blob: 9c51f9f58cacc8d4a9c9f363fd5f8778ebfac190 [file] [log] [blame]
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>
Michal Hocko778d3b02011-07-26 16:08:30 -070096#include <linux/random.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070097
Nick Piggin62695a82008-10-18 20:26:09 -070098#include "internal.h"
99
Christoph Lameter38e35862006-01-08 01:01:01 -0800100/* Internal flags */
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800101#define MPOL_MF_DISCONTIG_OK (MPOL_MF_INTERNAL << 0) /* Skip checks for continuous vmas */
Christoph Lameter38e35862006-01-08 01:01:01 -0800102#define MPOL_MF_INVERT (MPOL_MF_INTERNAL << 1) /* Invert check for nodemask */
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800103
Pekka Enbergfcc234f2006-03-22 00:08:13 -0800104static struct kmem_cache *policy_cache;
105static struct kmem_cache *sn_cache;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107/* Highest zone. An specific allocation for a zone below that is not
108 policied. */
Christoph Lameter62672762007-02-10 01:43:07 -0800109enum zone_type policy_zone = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110
Lee Schermerhornbea904d2008-04-28 02:13:18 -0700111/*
112 * run-time system-wide default policy => local allocation
113 */
Andi Kleend42c6992005-07-06 19:56:03 +0200114struct mempolicy default_policy = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115 .refcnt = ATOMIC_INIT(1), /* never free it */
Lee Schermerhornbea904d2008-04-28 02:13:18 -0700116 .mode = MPOL_PREFERRED,
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -0700117 .flags = MPOL_F_LOCAL,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118};
119
David Rientjes37012942008-04-28 02:12:33 -0700120static const struct mempolicy_operations {
121 int (*create)(struct mempolicy *pol, const nodemask_t *nodes);
Miao Xie708c1bb2010-05-24 14:32:07 -0700122 /*
123 * If read-side task has no lock to protect task->mempolicy, write-side
124 * task will rebind the task->mempolicy by two step. The first step is
125 * setting all the newly nodes, and the second step is cleaning all the
126 * disallowed nodes. In this way, we can avoid finding no node to alloc
127 * page.
128 * If we have a lock to protect task->mempolicy in read-side, we do
129 * rebind directly.
130 *
131 * step:
132 * MPOL_REBIND_ONCE - do rebind work at once
133 * MPOL_REBIND_STEP1 - set all the newly nodes
134 * MPOL_REBIND_STEP2 - clean all the disallowed nodes
135 */
136 void (*rebind)(struct mempolicy *pol, const nodemask_t *nodes,
137 enum mpol_rebind_step step);
David Rientjes37012942008-04-28 02:12:33 -0700138} mpol_ops[MPOL_MAX];
139
Mel Gorman19770b32008-04-28 02:12:18 -0700140/* Check that the nodemask contains at least one populated zone */
David Rientjes37012942008-04-28 02:12:33 -0700141static int is_valid_nodemask(const nodemask_t *nodemask)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142{
Mel Gorman19770b32008-04-28 02:12:18 -0700143 int nd, k;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144
Mel Gorman19770b32008-04-28 02:12:18 -0700145 for_each_node_mask(nd, *nodemask) {
146 struct zone *z;
147
148 for (k = 0; k <= policy_zone; k++) {
149 z = &NODE_DATA(nd)->node_zones[k];
150 if (z->present_pages > 0)
151 return 1;
Andi Kleendd942ae2006-02-17 01:39:16 +0100152 }
153 }
Mel Gorman19770b32008-04-28 02:12:18 -0700154
155 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156}
157
David Rientjesf5b087b2008-04-28 02:12:27 -0700158static inline int mpol_store_user_nodemask(const struct mempolicy *pol)
159{
Bob Liu6d556292010-05-24 14:31:59 -0700160 return pol->flags & MPOL_MODE_FLAGS;
David Rientjes4c50bc02008-04-28 02:12:30 -0700161}
162
163static void mpol_relative_nodemask(nodemask_t *ret, const nodemask_t *orig,
164 const nodemask_t *rel)
165{
166 nodemask_t tmp;
167 nodes_fold(tmp, *orig, nodes_weight(*rel));
168 nodes_onto(*ret, tmp, *rel);
David Rientjesf5b087b2008-04-28 02:12:27 -0700169}
170
David Rientjes37012942008-04-28 02:12:33 -0700171static int mpol_new_interleave(struct mempolicy *pol, const nodemask_t *nodes)
172{
173 if (nodes_empty(*nodes))
174 return -EINVAL;
175 pol->v.nodes = *nodes;
176 return 0;
177}
178
179static int mpol_new_preferred(struct mempolicy *pol, const nodemask_t *nodes)
180{
181 if (!nodes)
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -0700182 pol->flags |= MPOL_F_LOCAL; /* local allocation */
David Rientjes37012942008-04-28 02:12:33 -0700183 else if (nodes_empty(*nodes))
184 return -EINVAL; /* no allowed nodes */
185 else
186 pol->v.preferred_node = first_node(*nodes);
187 return 0;
188}
189
190static int mpol_new_bind(struct mempolicy *pol, const nodemask_t *nodes)
191{
192 if (!is_valid_nodemask(nodes))
193 return -EINVAL;
194 pol->v.nodes = *nodes;
195 return 0;
196}
197
Miao Xie58568d22009-06-16 15:31:49 -0700198/*
199 * mpol_set_nodemask is called after mpol_new() to set up the nodemask, if
200 * any, for the new policy. mpol_new() has already validated the nodes
201 * parameter with respect to the policy mode and flags. But, we need to
202 * handle an empty nodemask with MPOL_PREFERRED here.
203 *
204 * Must be called holding task's alloc_lock to protect task's mems_allowed
205 * and mempolicy. May also be called holding the mmap_semaphore for write.
206 */
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -0700207static int mpol_set_nodemask(struct mempolicy *pol,
208 const nodemask_t *nodes, struct nodemask_scratch *nsc)
Miao Xie58568d22009-06-16 15:31:49 -0700209{
Miao Xie58568d22009-06-16 15:31:49 -0700210 int ret;
211
212 /* if mode is MPOL_DEFAULT, pol is NULL. This is right. */
213 if (pol == NULL)
214 return 0;
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -0700215 /* Check N_HIGH_MEMORY */
216 nodes_and(nsc->mask1,
217 cpuset_current_mems_allowed, node_states[N_HIGH_MEMORY]);
Miao Xie58568d22009-06-16 15:31:49 -0700218
219 VM_BUG_ON(!nodes);
220 if (pol->mode == MPOL_PREFERRED && nodes_empty(*nodes))
221 nodes = NULL; /* explicit local allocation */
222 else {
223 if (pol->flags & MPOL_F_RELATIVE_NODES)
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -0700224 mpol_relative_nodemask(&nsc->mask2, nodes,&nsc->mask1);
Miao Xie58568d22009-06-16 15:31:49 -0700225 else
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -0700226 nodes_and(nsc->mask2, *nodes, nsc->mask1);
227
Miao Xie58568d22009-06-16 15:31:49 -0700228 if (mpol_store_user_nodemask(pol))
229 pol->w.user_nodemask = *nodes;
230 else
231 pol->w.cpuset_mems_allowed =
232 cpuset_current_mems_allowed;
233 }
234
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -0700235 if (nodes)
236 ret = mpol_ops[pol->mode].create(pol, &nsc->mask2);
237 else
238 ret = mpol_ops[pol->mode].create(pol, NULL);
Miao Xie58568d22009-06-16 15:31:49 -0700239 return ret;
240}
241
242/*
243 * This function just creates a new policy, does some check and simple
244 * initialization. You must invoke mpol_set_nodemask() to set nodes.
245 */
David Rientjes028fec42008-04-28 02:12:25 -0700246static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags,
247 nodemask_t *nodes)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248{
249 struct mempolicy *policy;
250
David Rientjes028fec42008-04-28 02:12:25 -0700251 pr_debug("setting mode %d flags %d nodes[0] %lx\n",
252 mode, flags, nodes ? nodes_addr(*nodes)[0] : -1);
Paul Mundt140d5a42007-07-15 23:38:16 -0700253
David Rientjes3e1f0642008-04-28 02:12:34 -0700254 if (mode == MPOL_DEFAULT) {
255 if (nodes && !nodes_empty(*nodes))
David Rientjes37012942008-04-28 02:12:33 -0700256 return ERR_PTR(-EINVAL);
Lee Schermerhornbea904d2008-04-28 02:13:18 -0700257 return NULL; /* simply delete any existing policy */
David Rientjes37012942008-04-28 02:12:33 -0700258 }
David Rientjes3e1f0642008-04-28 02:12:34 -0700259 VM_BUG_ON(!nodes);
260
261 /*
262 * MPOL_PREFERRED cannot be used with MPOL_F_STATIC_NODES or
263 * MPOL_F_RELATIVE_NODES if the nodemask is empty (local allocation).
264 * All other modes require a valid pointer to a non-empty nodemask.
265 */
266 if (mode == MPOL_PREFERRED) {
267 if (nodes_empty(*nodes)) {
268 if (((flags & MPOL_F_STATIC_NODES) ||
269 (flags & MPOL_F_RELATIVE_NODES)))
270 return ERR_PTR(-EINVAL);
David Rientjes3e1f0642008-04-28 02:12:34 -0700271 }
272 } else if (nodes_empty(*nodes))
273 return ERR_PTR(-EINVAL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274 policy = kmem_cache_alloc(policy_cache, GFP_KERNEL);
275 if (!policy)
276 return ERR_PTR(-ENOMEM);
277 atomic_set(&policy->refcnt, 1);
Lee Schermerhorn45c47452008-04-28 02:13:12 -0700278 policy->mode = mode;
David Rientjes3e1f0642008-04-28 02:12:34 -0700279 policy->flags = flags;
David Rientjesf5b087b2008-04-28 02:12:27 -0700280
David Rientjes37012942008-04-28 02:12:33 -0700281 return policy;
282}
283
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -0700284/* Slow path of a mpol destructor. */
285void __mpol_put(struct mempolicy *p)
286{
287 if (!atomic_dec_and_test(&p->refcnt))
288 return;
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -0700289 kmem_cache_free(policy_cache, p);
290}
291
Miao Xie708c1bb2010-05-24 14:32:07 -0700292static void mpol_rebind_default(struct mempolicy *pol, const nodemask_t *nodes,
293 enum mpol_rebind_step step)
David Rientjes37012942008-04-28 02:12:33 -0700294{
295}
296
Miao Xie708c1bb2010-05-24 14:32:07 -0700297/*
298 * step:
299 * MPOL_REBIND_ONCE - do rebind work at once
300 * MPOL_REBIND_STEP1 - set all the newly nodes
301 * MPOL_REBIND_STEP2 - clean all the disallowed nodes
302 */
303static void mpol_rebind_nodemask(struct mempolicy *pol, const nodemask_t *nodes,
304 enum mpol_rebind_step step)
David Rientjes37012942008-04-28 02:12:33 -0700305{
306 nodemask_t tmp;
307
308 if (pol->flags & MPOL_F_STATIC_NODES)
309 nodes_and(tmp, pol->w.user_nodemask, *nodes);
310 else if (pol->flags & MPOL_F_RELATIVE_NODES)
311 mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes);
312 else {
Miao Xie708c1bb2010-05-24 14:32:07 -0700313 /*
314 * if step == 1, we use ->w.cpuset_mems_allowed to cache the
315 * result
316 */
317 if (step == MPOL_REBIND_ONCE || step == MPOL_REBIND_STEP1) {
318 nodes_remap(tmp, pol->v.nodes,
319 pol->w.cpuset_mems_allowed, *nodes);
320 pol->w.cpuset_mems_allowed = step ? tmp : *nodes;
321 } else if (step == MPOL_REBIND_STEP2) {
322 tmp = pol->w.cpuset_mems_allowed;
323 pol->w.cpuset_mems_allowed = *nodes;
324 } else
325 BUG();
David Rientjes37012942008-04-28 02:12:33 -0700326 }
327
Miao Xie708c1bb2010-05-24 14:32:07 -0700328 if (nodes_empty(tmp))
329 tmp = *nodes;
330
331 if (step == MPOL_REBIND_STEP1)
332 nodes_or(pol->v.nodes, pol->v.nodes, tmp);
333 else if (step == MPOL_REBIND_ONCE || step == MPOL_REBIND_STEP2)
334 pol->v.nodes = tmp;
335 else
336 BUG();
337
David Rientjes37012942008-04-28 02:12:33 -0700338 if (!node_isset(current->il_next, tmp)) {
339 current->il_next = next_node(current->il_next, tmp);
340 if (current->il_next >= MAX_NUMNODES)
341 current->il_next = first_node(tmp);
342 if (current->il_next >= MAX_NUMNODES)
343 current->il_next = numa_node_id();
344 }
345}
346
347static void mpol_rebind_preferred(struct mempolicy *pol,
Miao Xie708c1bb2010-05-24 14:32:07 -0700348 const nodemask_t *nodes,
349 enum mpol_rebind_step step)
David Rientjes37012942008-04-28 02:12:33 -0700350{
351 nodemask_t tmp;
352
David Rientjes37012942008-04-28 02:12:33 -0700353 if (pol->flags & MPOL_F_STATIC_NODES) {
354 int node = first_node(pol->w.user_nodemask);
355
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -0700356 if (node_isset(node, *nodes)) {
David Rientjes37012942008-04-28 02:12:33 -0700357 pol->v.preferred_node = node;
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -0700358 pol->flags &= ~MPOL_F_LOCAL;
359 } else
360 pol->flags |= MPOL_F_LOCAL;
David Rientjes37012942008-04-28 02:12:33 -0700361 } else if (pol->flags & MPOL_F_RELATIVE_NODES) {
362 mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes);
363 pol->v.preferred_node = first_node(tmp);
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -0700364 } else if (!(pol->flags & MPOL_F_LOCAL)) {
David Rientjes37012942008-04-28 02:12:33 -0700365 pol->v.preferred_node = node_remap(pol->v.preferred_node,
366 pol->w.cpuset_mems_allowed,
367 *nodes);
368 pol->w.cpuset_mems_allowed = *nodes;
369 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370}
371
Miao Xie708c1bb2010-05-24 14:32:07 -0700372/*
373 * mpol_rebind_policy - Migrate a policy to a different set of nodes
374 *
375 * If read-side task has no lock to protect task->mempolicy, write-side
376 * task will rebind the task->mempolicy by two step. The first step is
377 * setting all the newly nodes, and the second step is cleaning all the
378 * disallowed nodes. In this way, we can avoid finding no node to alloc
379 * page.
380 * If we have a lock to protect task->mempolicy in read-side, we do
381 * rebind directly.
382 *
383 * step:
384 * MPOL_REBIND_ONCE - do rebind work at once
385 * MPOL_REBIND_STEP1 - set all the newly nodes
386 * MPOL_REBIND_STEP2 - clean all the disallowed nodes
387 */
388static void mpol_rebind_policy(struct mempolicy *pol, const nodemask_t *newmask,
389 enum mpol_rebind_step step)
David Rientjes1d0d2682008-04-28 02:12:32 -0700390{
David Rientjes1d0d2682008-04-28 02:12:32 -0700391 if (!pol)
392 return;
Miao Xie708c1bb2010-05-24 14:32:07 -0700393 if (!mpol_store_user_nodemask(pol) && step == 0 &&
David Rientjes1d0d2682008-04-28 02:12:32 -0700394 nodes_equal(pol->w.cpuset_mems_allowed, *newmask))
395 return;
Miao Xie708c1bb2010-05-24 14:32:07 -0700396
397 if (step == MPOL_REBIND_STEP1 && (pol->flags & MPOL_F_REBINDING))
398 return;
399
400 if (step == MPOL_REBIND_STEP2 && !(pol->flags & MPOL_F_REBINDING))
401 BUG();
402
403 if (step == MPOL_REBIND_STEP1)
404 pol->flags |= MPOL_F_REBINDING;
405 else if (step == MPOL_REBIND_STEP2)
406 pol->flags &= ~MPOL_F_REBINDING;
407 else if (step >= MPOL_REBIND_NSTEP)
408 BUG();
409
410 mpol_ops[pol->mode].rebind(pol, newmask, step);
David Rientjes1d0d2682008-04-28 02:12:32 -0700411}
412
413/*
414 * Wrapper for mpol_rebind_policy() that just requires task
415 * pointer, and updates task mempolicy.
Miao Xie58568d22009-06-16 15:31:49 -0700416 *
417 * Called with task's alloc_lock held.
David Rientjes1d0d2682008-04-28 02:12:32 -0700418 */
419
Miao Xie708c1bb2010-05-24 14:32:07 -0700420void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new,
421 enum mpol_rebind_step step)
David Rientjes1d0d2682008-04-28 02:12:32 -0700422{
Miao Xie708c1bb2010-05-24 14:32:07 -0700423 mpol_rebind_policy(tsk->mempolicy, new, step);
David Rientjes1d0d2682008-04-28 02:12:32 -0700424}
425
426/*
427 * Rebind each vma in mm to new nodemask.
428 *
429 * Call holding a reference to mm. Takes mm->mmap_sem during call.
430 */
431
432void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new)
433{
434 struct vm_area_struct *vma;
435
436 down_write(&mm->mmap_sem);
437 for (vma = mm->mmap; vma; vma = vma->vm_next)
Miao Xie708c1bb2010-05-24 14:32:07 -0700438 mpol_rebind_policy(vma->vm_policy, new, MPOL_REBIND_ONCE);
David Rientjes1d0d2682008-04-28 02:12:32 -0700439 up_write(&mm->mmap_sem);
440}
441
David Rientjes37012942008-04-28 02:12:33 -0700442static const struct mempolicy_operations mpol_ops[MPOL_MAX] = {
443 [MPOL_DEFAULT] = {
444 .rebind = mpol_rebind_default,
445 },
446 [MPOL_INTERLEAVE] = {
447 .create = mpol_new_interleave,
448 .rebind = mpol_rebind_nodemask,
449 },
450 [MPOL_PREFERRED] = {
451 .create = mpol_new_preferred,
452 .rebind = mpol_rebind_preferred,
453 },
454 [MPOL_BIND] = {
455 .create = mpol_new_bind,
456 .rebind = mpol_rebind_nodemask,
457 },
458};
459
Christoph Lameterfc301282006-01-18 17:42:29 -0800460static void migrate_page_add(struct page *page, struct list_head *pagelist,
461 unsigned long flags);
Christoph Lameter1a75a6c2006-01-08 01:01:02 -0800462
Christoph Lameter38e35862006-01-08 01:01:01 -0800463/* Scan through pages checking if pages follow certain conditions. */
Nick Pigginb5810032005-10-29 18:16:12 -0700464static int check_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800465 unsigned long addr, unsigned long end,
466 const nodemask_t *nodes, unsigned long flags,
Christoph Lameter38e35862006-01-08 01:01:01 -0800467 void *private)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468{
Hugh Dickins91612e02005-06-21 17:15:07 -0700469 pte_t *orig_pte;
470 pte_t *pte;
Hugh Dickins705e87c2005-10-29 18:16:27 -0700471 spinlock_t *ptl;
Hugh Dickins941150a2005-06-21 17:15:06 -0700472
Hugh Dickins705e87c2005-10-29 18:16:27 -0700473 orig_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
Hugh Dickins91612e02005-06-21 17:15:07 -0700474 do {
Linus Torvalds6aab3412005-11-28 14:34:23 -0800475 struct page *page;
Andy Whitcroft25ba77c2006-12-06 20:33:03 -0800476 int nid;
Hugh Dickins91612e02005-06-21 17:15:07 -0700477
478 if (!pte_present(*pte))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479 continue;
Linus Torvalds6aab3412005-11-28 14:34:23 -0800480 page = vm_normal_page(vma, addr, *pte);
481 if (!page)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700482 continue;
Nick Piggin053837f2006-01-18 17:42:27 -0800483 /*
Hugh Dickins62b61f62009-12-14 17:59:33 -0800484 * vm_normal_page() filters out zero pages, but there might
485 * still be PageReserved pages to skip, perhaps in a VDSO.
486 * And we cannot move PageKsm pages sensibly or safely yet.
Nick Piggin053837f2006-01-18 17:42:27 -0800487 */
Hugh Dickins62b61f62009-12-14 17:59:33 -0800488 if (PageReserved(page) || PageKsm(page))
Christoph Lameterf4598c82006-01-12 01:05:20 -0800489 continue;
Linus Torvalds6aab3412005-11-28 14:34:23 -0800490 nid = page_to_nid(page);
Christoph Lameter38e35862006-01-08 01:01:01 -0800491 if (node_isset(nid, *nodes) == !!(flags & MPOL_MF_INVERT))
492 continue;
493
Stephen Wilsonb1f72d12011-05-24 17:12:43 -0700494 if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
Christoph Lameterfc301282006-01-18 17:42:29 -0800495 migrate_page_add(page, private, flags);
Christoph Lameter38e35862006-01-08 01:01:01 -0800496 else
497 break;
Hugh Dickins91612e02005-06-21 17:15:07 -0700498 } while (pte++, addr += PAGE_SIZE, addr != end);
Hugh Dickins705e87c2005-10-29 18:16:27 -0700499 pte_unmap_unlock(orig_pte, ptl);
Hugh Dickins91612e02005-06-21 17:15:07 -0700500 return addr != end;
501}
502
Nick Pigginb5810032005-10-29 18:16:12 -0700503static inline int check_pmd_range(struct vm_area_struct *vma, pud_t *pud,
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800504 unsigned long addr, unsigned long end,
505 const nodemask_t *nodes, unsigned long flags,
Christoph Lameter38e35862006-01-08 01:01:01 -0800506 void *private)
Hugh Dickins91612e02005-06-21 17:15:07 -0700507{
508 pmd_t *pmd;
509 unsigned long next;
510
511 pmd = pmd_offset(pud, addr);
512 do {
513 next = pmd_addr_end(addr, end);
Andrea Arcangelibae9c192011-01-13 15:46:46 -0800514 split_huge_page_pmd(vma->vm_mm, pmd);
Hugh Dickins91612e02005-06-21 17:15:07 -0700515 if (pmd_none_or_clear_bad(pmd))
516 continue;
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800517 if (check_pte_range(vma, pmd, addr, next, nodes,
Christoph Lameter38e35862006-01-08 01:01:01 -0800518 flags, private))
Hugh Dickins91612e02005-06-21 17:15:07 -0700519 return -EIO;
520 } while (pmd++, addr = next, addr != end);
521 return 0;
522}
523
Nick Pigginb5810032005-10-29 18:16:12 -0700524static inline int check_pud_range(struct vm_area_struct *vma, pgd_t *pgd,
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800525 unsigned long addr, unsigned long end,
526 const nodemask_t *nodes, unsigned long flags,
Christoph Lameter38e35862006-01-08 01:01:01 -0800527 void *private)
Hugh Dickins91612e02005-06-21 17:15:07 -0700528{
529 pud_t *pud;
530 unsigned long next;
531
532 pud = pud_offset(pgd, addr);
533 do {
534 next = pud_addr_end(addr, end);
535 if (pud_none_or_clear_bad(pud))
536 continue;
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800537 if (check_pmd_range(vma, pud, addr, next, nodes,
Christoph Lameter38e35862006-01-08 01:01:01 -0800538 flags, private))
Hugh Dickins91612e02005-06-21 17:15:07 -0700539 return -EIO;
540 } while (pud++, addr = next, addr != end);
541 return 0;
542}
543
Nick Pigginb5810032005-10-29 18:16:12 -0700544static inline int check_pgd_range(struct vm_area_struct *vma,
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800545 unsigned long addr, unsigned long end,
546 const nodemask_t *nodes, unsigned long flags,
Christoph Lameter38e35862006-01-08 01:01:01 -0800547 void *private)
Hugh Dickins91612e02005-06-21 17:15:07 -0700548{
549 pgd_t *pgd;
550 unsigned long next;
551
Nick Pigginb5810032005-10-29 18:16:12 -0700552 pgd = pgd_offset(vma->vm_mm, addr);
Hugh Dickins91612e02005-06-21 17:15:07 -0700553 do {
554 next = pgd_addr_end(addr, end);
555 if (pgd_none_or_clear_bad(pgd))
556 continue;
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800557 if (check_pud_range(vma, pgd, addr, next, nodes,
Christoph Lameter38e35862006-01-08 01:01:01 -0800558 flags, private))
Hugh Dickins91612e02005-06-21 17:15:07 -0700559 return -EIO;
560 } while (pgd++, addr = next, addr != end);
561 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700562}
563
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800564/*
565 * Check if all pages in a range are on a set of nodes.
566 * If pagelist != NULL then isolate pages from the LRU and
567 * put them on the pagelist.
568 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700569static struct vm_area_struct *
570check_range(struct mm_struct *mm, unsigned long start, unsigned long end,
Christoph Lameter38e35862006-01-08 01:01:01 -0800571 const nodemask_t *nodes, unsigned long flags, void *private)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700572{
573 int err;
574 struct vm_area_struct *first, *vma, *prev;
575
Nick Piggin053837f2006-01-18 17:42:27 -0800576
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577 first = find_vma(mm, start);
578 if (!first)
579 return ERR_PTR(-EFAULT);
580 prev = NULL;
581 for (vma = first; vma && vma->vm_start < end; vma = vma->vm_next) {
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800582 if (!(flags & MPOL_MF_DISCONTIG_OK)) {
583 if (!vma->vm_next && vma->vm_end < end)
584 return ERR_PTR(-EFAULT);
585 if (prev && prev->vm_end < vma->vm_start)
586 return ERR_PTR(-EFAULT);
587 }
588 if (!is_vm_hugetlb_page(vma) &&
589 ((flags & MPOL_MF_STRICT) ||
590 ((flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) &&
591 vma_migratable(vma)))) {
Andi Kleen5b952b32005-09-13 01:25:08 -0700592 unsigned long endvma = vma->vm_end;
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800593
Andi Kleen5b952b32005-09-13 01:25:08 -0700594 if (endvma > end)
595 endvma = end;
596 if (vma->vm_start > start)
597 start = vma->vm_start;
Christoph Lameterdc9aa5b2006-01-08 01:00:50 -0800598 err = check_pgd_range(vma, start, endvma, nodes,
Christoph Lameter38e35862006-01-08 01:01:01 -0800599 flags, private);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700600 if (err) {
601 first = ERR_PTR(err);
602 break;
603 }
604 }
605 prev = vma;
606 }
607 return first;
608}
609
610/* Apply policy to a single VMA */
611static int policy_vma(struct vm_area_struct *vma, struct mempolicy *new)
612{
613 int err = 0;
614 struct mempolicy *old = vma->vm_policy;
615
Paul Mundt140d5a42007-07-15 23:38:16 -0700616 pr_debug("vma %lx-%lx/%lx vm_ops %p vm_file %p set_policy %p\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617 vma->vm_start, vma->vm_end, vma->vm_pgoff,
618 vma->vm_ops, vma->vm_file,
619 vma->vm_ops ? vma->vm_ops->set_policy : NULL);
620
621 if (vma->vm_ops && vma->vm_ops->set_policy)
622 err = vma->vm_ops->set_policy(vma, new);
623 if (!err) {
624 mpol_get(new);
625 vma->vm_policy = new;
Lee Schermerhornf0be3d32008-04-28 02:13:08 -0700626 mpol_put(old);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627 }
628 return err;
629}
630
631/* Step 2: apply policy to a range and do splits. */
KOSAKI Motohiro9d8cebd2010-03-05 13:41:57 -0800632static int mbind_range(struct mm_struct *mm, unsigned long start,
633 unsigned long end, struct mempolicy *new_pol)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700634{
635 struct vm_area_struct *next;
KOSAKI Motohiro9d8cebd2010-03-05 13:41:57 -0800636 struct vm_area_struct *prev;
637 struct vm_area_struct *vma;
638 int err = 0;
KOSAKI Motohiro9d8cebd2010-03-05 13:41:57 -0800639 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
KOSAKI Motohiro9d8cebd2010-03-05 13:41:57 -0800651 prev = vma_merge(mm, prev, vmstart, vmend, vma->vm_flags,
Caspar Zhang8aacc9f2011-09-14 16:20:58 -0700652 vma->anon_vma, vma->vm_file, vma->vm_pgoff,
653 new_pol);
KOSAKI Motohiro9d8cebd2010-03-05 13:41:57 -0800654 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) {
KAMEZAWA Hiroyuki2bbff6c2011-09-14 16:21:02 -07001414 unsigned long copy_size;
1415 copy_size = min_t(unsigned long, sizeof(bm), alloc_size);
1416 err = copy_from_user(bm, nm, copy_size);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001417 /* ensure entire bitmap is zeroed */
1418 err |= clear_user(nmask, ALIGN(maxnode-1, 8) / 8);
1419 err |= compat_put_bitmap(nmask, bm, nr_bits);
1420 }
1421
1422 return err;
1423}
1424
1425asmlinkage long compat_sys_set_mempolicy(int mode, compat_ulong_t __user *nmask,
1426 compat_ulong_t maxnode)
1427{
1428 long err = 0;
1429 unsigned long __user *nm = NULL;
1430 unsigned long nr_bits, alloc_size;
1431 DECLARE_BITMAP(bm, MAX_NUMNODES);
1432
1433 nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
1434 alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
1435
1436 if (nmask) {
1437 err = compat_get_bitmap(bm, nmask, nr_bits);
1438 nm = compat_alloc_user_space(alloc_size);
1439 err |= copy_to_user(nm, bm, alloc_size);
1440 }
1441
1442 if (err)
1443 return -EFAULT;
1444
1445 return sys_set_mempolicy(mode, nm, nr_bits+1);
1446}
1447
1448asmlinkage long compat_sys_mbind(compat_ulong_t start, compat_ulong_t len,
1449 compat_ulong_t mode, compat_ulong_t __user *nmask,
1450 compat_ulong_t maxnode, compat_ulong_t flags)
1451{
1452 long err = 0;
1453 unsigned long __user *nm = NULL;
1454 unsigned long nr_bits, alloc_size;
Andi Kleendfcd3c02005-10-29 18:15:48 -07001455 nodemask_t bm;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001456
1457 nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
1458 alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
1459
1460 if (nmask) {
Andi Kleendfcd3c02005-10-29 18:15:48 -07001461 err = compat_get_bitmap(nodes_addr(bm), nmask, nr_bits);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001462 nm = compat_alloc_user_space(alloc_size);
Andi Kleendfcd3c02005-10-29 18:15:48 -07001463 err |= copy_to_user(nm, nodes_addr(bm), alloc_size);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001464 }
1465
1466 if (err)
1467 return -EFAULT;
1468
1469 return sys_mbind(start, len, mode, nm, nr_bits+1, flags);
1470}
1471
1472#endif
1473
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001474/*
1475 * get_vma_policy(@task, @vma, @addr)
1476 * @task - task for fallback if vma policy == default
1477 * @vma - virtual memory area whose policy is sought
1478 * @addr - address in @vma for shared policy lookup
1479 *
1480 * Returns effective policy for a VMA at specified address.
1481 * Falls back to @task or system default policy, as necessary.
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001482 * Current or other task's task mempolicy and non-shared vma policies
1483 * are protected by the task's mmap_sem, which must be held for read by
1484 * the caller.
1485 * Shared policies [those marked as MPOL_F_SHARED] require an extra reference
1486 * count--added by the get_policy() vm_op, as appropriate--to protect against
1487 * freeing by another task. It is the caller's responsibility to free the
1488 * extra reference for shared policies.
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001489 */
Stephen Wilsond98f6cb2011-05-24 17:12:41 -07001490struct mempolicy *get_vma_policy(struct task_struct *task,
Christoph Lameter48fce342006-01-08 01:01:03 -08001491 struct vm_area_struct *vma, unsigned long addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001492{
Christoph Lameter6e21c8f2005-09-03 15:54:45 -07001493 struct mempolicy *pol = task->mempolicy;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001494
1495 if (vma) {
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001496 if (vma->vm_ops && vma->vm_ops->get_policy) {
Lee Schermerhornae4d8c12008-04-28 02:13:11 -07001497 struct mempolicy *vpol = vma->vm_ops->get_policy(vma,
1498 addr);
1499 if (vpol)
1500 pol = vpol;
Lee Schermerhornbea904d2008-04-28 02:13:18 -07001501 } else if (vma->vm_policy)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001502 pol = vma->vm_policy;
1503 }
1504 if (!pol)
1505 pol = &default_policy;
1506 return pol;
1507}
1508
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001509/*
1510 * Return a nodemask representing a mempolicy for filtering nodes for
1511 * page allocation
1512 */
1513static nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy)
Mel Gorman19770b32008-04-28 02:12:18 -07001514{
1515 /* Lower zones don't get a nodemask applied for MPOL_BIND */
Lee Schermerhorn45c47452008-04-28 02:13:12 -07001516 if (unlikely(policy->mode == MPOL_BIND) &&
Mel Gorman19770b32008-04-28 02:12:18 -07001517 gfp_zone(gfp) >= policy_zone &&
1518 cpuset_nodemask_valid_mems_allowed(&policy->v.nodes))
1519 return &policy->v.nodes;
1520
1521 return NULL;
1522}
1523
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001524/* Return a zonelist indicated by gfp for node representing a mempolicy */
Andi Kleen2f5f9482011-03-04 17:36:29 -08001525static struct zonelist *policy_zonelist(gfp_t gfp, struct mempolicy *policy,
1526 int nd)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001527{
Lee Schermerhorn45c47452008-04-28 02:13:12 -07001528 switch (policy->mode) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001529 case MPOL_PREFERRED:
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -07001530 if (!(policy->flags & MPOL_F_LOCAL))
1531 nd = policy->v.preferred_node;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001532 break;
1533 case MPOL_BIND:
Mel Gorman19770b32008-04-28 02:12:18 -07001534 /*
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001535 * Normally, MPOL_BIND allocations are node-local within the
1536 * allowed nodemask. However, if __GFP_THISNODE is set and the
Bob Liu6eb27e12010-05-24 14:32:00 -07001537 * current node isn't part of the mask, we use the zonelist for
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001538 * the first node in the mask instead.
Mel Gorman19770b32008-04-28 02:12:18 -07001539 */
Mel Gorman19770b32008-04-28 02:12:18 -07001540 if (unlikely(gfp & __GFP_THISNODE) &&
1541 unlikely(!node_isset(nd, policy->v.nodes)))
1542 nd = first_node(policy->v.nodes);
1543 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001544 default:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001545 BUG();
1546 }
Mel Gorman0e884602008-04-28 02:12:14 -07001547 return node_zonelist(nd, gfp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001548}
1549
1550/* Do dynamic interleaving for a process */
1551static unsigned interleave_nodes(struct mempolicy *policy)
1552{
1553 unsigned nid, next;
1554 struct task_struct *me = current;
1555
1556 nid = me->il_next;
Andi Kleendfcd3c02005-10-29 18:15:48 -07001557 next = next_node(nid, policy->v.nodes);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001558 if (next >= MAX_NUMNODES)
Andi Kleendfcd3c02005-10-29 18:15:48 -07001559 next = first_node(policy->v.nodes);
David Rientjesf5b087b2008-04-28 02:12:27 -07001560 if (next < MAX_NUMNODES)
1561 me->il_next = next;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001562 return nid;
1563}
1564
Christoph Lameterdc85da12006-01-18 17:42:36 -08001565/*
1566 * Depending on the memory policy provide a node from which to allocate the
1567 * next slab entry.
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001568 * @policy must be protected by freeing by the caller. If @policy is
1569 * the current task's mempolicy, this protection is implicit, as only the
1570 * task can change it's policy. The system default policy requires no
1571 * such protection.
Christoph Lameterdc85da12006-01-18 17:42:36 -08001572 */
1573unsigned slab_node(struct mempolicy *policy)
1574{
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -07001575 if (!policy || policy->flags & MPOL_F_LOCAL)
Lee Schermerhornbea904d2008-04-28 02:13:18 -07001576 return numa_node_id();
Christoph Lameter765c4502006-09-27 01:50:08 -07001577
Lee Schermerhornbea904d2008-04-28 02:13:18 -07001578 switch (policy->mode) {
1579 case MPOL_PREFERRED:
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -07001580 /*
1581 * handled MPOL_F_LOCAL above
1582 */
1583 return policy->v.preferred_node;
Lee Schermerhornbea904d2008-04-28 02:13:18 -07001584
Christoph Lameterdc85da12006-01-18 17:42:36 -08001585 case MPOL_INTERLEAVE:
1586 return interleave_nodes(policy);
1587
Mel Gormandd1a2392008-04-28 02:12:17 -07001588 case MPOL_BIND: {
Christoph Lameterdc85da12006-01-18 17:42:36 -08001589 /*
1590 * Follow bind policy behavior and start allocation at the
1591 * first node.
1592 */
Mel Gorman19770b32008-04-28 02:12:18 -07001593 struct zonelist *zonelist;
1594 struct zone *zone;
1595 enum zone_type highest_zoneidx = gfp_zone(GFP_KERNEL);
1596 zonelist = &NODE_DATA(numa_node_id())->node_zonelists[0];
1597 (void)first_zones_zonelist(zonelist, highest_zoneidx,
1598 &policy->v.nodes,
1599 &zone);
Eric Dumazet800416f2010-10-27 19:33:43 +02001600 return zone ? zone->node : numa_node_id();
Mel Gormandd1a2392008-04-28 02:12:17 -07001601 }
Christoph Lameterdc85da12006-01-18 17:42:36 -08001602
Christoph Lameterdc85da12006-01-18 17:42:36 -08001603 default:
Lee Schermerhornbea904d2008-04-28 02:13:18 -07001604 BUG();
Christoph Lameterdc85da12006-01-18 17:42:36 -08001605 }
1606}
1607
Linus Torvalds1da177e2005-04-16 15:20:36 -07001608/* Do static interleaving for a VMA with known offset. */
1609static unsigned offset_il_node(struct mempolicy *pol,
1610 struct vm_area_struct *vma, unsigned long off)
1611{
Andi Kleendfcd3c02005-10-29 18:15:48 -07001612 unsigned nnodes = nodes_weight(pol->v.nodes);
David Rientjesf5b087b2008-04-28 02:12:27 -07001613 unsigned target;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001614 int c;
1615 int nid = -1;
1616
David Rientjesf5b087b2008-04-28 02:12:27 -07001617 if (!nnodes)
1618 return numa_node_id();
1619 target = (unsigned int)off % nnodes;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001620 c = 0;
1621 do {
Andi Kleendfcd3c02005-10-29 18:15:48 -07001622 nid = next_node(nid, pol->v.nodes);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001623 c++;
1624 } while (c <= target);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001625 return nid;
1626}
1627
Christoph Lameter5da7ca82006-01-06 00:10:46 -08001628/* Determine a node number for interleave */
1629static inline unsigned interleave_nid(struct mempolicy *pol,
1630 struct vm_area_struct *vma, unsigned long addr, int shift)
1631{
1632 if (vma) {
1633 unsigned long off;
1634
Nishanth Aravamudan3b98b082006-08-31 21:27:53 -07001635 /*
1636 * for small pages, there is no difference between
1637 * shift and PAGE_SHIFT, so the bit-shift is safe.
1638 * for huge pages, since vm_pgoff is in units of small
1639 * pages, we need to shift off the always 0 bits to get
1640 * a useful offset.
1641 */
1642 BUG_ON(shift < PAGE_SHIFT);
1643 off = vma->vm_pgoff >> (shift - PAGE_SHIFT);
Christoph Lameter5da7ca82006-01-06 00:10:46 -08001644 off += (addr - vma->vm_start) >> shift;
1645 return offset_il_node(pol, vma, off);
1646 } else
1647 return interleave_nodes(pol);
1648}
1649
Michal Hocko778d3b02011-07-26 16:08:30 -07001650/*
1651 * Return the bit number of a random bit set in the nodemask.
1652 * (returns -1 if nodemask is empty)
1653 */
1654int node_random(const nodemask_t *maskp)
1655{
1656 int w, bit = -1;
1657
1658 w = nodes_weight(*maskp);
1659 if (w)
1660 bit = bitmap_ord_to_pos(maskp->bits,
1661 get_random_int() % w, MAX_NUMNODES);
1662 return bit;
1663}
1664
Chen, Kenneth W00ac59a2006-02-03 21:51:14 +01001665#ifdef CONFIG_HUGETLBFS
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001666/*
1667 * huge_zonelist(@vma, @addr, @gfp_flags, @mpol)
1668 * @vma = virtual memory area whose policy is sought
1669 * @addr = address in @vma for shared policy lookup and interleave policy
1670 * @gfp_flags = for requested zone
Mel Gorman19770b32008-04-28 02:12:18 -07001671 * @mpol = pointer to mempolicy pointer for reference counted mempolicy
1672 * @nodemask = pointer to nodemask pointer for MPOL_BIND nodemask
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001673 *
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001674 * Returns a zonelist suitable for a huge page allocation and a pointer
1675 * to the struct mempolicy for conditional unref after allocation.
1676 * If the effective policy is 'BIND, returns a pointer to the mempolicy's
1677 * @nodemask for filtering the zonelist.
Miao Xiec0ff7452010-05-24 14:32:08 -07001678 *
1679 * Must be protected by get_mems_allowed()
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001680 */
Mel Gorman396faf02007-07-17 04:03:13 -07001681struct zonelist *huge_zonelist(struct vm_area_struct *vma, unsigned long addr,
Mel Gorman19770b32008-04-28 02:12:18 -07001682 gfp_t gfp_flags, struct mempolicy **mpol,
1683 nodemask_t **nodemask)
Christoph Lameter5da7ca82006-01-06 00:10:46 -08001684{
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001685 struct zonelist *zl;
Christoph Lameter5da7ca82006-01-06 00:10:46 -08001686
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001687 *mpol = get_vma_policy(current, vma, addr);
Mel Gorman19770b32008-04-28 02:12:18 -07001688 *nodemask = NULL; /* assume !MPOL_BIND */
Christoph Lameter5da7ca82006-01-06 00:10:46 -08001689
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001690 if (unlikely((*mpol)->mode == MPOL_INTERLEAVE)) {
1691 zl = node_zonelist(interleave_nid(*mpol, vma, addr,
Andi Kleena5516432008-07-23 21:27:41 -07001692 huge_page_shift(hstate_vma(vma))), gfp_flags);
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001693 } else {
Andi Kleen2f5f9482011-03-04 17:36:29 -08001694 zl = policy_zonelist(gfp_flags, *mpol, numa_node_id());
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001695 if ((*mpol)->mode == MPOL_BIND)
1696 *nodemask = &(*mpol)->v.nodes;
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001697 }
1698 return zl;
Christoph Lameter5da7ca82006-01-06 00:10:46 -08001699}
Lee Schermerhorn06808b02009-12-14 17:58:21 -08001700
1701/*
1702 * init_nodemask_of_mempolicy
1703 *
1704 * If the current task's mempolicy is "default" [NULL], return 'false'
1705 * to indicate default policy. Otherwise, extract the policy nodemask
1706 * for 'bind' or 'interleave' policy into the argument nodemask, or
1707 * initialize the argument nodemask to contain the single node for
1708 * 'preferred' or 'local' policy and return 'true' to indicate presence
1709 * of non-default mempolicy.
1710 *
1711 * We don't bother with reference counting the mempolicy [mpol_get/put]
1712 * because the current task is examining it's own mempolicy and a task's
1713 * mempolicy is only ever changed by the task itself.
1714 *
1715 * N.B., it is the caller's responsibility to free a returned nodemask.
1716 */
1717bool init_nodemask_of_mempolicy(nodemask_t *mask)
1718{
1719 struct mempolicy *mempolicy;
1720 int nid;
1721
1722 if (!(mask && current->mempolicy))
1723 return false;
1724
Miao Xiec0ff7452010-05-24 14:32:08 -07001725 task_lock(current);
Lee Schermerhorn06808b02009-12-14 17:58:21 -08001726 mempolicy = current->mempolicy;
1727 switch (mempolicy->mode) {
1728 case MPOL_PREFERRED:
1729 if (mempolicy->flags & MPOL_F_LOCAL)
1730 nid = numa_node_id();
1731 else
1732 nid = mempolicy->v.preferred_node;
1733 init_nodemask_of_node(mask, nid);
1734 break;
1735
1736 case MPOL_BIND:
1737 /* Fall through */
1738 case MPOL_INTERLEAVE:
1739 *mask = mempolicy->v.nodes;
1740 break;
1741
1742 default:
1743 BUG();
1744 }
Miao Xiec0ff7452010-05-24 14:32:08 -07001745 task_unlock(current);
Lee Schermerhorn06808b02009-12-14 17:58:21 -08001746
1747 return true;
1748}
Chen, Kenneth W00ac59a2006-02-03 21:51:14 +01001749#endif
Christoph Lameter5da7ca82006-01-06 00:10:46 -08001750
David Rientjes6f48d0eb2010-08-09 17:18:52 -07001751/*
1752 * mempolicy_nodemask_intersects
1753 *
1754 * If tsk's mempolicy is "default" [NULL], return 'true' to indicate default
1755 * policy. Otherwise, check for intersection between mask and the policy
1756 * nodemask for 'bind' or 'interleave' policy. For 'perferred' or 'local'
1757 * policy, always return true since it may allocate elsewhere on fallback.
1758 *
1759 * Takes task_lock(tsk) to prevent freeing of its mempolicy.
1760 */
1761bool mempolicy_nodemask_intersects(struct task_struct *tsk,
1762 const nodemask_t *mask)
1763{
1764 struct mempolicy *mempolicy;
1765 bool ret = true;
1766
1767 if (!mask)
1768 return ret;
1769 task_lock(tsk);
1770 mempolicy = tsk->mempolicy;
1771 if (!mempolicy)
1772 goto out;
1773
1774 switch (mempolicy->mode) {
1775 case MPOL_PREFERRED:
1776 /*
1777 * MPOL_PREFERRED and MPOL_F_LOCAL are only preferred nodes to
1778 * allocate from, they may fallback to other nodes when oom.
1779 * Thus, it's possible for tsk to have allocated memory from
1780 * nodes in mask.
1781 */
1782 break;
1783 case MPOL_BIND:
1784 case MPOL_INTERLEAVE:
1785 ret = nodes_intersects(mempolicy->v.nodes, *mask);
1786 break;
1787 default:
1788 BUG();
1789 }
1790out:
1791 task_unlock(tsk);
1792 return ret;
1793}
1794
Linus Torvalds1da177e2005-04-16 15:20:36 -07001795/* Allocate a page in interleaved policy.
1796 Own path because it needs to do special accounting. */
Andi Kleen662f3a02005-10-29 18:15:49 -07001797static struct page *alloc_page_interleave(gfp_t gfp, unsigned order,
1798 unsigned nid)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001799{
1800 struct zonelist *zl;
1801 struct page *page;
1802
Mel Gorman0e884602008-04-28 02:12:14 -07001803 zl = node_zonelist(nid, gfp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001804 page = __alloc_pages(gfp, order, zl);
Mel Gormandd1a2392008-04-28 02:12:17 -07001805 if (page && page_zone(page) == zonelist_zone(&zl->_zonerefs[0]))
Christoph Lameterca889e62006-06-30 01:55:44 -07001806 inc_zone_page_state(page, NUMA_INTERLEAVE_HIT);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001807 return page;
1808}
1809
1810/**
Andrea Arcangeli0bbbc0b2011-01-13 15:47:05 -08001811 * alloc_pages_vma - Allocate a page for a VMA.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001812 *
1813 * @gfp:
1814 * %GFP_USER user allocation.
1815 * %GFP_KERNEL kernel allocations,
1816 * %GFP_HIGHMEM highmem/user allocations,
1817 * %GFP_FS allocation should not call back into a file system.
1818 * %GFP_ATOMIC don't sleep.
1819 *
Andrea Arcangeli0bbbc0b2011-01-13 15:47:05 -08001820 * @order:Order of the GFP allocation.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001821 * @vma: Pointer to VMA or NULL if not available.
1822 * @addr: Virtual Address of the allocation. Must be inside the VMA.
1823 *
1824 * This function allocates a page from the kernel page pool and applies
1825 * a NUMA policy associated with the VMA or the current process.
1826 * When VMA is not NULL caller must hold down_read on the mmap_sem of the
1827 * mm_struct of the VMA to prevent it from going away. Should be used for
1828 * all allocations for pages that will be mapped into
1829 * user space. Returns NULL when no page can be allocated.
1830 *
1831 * Should be called with the mm_sem of the vma hold.
1832 */
1833struct page *
Andrea Arcangeli0bbbc0b2011-01-13 15:47:05 -08001834alloc_pages_vma(gfp_t gfp, int order, struct vm_area_struct *vma,
Andi Kleen2f5f9482011-03-04 17:36:29 -08001835 unsigned long addr, int node)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001836{
Christoph Lameter6e21c8f2005-09-03 15:54:45 -07001837 struct mempolicy *pol = get_vma_policy(current, vma, addr);
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001838 struct zonelist *zl;
Miao Xiec0ff7452010-05-24 14:32:08 -07001839 struct page *page;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001840
Miao Xiec0ff7452010-05-24 14:32:08 -07001841 get_mems_allowed();
Lee Schermerhorn45c47452008-04-28 02:13:12 -07001842 if (unlikely(pol->mode == MPOL_INTERLEAVE)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001843 unsigned nid;
Christoph Lameter5da7ca82006-01-06 00:10:46 -08001844
Andi Kleen8eac5632011-02-25 14:44:28 -08001845 nid = interleave_nid(pol, vma, addr, PAGE_SHIFT + order);
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001846 mpol_cond_put(pol);
Andrea Arcangeli0bbbc0b2011-01-13 15:47:05 -08001847 page = alloc_page_interleave(gfp, order, nid);
Miao Xiec0ff7452010-05-24 14:32:08 -07001848 put_mems_allowed();
1849 return page;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001850 }
Andi Kleen2f5f9482011-03-04 17:36:29 -08001851 zl = policy_zonelist(gfp, pol, node);
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001852 if (unlikely(mpol_needs_cond_ref(pol))) {
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001853 /*
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001854 * slow path: ref counted shared policy
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001855 */
Andrea Arcangeli0bbbc0b2011-01-13 15:47:05 -08001856 struct page *page = __alloc_pages_nodemask(gfp, order,
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001857 zl, policy_nodemask(gfp, pol));
Lee Schermerhornf0be3d32008-04-28 02:13:08 -07001858 __mpol_put(pol);
Miao Xiec0ff7452010-05-24 14:32:08 -07001859 put_mems_allowed();
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001860 return page;
1861 }
1862 /*
1863 * fast path: default or task policy
1864 */
Andrea Arcangeli0bbbc0b2011-01-13 15:47:05 -08001865 page = __alloc_pages_nodemask(gfp, order, zl,
1866 policy_nodemask(gfp, pol));
Miao Xiec0ff7452010-05-24 14:32:08 -07001867 put_mems_allowed();
1868 return page;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001869}
1870
1871/**
1872 * alloc_pages_current - Allocate pages.
1873 *
1874 * @gfp:
1875 * %GFP_USER user allocation,
1876 * %GFP_KERNEL kernel allocation,
1877 * %GFP_HIGHMEM highmem allocation,
1878 * %GFP_FS don't call back into a file system.
1879 * %GFP_ATOMIC don't sleep.
1880 * @order: Power of two of allocation size in pages. 0 is a single page.
1881 *
1882 * Allocate a page from the kernel page pool. When not in
1883 * interrupt context and apply the current process NUMA policy.
1884 * Returns NULL when no page can be allocated.
1885 *
Paul Jacksoncf2a473c2006-01-08 01:01:54 -08001886 * Don't call cpuset_update_task_memory_state() unless
Linus Torvalds1da177e2005-04-16 15:20:36 -07001887 * 1) it's ok to take cpuset_sem (can WAIT), and
1888 * 2) allocating for current task (not interrupt).
1889 */
Al Virodd0fc662005-10-07 07:46:04 +01001890struct page *alloc_pages_current(gfp_t gfp, unsigned order)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001891{
1892 struct mempolicy *pol = current->mempolicy;
Miao Xiec0ff7452010-05-24 14:32:08 -07001893 struct page *page;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001894
Christoph Lameter9b819d22006-09-25 23:31:40 -07001895 if (!pol || in_interrupt() || (gfp & __GFP_THISNODE))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001896 pol = &default_policy;
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001897
Miao Xiec0ff7452010-05-24 14:32:08 -07001898 get_mems_allowed();
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001899 /*
1900 * No reference counting needed for current->mempolicy
1901 * nor system default_policy
1902 */
Lee Schermerhorn45c47452008-04-28 02:13:12 -07001903 if (pol->mode == MPOL_INTERLEAVE)
Miao Xiec0ff7452010-05-24 14:32:08 -07001904 page = alloc_page_interleave(gfp, order, interleave_nodes(pol));
1905 else
1906 page = __alloc_pages_nodemask(gfp, order,
Andi Kleen5c4b4be2011-03-04 17:36:32 -08001907 policy_zonelist(gfp, pol, numa_node_id()),
1908 policy_nodemask(gfp, pol));
Miao Xiec0ff7452010-05-24 14:32:08 -07001909 put_mems_allowed();
1910 return page;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001911}
1912EXPORT_SYMBOL(alloc_pages_current);
1913
Paul Jackson42253992006-01-08 01:01:59 -08001914/*
Lee Schermerhorn846a16b2008-04-28 02:13:09 -07001915 * If mpol_dup() sees current->cpuset == cpuset_being_rebound, then it
Paul Jackson42253992006-01-08 01:01:59 -08001916 * rebinds the mempolicy its copying by calling mpol_rebind_policy()
1917 * with the mems_allowed returned by cpuset_mems_allowed(). This
1918 * keeps mempolicies cpuset relative after its cpuset moves. See
1919 * further kernel/cpuset.c update_nodemask().
Miao Xie708c1bb2010-05-24 14:32:07 -07001920 *
1921 * current's mempolicy may be rebinded by the other task(the task that changes
1922 * cpuset's mems), so we needn't do rebind work for current task.
Paul Jackson42253992006-01-08 01:01:59 -08001923 */
Paul Jackson42253992006-01-08 01:01:59 -08001924
Lee Schermerhorn846a16b2008-04-28 02:13:09 -07001925/* Slow path of a mempolicy duplicate */
1926struct mempolicy *__mpol_dup(struct mempolicy *old)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001927{
1928 struct mempolicy *new = kmem_cache_alloc(policy_cache, GFP_KERNEL);
1929
1930 if (!new)
1931 return ERR_PTR(-ENOMEM);
Miao Xie708c1bb2010-05-24 14:32:07 -07001932
1933 /* task's mempolicy is protected by alloc_lock */
1934 if (old == current->mempolicy) {
1935 task_lock(current);
1936 *new = *old;
1937 task_unlock(current);
1938 } else
1939 *new = *old;
1940
Paul E. McKenney99ee4ca2010-03-03 17:50:17 -08001941 rcu_read_lock();
Paul Jackson42253992006-01-08 01:01:59 -08001942 if (current_cpuset_is_being_rebound()) {
1943 nodemask_t mems = cpuset_mems_allowed(current);
Miao Xie708c1bb2010-05-24 14:32:07 -07001944 if (new->flags & MPOL_F_REBINDING)
1945 mpol_rebind_policy(new, &mems, MPOL_REBIND_STEP2);
1946 else
1947 mpol_rebind_policy(new, &mems, MPOL_REBIND_ONCE);
Paul Jackson42253992006-01-08 01:01:59 -08001948 }
Paul E. McKenney99ee4ca2010-03-03 17:50:17 -08001949 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001950 atomic_set(&new->refcnt, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001951 return new;
1952}
1953
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001954/*
1955 * If *frompol needs [has] an extra ref, copy *frompol to *tompol ,
1956 * eliminate the * MPOL_F_* flags that require conditional ref and
1957 * [NOTE!!!] drop the extra ref. Not safe to reference *frompol directly
1958 * after return. Use the returned value.
1959 *
1960 * Allows use of a mempolicy for, e.g., multiple allocations with a single
1961 * policy lookup, even if the policy needs/has extra ref on lookup.
1962 * shmem_readahead needs this.
1963 */
1964struct mempolicy *__mpol_cond_copy(struct mempolicy *tompol,
1965 struct mempolicy *frompol)
1966{
1967 if (!mpol_needs_cond_ref(frompol))
1968 return frompol;
1969
1970 *tompol = *frompol;
1971 tompol->flags &= ~MPOL_F_SHARED; /* copy doesn't need unref */
1972 __mpol_put(frompol);
1973 return tompol;
1974}
1975
Linus Torvalds1da177e2005-04-16 15:20:36 -07001976/* Slow path of a mempolicy comparison */
1977int __mpol_equal(struct mempolicy *a, struct mempolicy *b)
1978{
1979 if (!a || !b)
1980 return 0;
Lee Schermerhorn45c47452008-04-28 02:13:12 -07001981 if (a->mode != b->mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001982 return 0;
Bob Liu19800502010-05-24 14:32:01 -07001983 if (a->flags != b->flags)
David Rientjesf5b087b2008-04-28 02:12:27 -07001984 return 0;
Bob Liu19800502010-05-24 14:32:01 -07001985 if (mpol_store_user_nodemask(a))
1986 if (!nodes_equal(a->w.user_nodemask, b->w.user_nodemask))
1987 return 0;
1988
Lee Schermerhorn45c47452008-04-28 02:13:12 -07001989 switch (a->mode) {
Mel Gorman19770b32008-04-28 02:12:18 -07001990 case MPOL_BIND:
1991 /* Fall through */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001992 case MPOL_INTERLEAVE:
Andi Kleendfcd3c02005-10-29 18:15:48 -07001993 return nodes_equal(a->v.nodes, b->v.nodes);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001994 case MPOL_PREFERRED:
Namhyung Kim75719662011-03-22 16:33:02 -07001995 return a->v.preferred_node == b->v.preferred_node;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001996 default:
1997 BUG();
1998 return 0;
1999 }
2000}
2001
Linus Torvalds1da177e2005-04-16 15:20:36 -07002002/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07002003 * Shared memory backing store policy support.
2004 *
2005 * Remember policies even when nobody has shared memory mapped.
2006 * The policies are kept in Red-Black tree linked from the inode.
2007 * They are protected by the sp->lock spinlock, which should be held
2008 * for any accesses to the tree.
2009 */
2010
2011/* lookup first element intersecting start-end */
2012/* Caller holds sp->lock */
2013static struct sp_node *
2014sp_lookup(struct shared_policy *sp, unsigned long start, unsigned long end)
2015{
2016 struct rb_node *n = sp->root.rb_node;
2017
2018 while (n) {
2019 struct sp_node *p = rb_entry(n, struct sp_node, nd);
2020
2021 if (start >= p->end)
2022 n = n->rb_right;
2023 else if (end <= p->start)
2024 n = n->rb_left;
2025 else
2026 break;
2027 }
2028 if (!n)
2029 return NULL;
2030 for (;;) {
2031 struct sp_node *w = NULL;
2032 struct rb_node *prev = rb_prev(n);
2033 if (!prev)
2034 break;
2035 w = rb_entry(prev, struct sp_node, nd);
2036 if (w->end <= start)
2037 break;
2038 n = prev;
2039 }
2040 return rb_entry(n, struct sp_node, nd);
2041}
2042
2043/* Insert a new shared policy into the list. */
2044/* Caller holds sp->lock */
2045static void sp_insert(struct shared_policy *sp, struct sp_node *new)
2046{
2047 struct rb_node **p = &sp->root.rb_node;
2048 struct rb_node *parent = NULL;
2049 struct sp_node *nd;
2050
2051 while (*p) {
2052 parent = *p;
2053 nd = rb_entry(parent, struct sp_node, nd);
2054 if (new->start < nd->start)
2055 p = &(*p)->rb_left;
2056 else if (new->end > nd->end)
2057 p = &(*p)->rb_right;
2058 else
2059 BUG();
2060 }
2061 rb_link_node(&new->nd, parent, p);
2062 rb_insert_color(&new->nd, &sp->root);
Paul Mundt140d5a42007-07-15 23:38:16 -07002063 pr_debug("inserting %lx-%lx: %d\n", new->start, new->end,
Lee Schermerhorn45c47452008-04-28 02:13:12 -07002064 new->policy ? new->policy->mode : 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002065}
2066
2067/* Find shared policy intersecting idx */
2068struct mempolicy *
2069mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx)
2070{
2071 struct mempolicy *pol = NULL;
2072 struct sp_node *sn;
2073
2074 if (!sp->root.rb_node)
2075 return NULL;
2076 spin_lock(&sp->lock);
2077 sn = sp_lookup(sp, idx, idx+1);
2078 if (sn) {
2079 mpol_get(sn->policy);
2080 pol = sn->policy;
2081 }
2082 spin_unlock(&sp->lock);
2083 return pol;
2084}
2085
2086static void sp_delete(struct shared_policy *sp, struct sp_node *n)
2087{
Paul Mundt140d5a42007-07-15 23:38:16 -07002088 pr_debug("deleting %lx-l%lx\n", n->start, n->end);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002089 rb_erase(&n->nd, &sp->root);
Lee Schermerhornf0be3d32008-04-28 02:13:08 -07002090 mpol_put(n->policy);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002091 kmem_cache_free(sn_cache, n);
2092}
2093
Adrian Bunkdbcb0f12007-10-16 01:26:26 -07002094static struct sp_node *sp_alloc(unsigned long start, unsigned long end,
2095 struct mempolicy *pol)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002096{
2097 struct sp_node *n = kmem_cache_alloc(sn_cache, GFP_KERNEL);
2098
2099 if (!n)
2100 return NULL;
2101 n->start = start;
2102 n->end = end;
2103 mpol_get(pol);
Lee Schermerhornaab0b102008-04-28 02:13:13 -07002104 pol->flags |= MPOL_F_SHARED; /* for unref */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002105 n->policy = pol;
2106 return n;
2107}
2108
2109/* Replace a policy range. */
2110static int shared_policy_replace(struct shared_policy *sp, unsigned long start,
2111 unsigned long end, struct sp_node *new)
2112{
2113 struct sp_node *n, *new2 = NULL;
2114
2115restart:
2116 spin_lock(&sp->lock);
2117 n = sp_lookup(sp, start, end);
2118 /* Take care of old policies in the same range. */
2119 while (n && n->start < end) {
2120 struct rb_node *next = rb_next(&n->nd);
2121 if (n->start >= start) {
2122 if (n->end <= end)
2123 sp_delete(sp, n);
2124 else
2125 n->start = end;
2126 } else {
2127 /* Old policy spanning whole new range. */
2128 if (n->end > end) {
2129 if (!new2) {
2130 spin_unlock(&sp->lock);
2131 new2 = sp_alloc(end, n->end, n->policy);
2132 if (!new2)
2133 return -ENOMEM;
2134 goto restart;
2135 }
2136 n->end = start;
2137 sp_insert(sp, new2);
2138 new2 = NULL;
2139 break;
2140 } else
2141 n->end = start;
2142 }
2143 if (!next)
2144 break;
2145 n = rb_entry(next, struct sp_node, nd);
2146 }
2147 if (new)
2148 sp_insert(sp, new);
2149 spin_unlock(&sp->lock);
2150 if (new2) {
Lee Schermerhornf0be3d32008-04-28 02:13:08 -07002151 mpol_put(new2->policy);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002152 kmem_cache_free(sn_cache, new2);
2153 }
2154 return 0;
2155}
2156
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002157/**
2158 * mpol_shared_policy_init - initialize shared policy for inode
2159 * @sp: pointer to inode shared policy
2160 * @mpol: struct mempolicy to install
2161 *
2162 * Install non-NULL @mpol in inode's shared policy rb-tree.
2163 * On entry, the current task has a reference on a non-NULL @mpol.
2164 * This must be released on exit.
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -07002165 * This is called at get_inode() calls and we can use GFP_KERNEL.
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002166 */
2167void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol)
Robin Holt7339ff82006-01-14 13:20:48 -08002168{
Miao Xie58568d22009-06-16 15:31:49 -07002169 int ret;
2170
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002171 sp->root = RB_ROOT; /* empty tree == default mempolicy */
2172 spin_lock_init(&sp->lock);
Robin Holt7339ff82006-01-14 13:20:48 -08002173
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002174 if (mpol) {
2175 struct vm_area_struct pvma;
2176 struct mempolicy *new;
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -07002177 NODEMASK_SCRATCH(scratch);
Robin Holt7339ff82006-01-14 13:20:48 -08002178
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -07002179 if (!scratch)
Lee Schermerhorn5c0c1652010-06-29 15:05:30 -07002180 goto put_mpol;
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002181 /* contextualize the tmpfs mount point mempolicy */
2182 new = mpol_new(mpol->mode, mpol->flags, &mpol->w.user_nodemask);
Lee Schermerhorn15d77832010-05-24 14:32:04 -07002183 if (IS_ERR(new))
Dan Carpenter0cae3452010-05-25 23:42:58 -07002184 goto free_scratch; /* no valid nodemask intersection */
Miao Xie58568d22009-06-16 15:31:49 -07002185
2186 task_lock(current);
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -07002187 ret = mpol_set_nodemask(new, &mpol->w.user_nodemask, scratch);
Miao Xie58568d22009-06-16 15:31:49 -07002188 task_unlock(current);
Lee Schermerhorn15d77832010-05-24 14:32:04 -07002189 if (ret)
Lee Schermerhorn5c0c1652010-06-29 15:05:30 -07002190 goto put_new;
Robin Holt7339ff82006-01-14 13:20:48 -08002191
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002192 /* Create pseudo-vma that contains just the policy */
2193 memset(&pvma, 0, sizeof(struct vm_area_struct));
2194 pvma.vm_end = TASK_SIZE; /* policy covers entire file */
2195 mpol_set_shared_policy(sp, &pvma, new); /* adds ref */
Lee Schermerhorn15d77832010-05-24 14:32:04 -07002196
Lee Schermerhorn5c0c1652010-06-29 15:05:30 -07002197put_new:
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002198 mpol_put(new); /* drop initial ref */
Dan Carpenter0cae3452010-05-25 23:42:58 -07002199free_scratch:
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -07002200 NODEMASK_SCRATCH_FREE(scratch);
Lee Schermerhorn5c0c1652010-06-29 15:05:30 -07002201put_mpol:
2202 mpol_put(mpol); /* drop our incoming ref on sb mpol */
Robin Holt7339ff82006-01-14 13:20:48 -08002203 }
2204}
2205
Linus Torvalds1da177e2005-04-16 15:20:36 -07002206int mpol_set_shared_policy(struct shared_policy *info,
2207 struct vm_area_struct *vma, struct mempolicy *npol)
2208{
2209 int err;
2210 struct sp_node *new = NULL;
2211 unsigned long sz = vma_pages(vma);
2212
David Rientjes028fec42008-04-28 02:12:25 -07002213 pr_debug("set_shared_policy %lx sz %lu %d %d %lx\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07002214 vma->vm_pgoff,
Lee Schermerhorn45c47452008-04-28 02:13:12 -07002215 sz, npol ? npol->mode : -1,
David Rientjes028fec42008-04-28 02:12:25 -07002216 npol ? npol->flags : -1,
Paul Mundt140d5a42007-07-15 23:38:16 -07002217 npol ? nodes_addr(npol->v.nodes)[0] : -1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002218
2219 if (npol) {
2220 new = sp_alloc(vma->vm_pgoff, vma->vm_pgoff + sz, npol);
2221 if (!new)
2222 return -ENOMEM;
2223 }
2224 err = shared_policy_replace(info, vma->vm_pgoff, vma->vm_pgoff+sz, new);
2225 if (err && new)
2226 kmem_cache_free(sn_cache, new);
2227 return err;
2228}
2229
2230/* Free a backing policy store on inode delete. */
2231void mpol_free_shared_policy(struct shared_policy *p)
2232{
2233 struct sp_node *n;
2234 struct rb_node *next;
2235
2236 if (!p->root.rb_node)
2237 return;
2238 spin_lock(&p->lock);
2239 next = rb_first(&p->root);
2240 while (next) {
2241 n = rb_entry(next, struct sp_node, nd);
2242 next = rb_next(&n->nd);
Andi Kleen90c50292005-07-27 11:43:50 -07002243 rb_erase(&n->nd, &p->root);
Lee Schermerhornf0be3d32008-04-28 02:13:08 -07002244 mpol_put(n->policy);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002245 kmem_cache_free(sn_cache, n);
2246 }
2247 spin_unlock(&p->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002248}
2249
2250/* assumes fs == KERNEL_DS */
2251void __init numa_policy_init(void)
2252{
Paul Mundtb71636e2007-07-15 23:38:15 -07002253 nodemask_t interleave_nodes;
2254 unsigned long largest = 0;
2255 int nid, prefer = 0;
2256
Linus Torvalds1da177e2005-04-16 15:20:36 -07002257 policy_cache = kmem_cache_create("numa_policy",
2258 sizeof(struct mempolicy),
Paul Mundt20c2df82007-07-20 10:11:58 +09002259 0, SLAB_PANIC, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002260
2261 sn_cache = kmem_cache_create("shared_policy_node",
2262 sizeof(struct sp_node),
Paul Mundt20c2df82007-07-20 10:11:58 +09002263 0, SLAB_PANIC, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002264
Paul Mundtb71636e2007-07-15 23:38:15 -07002265 /*
2266 * Set interleaving policy for system init. Interleaving is only
2267 * enabled across suitably sized nodes (default is >= 16MB), or
2268 * fall back to the largest node if they're all smaller.
2269 */
2270 nodes_clear(interleave_nodes);
Christoph Lameter56bbd652007-10-16 01:25:35 -07002271 for_each_node_state(nid, N_HIGH_MEMORY) {
Paul Mundtb71636e2007-07-15 23:38:15 -07002272 unsigned long total_pages = node_present_pages(nid);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002273
Paul Mundtb71636e2007-07-15 23:38:15 -07002274 /* Preserve the largest node */
2275 if (largest < total_pages) {
2276 largest = total_pages;
2277 prefer = nid;
2278 }
2279
2280 /* Interleave this node? */
2281 if ((total_pages << PAGE_SHIFT) >= (16 << 20))
2282 node_set(nid, interleave_nodes);
2283 }
2284
2285 /* All too small, use the largest */
2286 if (unlikely(nodes_empty(interleave_nodes)))
2287 node_set(prefer, interleave_nodes);
2288
David Rientjes028fec42008-04-28 02:12:25 -07002289 if (do_set_mempolicy(MPOL_INTERLEAVE, 0, &interleave_nodes))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002290 printk("numa_policy_init: interleaving failed\n");
2291}
2292
Christoph Lameter8bccd852005-10-29 18:16:59 -07002293/* Reset policy of current process to default */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002294void numa_default_policy(void)
2295{
David Rientjes028fec42008-04-28 02:12:25 -07002296 do_set_mempolicy(MPOL_DEFAULT, 0, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002297}
Paul Jackson68860ec2005-10-30 15:02:36 -08002298
Paul Jackson42253992006-01-08 01:01:59 -08002299/*
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002300 * Parse and format mempolicy from/to strings
2301 */
2302
2303/*
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -07002304 * "local" is pseudo-policy: MPOL_PREFERRED with MPOL_F_LOCAL flag
Lee Schermerhorn3f226aa2008-04-28 02:13:24 -07002305 * Used only for mpol_parse_str() and mpol_to_str()
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002306 */
Lee Schermerhorn345ace92010-05-24 14:32:04 -07002307#define MPOL_LOCAL MPOL_MAX
2308static const char * const policy_modes[] =
2309{
2310 [MPOL_DEFAULT] = "default",
2311 [MPOL_PREFERRED] = "prefer",
2312 [MPOL_BIND] = "bind",
2313 [MPOL_INTERLEAVE] = "interleave",
2314 [MPOL_LOCAL] = "local"
2315};
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002316
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002317
2318#ifdef CONFIG_TMPFS
2319/**
2320 * mpol_parse_str - parse string to mempolicy
2321 * @str: string containing mempolicy to parse
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002322 * @mpol: pointer to struct mempolicy pointer, returned on success.
2323 * @no_context: flag whether to "contextualize" the mempolicy
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002324 *
2325 * Format of input:
2326 * <mode>[=<flags>][:<nodelist>]
2327 *
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002328 * if @no_context is true, save the input nodemask in w.user_nodemask in
2329 * the returned mempolicy. This will be used to "clone" the mempolicy in
2330 * a specific context [cpuset] at a later time. Used to parse tmpfs mpol
2331 * mount option. Note that if 'static' or 'relative' mode flags were
2332 * specified, the input nodemask will already have been saved. Saving
2333 * it again is redundant, but safe.
2334 *
2335 * On success, returns 0, else 1
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002336 */
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002337int mpol_parse_str(char *str, struct mempolicy **mpol, int no_context)
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002338{
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002339 struct mempolicy *new = NULL;
Lee Schermerhornb4652e82010-05-24 14:32:03 -07002340 unsigned short mode;
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002341 unsigned short uninitialized_var(mode_flags);
2342 nodemask_t nodes;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002343 char *nodelist = strchr(str, ':');
2344 char *flags = strchr(str, '=');
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002345 int err = 1;
2346
2347 if (nodelist) {
2348 /* NUL-terminate mode or flags string */
2349 *nodelist++ = '\0';
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002350 if (nodelist_parse(nodelist, nodes))
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002351 goto out;
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002352 if (!nodes_subset(nodes, node_states[N_HIGH_MEMORY]))
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002353 goto out;
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002354 } else
2355 nodes_clear(nodes);
2356
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002357 if (flags)
2358 *flags++ = '\0'; /* terminate mode string */
2359
Lee Schermerhornb4652e82010-05-24 14:32:03 -07002360 for (mode = 0; mode <= MPOL_LOCAL; mode++) {
Lee Schermerhorn345ace92010-05-24 14:32:04 -07002361 if (!strcmp(str, policy_modes[mode])) {
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002362 break;
2363 }
2364 }
Lee Schermerhornb4652e82010-05-24 14:32:03 -07002365 if (mode > MPOL_LOCAL)
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002366 goto out;
2367
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002368 switch (mode) {
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002369 case MPOL_PREFERRED:
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002370 /*
2371 * Insist on a nodelist of one node only
2372 */
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002373 if (nodelist) {
2374 char *rest = nodelist;
2375 while (isdigit(*rest))
2376 rest++;
KOSAKI Motohiro926f2ae2010-03-23 13:35:32 -07002377 if (*rest)
2378 goto out;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002379 }
2380 break;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002381 case MPOL_INTERLEAVE:
2382 /*
2383 * Default to online nodes with memory if no nodelist
2384 */
2385 if (!nodelist)
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002386 nodes = node_states[N_HIGH_MEMORY];
Lee Schermerhorn3f226aa2008-04-28 02:13:24 -07002387 break;
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002388 case MPOL_LOCAL:
Lee Schermerhorn3f226aa2008-04-28 02:13:24 -07002389 /*
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002390 * Don't allow a nodelist; mpol_new() checks flags
Lee Schermerhorn3f226aa2008-04-28 02:13:24 -07002391 */
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002392 if (nodelist)
Lee Schermerhorn3f226aa2008-04-28 02:13:24 -07002393 goto out;
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002394 mode = MPOL_PREFERRED;
Lee Schermerhorn3f226aa2008-04-28 02:13:24 -07002395 break;
Ravikiran G Thirumalai413b43d2010-03-23 13:35:28 -07002396 case MPOL_DEFAULT:
2397 /*
2398 * Insist on a empty nodelist
2399 */
2400 if (!nodelist)
2401 err = 0;
2402 goto out;
KOSAKI Motohirod69b2e62010-03-23 13:35:30 -07002403 case MPOL_BIND:
2404 /*
2405 * Insist on a nodelist
2406 */
2407 if (!nodelist)
2408 goto out;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002409 }
2410
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002411 mode_flags = 0;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002412 if (flags) {
2413 /*
2414 * Currently, we only support two mutually exclusive
2415 * mode flags.
2416 */
2417 if (!strcmp(flags, "static"))
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002418 mode_flags |= MPOL_F_STATIC_NODES;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002419 else if (!strcmp(flags, "relative"))
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002420 mode_flags |= MPOL_F_RELATIVE_NODES;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002421 else
KOSAKI Motohiro926f2ae2010-03-23 13:35:32 -07002422 goto out;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002423 }
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002424
2425 new = mpol_new(mode, mode_flags, &nodes);
2426 if (IS_ERR(new))
KOSAKI Motohiro926f2ae2010-03-23 13:35:32 -07002427 goto out;
2428
Lee Schermerhorne17f74a2010-05-24 14:32:02 -07002429 if (no_context) {
2430 /* save for contextualization */
2431 new->w.user_nodemask = nodes;
2432 } else {
Miao Xie58568d22009-06-16 15:31:49 -07002433 int ret;
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -07002434 NODEMASK_SCRATCH(scratch);
2435 if (scratch) {
2436 task_lock(current);
2437 ret = mpol_set_nodemask(new, &nodes, scratch);
2438 task_unlock(current);
2439 } else
2440 ret = -ENOMEM;
2441 NODEMASK_SCRATCH_FREE(scratch);
2442 if (ret) {
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -07002443 mpol_put(new);
KOSAKI Motohiro926f2ae2010-03-23 13:35:32 -07002444 goto out;
Miao Xie58568d22009-06-16 15:31:49 -07002445 }
2446 }
KOSAKI Motohiro926f2ae2010-03-23 13:35:32 -07002447 err = 0;
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002448
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002449out:
2450 /* Restore string for error message */
2451 if (nodelist)
2452 *--nodelist = ':';
2453 if (flags)
2454 *--flags = '=';
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002455 if (!err)
2456 *mpol = new;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002457 return err;
2458}
2459#endif /* CONFIG_TMPFS */
2460
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002461/**
2462 * mpol_to_str - format a mempolicy structure for printing
2463 * @buffer: to contain formatted mempolicy string
2464 * @maxlen: length of @buffer
2465 * @pol: pointer to mempolicy to be formatted
2466 * @no_context: "context free" mempolicy - use nodemask in w.user_nodemask
2467 *
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002468 * Convert a mempolicy into a string.
2469 * Returns the number of characters in buffer (if positive)
2470 * or an error (negative)
2471 */
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002472int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol, int no_context)
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002473{
2474 char *p = buffer;
2475 int l;
2476 nodemask_t nodes;
Lee Schermerhornbea904d2008-04-28 02:13:18 -07002477 unsigned short mode;
David Rientjesf5b087b2008-04-28 02:12:27 -07002478 unsigned short flags = pol ? pol->flags : 0;
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002479
Lee Schermerhorn22919902008-04-28 02:13:22 -07002480 /*
2481 * Sanity check: room for longest mode, flag and some nodes
2482 */
2483 VM_BUG_ON(maxlen < strlen("interleave") + strlen("relative") + 16);
2484
Lee Schermerhornbea904d2008-04-28 02:13:18 -07002485 if (!pol || pol == &default_policy)
2486 mode = MPOL_DEFAULT;
2487 else
2488 mode = pol->mode;
2489
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002490 switch (mode) {
2491 case MPOL_DEFAULT:
2492 nodes_clear(nodes);
2493 break;
2494
2495 case MPOL_PREFERRED:
2496 nodes_clear(nodes);
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -07002497 if (flags & MPOL_F_LOCAL)
Lee Schermerhorn53f25562008-04-28 02:13:20 -07002498 mode = MPOL_LOCAL; /* pseudo-policy */
2499 else
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -07002500 node_set(pol->v.preferred_node, nodes);
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002501 break;
2502
2503 case MPOL_BIND:
Mel Gorman19770b32008-04-28 02:12:18 -07002504 /* Fall through */
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002505 case MPOL_INTERLEAVE:
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002506 if (no_context)
2507 nodes = pol->w.user_nodemask;
2508 else
2509 nodes = pol->v.nodes;
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002510 break;
2511
2512 default:
2513 BUG();
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002514 }
2515
Lee Schermerhorn345ace92010-05-24 14:32:04 -07002516 l = strlen(policy_modes[mode]);
Lee Schermerhorn53f25562008-04-28 02:13:20 -07002517 if (buffer + maxlen < p + l + 1)
2518 return -ENOSPC;
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002519
Lee Schermerhorn345ace92010-05-24 14:32:04 -07002520 strcpy(p, policy_modes[mode]);
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002521 p += l;
2522
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -07002523 if (flags & MPOL_MODE_FLAGS) {
David Rientjesf5b087b2008-04-28 02:12:27 -07002524 if (buffer + maxlen < p + 2)
2525 return -ENOSPC;
2526 *p++ = '=';
2527
Lee Schermerhorn22919902008-04-28 02:13:22 -07002528 /*
2529 * Currently, the only defined flags are mutually exclusive
2530 */
David Rientjesf5b087b2008-04-28 02:12:27 -07002531 if (flags & MPOL_F_STATIC_NODES)
Lee Schermerhorn22919902008-04-28 02:13:22 -07002532 p += snprintf(p, buffer + maxlen - p, "static");
2533 else if (flags & MPOL_F_RELATIVE_NODES)
2534 p += snprintf(p, buffer + maxlen - p, "relative");
David Rientjesf5b087b2008-04-28 02:12:27 -07002535 }
2536
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002537 if (!nodes_empty(nodes)) {
2538 if (buffer + maxlen < p + 2)
2539 return -ENOSPC;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002540 *p++ = ':';
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002541 p += nodelist_scnprintf(p, buffer + maxlen - p, nodes);
2542 }
2543 return p - buffer;
2544}