb_entry(prev, struct sp_node, nd);
2019 if (w->end <= start)
2020 break;
2021 n = prev;
2022 }
2023 return rb_entry(n, struct sp_node, nd);
2024}
2025
2026/* Insert a new shared policy into the list. */
2027/* Caller holds sp->lock */
2028static void sp_insert(struct shared_policy *sp, struct sp_node *new)
2029{
2030 struct rb_node **p = &sp->root.rb_node;
2031 struct rb_node *parent = NULL;
2032 struct sp_node *nd;
2033
2034 while (*p) {
2035 parent = *p;
2036 nd = rb_entry(parent, struct sp_node, nd);
2037 if (new->start < nd->start)
2038 p = &(*p)->rb_left;
2039 else if (new->end > nd->end)
2040 p = &(*p)->rb_right;
2041 else
2042 BUG();
2043 }
2044 rb_link_node(&new->nd, parent, p);
2045 rb_insert_color(&new->nd, &sp->root);
Paul Mundt140d5a42007-07-15 23:38:16 -07002046 pr_debug("inserting %lx-%lx: %d\n", new->start, new->end,
Lee Schermerhorn45c47452008-04-28 02:13:12 -07002047 new->policy ? new->policy->mode : 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002048}
2049
2050/* Find shared policy intersecting idx */
2051struct mempolicy *
2052mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx)
2053{
2054 struct mempolicy *pol = NULL;
2055 struct sp_node *sn;
2056
2057 if (!sp->root.rb_node)
2058 return NULL;
2059 spin_lock(&sp->lock);
2060 sn = sp_lookup(sp, idx, idx+1);
2061 if (sn) {
2062 mpol_get(sn->policy);
2063 pol = sn->policy;
2064 }
2065 spin_unlock(&sp->lock);
2066 return pol;
2067}
2068
2069static void sp_delete(struct shared_policy *sp, struct sp_node *n)
2070{
Paul Mundt140d5a42007-07-15 23:38:16 -07002071 pr_debug("deleting %lx-l%lx\n", n->start, n->end);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002072 rb_erase(&n->nd, &sp->root);
Lee Schermerhornf0be3d32008-04-28 02:13:08 -07002073 mpol_put(n->policy);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002074 kmem_cache_free(sn_cache, n);
2075}
2076
Adrian Bunkdbcb0f12007-10-16 01:26:26 -07002077static struct sp_node *sp_alloc(unsigned long start, unsigned long end,
2078 struct mempolicy *pol)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002079{
2080 struct sp_node *n = kmem_cache_alloc(sn_cache, GFP_KERNEL);
2081
2082 if (!n)
2083 return NULL;
2084 n->start = start;
2085 n->end = end;
2086 mpol_get(pol);
Lee Schermerhornaab0b102008-04-28 02:13:13 -07002087 pol->flags |= MPOL_F_SHARED; /* for unref */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002088 n->policy = pol;
2089 return n;
2090}
2091
2092/* Replace a policy range. */
2093static int shared_policy_replace(struct shared_policy *sp, unsigned long start,
2094 unsigned long end, struct sp_node *new)
2095{
2096 struct sp_node *n, *new2 = NULL;
2097
2098restart:
2099 spin_lock(&sp->lock);
2100 n = sp_lookup(sp, start, end);
2101 /* Take care of old policies in the same range. */
2102 while (n && n->start < end) {
2103 struct rb_node *next = rb_next(&n->nd);
2104 if (n->start >= start) {
2105 if (n->end <= end)
2106 sp_delete(sp, n);
2107 else
2108 n->start = end;
2109 } else {
2110 /* Old policy spanning whole new range. */
2111 if (n->end > end) {
2112 if (!new2) {
2113 spin_unlock(&sp->lock);
2114 new2 = sp_alloc(end, n->end, n->policy);
2115 if (!new2)
2116 return -ENOMEM;
2117 goto restart;
2118 }
2119 n->end = start;
2120 sp_insert(sp, new2);
2121 new2 = NULL;
2122 break;
2123 } else
2124 n->end = start;
2125 }
2126 if (!next)
2127 break;
2128 n = rb_entry(next, struct sp_node, nd);
2129 }
2130 if (new)
2131 sp_insert(sp, new);
2132 spin_unlock(&sp->lock);
2133 if (new2) {
Lee Schermerhornf0be3d32008-04-28 02:13:08 -07002134 mpol_put(new2->policy);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002135 kmem_cache_free(sn_cache, new2);
2136 }
2137 return 0;
2138}
2139
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002140/**
2141 * mpol_shared_policy_init - initialize shared policy for inode
2142 * @sp: pointer to inode shared policy
2143 * @mpol: struct mempolicy to install
2144 *
2145 * Install non-NULL @mpol in inode's shared policy rb-tree.
2146 * On entry, the current task has a reference on a non-NULL @mpol.
2147 * This must be released on exit.
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -07002148 * This is called at get_inode() calls and we can use GFP_KERNEL.
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002149 */
2150void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol)
Robin Holt7339ff82006-01-14 13:20:48 -08002151{
Miao Xie58568d22009-06-16 15:31:49 -07002152 int ret;
2153
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002154 sp->root = RB_ROOT; /* empty tree == default mempolicy */
2155 spin_lock_init(&sp->lock);
Robin Holt7339ff82006-01-14 13:20:48 -08002156
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002157 if (mpol) {
2158 struct vm_area_struct pvma;
2159 struct mempolicy *new;
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -07002160 NODEMASK_SCRATCH(scratch);
Robin Holt7339ff82006-01-14 13:20:48 -08002161
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -07002162 if (!scratch)
Lee Schermerhorn5c0c1652010-06-29 15:05:30 -07002163 goto put_mpol;
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002164 /* contextualize the tmpfs mount point mempolicy */
2165 new = mpol_new(mpol->mode, mpol->flags, &mpol->w.user_nodemask);
Lee Schermerhorn15d77832010-05-24 14:32:04 -07002166 if (IS_ERR(new))
Dan Carpenter0cae3452010-05-25 23:42:58 -07002167 goto free_scratch; /* no valid nodemask intersection */
Miao Xie58568d22009-06-16 15:31:49 -07002168
2169 task_lock(current);
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -07002170 ret = mpol_set_nodemask(new, &mpol->w.user_nodemask, scratch);
Miao Xie58568d22009-06-16 15:31:49 -07002171 task_unlock(current);
Lee Schermerhorn15d77832010-05-24 14:32:04 -07002172 if (ret)
Lee Schermerhorn5c0c1652010-06-29 15:05:30 -07002173 goto put_new;
Robin Holt7339ff82006-01-14 13:20:48 -08002174
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002175 /* Create pseudo-vma that contains just the policy */
2176 memset(&pvma, 0, sizeof(struct vm_area_struct));
2177 pvma.vm_end = TASK_SIZE; /* policy covers entire file */
2178 mpol_set_shared_policy(sp, &pvma, new); /* adds ref */
Lee Schermerhorn15d77832010-05-24 14:32:04 -07002179
Lee Schermerhorn5c0c1652010-06-29 15:05:30 -07002180put_new:
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002181 mpol_put(new); /* drop initial ref */
Dan Carpenter0cae3452010-05-25 23:42:58 -07002182free_scratch:
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -07002183 NODEMASK_SCRATCH_FREE(scratch);
Lee Schermerhorn5c0c1652010-06-29 15:05:30 -07002184put_mpol:
2185 mpol_put(mpol); /* drop our incoming ref on sb mpol */
Robin Holt7339ff82006-01-14 13:20:48 -08002186 }
2187}
2188
Linus Torvalds1da177e2005-04-16 15:20:36 -07002189int mpol_set_shared_policy(struct shared_policy *info,
2190 struct vm_area_struct *vma, struct mempolicy *npol)
2191{
2192 int err;
2193 struct sp_node *new = NULL;
2194 unsigned long sz = vma_pages(vma);
2195
David Rientjes028fec42008-04-28 02:12:25 -07002196 pr_debug("set_shared_policy %lx sz %lu %d %d %lx\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07002197 vma->vm_pgoff,
Lee Schermerhorn45c47452008-04-28 02:13:12 -07002198 sz, npol ? npol->mode : -1,
David Rientjes028fec42008-04-28 02:12:25 -07002199 npol ? npol->flags : -1,
Paul Mundt140d5a42007-07-15 23:38:16 -07002200 npol ? nodes_addr(npol->v.nodes)[0] : -1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002201
2202 if (npol) {
2203 new = sp_alloc(vma->vm_pgoff, vma->vm_pgoff + sz, npol);
2204 if (!new)
2205 return -ENOMEM;
2206 }
2207 err = shared_policy_replace(info, vma->vm_pgoff, vma->vm_pgoff+sz, new);
2208 if (err && new)
2209 kmem_cache_free(sn_cache, new);
2210 return err;
2211}
2212
2213/* Free a backing policy store on inode delete. */
2214void mpol_free_shared_policy(struct shared_policy *p)
2215{
2216 struct sp_node *n;
2217 struct rb_node *next;
2218
2219 if (!p->root.rb_node)
2220 return;
2221 spin_lock(&p->lock);
2222 next = rb_first(&p->root);
2223 while (next) {
2224 n = rb_entry(next, struct sp_node, nd);
2225 next = rb_next(&n->nd);
Andi Kleen90c50292005-07-27 11:43:50 -07002226 rb_erase(&n->nd, &p->root);
Lee Schermerhornf0be3d32008-04-28 02:13:08 -07002227 mpol_put(n->policy);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002228 kmem_cache_free(sn_cache, n);
2229 }
2230 spin_unlock(&p->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002231}
2232
2233/* assumes fs == KERNEL_DS */
2234void __init numa_policy_init(void)
2235{
Paul Mundtb71636e2007-07-15 23:38:15 -07002236 nodemask_t interleave_nodes;
2237 unsigned long largest = 0;
2238 int nid, prefer = 0;
2239
Linus Torvalds1da177e2005-04-16 15:20:36 -07002240 policy_cache = kmem_cache_create("numa_policy",
2241 sizeof(struct mempolicy),
Paul Mundt20c2df82007-07-20 10:11:58 +09002242 0, SLAB_PANIC, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002243
2244 sn_cache = kmem_cache_create("shared_policy_node",
2245 sizeof(struct sp_node),
Paul Mundt20c2df82007-07-20 10:11:58 +09002246 0, SLAB_PANIC, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002247
Paul Mundtb71636e2007-07-15 23:38:15 -07002248 /*
2249 * Set interleaving policy for system init. Interleaving is only
2250 * enabled across suitably sized nodes (default is >= 16MB), or
2251 * fall back to the largest node if they're all smaller.
2252 */
2253 nodes_clear(interleave_nodes);
Christoph Lameter56bbd652007-10-16 01:25:35 -07002254 for_each_node_state(nid, N_HIGH_MEMORY) {
Paul Mundtb71636e2007-07-15 23:38:15 -07002255 unsigned long total_pages = node_present_pages(nid);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002256
Paul Mundtb71636e2007-07-15 23:38:15 -07002257 /* Preserve the largest node */
2258 if (largest < total_pages) {
2259 largest = total_pages;
2260 prefer = nid;
2261 }
2262
2263 /* Interleave this node? */
2264 if ((total_pages << PAGE_SHIFT) >= (16 << 20))
2265 node_set(nid, interleave_nodes);
2266 }
2267
2268 /* All too small, use the largest */
2269 if (unlikely(nodes_empty(interleave_nodes)))
2270 node_set(prefer, interleave_nodes);
2271
David Rientjes028fec42008-04-28 02:12:25 -07002272 if (do_set_mempolicy(MPOL_INTERLEAVE, 0, &interleave_nodes))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002273 printk("numa_policy_init: interleaving failed\n");
2274}
2275
Christoph Lameter8bccd852005-10-29 18:16:59 -07002276/* Reset policy of current process to default */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002277void numa_default_policy(void)
2278{
David Rientjes028fec42008-04-28 02:12:25 -07002279 do_set_mempolicy(MPOL_DEFAULT, 0, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002280}
Paul Jackson68860ec2005-10-30 15:02:36 -08002281
Paul Jackson42253992006-01-08 01:01:59 -08002282/*
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002283 * Parse and format mempolicy from/to strings
2284 */
2285
2286/*
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -07002287 * "local" is pseudo-policy: MPOL_PREFERRED with MPOL_F_LOCAL flag
Lee Schermerhorn3f226aa2008-04-28 02:13:24 -07002288 * Used only for mpol_parse_str() and mpol_to_str()
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002289 */
Lee Schermerhorn345ace92010-05-24 14:32:04 -07002290#define MPOL_LOCAL MPOL_MAX
2291static const char * const policy_modes[] =
2292{
2293 [MPOL_DEFAULT] = "default",
2294 [MPOL_PREFERRED] = "prefer",
2295 [MPOL_BIND] = "bind",
2296 [MPOL_INTERLEAVE] = "interleave",
2297 [MPOL_LOCAL] = "local"
2298};
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002299
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002300
2301#ifdef CONFIG_TMPFS
2302/**
2303 * mpol_parse_str - parse string to mempolicy
2304 * @str: string containing mempolicy to parse
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002305 * @mpol: pointer to struct mempolicy pointer, returned on success.
2306 * @no_context: flag whether to "contextualize" the mempolicy
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002307 *
2308 * Format of input:
2309 * <mode>[=<flags>][:<nodelist>]
2310 *
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002311 * if @no_context is true, save the input nodemask in w.user_nodemask in
2312 * the returned mempolicy. This will be used to "clone" the mempolicy in
2313 * a specific context [cpuset] at a later time. Used to parse tmpfs mpol
2314 * mount option. Note that if 'static' or 'relative' mode flags were
2315 * specified, the input nodemask will already have been saved. Saving
2316 * it again is redundant, but safe.
2317 *
2318 * On success, returns 0, else 1
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002319 */
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002320int mpol_parse_str(char *str, struct mempolicy **mpol, int no_context)
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002321{
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002322 struct mempolicy *new = NULL;
Lee Schermerhornb4652e82010-05-24 14:32:03 -07002323 unsigned short mode;
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002324 unsigned short uninitialized_var(mode_flags);
2325 nodemask_t nodes;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002326 char *nodelist = strchr(str, ':');
2327 char *flags = strchr(str, '=');
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002328 int err = 1;
2329
2330 if (nodelist) {
2331 /* NUL-terminate mode or flags string */
2332 *nodelist++ = '\0';
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002333 if (nodelist_parse(nodelist, nodes))
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002334 goto out;
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002335 if (!nodes_subset(nodes, node_states[N_HIGH_MEMORY]))
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002336 goto out;
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002337 } else
2338 nodes_clear(nodes);
2339
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002340 if (flags)
2341 *flags++ = '\0'; /* terminate mode string */
2342
Lee Schermerhornb4652e82010-05-24 14:32:03 -07002343 for (mode = 0; mode <= MPOL_LOCAL; mode++) {
Lee Schermerhorn345ace92010-05-24 14:32:04 -07002344 if (!strcmp(str, policy_modes[mode])) {
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002345 break;
2346 }
2347 }
Lee Schermerhornb4652e82010-05-24 14:32:03 -07002348 if (mode > MPOL_LOCAL)
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002349 goto out;
2350
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002351 switch (mode) {
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002352 case MPOL_PREFERRED:
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002353 /*
2354 * Insist on a nodelist of one node only
2355 */
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002356 if (nodelist) {
2357 char *rest = nodelist;
2358 while (isdigit(*rest))
2359 rest++;
KOSAKI Motohiro926f2ae2010-03-23 13:35:32 -07002360 if (*rest)
2361 goto out;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002362 }
2363 break;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002364 case MPOL_INTERLEAVE:
2365 /*
2366 * Default to online nodes with memory if no nodelist
2367 */
2368 if (!nodelist)
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002369 nodes = node_states[N_HIGH_MEMORY];
Lee Schermerhorn3f226aa2008-04-28 02:13:24 -07002370 break;
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002371 case MPOL_LOCAL:
Lee Schermerhorn3f226aa2008-04-28 02:13:24 -07002372 /*
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002373 * Don't allow a nodelist; mpol_new() checks flags
Lee Schermerhorn3f226aa2008-04-28 02:13:24 -07002374 */
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002375 if (nodelist)
Lee Schermerhorn3f226aa2008-04-28 02:13:24 -07002376 goto out;
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002377 mode = MPOL_PREFERRED;
Lee Schermerhorn3f226aa2008-04-28 02:13:24 -07002378 break;
Ravikiran G Thirumalai413b43d2010-03-23 13:35:28 -07002379 case MPOL_DEFAULT:
2380 /*
2381 * Insist on a empty nodelist
2382 */
2383 if (!nodelist)
2384 err = 0;
2385 goto out;
KOSAKI Motohirod69b2e62010-03-23 13:35:30 -07002386 case MPOL_BIND:
2387 /*
2388 * Insist on a nodelist
2389 */
2390 if (!nodelist)
2391 goto out;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002392 }
2393
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002394 mode_flags = 0;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002395 if (flags) {
2396 /*
2397 * Currently, we only support two mutually exclusive
2398 * mode flags.
2399 */
2400 if (!strcmp(flags, "static"))
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002401 mode_flags |= MPOL_F_STATIC_NODES;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002402 else if (!strcmp(flags, "relative"))
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002403 mode_flags |= MPOL_F_RELATIVE_NODES;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002404 else
KOSAKI Motohiro926f2ae2010-03-23 13:35:32 -07002405 goto out;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002406 }
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002407
2408 new = mpol_new(mode, mode_flags, &nodes);
2409 if (IS_ERR(new))
KOSAKI Motohiro926f2ae2010-03-23 13:35:32 -07002410 goto out;
2411
Lee Schermerhorne17f74a2010-05-24 14:32:02 -07002412 if (no_context) {
2413 /* save for contextualization */
2414 new->w.user_nodemask = nodes;
2415 } else {
Miao Xie58568d22009-06-16 15:31:49 -07002416 int ret;
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -07002417 NODEMASK_SCRATCH(scratch);
2418 if (scratch) {
2419 task_lock(current);
2420 ret = mpol_set_nodemask(new, &nodes, scratch);
2421 task_unlock(current);
2422 } else
2423 ret = -ENOMEM;
2424 NODEMASK_SCRATCH_FREE(scratch);
2425 if (ret) {
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -07002426 mpol_put(new);
KOSAKI Motohiro926f2ae2010-03-23 13:35:32 -07002427 goto out;
Miao Xie58568d22009-06-16 15:31:49 -07002428 }
2429 }
KOSAKI Motohiro926f2ae2010-03-23 13:35:32 -07002430 err = 0;
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002431
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002432out:
2433 /* Restore string for error message */
2434 if (nodelist)
2435 *--nodelist = ':';
2436 if (flags)
2437 *--flags = '=';
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002438 if (!err)
2439 *mpol = new;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002440 return err;
2441}
2442#endif /* CONFIG_TMPFS */
2443
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002444/**
2445 * mpol_to_str - format a mempolicy structure for printing
2446 * @buffer: to contain formatted mempolicy string
2447 * @maxlen: length of @buffer
2448 * @pol: pointer to mempolicy to be formatted
2449 * @no_context: "context free" mempolicy - use nodemask in w.user_nodemask
2450 *
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002451 * Convert a mempolicy into a string.
2452 * Returns the number of characters in buffer (if positive)
2453 * or an error (negative)
2454 */
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002455int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol, int no_context)
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002456{
2457 char *p = buffer;
2458 int l;
2459 nodemask_t nodes;
Lee Schermerhornbea904d2008-04-28 02:13:18 -07002460 unsigned short mode;
David Rientjesf5b087b2008-04-28 02:12:27 -07002461 unsigned short flags = pol ? pol->flags : 0;
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002462
Lee Schermerhorn22919902008-04-28 02:13:22 -07002463 /*
2464 * Sanity check: room for longest mode, flag and some nodes
2465 */
2466 VM_BUG_ON(maxlen < strlen("interleave") + strlen("relative") + 16);
2467
Lee Schermerhornbea904d2008-04-28 02:13:18 -07002468 if (!pol || pol == &default_policy)
2469 mode = MPOL_DEFAULT;
2470 else
2471 mode = pol->mode;
2472
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002473 switch (mode) {
2474 case MPOL_DEFAULT:
2475 nodes_clear(nodes);
2476 break;
2477
2478 case MPOL_PREFERRED:
2479 nodes_clear(nodes);
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -07002480 if (flags & MPOL_F_LOCAL)
Lee Schermerhorn53f25562008-04-28 02:13:20 -07002481 mode = MPOL_LOCAL; /* pseudo-policy */
2482 else
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -07002483 node_set(pol->v.preferred_node, nodes);
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002484 break;
2485
2486 case MPOL_BIND:
Mel Gorman19770b32008-04-28 02:12:18 -07002487 /* Fall through */
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002488 case MPOL_INTERLEAVE:
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002489 if (no_context)
2490 nodes = pol->w.user_nodemask;
2491 else
2492 nodes = pol->v.nodes;
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002493 break;
2494
2495 default:
2496 BUG();
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002497 }
2498
Lee Schermerhorn345ace92010-05-24 14:32:04 -07002499 l = strlen(policy_modes[mode]);
Lee Schermerhorn53f25562008-04-28 02:13:20 -07002500 if (buffer + maxlen < p + l + 1)
2501 return -ENOSPC;
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002502
Lee Schermerhorn345ace92010-05-24 14:32:04 -07002503 strcpy(p, policy_modes[mode]);
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002504 p += l;
2505
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -07002506 if (flags & MPOL_MODE_FLAGS) {
David Rientjesf5b087b2008-04-28 02:12:27 -07002507 if (buffer + maxlen < p + 2)
2508 return -ENOSPC;
2509 *p++ = '=';
2510
Lee Schermerhorn22919902008-04-28 02:13:22 -07002511 /*
2512 * Currently, the only defined flags are mutually exclusive
2513 */
David Rientjesf5b087b2008-04-28 02:12:27 -07002514 if (flags & MPOL_F_STATIC_NODES)
Lee Schermerhorn22919902008-04-28 02:13:22 -07002515 p += snprintf(p, buffer + maxlen - p, "static");
2516 else if (flags & MPOL_F_RELATIVE_NODES)
2517 p += snprintf(p, buffer + maxlen - p, "relative");
David Rientjesf5b087b2008-04-28 02:12:27 -07002518 }
2519
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002520 if (!nodes_empty(nodes)) {
2521 if (buffer + maxlen < p + 2)
2522 return -ENOSPC;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002523 *p++ = ':';
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002524 p += nodelist_scnprintf(p, buffer + maxlen - p, nodes);
2525 }
2526 return p - buffer;
2527}