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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Simple NUMA memory policy for the Linux kernel.
3 *
4 * Copyright 2003,2004 Andi Kleen, SuSE Labs.
Christoph Lameter8bccd852005-10-29 18:16:59 -07005 * (C) Copyright 2005 Christoph Lameter, Silicon Graphics, Inc.
Linus Torvalds1da177e2005-04-16 15:20:36 -07006 * Subject to the GNU Public License, version 2.
7 *
8 * NUMA policy allows the user to give hints in which node(s) memory should
9 * be allocated.
10 *
11 * Support four policies per VMA and per process:
12 *
13 * The VMA policy has priority over the process policy for a page fault.
14 *
15 * interleave Allocate memory interleaved over a set of nodes,
16 * with normal fallback if it fails.
17 * For VMA based allocations this interleaves based on the
18 * offset into the backing object or offset into the mapping
19 * for anonymous memory. For process policy an process counter
20 * is used.
Christoph Lameter8bccd852005-10-29 18:16:59 -070021 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070022 * bind Only allocate memory on a specific set of nodes,
23 * no fallback.
Christoph Lameter8bccd852005-10-29 18:16:59 -070024 * FIXME: memory is allocated starting with the first node
25 * to the last. It would be better if bind would truly restrict
26 * the allocation to memory nodes instead
27 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070028 * preferred Try a specific node first before normal fallback.
29 * As a special case node -1 here means do the allocation
30 * on the local CPU. This is normally identical to default,
31 * but useful to set in a VMA when you have a non default
32 * process policy.
Christoph Lameter8bccd852005-10-29 18:16:59 -070033 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070034 * default Allocate on the local node first, or when on a VMA
35 * use the process policy. This is what Linux always did
36 * in a NUMA aware kernel and still does by, ahem, default.
37 *
38 * The process policy is applied for most non interrupt memory allocations
39 * in that process' context. Interrupts ignore the policies and always
40 * try to allocate on the local CPU. The VMA policy is only applied for memory
41 * allocations for a VMA in the VM.
42 *
43 * Currently there are a few corner cases in swapping where the policy
44 * is not applied, but the majority should be handled. When process policy
45 * is used it is not remembered over swap outs/swap ins.
46 *
47 * Only the highest zone in the zone hierarchy gets policied. Allocations
48 * requesting a lower zone just use default policy. This implies that
49 * on systems with highmem kernel lowmem allocation don't get policied.
50 * Same with GFP_DMA allocations.
51 *
52 * For shmfs/tmpfs/hugetlbfs shared memory the policy is shared between
53 * all users and remembered even when nobody has memory mapped.
54 */
55
56/* Notebook:
57 fix mmap readahead to honour policy and enable policy for any page cache
58 object
59 statistics for bigpages
60 global policy for page cache? currently it uses process policy. Requires
61 first item above.
62 handle mremap for shared memory (currently ignored for the policy)
63 grows down?
64 make bind policy root only? It can trigger oom much faster and the
65 kernel is not always grateful with that.
Linus Torvalds1da177e2005-04-16 15:20:36 -070066*/
67
68#include <linux/mempolicy.h>
69#include <linux/mm.h>
70#include <linux/highmem.h>
71#include <linux/hugetlb.h>
72#include <linux/kernel.h>
73#include <linux/sched.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070074#include <linux/nodemask.h>
75#include <linux/cpuset.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070076#include <linux/slab.h>
77#include <linux/string.h>
Paul Gortmakerb95f1b312011-10-16 02:01:52 -040078#include <linux/export.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 */
H Hartley Sweetene754d792011-10-31 17:09:23 -0700114static struct 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;
Wang Sheng-Hui89c522c2012-05-29 15:06:16 -0700393 if (!mpol_store_user_nodemask(pol) && step == MPOL_REBIND_ONCE &&
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);
Andrea Arcangeli1a5a9902012-03-21 16:33:42 -0700515 if (pmd_none_or_trans_huge_or_clear_bad(pmd))
Hugh Dickins91612e02005-06-21 17:15:07 -0700516 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
KOSAKI Motohiro869833f22012-10-08 16:29:16 -0700610/*
611 * Apply policy to a single VMA
612 * This must be called with the mmap_sem held for writing.
613 */
614static int vma_replace_policy(struct vm_area_struct *vma,
615 struct mempolicy *pol)
KOSAKI Motohiro8d34694c12012-10-08 16:29:14 -0700616{
KOSAKI Motohiro869833f22012-10-08 16:29:16 -0700617 int err;
618 struct mempolicy *old;
619 struct mempolicy *new;
KOSAKI Motohiro8d34694c12012-10-08 16:29:14 -0700620
621 pr_debug("vma %lx-%lx/%lx vm_ops %p vm_file %p set_policy %p\n",
622 vma->vm_start, vma->vm_end, vma->vm_pgoff,
623 vma->vm_ops, vma->vm_file,
624 vma->vm_ops ? vma->vm_ops->set_policy : NULL);
625
KOSAKI Motohiro869833f22012-10-08 16:29:16 -0700626 new = mpol_dup(pol);
627 if (IS_ERR(new))
628 return PTR_ERR(new);
629
630 if (vma->vm_ops && vma->vm_ops->set_policy) {
KOSAKI Motohiro8d34694c12012-10-08 16:29:14 -0700631 err = vma->vm_ops->set_policy(vma, new);
KOSAKI Motohiro869833f22012-10-08 16:29:16 -0700632 if (err)
633 goto err_out;
KOSAKI Motohiro8d34694c12012-10-08 16:29:14 -0700634 }
KOSAKI Motohiro869833f22012-10-08 16:29:16 -0700635
636 old = vma->vm_policy;
637 vma->vm_policy = new; /* protected by mmap_sem */
638 mpol_put(old);
639
640 return 0;
641 err_out:
642 mpol_put(new);
KOSAKI Motohiro8d34694c12012-10-08 16:29:14 -0700643 return err;
644}
645
Linus Torvalds1da177e2005-04-16 15:20:36 -0700646/* Step 2: apply policy to a range and do splits. */
KOSAKI Motohiro9d8cebd2010-03-05 13:41:57 -0800647static int mbind_range(struct mm_struct *mm, unsigned long start,
648 unsigned long end, struct mempolicy *new_pol)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700649{
650 struct vm_area_struct *next;
KOSAKI Motohiro9d8cebd2010-03-05 13:41:57 -0800651 struct vm_area_struct *prev;
652 struct vm_area_struct *vma;
653 int err = 0;
KOSAKI Motohiroe26a5112011-12-28 15:57:11 -0800654 pgoff_t pgoff;
KOSAKI Motohiro9d8cebd2010-03-05 13:41:57 -0800655 unsigned long vmstart;
656 unsigned long vmend;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657
Linus Torvalds097d5912012-03-06 18:23:36 -0800658 vma = find_vma(mm, start);
KOSAKI Motohiro9d8cebd2010-03-05 13:41:57 -0800659 if (!vma || vma->vm_start > start)
660 return -EFAULT;
661
Linus Torvalds097d5912012-03-06 18:23:36 -0800662 prev = vma->vm_prev;
KOSAKI Motohiroe26a5112011-12-28 15:57:11 -0800663 if (start > vma->vm_start)
664 prev = vma;
665
KOSAKI Motohiro9d8cebd2010-03-05 13:41:57 -0800666 for (; vma && vma->vm_start < end; prev = vma, vma = next) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667 next = vma->vm_next;
KOSAKI Motohiro9d8cebd2010-03-05 13:41:57 -0800668 vmstart = max(start, vma->vm_start);
669 vmend = min(end, vma->vm_end);
670
KOSAKI Motohiroe26a5112011-12-28 15:57:11 -0800671 if (mpol_equal(vma_policy(vma), new_pol))
672 continue;
673
674 pgoff = vma->vm_pgoff +
675 ((vmstart - vma->vm_start) >> PAGE_SHIFT);
KOSAKI Motohiro9d8cebd2010-03-05 13:41:57 -0800676 prev = vma_merge(mm, prev, vmstart, vmend, vma->vm_flags,
KOSAKI Motohiroe26a5112011-12-28 15:57:11 -0800677 vma->anon_vma, vma->vm_file, pgoff,
Caspar Zhang8aacc9f2011-09-14 16:20:58 -0700678 new_pol);
KOSAKI Motohiro9d8cebd2010-03-05 13:41:57 -0800679 if (prev) {
680 vma = prev;
681 next = vma->vm_next;
682 continue;
683 }
684 if (vma->vm_start != vmstart) {
685 err = split_vma(vma->vm_mm, vma, vmstart, 1);
686 if (err)
687 goto out;
688 }
689 if (vma->vm_end != vmend) {
690 err = split_vma(vma->vm_mm, vma, vmend, 0);
691 if (err)
692 goto out;
693 }
KOSAKI Motohiro869833f22012-10-08 16:29:16 -0700694 err = vma_replace_policy(vma, new_pol);
KOSAKI Motohiro8d34694c12012-10-08 16:29:14 -0700695 if (err)
696 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700697 }
KOSAKI Motohiro9d8cebd2010-03-05 13:41:57 -0800698
699 out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700700 return err;
701}
702
Paul Jacksonc61afb12006-03-24 03:16:08 -0800703/*
704 * Update task->flags PF_MEMPOLICY bit: set iff non-default
705 * mempolicy. Allows more rapid checking of this (combined perhaps
706 * with other PF_* flag bits) on memory allocation hot code paths.
707 *
708 * If called from outside this file, the task 'p' should -only- be
709 * a newly forked child not yet visible on the task list, because
710 * manipulating the task flags of a visible task is not safe.
711 *
712 * The above limitation is why this routine has the funny name
713 * mpol_fix_fork_child_flag().
714 *
715 * It is also safe to call this with a task pointer of current,
716 * which the static wrapper mpol_set_task_struct_flag() does,
717 * for use within this file.
718 */
719
720void mpol_fix_fork_child_flag(struct task_struct *p)
721{
722 if (p->mempolicy)
723 p->flags |= PF_MEMPOLICY;
724 else
725 p->flags &= ~PF_MEMPOLICY;
726}
727
728static void mpol_set_task_struct_flag(void)
729{
730 mpol_fix_fork_child_flag(current);
731}
732
Linus Torvalds1da177e2005-04-16 15:20:36 -0700733/* Set the process memory policy */
David Rientjes028fec42008-04-28 02:12:25 -0700734static long do_set_mempolicy(unsigned short mode, unsigned short flags,
735 nodemask_t *nodes)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736{
Miao Xie58568d22009-06-16 15:31:49 -0700737 struct mempolicy *new, *old;
Lee Schermerhornf4e53d92008-04-28 02:13:10 -0700738 struct mm_struct *mm = current->mm;
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -0700739 NODEMASK_SCRATCH(scratch);
Miao Xie58568d22009-06-16 15:31:49 -0700740 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700741
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -0700742 if (!scratch)
743 return -ENOMEM;
Lee Schermerhornf4e53d92008-04-28 02:13:10 -0700744
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -0700745 new = mpol_new(mode, flags, nodes);
746 if (IS_ERR(new)) {
747 ret = PTR_ERR(new);
748 goto out;
749 }
Lee Schermerhornf4e53d92008-04-28 02:13:10 -0700750 /*
751 * prevent changing our mempolicy while show_numa_maps()
752 * is using it.
753 * Note: do_set_mempolicy() can be called at init time
754 * with no 'mm'.
755 */
756 if (mm)
757 down_write(&mm->mmap_sem);
Miao Xie58568d22009-06-16 15:31:49 -0700758 task_lock(current);
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -0700759 ret = mpol_set_nodemask(new, nodes, scratch);
Miao Xie58568d22009-06-16 15:31:49 -0700760 if (ret) {
761 task_unlock(current);
762 if (mm)
763 up_write(&mm->mmap_sem);
764 mpol_put(new);
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -0700765 goto out;
Miao Xie58568d22009-06-16 15:31:49 -0700766 }
767 old = current->mempolicy;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700768 current->mempolicy = new;
Paul Jacksonc61afb12006-03-24 03:16:08 -0800769 mpol_set_task_struct_flag();
Lee Schermerhorn45c47452008-04-28 02:13:12 -0700770 if (new && new->mode == MPOL_INTERLEAVE &&
David Rientjesf5b087b2008-04-28 02:12:27 -0700771 nodes_weight(new->v.nodes))
Andi Kleendfcd3c02005-10-29 18:15:48 -0700772 current->il_next = first_node(new->v.nodes);
Miao Xie58568d22009-06-16 15:31:49 -0700773 task_unlock(current);
Lee Schermerhornf4e53d92008-04-28 02:13:10 -0700774 if (mm)
775 up_write(&mm->mmap_sem);
776
Miao Xie58568d22009-06-16 15:31:49 -0700777 mpol_put(old);
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -0700778 ret = 0;
779out:
780 NODEMASK_SCRATCH_FREE(scratch);
781 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700782}
783
Lee Schermerhornbea904d2008-04-28 02:13:18 -0700784/*
785 * Return nodemask for policy for get_mempolicy() query
Miao Xie58568d22009-06-16 15:31:49 -0700786 *
787 * Called with task's alloc_lock held
Lee Schermerhornbea904d2008-04-28 02:13:18 -0700788 */
789static void get_policy_nodemask(struct mempolicy *p, nodemask_t *nodes)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790{
Andi Kleendfcd3c02005-10-29 18:15:48 -0700791 nodes_clear(*nodes);
Lee Schermerhornbea904d2008-04-28 02:13:18 -0700792 if (p == &default_policy)
793 return;
794
Lee Schermerhorn45c47452008-04-28 02:13:12 -0700795 switch (p->mode) {
Mel Gorman19770b32008-04-28 02:12:18 -0700796 case MPOL_BIND:
797 /* Fall through */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700798 case MPOL_INTERLEAVE:
Andi Kleendfcd3c02005-10-29 18:15:48 -0700799 *nodes = p->v.nodes;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700800 break;
801 case MPOL_PREFERRED:
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -0700802 if (!(p->flags & MPOL_F_LOCAL))
Andi Kleendfcd3c02005-10-29 18:15:48 -0700803 node_set(p->v.preferred_node, *nodes);
Lee Schermerhorn53f25562008-04-28 02:13:20 -0700804 /* else return empty node mask for local allocation */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700805 break;
806 default:
807 BUG();
808 }
809}
810
811static int lookup_node(struct mm_struct *mm, unsigned long addr)
812{
813 struct page *p;
814 int err;
815
816 err = get_user_pages(current, mm, addr & PAGE_MASK, 1, 0, 0, &p, NULL);
817 if (err >= 0) {
818 err = page_to_nid(p);
819 put_page(p);
820 }
821 return err;
822}
823
Linus Torvalds1da177e2005-04-16 15:20:36 -0700824/* Retrieve NUMA policy */
Adrian Bunkdbcb0f12007-10-16 01:26:26 -0700825static long do_get_mempolicy(int *policy, nodemask_t *nmask,
826 unsigned long addr, unsigned long flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700827{
Christoph Lameter8bccd852005-10-29 18:16:59 -0700828 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700829 struct mm_struct *mm = current->mm;
830 struct vm_area_struct *vma = NULL;
831 struct mempolicy *pol = current->mempolicy;
832
Lee Schermerhorn754af6f2007-10-16 01:24:51 -0700833 if (flags &
834 ~(unsigned long)(MPOL_F_NODE|MPOL_F_ADDR|MPOL_F_MEMS_ALLOWED))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700835 return -EINVAL;
Lee Schermerhorn754af6f2007-10-16 01:24:51 -0700836
837 if (flags & MPOL_F_MEMS_ALLOWED) {
838 if (flags & (MPOL_F_NODE|MPOL_F_ADDR))
839 return -EINVAL;
840 *policy = 0; /* just so it's initialized */
Miao Xie58568d22009-06-16 15:31:49 -0700841 task_lock(current);
Lee Schermerhorn754af6f2007-10-16 01:24:51 -0700842 *nmask = cpuset_current_mems_allowed;
Miao Xie58568d22009-06-16 15:31:49 -0700843 task_unlock(current);
Lee Schermerhorn754af6f2007-10-16 01:24:51 -0700844 return 0;
845 }
846
Linus Torvalds1da177e2005-04-16 15:20:36 -0700847 if (flags & MPOL_F_ADDR) {
Lee Schermerhornbea904d2008-04-28 02:13:18 -0700848 /*
849 * Do NOT fall back to task policy if the
850 * vma/shared policy at addr is NULL. We
851 * want to return MPOL_DEFAULT in this case.
852 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700853 down_read(&mm->mmap_sem);
854 vma = find_vma_intersection(mm, addr, addr+1);
855 if (!vma) {
856 up_read(&mm->mmap_sem);
857 return -EFAULT;
858 }
859 if (vma->vm_ops && vma->vm_ops->get_policy)
860 pol = vma->vm_ops->get_policy(vma, addr);
861 else
862 pol = vma->vm_policy;
863 } else if (addr)
864 return -EINVAL;
865
866 if (!pol)
Lee Schermerhornbea904d2008-04-28 02:13:18 -0700867 pol = &default_policy; /* indicates default behavior */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700868
869 if (flags & MPOL_F_NODE) {
870 if (flags & MPOL_F_ADDR) {
871 err = lookup_node(mm, addr);
872 if (err < 0)
873 goto out;
Christoph Lameter8bccd852005-10-29 18:16:59 -0700874 *policy = err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700875 } else if (pol == current->mempolicy &&
Lee Schermerhorn45c47452008-04-28 02:13:12 -0700876 pol->mode == MPOL_INTERLEAVE) {
Christoph Lameter8bccd852005-10-29 18:16:59 -0700877 *policy = current->il_next;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700878 } else {
879 err = -EINVAL;
880 goto out;
881 }
Lee Schermerhornbea904d2008-04-28 02:13:18 -0700882 } else {
883 *policy = pol == &default_policy ? MPOL_DEFAULT :
884 pol->mode;
David Rientjesd79df632008-07-04 12:24:13 -0700885 /*
886 * Internal mempolicy flags must be masked off before exposing
887 * the policy to userspace.
888 */
889 *policy |= (pol->flags & MPOL_MODE_FLAGS);
Lee Schermerhornbea904d2008-04-28 02:13:18 -0700890 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700891
892 if (vma) {
893 up_read(&current->mm->mmap_sem);
894 vma = NULL;
895 }
896
Linus Torvalds1da177e2005-04-16 15:20:36 -0700897 err = 0;
Miao Xie58568d22009-06-16 15:31:49 -0700898 if (nmask) {
Lee Schermerhornc6b6ef82010-03-23 13:35:41 -0700899 if (mpol_store_user_nodemask(pol)) {
900 *nmask = pol->w.user_nodemask;
901 } else {
902 task_lock(current);
903 get_policy_nodemask(pol, nmask);
904 task_unlock(current);
905 }
Miao Xie58568d22009-06-16 15:31:49 -0700906 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700907
908 out:
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -0700909 mpol_cond_put(pol);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700910 if (vma)
911 up_read(&current->mm->mmap_sem);
912 return err;
913}
914
Christoph Lameterb20a3502006-03-22 00:09:12 -0800915#ifdef CONFIG_MIGRATION
Christoph Lameter8bccd852005-10-29 18:16:59 -0700916/*
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -0800917 * page migration
918 */
Christoph Lameterfc301282006-01-18 17:42:29 -0800919static void migrate_page_add(struct page *page, struct list_head *pagelist,
920 unsigned long flags)
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -0800921{
922 /*
Christoph Lameterfc301282006-01-18 17:42:29 -0800923 * Avoid migrating a page that is shared with others.
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -0800924 */
Nick Piggin62695a82008-10-18 20:26:09 -0700925 if ((flags & MPOL_MF_MOVE_ALL) || page_mapcount(page) == 1) {
926 if (!isolate_lru_page(page)) {
927 list_add_tail(&page->lru, pagelist);
KOSAKI Motohiro6d9c2852009-12-14 17:58:11 -0800928 inc_zone_page_state(page, NR_ISOLATED_ANON +
929 page_is_file_cache(page));
Nick Piggin62695a82008-10-18 20:26:09 -0700930 }
931 }
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -0800932}
933
Christoph Lameter742755a2006-06-23 02:03:55 -0700934static struct page *new_node_page(struct page *page, unsigned long node, int **x)
Christoph Lameter95a402c2006-06-23 02:03:53 -0700935{
Mel Gorman6484eb32009-06-16 15:31:54 -0700936 return alloc_pages_exact_node(node, GFP_HIGHUSER_MOVABLE, 0);
Christoph Lameter95a402c2006-06-23 02:03:53 -0700937}
938
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -0800939/*
Christoph Lameter7e2ab152006-02-01 03:05:40 -0800940 * Migrate pages from one node to a target node.
941 * Returns error or the number of pages not migrated.
942 */
Adrian Bunkdbcb0f12007-10-16 01:26:26 -0700943static int migrate_to_node(struct mm_struct *mm, int source, int dest,
944 int flags)
Christoph Lameter7e2ab152006-02-01 03:05:40 -0800945{
946 nodemask_t nmask;
947 LIST_HEAD(pagelist);
948 int err = 0;
949
950 nodes_clear(nmask);
951 node_set(source, nmask);
952
Minchan Kim08270802012-10-08 16:33:38 -0700953 /*
954 * This does not "check" the range but isolates all pages that
955 * need migration. Between passing in the full user address
956 * space range and MPOL_MF_DISCONTIG_OK, this call can not fail.
957 */
958 VM_BUG_ON(!(flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)));
959 check_range(mm, mm->mmap->vm_start, mm->task_size, &nmask,
Christoph Lameter7e2ab152006-02-01 03:05:40 -0800960 flags | MPOL_MF_DISCONTIG_OK, &pagelist);
961
Minchan Kimcf608ac2010-10-26 14:21:29 -0700962 if (!list_empty(&pagelist)) {
Mel Gorman7f0f2492011-01-13 15:45:58 -0800963 err = migrate_pages(&pagelist, new_node_page, dest,
Mel Gormana6bc32b2012-01-12 17:19:43 -0800964 false, MIGRATE_SYNC);
Minchan Kimcf608ac2010-10-26 14:21:29 -0700965 if (err)
966 putback_lru_pages(&pagelist);
967 }
Christoph Lameter95a402c2006-06-23 02:03:53 -0700968
Christoph Lameter7e2ab152006-02-01 03:05:40 -0800969 return err;
970}
971
972/*
973 * Move pages between the two nodesets so as to preserve the physical
974 * layout as much as possible.
Christoph Lameter39743882006-01-08 01:00:51 -0800975 *
976 * Returns the number of page that could not be moved.
977 */
Andrew Morton0ce72d42012-05-29 15:06:24 -0700978int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
979 const nodemask_t *to, int flags)
Christoph Lameter39743882006-01-08 01:00:51 -0800980{
Christoph Lameter7e2ab152006-02-01 03:05:40 -0800981 int busy = 0;
Christoph Lameter0aedadf2008-11-06 12:53:30 -0800982 int err;
Christoph Lameter7e2ab152006-02-01 03:05:40 -0800983 nodemask_t tmp;
Christoph Lameter39743882006-01-08 01:00:51 -0800984
Christoph Lameter0aedadf2008-11-06 12:53:30 -0800985 err = migrate_prep();
986 if (err)
987 return err;
988
Lee Schermerhorn53f25562008-04-28 02:13:20 -0700989 down_read(&mm->mmap_sem);
Christoph Lameter39743882006-01-08 01:00:51 -0800990
Andrew Morton0ce72d42012-05-29 15:06:24 -0700991 err = migrate_vmas(mm, from, to, flags);
Christoph Lameter7b2259b2006-06-25 05:46:48 -0700992 if (err)
993 goto out;
994
KOSAKI Motohiroda0aa132010-03-05 13:41:59 -0800995 /*
996 * Find a 'source' bit set in 'tmp' whose corresponding 'dest'
997 * bit in 'to' is not also set in 'tmp'. Clear the found 'source'
998 * bit in 'tmp', and return that <source, dest> pair for migration.
999 * The pair of nodemasks 'to' and 'from' define the map.
1000 *
1001 * If no pair of bits is found that way, fallback to picking some
1002 * pair of 'source' and 'dest' bits that are not the same. If the
1003 * 'source' and 'dest' bits are the same, this represents a node
1004 * that will be migrating to itself, so no pages need move.
1005 *
1006 * If no bits are left in 'tmp', or if all remaining bits left
1007 * in 'tmp' correspond to the same bit in 'to', return false
1008 * (nothing left to migrate).
1009 *
1010 * This lets us pick a pair of nodes to migrate between, such that
1011 * if possible the dest node is not already occupied by some other
1012 * source node, minimizing the risk of overloading the memory on a
1013 * node that would happen if we migrated incoming memory to a node
1014 * before migrating outgoing memory source that same node.
1015 *
1016 * A single scan of tmp is sufficient. As we go, we remember the
1017 * most recent <s, d> pair that moved (s != d). If we find a pair
1018 * that not only moved, but what's better, moved to an empty slot
1019 * (d is not set in tmp), then we break out then, with that pair.
Justin P. Mattockae0e47f2011-03-01 15:06:02 +01001020 * Otherwise when we finish scanning from_tmp, we at least have the
KOSAKI Motohiroda0aa132010-03-05 13:41:59 -08001021 * most recent <s, d> pair that moved. If we get all the way through
1022 * the scan of tmp without finding any node that moved, much less
1023 * moved to an empty node, then there is nothing left worth migrating.
1024 */
Christoph Lameterd4984712006-01-08 01:00:55 -08001025
Andrew Morton0ce72d42012-05-29 15:06:24 -07001026 tmp = *from;
Christoph Lameter7e2ab152006-02-01 03:05:40 -08001027 while (!nodes_empty(tmp)) {
1028 int s,d;
1029 int source = -1;
1030 int dest = 0;
1031
1032 for_each_node_mask(s, tmp) {
Larry Woodman4a5b18c2012-05-29 15:06:24 -07001033
1034 /*
1035 * do_migrate_pages() tries to maintain the relative
1036 * node relationship of the pages established between
1037 * threads and memory areas.
1038 *
1039 * However if the number of source nodes is not equal to
1040 * the number of destination nodes we can not preserve
1041 * this node relative relationship. In that case, skip
1042 * copying memory from a node that is in the destination
1043 * mask.
1044 *
1045 * Example: [2,3,4] -> [3,4,5] moves everything.
1046 * [0-7] - > [3,4,5] moves only 0,1,2,6,7.
1047 */
1048
Andrew Morton0ce72d42012-05-29 15:06:24 -07001049 if ((nodes_weight(*from) != nodes_weight(*to)) &&
1050 (node_isset(s, *to)))
Larry Woodman4a5b18c2012-05-29 15:06:24 -07001051 continue;
1052
Andrew Morton0ce72d42012-05-29 15:06:24 -07001053 d = node_remap(s, *from, *to);
Christoph Lameter7e2ab152006-02-01 03:05:40 -08001054 if (s == d)
1055 continue;
1056
1057 source = s; /* Node moved. Memorize */
1058 dest = d;
1059
1060 /* dest not in remaining from nodes? */
1061 if (!node_isset(dest, tmp))
1062 break;
1063 }
1064 if (source == -1)
1065 break;
1066
1067 node_clear(source, tmp);
1068 err = migrate_to_node(mm, source, dest, flags);
1069 if (err > 0)
1070 busy += err;
1071 if (err < 0)
1072 break;
Christoph Lameter39743882006-01-08 01:00:51 -08001073 }
Christoph Lameter7b2259b2006-06-25 05:46:48 -07001074out:
Christoph Lameter39743882006-01-08 01:00:51 -08001075 up_read(&mm->mmap_sem);
Christoph Lameter7e2ab152006-02-01 03:05:40 -08001076 if (err < 0)
1077 return err;
1078 return busy;
Christoph Lameterb20a3502006-03-22 00:09:12 -08001079
Christoph Lameter39743882006-01-08 01:00:51 -08001080}
1081
Lee Schermerhorn3ad33b22007-11-14 16:59:10 -08001082/*
1083 * Allocate a new page for page migration based on vma policy.
1084 * Start assuming that page is mapped by vma pointed to by @private.
1085 * Search forward from there, if not. N.B., this assumes that the
1086 * list of pages handed to migrate_pages()--which is how we get here--
1087 * is in virtual address order.
1088 */
Christoph Lameter742755a2006-06-23 02:03:55 -07001089static struct page *new_vma_page(struct page *page, unsigned long private, int **x)
Christoph Lameter95a402c2006-06-23 02:03:53 -07001090{
1091 struct vm_area_struct *vma = (struct vm_area_struct *)private;
Lee Schermerhorn3ad33b22007-11-14 16:59:10 -08001092 unsigned long uninitialized_var(address);
Christoph Lameter95a402c2006-06-23 02:03:53 -07001093
Lee Schermerhorn3ad33b22007-11-14 16:59:10 -08001094 while (vma) {
1095 address = page_address_in_vma(page, vma);
1096 if (address != -EFAULT)
1097 break;
1098 vma = vma->vm_next;
1099 }
1100
1101 /*
1102 * if !vma, alloc_page_vma() will use task or system default policy
1103 */
1104 return alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
Christoph Lameter95a402c2006-06-23 02:03:53 -07001105}
Christoph Lameterb20a3502006-03-22 00:09:12 -08001106#else
1107
1108static void migrate_page_add(struct page *page, struct list_head *pagelist,
1109 unsigned long flags)
1110{
1111}
1112
Andrew Morton0ce72d42012-05-29 15:06:24 -07001113int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
1114 const nodemask_t *to, int flags)
Christoph Lameterb20a3502006-03-22 00:09:12 -08001115{
1116 return -ENOSYS;
1117}
Christoph Lameter95a402c2006-06-23 02:03:53 -07001118
Keith Owens69939742006-10-11 01:21:28 -07001119static struct page *new_vma_page(struct page *page, unsigned long private, int **x)
Christoph Lameter95a402c2006-06-23 02:03:53 -07001120{
1121 return NULL;
1122}
Christoph Lameterb20a3502006-03-22 00:09:12 -08001123#endif
1124
Adrian Bunkdbcb0f12007-10-16 01:26:26 -07001125static long do_mbind(unsigned long start, unsigned long len,
David Rientjes028fec42008-04-28 02:12:25 -07001126 unsigned short mode, unsigned short mode_flags,
1127 nodemask_t *nmask, unsigned long flags)
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -08001128{
1129 struct vm_area_struct *vma;
1130 struct mm_struct *mm = current->mm;
1131 struct mempolicy *new;
1132 unsigned long end;
1133 int err;
1134 LIST_HEAD(pagelist);
1135
David Rientjesa3b51e02008-04-28 02:12:23 -07001136 if (flags & ~(unsigned long)(MPOL_MF_STRICT |
1137 MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -08001138 return -EINVAL;
Christoph Lameter74c00242006-03-14 19:50:21 -08001139 if ((flags & MPOL_MF_MOVE_ALL) && !capable(CAP_SYS_NICE))
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -08001140 return -EPERM;
1141
1142 if (start & ~PAGE_MASK)
1143 return -EINVAL;
1144
1145 if (mode == MPOL_DEFAULT)
1146 flags &= ~MPOL_MF_STRICT;
1147
1148 len = (len + PAGE_SIZE - 1) & PAGE_MASK;
1149 end = start + len;
1150
1151 if (end < start)
1152 return -EINVAL;
1153 if (end == start)
1154 return 0;
1155
David Rientjes028fec42008-04-28 02:12:25 -07001156 new = mpol_new(mode, mode_flags, nmask);
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -08001157 if (IS_ERR(new))
1158 return PTR_ERR(new);
1159
1160 /*
1161 * If we are using the default policy then operation
1162 * on discontinuous address spaces is okay after all
1163 */
1164 if (!new)
1165 flags |= MPOL_MF_DISCONTIG_OK;
1166
David Rientjes028fec42008-04-28 02:12:25 -07001167 pr_debug("mbind %lx-%lx mode:%d flags:%d nodes:%lx\n",
1168 start, start + len, mode, mode_flags,
1169 nmask ? nodes_addr(*nmask)[0] : -1);
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -08001170
Christoph Lameter0aedadf2008-11-06 12:53:30 -08001171 if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) {
1172
1173 err = migrate_prep();
1174 if (err)
KOSAKI Motohirob05ca732009-10-26 16:49:59 -07001175 goto mpol_out;
Christoph Lameter0aedadf2008-11-06 12:53:30 -08001176 }
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -07001177 {
1178 NODEMASK_SCRATCH(scratch);
1179 if (scratch) {
1180 down_write(&mm->mmap_sem);
1181 task_lock(current);
1182 err = mpol_set_nodemask(new, nmask, scratch);
1183 task_unlock(current);
1184 if (err)
1185 up_write(&mm->mmap_sem);
1186 } else
1187 err = -ENOMEM;
1188 NODEMASK_SCRATCH_FREE(scratch);
1189 }
KOSAKI Motohirob05ca732009-10-26 16:49:59 -07001190 if (err)
1191 goto mpol_out;
1192
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -08001193 vma = check_range(mm, start, end, nmask,
1194 flags | MPOL_MF_INVERT, &pagelist);
1195
1196 err = PTR_ERR(vma);
1197 if (!IS_ERR(vma)) {
1198 int nr_failed = 0;
1199
KOSAKI Motohiro9d8cebd2010-03-05 13:41:57 -08001200 err = mbind_range(mm, start, end, new);
Christoph Lameter7e2ab152006-02-01 03:05:40 -08001201
Minchan Kimcf608ac2010-10-26 14:21:29 -07001202 if (!list_empty(&pagelist)) {
Christoph Lameter95a402c2006-06-23 02:03:53 -07001203 nr_failed = migrate_pages(&pagelist, new_vma_page,
Mel Gorman7f0f2492011-01-13 15:45:58 -08001204 (unsigned long)vma,
David Rientjesc4c0e9e2012-06-20 18:00:12 -07001205 false, MIGRATE_SYNC);
Minchan Kimcf608ac2010-10-26 14:21:29 -07001206 if (nr_failed)
1207 putback_lru_pages(&pagelist);
1208 }
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -08001209
1210 if (!err && nr_failed && (flags & MPOL_MF_STRICT))
1211 err = -EIO;
KOSAKI Motohiroab8a3e12009-10-26 16:49:58 -07001212 } else
1213 putback_lru_pages(&pagelist);
Christoph Lameterb20a3502006-03-22 00:09:12 -08001214
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -08001215 up_write(&mm->mmap_sem);
KOSAKI Motohirob05ca732009-10-26 16:49:59 -07001216 mpol_out:
Lee Schermerhornf0be3d32008-04-28 02:13:08 -07001217 mpol_put(new);
Christoph Lameter6ce3c4c2006-01-08 01:01:04 -08001218 return err;
1219}
1220
Christoph Lameter39743882006-01-08 01:00:51 -08001221/*
Christoph Lameter8bccd852005-10-29 18:16:59 -07001222 * User space interface with variable sized bitmaps for nodelists.
1223 */
1224
1225/* Copy a node mask from user space. */
Christoph Lameter39743882006-01-08 01:00:51 -08001226static int get_nodes(nodemask_t *nodes, const unsigned long __user *nmask,
Christoph Lameter8bccd852005-10-29 18:16:59 -07001227 unsigned long maxnode)
1228{
1229 unsigned long k;
1230 unsigned long nlongs;
1231 unsigned long endmask;
1232
1233 --maxnode;
1234 nodes_clear(*nodes);
1235 if (maxnode == 0 || !nmask)
1236 return 0;
Andi Kleena9c930b2006-02-20 18:27:59 -08001237 if (maxnode > PAGE_SIZE*BITS_PER_BYTE)
Chris Wright636f13c2006-02-17 13:59:36 -08001238 return -EINVAL;
Christoph Lameter8bccd852005-10-29 18:16:59 -07001239
1240 nlongs = BITS_TO_LONGS(maxnode);
1241 if ((maxnode % BITS_PER_LONG) == 0)
1242 endmask = ~0UL;
1243 else
1244 endmask = (1UL << (maxnode % BITS_PER_LONG)) - 1;
1245
1246 /* When the user specified more nodes than supported just check
1247 if the non supported part is all zero. */
1248 if (nlongs > BITS_TO_LONGS(MAX_NUMNODES)) {
1249 if (nlongs > PAGE_SIZE/sizeof(long))
1250 return -EINVAL;
1251 for (k = BITS_TO_LONGS(MAX_NUMNODES); k < nlongs; k++) {
1252 unsigned long t;
1253 if (get_user(t, nmask + k))
1254 return -EFAULT;
1255 if (k == nlongs - 1) {
1256 if (t & endmask)
1257 return -EINVAL;
1258 } else if (t)
1259 return -EINVAL;
1260 }
1261 nlongs = BITS_TO_LONGS(MAX_NUMNODES);
1262 endmask = ~0UL;
1263 }
1264
1265 if (copy_from_user(nodes_addr(*nodes), nmask, nlongs*sizeof(unsigned long)))
1266 return -EFAULT;
1267 nodes_addr(*nodes)[nlongs-1] &= endmask;
1268 return 0;
1269}
1270
1271/* Copy a kernel node mask to user space */
1272static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode,
1273 nodemask_t *nodes)
1274{
1275 unsigned long copy = ALIGN(maxnode-1, 64) / 8;
1276 const int nbytes = BITS_TO_LONGS(MAX_NUMNODES) * sizeof(long);
1277
1278 if (copy > nbytes) {
1279 if (copy > PAGE_SIZE)
1280 return -EINVAL;
1281 if (clear_user((char __user *)mask + nbytes, copy - nbytes))
1282 return -EFAULT;
1283 copy = nbytes;
1284 }
1285 return copy_to_user(mask, nodes_addr(*nodes), copy) ? -EFAULT : 0;
1286}
1287
Heiko Carstens938bb9f2009-01-14 14:14:30 +01001288SYSCALL_DEFINE6(mbind, unsigned long, start, unsigned long, len,
1289 unsigned long, mode, unsigned long __user *, nmask,
1290 unsigned long, maxnode, unsigned, flags)
Christoph Lameter8bccd852005-10-29 18:16:59 -07001291{
1292 nodemask_t nodes;
1293 int err;
David Rientjes028fec42008-04-28 02:12:25 -07001294 unsigned short mode_flags;
Christoph Lameter8bccd852005-10-29 18:16:59 -07001295
David Rientjes028fec42008-04-28 02:12:25 -07001296 mode_flags = mode & MPOL_MODE_FLAGS;
1297 mode &= ~MPOL_MODE_FLAGS;
David Rientjesa3b51e02008-04-28 02:12:23 -07001298 if (mode >= MPOL_MAX)
1299 return -EINVAL;
David Rientjes4c50bc02008-04-28 02:12:30 -07001300 if ((mode_flags & MPOL_F_STATIC_NODES) &&
1301 (mode_flags & MPOL_F_RELATIVE_NODES))
1302 return -EINVAL;
Christoph Lameter8bccd852005-10-29 18:16:59 -07001303 err = get_nodes(&nodes, nmask, maxnode);
1304 if (err)
1305 return err;
David Rientjes028fec42008-04-28 02:12:25 -07001306 return do_mbind(start, len, mode, mode_flags, &nodes, flags);
Christoph Lameter8bccd852005-10-29 18:16:59 -07001307}
1308
1309/* Set the process memory policy */
Heiko Carstens938bb9f2009-01-14 14:14:30 +01001310SYSCALL_DEFINE3(set_mempolicy, int, mode, unsigned long __user *, nmask,
1311 unsigned long, maxnode)
Christoph Lameter8bccd852005-10-29 18:16:59 -07001312{
1313 int err;
1314 nodemask_t nodes;
David Rientjes028fec42008-04-28 02:12:25 -07001315 unsigned short flags;
Christoph Lameter8bccd852005-10-29 18:16:59 -07001316
David Rientjes028fec42008-04-28 02:12:25 -07001317 flags = mode & MPOL_MODE_FLAGS;
1318 mode &= ~MPOL_MODE_FLAGS;
1319 if ((unsigned int)mode >= MPOL_MAX)
Christoph Lameter8bccd852005-10-29 18:16:59 -07001320 return -EINVAL;
David Rientjes4c50bc02008-04-28 02:12:30 -07001321 if ((flags & MPOL_F_STATIC_NODES) && (flags & MPOL_F_RELATIVE_NODES))
1322 return -EINVAL;
Christoph Lameter8bccd852005-10-29 18:16:59 -07001323 err = get_nodes(&nodes, nmask, maxnode);
1324 if (err)
1325 return err;
David Rientjes028fec42008-04-28 02:12:25 -07001326 return do_set_mempolicy(mode, flags, &nodes);
Christoph Lameter8bccd852005-10-29 18:16:59 -07001327}
1328
Heiko Carstens938bb9f2009-01-14 14:14:30 +01001329SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode,
1330 const unsigned long __user *, old_nodes,
1331 const unsigned long __user *, new_nodes)
Christoph Lameter39743882006-01-08 01:00:51 -08001332{
David Howellsc69e8d92008-11-14 10:39:19 +11001333 const struct cred *cred = current_cred(), *tcred;
KOSAKI Motohiro596d7cf2010-08-09 17:19:01 -07001334 struct mm_struct *mm = NULL;
Christoph Lameter39743882006-01-08 01:00:51 -08001335 struct task_struct *task;
Christoph Lameter39743882006-01-08 01:00:51 -08001336 nodemask_t task_nodes;
1337 int err;
KOSAKI Motohiro596d7cf2010-08-09 17:19:01 -07001338 nodemask_t *old;
1339 nodemask_t *new;
1340 NODEMASK_SCRATCH(scratch);
Christoph Lameter39743882006-01-08 01:00:51 -08001341
KOSAKI Motohiro596d7cf2010-08-09 17:19:01 -07001342 if (!scratch)
1343 return -ENOMEM;
Christoph Lameter39743882006-01-08 01:00:51 -08001344
KOSAKI Motohiro596d7cf2010-08-09 17:19:01 -07001345 old = &scratch->mask1;
1346 new = &scratch->mask2;
1347
1348 err = get_nodes(old, old_nodes, maxnode);
Christoph Lameter39743882006-01-08 01:00:51 -08001349 if (err)
KOSAKI Motohiro596d7cf2010-08-09 17:19:01 -07001350 goto out;
1351
1352 err = get_nodes(new, new_nodes, maxnode);
1353 if (err)
1354 goto out;
Christoph Lameter39743882006-01-08 01:00:51 -08001355
1356 /* Find the mm_struct */
Zeng Zhaoming55cfaa32010-12-02 14:31:13 -08001357 rcu_read_lock();
Pavel Emelyanov228ebcb2007-10-18 23:40:16 -07001358 task = pid ? find_task_by_vpid(pid) : current;
Christoph Lameter39743882006-01-08 01:00:51 -08001359 if (!task) {
Zeng Zhaoming55cfaa32010-12-02 14:31:13 -08001360 rcu_read_unlock();
KOSAKI Motohiro596d7cf2010-08-09 17:19:01 -07001361 err = -ESRCH;
1362 goto out;
Christoph Lameter39743882006-01-08 01:00:51 -08001363 }
Christoph Lameter3268c632012-03-21 16:34:06 -07001364 get_task_struct(task);
Christoph Lameter39743882006-01-08 01:00:51 -08001365
KOSAKI Motohiro596d7cf2010-08-09 17:19:01 -07001366 err = -EINVAL;
Christoph Lameter39743882006-01-08 01:00:51 -08001367
1368 /*
1369 * Check if this process has the right to modify the specified
1370 * process. The right exists if the process has administrative
Alexey Dobriyan7f927fc2006-03-28 01:56:53 -08001371 * capabilities, superuser privileges or the same
Christoph Lameter39743882006-01-08 01:00:51 -08001372 * userid as the target process.
1373 */
David Howellsc69e8d92008-11-14 10:39:19 +11001374 tcred = __task_cred(task);
Eric W. Biedermanb38a86e2012-03-12 15:48:24 -07001375 if (!uid_eq(cred->euid, tcred->suid) && !uid_eq(cred->euid, tcred->uid) &&
1376 !uid_eq(cred->uid, tcred->suid) && !uid_eq(cred->uid, tcred->uid) &&
Christoph Lameter74c00242006-03-14 19:50:21 -08001377 !capable(CAP_SYS_NICE)) {
David Howellsc69e8d92008-11-14 10:39:19 +11001378 rcu_read_unlock();
Christoph Lameter39743882006-01-08 01:00:51 -08001379 err = -EPERM;
Christoph Lameter3268c632012-03-21 16:34:06 -07001380 goto out_put;
Christoph Lameter39743882006-01-08 01:00:51 -08001381 }
David Howellsc69e8d92008-11-14 10:39:19 +11001382 rcu_read_unlock();
Christoph Lameter39743882006-01-08 01:00:51 -08001383
1384 task_nodes = cpuset_mems_allowed(task);
1385 /* Is the user allowed to access the target nodes? */
KOSAKI Motohiro596d7cf2010-08-09 17:19:01 -07001386 if (!nodes_subset(*new, task_nodes) && !capable(CAP_SYS_NICE)) {
Christoph Lameter39743882006-01-08 01:00:51 -08001387 err = -EPERM;
Christoph Lameter3268c632012-03-21 16:34:06 -07001388 goto out_put;
Christoph Lameter39743882006-01-08 01:00:51 -08001389 }
1390
KOSAKI Motohiro596d7cf2010-08-09 17:19:01 -07001391 if (!nodes_subset(*new, node_states[N_HIGH_MEMORY])) {
Christoph Lameter3b42d282007-08-31 00:12:08 -07001392 err = -EINVAL;
Christoph Lameter3268c632012-03-21 16:34:06 -07001393 goto out_put;
Christoph Lameter3b42d282007-08-31 00:12:08 -07001394 }
1395
David Quigley86c3a762006-06-23 02:04:02 -07001396 err = security_task_movememory(task);
1397 if (err)
Christoph Lameter3268c632012-03-21 16:34:06 -07001398 goto out_put;
David Quigley86c3a762006-06-23 02:04:02 -07001399
Christoph Lameter3268c632012-03-21 16:34:06 -07001400 mm = get_task_mm(task);
1401 put_task_struct(task);
Sasha Levinf2a9ef82012-04-25 16:01:52 -07001402
1403 if (!mm) {
Christoph Lameter3268c632012-03-21 16:34:06 -07001404 err = -EINVAL;
Sasha Levinf2a9ef82012-04-25 16:01:52 -07001405 goto out;
1406 }
1407
1408 err = do_migrate_pages(mm, old, new,
1409 capable(CAP_SYS_NICE) ? MPOL_MF_MOVE_ALL : MPOL_MF_MOVE);
Christoph Lameter3268c632012-03-21 16:34:06 -07001410
1411 mmput(mm);
1412out:
KOSAKI Motohiro596d7cf2010-08-09 17:19:01 -07001413 NODEMASK_SCRATCH_FREE(scratch);
1414
Christoph Lameter39743882006-01-08 01:00:51 -08001415 return err;
Christoph Lameter3268c632012-03-21 16:34:06 -07001416
1417out_put:
1418 put_task_struct(task);
1419 goto out;
1420
Christoph Lameter39743882006-01-08 01:00:51 -08001421}
1422
1423
Christoph Lameter8bccd852005-10-29 18:16:59 -07001424/* Retrieve NUMA policy */
Heiko Carstens938bb9f2009-01-14 14:14:30 +01001425SYSCALL_DEFINE5(get_mempolicy, int __user *, policy,
1426 unsigned long __user *, nmask, unsigned long, maxnode,
1427 unsigned long, addr, unsigned long, flags)
Christoph Lameter8bccd852005-10-29 18:16:59 -07001428{
Adrian Bunkdbcb0f12007-10-16 01:26:26 -07001429 int err;
1430 int uninitialized_var(pval);
Christoph Lameter8bccd852005-10-29 18:16:59 -07001431 nodemask_t nodes;
1432
1433 if (nmask != NULL && maxnode < MAX_NUMNODES)
1434 return -EINVAL;
1435
1436 err = do_get_mempolicy(&pval, &nodes, addr, flags);
1437
1438 if (err)
1439 return err;
1440
1441 if (policy && put_user(pval, policy))
1442 return -EFAULT;
1443
1444 if (nmask)
1445 err = copy_nodes_to_user(nmask, maxnode, &nodes);
1446
1447 return err;
1448}
1449
Linus Torvalds1da177e2005-04-16 15:20:36 -07001450#ifdef CONFIG_COMPAT
1451
1452asmlinkage long compat_sys_get_mempolicy(int __user *policy,
1453 compat_ulong_t __user *nmask,
1454 compat_ulong_t maxnode,
1455 compat_ulong_t addr, compat_ulong_t flags)
1456{
1457 long err;
1458 unsigned long __user *nm = NULL;
1459 unsigned long nr_bits, alloc_size;
1460 DECLARE_BITMAP(bm, MAX_NUMNODES);
1461
1462 nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
1463 alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
1464
1465 if (nmask)
1466 nm = compat_alloc_user_space(alloc_size);
1467
1468 err = sys_get_mempolicy(policy, nm, nr_bits+1, addr, flags);
1469
1470 if (!err && nmask) {
KAMEZAWA Hiroyuki2bbff6c2011-09-14 16:21:02 -07001471 unsigned long copy_size;
1472 copy_size = min_t(unsigned long, sizeof(bm), alloc_size);
1473 err = copy_from_user(bm, nm, copy_size);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001474 /* ensure entire bitmap is zeroed */
1475 err |= clear_user(nmask, ALIGN(maxnode-1, 8) / 8);
1476 err |= compat_put_bitmap(nmask, bm, nr_bits);
1477 }
1478
1479 return err;
1480}
1481
1482asmlinkage long compat_sys_set_mempolicy(int mode, compat_ulong_t __user *nmask,
1483 compat_ulong_t maxnode)
1484{
1485 long err = 0;
1486 unsigned long __user *nm = NULL;
1487 unsigned long nr_bits, alloc_size;
1488 DECLARE_BITMAP(bm, MAX_NUMNODES);
1489
1490 nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
1491 alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
1492
1493 if (nmask) {
1494 err = compat_get_bitmap(bm, nmask, nr_bits);
1495 nm = compat_alloc_user_space(alloc_size);
1496 err |= copy_to_user(nm, bm, alloc_size);
1497 }
1498
1499 if (err)
1500 return -EFAULT;
1501
1502 return sys_set_mempolicy(mode, nm, nr_bits+1);
1503}
1504
1505asmlinkage long compat_sys_mbind(compat_ulong_t start, compat_ulong_t len,
1506 compat_ulong_t mode, compat_ulong_t __user *nmask,
1507 compat_ulong_t maxnode, compat_ulong_t flags)
1508{
1509 long err = 0;
1510 unsigned long __user *nm = NULL;
1511 unsigned long nr_bits, alloc_size;
Andi Kleendfcd3c02005-10-29 18:15:48 -07001512 nodemask_t bm;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001513
1514 nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
1515 alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
1516
1517 if (nmask) {
Andi Kleendfcd3c02005-10-29 18:15:48 -07001518 err = compat_get_bitmap(nodes_addr(bm), nmask, nr_bits);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001519 nm = compat_alloc_user_space(alloc_size);
Andi Kleendfcd3c02005-10-29 18:15:48 -07001520 err |= copy_to_user(nm, nodes_addr(bm), alloc_size);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001521 }
1522
1523 if (err)
1524 return -EFAULT;
1525
1526 return sys_mbind(start, len, mode, nm, nr_bits+1, flags);
1527}
1528
1529#endif
1530
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001531/*
1532 * get_vma_policy(@task, @vma, @addr)
1533 * @task - task for fallback if vma policy == default
1534 * @vma - virtual memory area whose policy is sought
1535 * @addr - address in @vma for shared policy lookup
1536 *
1537 * Returns effective policy for a VMA at specified address.
1538 * Falls back to @task or system default policy, as necessary.
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001539 * Current or other task's task mempolicy and non-shared vma policies
1540 * are protected by the task's mmap_sem, which must be held for read by
1541 * the caller.
1542 * Shared policies [those marked as MPOL_F_SHARED] require an extra reference
1543 * count--added by the get_policy() vm_op, as appropriate--to protect against
1544 * freeing by another task. It is the caller's responsibility to free the
1545 * extra reference for shared policies.
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001546 */
Stephen Wilsond98f6cb2011-05-24 17:12:41 -07001547struct mempolicy *get_vma_policy(struct task_struct *task,
Christoph Lameter48fce342006-01-08 01:01:03 -08001548 struct vm_area_struct *vma, unsigned long addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001549{
Christoph Lameter6e21c8f2005-09-03 15:54:45 -07001550 struct mempolicy *pol = task->mempolicy;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001551
1552 if (vma) {
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001553 if (vma->vm_ops && vma->vm_ops->get_policy) {
Lee Schermerhornae4d8c12008-04-28 02:13:11 -07001554 struct mempolicy *vpol = vma->vm_ops->get_policy(vma,
1555 addr);
1556 if (vpol)
1557 pol = vpol;
Mel Gorman00442ad2012-10-08 16:29:20 -07001558 } else if (vma->vm_policy) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001559 pol = vma->vm_policy;
Mel Gorman00442ad2012-10-08 16:29:20 -07001560
1561 /*
1562 * shmem_alloc_page() passes MPOL_F_SHARED policy with
1563 * a pseudo vma whose vma->vm_ops=NULL. Take a reference
1564 * count on these policies which will be dropped by
1565 * mpol_cond_put() later
1566 */
1567 if (mpol_needs_cond_ref(pol))
1568 mpol_get(pol);
1569 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001570 }
1571 if (!pol)
1572 pol = &default_policy;
1573 return pol;
1574}
1575
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001576/*
1577 * Return a nodemask representing a mempolicy for filtering nodes for
1578 * page allocation
1579 */
1580static nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy)
Mel Gorman19770b32008-04-28 02:12:18 -07001581{
1582 /* Lower zones don't get a nodemask applied for MPOL_BIND */
Lee Schermerhorn45c47452008-04-28 02:13:12 -07001583 if (unlikely(policy->mode == MPOL_BIND) &&
Mel Gorman19770b32008-04-28 02:12:18 -07001584 gfp_zone(gfp) >= policy_zone &&
1585 cpuset_nodemask_valid_mems_allowed(&policy->v.nodes))
1586 return &policy->v.nodes;
1587
1588 return NULL;
1589}
1590
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001591/* Return a zonelist indicated by gfp for node representing a mempolicy */
Andi Kleen2f5f9482011-03-04 17:36:29 -08001592static struct zonelist *policy_zonelist(gfp_t gfp, struct mempolicy *policy,
1593 int nd)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001594{
Lee Schermerhorn45c47452008-04-28 02:13:12 -07001595 switch (policy->mode) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001596 case MPOL_PREFERRED:
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -07001597 if (!(policy->flags & MPOL_F_LOCAL))
1598 nd = policy->v.preferred_node;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001599 break;
1600 case MPOL_BIND:
Mel Gorman19770b32008-04-28 02:12:18 -07001601 /*
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001602 * Normally, MPOL_BIND allocations are node-local within the
1603 * allowed nodemask. However, if __GFP_THISNODE is set and the
Bob Liu6eb27e12010-05-24 14:32:00 -07001604 * current node isn't part of the mask, we use the zonelist for
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001605 * the first node in the mask instead.
Mel Gorman19770b32008-04-28 02:12:18 -07001606 */
Mel Gorman19770b32008-04-28 02:12:18 -07001607 if (unlikely(gfp & __GFP_THISNODE) &&
1608 unlikely(!node_isset(nd, policy->v.nodes)))
1609 nd = first_node(policy->v.nodes);
1610 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001611 default:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001612 BUG();
1613 }
Mel Gorman0e884602008-04-28 02:12:14 -07001614 return node_zonelist(nd, gfp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001615}
1616
1617/* Do dynamic interleaving for a process */
1618static unsigned interleave_nodes(struct mempolicy *policy)
1619{
1620 unsigned nid, next;
1621 struct task_struct *me = current;
1622
1623 nid = me->il_next;
Andi Kleendfcd3c02005-10-29 18:15:48 -07001624 next = next_node(nid, policy->v.nodes);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001625 if (next >= MAX_NUMNODES)
Andi Kleendfcd3c02005-10-29 18:15:48 -07001626 next = first_node(policy->v.nodes);
David Rientjesf5b087b2008-04-28 02:12:27 -07001627 if (next < MAX_NUMNODES)
1628 me->il_next = next;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001629 return nid;
1630}
1631
Christoph Lameterdc85da12006-01-18 17:42:36 -08001632/*
1633 * Depending on the memory policy provide a node from which to allocate the
1634 * next slab entry.
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001635 * @policy must be protected by freeing by the caller. If @policy is
1636 * the current task's mempolicy, this protection is implicit, as only the
1637 * task can change it's policy. The system default policy requires no
1638 * such protection.
Christoph Lameterdc85da12006-01-18 17:42:36 -08001639 */
Andi Kleene7b691b2012-06-09 02:40:03 -07001640unsigned slab_node(void)
Christoph Lameterdc85da12006-01-18 17:42:36 -08001641{
Andi Kleene7b691b2012-06-09 02:40:03 -07001642 struct mempolicy *policy;
1643
1644 if (in_interrupt())
1645 return numa_node_id();
1646
1647 policy = current->mempolicy;
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -07001648 if (!policy || policy->flags & MPOL_F_LOCAL)
Lee Schermerhornbea904d2008-04-28 02:13:18 -07001649 return numa_node_id();
Christoph Lameter765c4502006-09-27 01:50:08 -07001650
Lee Schermerhornbea904d2008-04-28 02:13:18 -07001651 switch (policy->mode) {
1652 case MPOL_PREFERRED:
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -07001653 /*
1654 * handled MPOL_F_LOCAL above
1655 */
1656 return policy->v.preferred_node;
Lee Schermerhornbea904d2008-04-28 02:13:18 -07001657
Christoph Lameterdc85da12006-01-18 17:42:36 -08001658 case MPOL_INTERLEAVE:
1659 return interleave_nodes(policy);
1660
Mel Gormandd1a2392008-04-28 02:12:17 -07001661 case MPOL_BIND: {
Christoph Lameterdc85da12006-01-18 17:42:36 -08001662 /*
1663 * Follow bind policy behavior and start allocation at the
1664 * first node.
1665 */
Mel Gorman19770b32008-04-28 02:12:18 -07001666 struct zonelist *zonelist;
1667 struct zone *zone;
1668 enum zone_type highest_zoneidx = gfp_zone(GFP_KERNEL);
1669 zonelist = &NODE_DATA(numa_node_id())->node_zonelists[0];
1670 (void)first_zones_zonelist(zonelist, highest_zoneidx,
1671 &policy->v.nodes,
1672 &zone);
Eric Dumazet800416f2010-10-27 19:33:43 +02001673 return zone ? zone->node : numa_node_id();
Mel Gormandd1a2392008-04-28 02:12:17 -07001674 }
Christoph Lameterdc85da12006-01-18 17:42:36 -08001675
Christoph Lameterdc85da12006-01-18 17:42:36 -08001676 default:
Lee Schermerhornbea904d2008-04-28 02:13:18 -07001677 BUG();
Christoph Lameterdc85da12006-01-18 17:42:36 -08001678 }
1679}
1680
Linus Torvalds1da177e2005-04-16 15:20:36 -07001681/* Do static interleaving for a VMA with known offset. */
1682static unsigned offset_il_node(struct mempolicy *pol,
1683 struct vm_area_struct *vma, unsigned long off)
1684{
Andi Kleendfcd3c02005-10-29 18:15:48 -07001685 unsigned nnodes = nodes_weight(pol->v.nodes);
David Rientjesf5b087b2008-04-28 02:12:27 -07001686 unsigned target;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001687 int c;
1688 int nid = -1;
1689
David Rientjesf5b087b2008-04-28 02:12:27 -07001690 if (!nnodes)
1691 return numa_node_id();
1692 target = (unsigned int)off % nnodes;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001693 c = 0;
1694 do {
Andi Kleendfcd3c02005-10-29 18:15:48 -07001695 nid = next_node(nid, pol->v.nodes);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001696 c++;
1697 } while (c <= target);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001698 return nid;
1699}
1700
Christoph Lameter5da7ca82006-01-06 00:10:46 -08001701/* Determine a node number for interleave */
1702static inline unsigned interleave_nid(struct mempolicy *pol,
1703 struct vm_area_struct *vma, unsigned long addr, int shift)
1704{
1705 if (vma) {
1706 unsigned long off;
1707
Nishanth Aravamudan3b98b082006-08-31 21:27:53 -07001708 /*
1709 * for small pages, there is no difference between
1710 * shift and PAGE_SHIFT, so the bit-shift is safe.
1711 * for huge pages, since vm_pgoff is in units of small
1712 * pages, we need to shift off the always 0 bits to get
1713 * a useful offset.
1714 */
1715 BUG_ON(shift < PAGE_SHIFT);
1716 off = vma->vm_pgoff >> (shift - PAGE_SHIFT);
Christoph Lameter5da7ca82006-01-06 00:10:46 -08001717 off += (addr - vma->vm_start) >> shift;
1718 return offset_il_node(pol, vma, off);
1719 } else
1720 return interleave_nodes(pol);
1721}
1722
Michal Hocko778d3b02011-07-26 16:08:30 -07001723/*
1724 * Return the bit number of a random bit set in the nodemask.
1725 * (returns -1 if nodemask is empty)
1726 */
1727int node_random(const nodemask_t *maskp)
1728{
1729 int w, bit = -1;
1730
1731 w = nodes_weight(*maskp);
1732 if (w)
1733 bit = bitmap_ord_to_pos(maskp->bits,
1734 get_random_int() % w, MAX_NUMNODES);
1735 return bit;
1736}
1737
Chen, Kenneth W00ac59a2006-02-03 21:51:14 +01001738#ifdef CONFIG_HUGETLBFS
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001739/*
1740 * huge_zonelist(@vma, @addr, @gfp_flags, @mpol)
1741 * @vma = virtual memory area whose policy is sought
1742 * @addr = address in @vma for shared policy lookup and interleave policy
1743 * @gfp_flags = for requested zone
Mel Gorman19770b32008-04-28 02:12:18 -07001744 * @mpol = pointer to mempolicy pointer for reference counted mempolicy
1745 * @nodemask = pointer to nodemask pointer for MPOL_BIND nodemask
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001746 *
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001747 * Returns a zonelist suitable for a huge page allocation and a pointer
1748 * to the struct mempolicy for conditional unref after allocation.
1749 * If the effective policy is 'BIND, returns a pointer to the mempolicy's
1750 * @nodemask for filtering the zonelist.
Miao Xiec0ff7452010-05-24 14:32:08 -07001751 *
1752 * Must be protected by get_mems_allowed()
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001753 */
Mel Gorman396faf02007-07-17 04:03:13 -07001754struct zonelist *huge_zonelist(struct vm_area_struct *vma, unsigned long addr,
Mel Gorman19770b32008-04-28 02:12:18 -07001755 gfp_t gfp_flags, struct mempolicy **mpol,
1756 nodemask_t **nodemask)
Christoph Lameter5da7ca82006-01-06 00:10:46 -08001757{
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001758 struct zonelist *zl;
Christoph Lameter5da7ca82006-01-06 00:10:46 -08001759
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001760 *mpol = get_vma_policy(current, vma, addr);
Mel Gorman19770b32008-04-28 02:12:18 -07001761 *nodemask = NULL; /* assume !MPOL_BIND */
Christoph Lameter5da7ca82006-01-06 00:10:46 -08001762
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001763 if (unlikely((*mpol)->mode == MPOL_INTERLEAVE)) {
1764 zl = node_zonelist(interleave_nid(*mpol, vma, addr,
Andi Kleena5516432008-07-23 21:27:41 -07001765 huge_page_shift(hstate_vma(vma))), gfp_flags);
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001766 } else {
Andi Kleen2f5f9482011-03-04 17:36:29 -08001767 zl = policy_zonelist(gfp_flags, *mpol, numa_node_id());
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001768 if ((*mpol)->mode == MPOL_BIND)
1769 *nodemask = &(*mpol)->v.nodes;
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001770 }
1771 return zl;
Christoph Lameter5da7ca82006-01-06 00:10:46 -08001772}
Lee Schermerhorn06808b02009-12-14 17:58:21 -08001773
1774/*
1775 * init_nodemask_of_mempolicy
1776 *
1777 * If the current task's mempolicy is "default" [NULL], return 'false'
1778 * to indicate default policy. Otherwise, extract the policy nodemask
1779 * for 'bind' or 'interleave' policy into the argument nodemask, or
1780 * initialize the argument nodemask to contain the single node for
1781 * 'preferred' or 'local' policy and return 'true' to indicate presence
1782 * of non-default mempolicy.
1783 *
1784 * We don't bother with reference counting the mempolicy [mpol_get/put]
1785 * because the current task is examining it's own mempolicy and a task's
1786 * mempolicy is only ever changed by the task itself.
1787 *
1788 * N.B., it is the caller's responsibility to free a returned nodemask.
1789 */
1790bool init_nodemask_of_mempolicy(nodemask_t *mask)
1791{
1792 struct mempolicy *mempolicy;
1793 int nid;
1794
1795 if (!(mask && current->mempolicy))
1796 return false;
1797
Miao Xiec0ff7452010-05-24 14:32:08 -07001798 task_lock(current);
Lee Schermerhorn06808b02009-12-14 17:58:21 -08001799 mempolicy = current->mempolicy;
1800 switch (mempolicy->mode) {
1801 case MPOL_PREFERRED:
1802 if (mempolicy->flags & MPOL_F_LOCAL)
1803 nid = numa_node_id();
1804 else
1805 nid = mempolicy->v.preferred_node;
1806 init_nodemask_of_node(mask, nid);
1807 break;
1808
1809 case MPOL_BIND:
1810 /* Fall through */
1811 case MPOL_INTERLEAVE:
1812 *mask = mempolicy->v.nodes;
1813 break;
1814
1815 default:
1816 BUG();
1817 }
Miao Xiec0ff7452010-05-24 14:32:08 -07001818 task_unlock(current);
Lee Schermerhorn06808b02009-12-14 17:58:21 -08001819
1820 return true;
1821}
Chen, Kenneth W00ac59a2006-02-03 21:51:14 +01001822#endif
Christoph Lameter5da7ca82006-01-06 00:10:46 -08001823
David Rientjes6f48d0eb2010-08-09 17:18:52 -07001824/*
1825 * mempolicy_nodemask_intersects
1826 *
1827 * If tsk's mempolicy is "default" [NULL], return 'true' to indicate default
1828 * policy. Otherwise, check for intersection between mask and the policy
1829 * nodemask for 'bind' or 'interleave' policy. For 'perferred' or 'local'
1830 * policy, always return true since it may allocate elsewhere on fallback.
1831 *
1832 * Takes task_lock(tsk) to prevent freeing of its mempolicy.
1833 */
1834bool mempolicy_nodemask_intersects(struct task_struct *tsk,
1835 const nodemask_t *mask)
1836{
1837 struct mempolicy *mempolicy;
1838 bool ret = true;
1839
1840 if (!mask)
1841 return ret;
1842 task_lock(tsk);
1843 mempolicy = tsk->mempolicy;
1844 if (!mempolicy)
1845 goto out;
1846
1847 switch (mempolicy->mode) {
1848 case MPOL_PREFERRED:
1849 /*
1850 * MPOL_PREFERRED and MPOL_F_LOCAL are only preferred nodes to
1851 * allocate from, they may fallback to other nodes when oom.
1852 * Thus, it's possible for tsk to have allocated memory from
1853 * nodes in mask.
1854 */
1855 break;
1856 case MPOL_BIND:
1857 case MPOL_INTERLEAVE:
1858 ret = nodes_intersects(mempolicy->v.nodes, *mask);
1859 break;
1860 default:
1861 BUG();
1862 }
1863out:
1864 task_unlock(tsk);
1865 return ret;
1866}
1867
Linus Torvalds1da177e2005-04-16 15:20:36 -07001868/* Allocate a page in interleaved policy.
1869 Own path because it needs to do special accounting. */
Andi Kleen662f3a02005-10-29 18:15:49 -07001870static struct page *alloc_page_interleave(gfp_t gfp, unsigned order,
1871 unsigned nid)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001872{
1873 struct zonelist *zl;
1874 struct page *page;
1875
Mel Gorman0e884602008-04-28 02:12:14 -07001876 zl = node_zonelist(nid, gfp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001877 page = __alloc_pages(gfp, order, zl);
Mel Gormandd1a2392008-04-28 02:12:17 -07001878 if (page && page_zone(page) == zonelist_zone(&zl->_zonerefs[0]))
Christoph Lameterca889e62006-06-30 01:55:44 -07001879 inc_zone_page_state(page, NUMA_INTERLEAVE_HIT);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001880 return page;
1881}
1882
1883/**
Andrea Arcangeli0bbbc0b2011-01-13 15:47:05 -08001884 * alloc_pages_vma - Allocate a page for a VMA.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001885 *
1886 * @gfp:
1887 * %GFP_USER user allocation.
1888 * %GFP_KERNEL kernel allocations,
1889 * %GFP_HIGHMEM highmem/user allocations,
1890 * %GFP_FS allocation should not call back into a file system.
1891 * %GFP_ATOMIC don't sleep.
1892 *
Andrea Arcangeli0bbbc0b2011-01-13 15:47:05 -08001893 * @order:Order of the GFP allocation.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001894 * @vma: Pointer to VMA or NULL if not available.
1895 * @addr: Virtual Address of the allocation. Must be inside the VMA.
1896 *
1897 * This function allocates a page from the kernel page pool and applies
1898 * a NUMA policy associated with the VMA or the current process.
1899 * When VMA is not NULL caller must hold down_read on the mmap_sem of the
1900 * mm_struct of the VMA to prevent it from going away. Should be used for
1901 * all allocations for pages that will be mapped into
1902 * user space. Returns NULL when no page can be allocated.
1903 *
1904 * Should be called with the mm_sem of the vma hold.
1905 */
1906struct page *
Andrea Arcangeli0bbbc0b2011-01-13 15:47:05 -08001907alloc_pages_vma(gfp_t gfp, int order, struct vm_area_struct *vma,
Andi Kleen2f5f9482011-03-04 17:36:29 -08001908 unsigned long addr, int node)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001909{
Mel Gormancc9a6c82012-03-21 16:34:11 -07001910 struct mempolicy *pol;
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001911 struct zonelist *zl;
Miao Xiec0ff7452010-05-24 14:32:08 -07001912 struct page *page;
Mel Gormancc9a6c82012-03-21 16:34:11 -07001913 unsigned int cpuset_mems_cookie;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001914
Mel Gormancc9a6c82012-03-21 16:34:11 -07001915retry_cpuset:
1916 pol = get_vma_policy(current, vma, addr);
1917 cpuset_mems_cookie = get_mems_allowed();
1918
Lee Schermerhorn45c47452008-04-28 02:13:12 -07001919 if (unlikely(pol->mode == MPOL_INTERLEAVE)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001920 unsigned nid;
Christoph Lameter5da7ca82006-01-06 00:10:46 -08001921
Andi Kleen8eac5632011-02-25 14:44:28 -08001922 nid = interleave_nid(pol, vma, addr, PAGE_SHIFT + order);
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001923 mpol_cond_put(pol);
Andrea Arcangeli0bbbc0b2011-01-13 15:47:05 -08001924 page = alloc_page_interleave(gfp, order, nid);
Mel Gormancc9a6c82012-03-21 16:34:11 -07001925 if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page))
1926 goto retry_cpuset;
1927
Miao Xiec0ff7452010-05-24 14:32:08 -07001928 return page;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001929 }
Andi Kleen2f5f9482011-03-04 17:36:29 -08001930 zl = policy_zonelist(gfp, pol, node);
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001931 if (unlikely(mpol_needs_cond_ref(pol))) {
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001932 /*
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001933 * slow path: ref counted shared policy
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001934 */
Andrea Arcangeli0bbbc0b2011-01-13 15:47:05 -08001935 struct page *page = __alloc_pages_nodemask(gfp, order,
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001936 zl, policy_nodemask(gfp, pol));
Lee Schermerhornf0be3d32008-04-28 02:13:08 -07001937 __mpol_put(pol);
Mel Gormancc9a6c82012-03-21 16:34:11 -07001938 if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page))
1939 goto retry_cpuset;
Lee Schermerhorn480eccf2007-09-18 22:46:47 -07001940 return page;
1941 }
1942 /*
1943 * fast path: default or task policy
1944 */
Andrea Arcangeli0bbbc0b2011-01-13 15:47:05 -08001945 page = __alloc_pages_nodemask(gfp, order, zl,
1946 policy_nodemask(gfp, pol));
Mel Gormancc9a6c82012-03-21 16:34:11 -07001947 if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page))
1948 goto retry_cpuset;
Miao Xiec0ff7452010-05-24 14:32:08 -07001949 return page;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001950}
1951
1952/**
1953 * alloc_pages_current - Allocate pages.
1954 *
1955 * @gfp:
1956 * %GFP_USER user allocation,
1957 * %GFP_KERNEL kernel allocation,
1958 * %GFP_HIGHMEM highmem allocation,
1959 * %GFP_FS don't call back into a file system.
1960 * %GFP_ATOMIC don't sleep.
1961 * @order: Power of two of allocation size in pages. 0 is a single page.
1962 *
1963 * Allocate a page from the kernel page pool. When not in
1964 * interrupt context and apply the current process NUMA policy.
1965 * Returns NULL when no page can be allocated.
1966 *
Paul Jacksoncf2a473c2006-01-08 01:01:54 -08001967 * Don't call cpuset_update_task_memory_state() unless
Linus Torvalds1da177e2005-04-16 15:20:36 -07001968 * 1) it's ok to take cpuset_sem (can WAIT), and
1969 * 2) allocating for current task (not interrupt).
1970 */
Al Virodd0fc662005-10-07 07:46:04 +01001971struct page *alloc_pages_current(gfp_t gfp, unsigned order)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001972{
1973 struct mempolicy *pol = current->mempolicy;
Miao Xiec0ff7452010-05-24 14:32:08 -07001974 struct page *page;
Mel Gormancc9a6c82012-03-21 16:34:11 -07001975 unsigned int cpuset_mems_cookie;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001976
Christoph Lameter9b819d22006-09-25 23:31:40 -07001977 if (!pol || in_interrupt() || (gfp & __GFP_THISNODE))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001978 pol = &default_policy;
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001979
Mel Gormancc9a6c82012-03-21 16:34:11 -07001980retry_cpuset:
1981 cpuset_mems_cookie = get_mems_allowed();
1982
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07001983 /*
1984 * No reference counting needed for current->mempolicy
1985 * nor system default_policy
1986 */
Lee Schermerhorn45c47452008-04-28 02:13:12 -07001987 if (pol->mode == MPOL_INTERLEAVE)
Miao Xiec0ff7452010-05-24 14:32:08 -07001988 page = alloc_page_interleave(gfp, order, interleave_nodes(pol));
1989 else
1990 page = __alloc_pages_nodemask(gfp, order,
Andi Kleen5c4b4be2011-03-04 17:36:32 -08001991 policy_zonelist(gfp, pol, numa_node_id()),
1992 policy_nodemask(gfp, pol));
Mel Gormancc9a6c82012-03-21 16:34:11 -07001993
1994 if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page))
1995 goto retry_cpuset;
1996
Miao Xiec0ff7452010-05-24 14:32:08 -07001997 return page;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001998}
1999EXPORT_SYMBOL(alloc_pages_current);
2000
Paul Jackson42253992006-01-08 01:01:59 -08002001/*
Lee Schermerhorn846a16b2008-04-28 02:13:09 -07002002 * If mpol_dup() sees current->cpuset == cpuset_being_rebound, then it
Paul Jackson42253992006-01-08 01:01:59 -08002003 * rebinds the mempolicy its copying by calling mpol_rebind_policy()
2004 * with the mems_allowed returned by cpuset_mems_allowed(). This
2005 * keeps mempolicies cpuset relative after its cpuset moves. See
2006 * further kernel/cpuset.c update_nodemask().
Miao Xie708c1bb2010-05-24 14:32:07 -07002007 *
2008 * current's mempolicy may be rebinded by the other task(the task that changes
2009 * cpuset's mems), so we needn't do rebind work for current task.
Paul Jackson42253992006-01-08 01:01:59 -08002010 */
Paul Jackson42253992006-01-08 01:01:59 -08002011
Lee Schermerhorn846a16b2008-04-28 02:13:09 -07002012/* Slow path of a mempolicy duplicate */
2013struct mempolicy *__mpol_dup(struct mempolicy *old)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002014{
2015 struct mempolicy *new = kmem_cache_alloc(policy_cache, GFP_KERNEL);
2016
2017 if (!new)
2018 return ERR_PTR(-ENOMEM);
Miao Xie708c1bb2010-05-24 14:32:07 -07002019
2020 /* task's mempolicy is protected by alloc_lock */
2021 if (old == current->mempolicy) {
2022 task_lock(current);
2023 *new = *old;
2024 task_unlock(current);
2025 } else
2026 *new = *old;
2027
Paul E. McKenney99ee4ca2010-03-03 17:50:17 -08002028 rcu_read_lock();
Paul Jackson42253992006-01-08 01:01:59 -08002029 if (current_cpuset_is_being_rebound()) {
2030 nodemask_t mems = cpuset_mems_allowed(current);
Miao Xie708c1bb2010-05-24 14:32:07 -07002031 if (new->flags & MPOL_F_REBINDING)
2032 mpol_rebind_policy(new, &mems, MPOL_REBIND_STEP2);
2033 else
2034 mpol_rebind_policy(new, &mems, MPOL_REBIND_ONCE);
Paul Jackson42253992006-01-08 01:01:59 -08002035 }
Paul E. McKenney99ee4ca2010-03-03 17:50:17 -08002036 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -07002037 atomic_set(&new->refcnt, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002038 return new;
2039}
2040
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -07002041/*
2042 * If *frompol needs [has] an extra ref, copy *frompol to *tompol ,
2043 * eliminate the * MPOL_F_* flags that require conditional ref and
2044 * [NOTE!!!] drop the extra ref. Not safe to reference *frompol directly
2045 * after return. Use the returned value.
2046 *
2047 * Allows use of a mempolicy for, e.g., multiple allocations with a single
2048 * policy lookup, even if the policy needs/has extra ref on lookup.
2049 * shmem_readahead needs this.
2050 */
2051struct mempolicy *__mpol_cond_copy(struct mempolicy *tompol,
2052 struct mempolicy *frompol)
2053{
2054 if (!mpol_needs_cond_ref(frompol))
2055 return frompol;
2056
2057 *tompol = *frompol;
2058 tompol->flags &= ~MPOL_F_SHARED; /* copy doesn't need unref */
2059 __mpol_put(frompol);
2060 return tompol;
2061}
2062
Linus Torvalds1da177e2005-04-16 15:20:36 -07002063/* Slow path of a mempolicy comparison */
KOSAKI Motohirofcfb4dc2012-01-10 15:08:21 -08002064bool __mpol_equal(struct mempolicy *a, struct mempolicy *b)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002065{
2066 if (!a || !b)
KOSAKI Motohirofcfb4dc2012-01-10 15:08:21 -08002067 return false;
Lee Schermerhorn45c47452008-04-28 02:13:12 -07002068 if (a->mode != b->mode)
KOSAKI Motohirofcfb4dc2012-01-10 15:08:21 -08002069 return false;
Bob Liu19800502010-05-24 14:32:01 -07002070 if (a->flags != b->flags)
KOSAKI Motohirofcfb4dc2012-01-10 15:08:21 -08002071 return false;
Bob Liu19800502010-05-24 14:32:01 -07002072 if (mpol_store_user_nodemask(a))
2073 if (!nodes_equal(a->w.user_nodemask, b->w.user_nodemask))
KOSAKI Motohirofcfb4dc2012-01-10 15:08:21 -08002074 return false;
Bob Liu19800502010-05-24 14:32:01 -07002075
Lee Schermerhorn45c47452008-04-28 02:13:12 -07002076 switch (a->mode) {
Mel Gorman19770b32008-04-28 02:12:18 -07002077 case MPOL_BIND:
2078 /* Fall through */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002079 case MPOL_INTERLEAVE:
KOSAKI Motohirofcfb4dc2012-01-10 15:08:21 -08002080 return !!nodes_equal(a->v.nodes, b->v.nodes);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002081 case MPOL_PREFERRED:
Namhyung Kim75719662011-03-22 16:33:02 -07002082 return a->v.preferred_node == b->v.preferred_node;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002083 default:
2084 BUG();
KOSAKI Motohirofcfb4dc2012-01-10 15:08:21 -08002085 return false;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002086 }
2087}
2088
Linus Torvalds1da177e2005-04-16 15:20:36 -07002089/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07002090 * Shared memory backing store policy support.
2091 *
2092 * Remember policies even when nobody has shared memory mapped.
2093 * The policies are kept in Red-Black tree linked from the inode.
2094 * They are protected by the sp->lock spinlock, which should be held
2095 * for any accesses to the tree.
2096 */
2097
2098/* lookup first element intersecting start-end */
Mel Gormanb22d1272012-10-08 16:29:17 -07002099/* Caller holds sp->mutex */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002100static struct sp_node *
2101sp_lookup(struct shared_policy *sp, unsigned long start, unsigned long end)
2102{
2103 struct rb_node *n = sp->root.rb_node;
2104
2105 while (n) {
2106 struct sp_node *p = rb_entry(n, struct sp_node, nd);
2107
2108 if (start >= p->end)
2109 n = n->rb_right;
2110 else if (end <= p->start)
2111 n = n->rb_left;
2112 else
2113 break;
2114 }
2115 if (!n)
2116 return NULL;
2117 for (;;) {
2118 struct sp_node *w = NULL;
2119 struct rb_node *prev = rb_prev(n);
2120 if (!prev)
2121 break;
2122 w = rb_entry(prev, struct sp_node, nd);
2123 if (w->end <= start)
2124 break;
2125 n = prev;
2126 }
2127 return rb_entry(n, struct sp_node, nd);
2128}
2129
2130/* Insert a new shared policy into the list. */
2131/* Caller holds sp->lock */
2132static void sp_insert(struct shared_policy *sp, struct sp_node *new)
2133{
2134 struct rb_node **p = &sp->root.rb_node;
2135 struct rb_node *parent = NULL;
2136 struct sp_node *nd;
2137
2138 while (*p) {
2139 parent = *p;
2140 nd = rb_entry(parent, struct sp_node, nd);
2141 if (new->start < nd->start)
2142 p = &(*p)->rb_left;
2143 else if (new->end > nd->end)
2144 p = &(*p)->rb_right;
2145 else
2146 BUG();
2147 }
2148 rb_link_node(&new->nd, parent, p);
2149 rb_insert_color(&new->nd, &sp->root);
Paul Mundt140d5a42007-07-15 23:38:16 -07002150 pr_debug("inserting %lx-%lx: %d\n", new->start, new->end,
Lee Schermerhorn45c47452008-04-28 02:13:12 -07002151 new->policy ? new->policy->mode : 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002152}
2153
2154/* Find shared policy intersecting idx */
2155struct mempolicy *
2156mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx)
2157{
2158 struct mempolicy *pol = NULL;
2159 struct sp_node *sn;
2160
2161 if (!sp->root.rb_node)
2162 return NULL;
Mel Gormanb22d1272012-10-08 16:29:17 -07002163 mutex_lock(&sp->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002164 sn = sp_lookup(sp, idx, idx+1);
2165 if (sn) {
2166 mpol_get(sn->policy);
2167 pol = sn->policy;
2168 }
Mel Gormanb22d1272012-10-08 16:29:17 -07002169 mutex_unlock(&sp->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002170 return pol;
2171}
2172
KOSAKI Motohiro63f74ca2012-10-08 16:29:19 -07002173static void sp_free(struct sp_node *n)
2174{
2175 mpol_put(n->policy);
2176 kmem_cache_free(sn_cache, n);
2177}
2178
Linus Torvalds1da177e2005-04-16 15:20:36 -07002179static void sp_delete(struct shared_policy *sp, struct sp_node *n)
2180{
Paul Mundt140d5a42007-07-15 23:38:16 -07002181 pr_debug("deleting %lx-l%lx\n", n->start, n->end);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002182 rb_erase(&n->nd, &sp->root);
KOSAKI Motohiro63f74ca2012-10-08 16:29:19 -07002183 sp_free(n);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002184}
2185
Adrian Bunkdbcb0f12007-10-16 01:26:26 -07002186static struct sp_node *sp_alloc(unsigned long start, unsigned long end,
2187 struct mempolicy *pol)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002188{
KOSAKI Motohiro869833f22012-10-08 16:29:16 -07002189 struct sp_node *n;
2190 struct mempolicy *newpol;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002191
KOSAKI Motohiro869833f22012-10-08 16:29:16 -07002192 n = kmem_cache_alloc(sn_cache, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002193 if (!n)
2194 return NULL;
KOSAKI Motohiro869833f22012-10-08 16:29:16 -07002195
2196 newpol = mpol_dup(pol);
2197 if (IS_ERR(newpol)) {
2198 kmem_cache_free(sn_cache, n);
2199 return NULL;
2200 }
2201 newpol->flags |= MPOL_F_SHARED;
2202
Linus Torvalds1da177e2005-04-16 15:20:36 -07002203 n->start = start;
2204 n->end = end;
KOSAKI Motohiro869833f22012-10-08 16:29:16 -07002205 n->policy = newpol;
2206
Linus Torvalds1da177e2005-04-16 15:20:36 -07002207 return n;
2208}
2209
2210/* Replace a policy range. */
2211static int shared_policy_replace(struct shared_policy *sp, unsigned long start,
2212 unsigned long end, struct sp_node *new)
2213{
Mel Gormanb22d1272012-10-08 16:29:17 -07002214 struct sp_node *n;
2215 int ret = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002216
Mel Gormanb22d1272012-10-08 16:29:17 -07002217 mutex_lock(&sp->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002218 n = sp_lookup(sp, start, end);
2219 /* Take care of old policies in the same range. */
2220 while (n && n->start < end) {
2221 struct rb_node *next = rb_next(&n->nd);
2222 if (n->start >= start) {
2223 if (n->end <= end)
2224 sp_delete(sp, n);
2225 else
2226 n->start = end;
2227 } else {
2228 /* Old policy spanning whole new range. */
2229 if (n->end > end) {
Mel Gormanb22d1272012-10-08 16:29:17 -07002230 struct sp_node *new2;
2231 new2 = sp_alloc(end, n->end, n->policy);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002232 if (!new2) {
Mel Gormanb22d1272012-10-08 16:29:17 -07002233 ret = -ENOMEM;
2234 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002235 }
2236 n->end = start;
2237 sp_insert(sp, new2);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002238 break;
2239 } else
2240 n->end = start;
2241 }
2242 if (!next)
2243 break;
2244 n = rb_entry(next, struct sp_node, nd);
2245 }
2246 if (new)
2247 sp_insert(sp, new);
Mel Gormanb22d1272012-10-08 16:29:17 -07002248out:
2249 mutex_unlock(&sp->mutex);
2250 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002251}
2252
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002253/**
2254 * mpol_shared_policy_init - initialize shared policy for inode
2255 * @sp: pointer to inode shared policy
2256 * @mpol: struct mempolicy to install
2257 *
2258 * Install non-NULL @mpol in inode's shared policy rb-tree.
2259 * On entry, the current task has a reference on a non-NULL @mpol.
2260 * This must be released on exit.
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -07002261 * This is called at get_inode() calls and we can use GFP_KERNEL.
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002262 */
2263void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol)
Robin Holt7339ff82006-01-14 13:20:48 -08002264{
Miao Xie58568d22009-06-16 15:31:49 -07002265 int ret;
2266
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002267 sp->root = RB_ROOT; /* empty tree == default mempolicy */
Mel Gormanb22d1272012-10-08 16:29:17 -07002268 mutex_init(&sp->mutex);
Robin Holt7339ff82006-01-14 13:20:48 -08002269
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002270 if (mpol) {
2271 struct vm_area_struct pvma;
2272 struct mempolicy *new;
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -07002273 NODEMASK_SCRATCH(scratch);
Robin Holt7339ff82006-01-14 13:20:48 -08002274
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -07002275 if (!scratch)
Lee Schermerhorn5c0c1652010-06-29 15:05:30 -07002276 goto put_mpol;
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002277 /* contextualize the tmpfs mount point mempolicy */
2278 new = mpol_new(mpol->mode, mpol->flags, &mpol->w.user_nodemask);
Lee Schermerhorn15d77832010-05-24 14:32:04 -07002279 if (IS_ERR(new))
Dan Carpenter0cae3452010-05-25 23:42:58 -07002280 goto free_scratch; /* no valid nodemask intersection */
Miao Xie58568d22009-06-16 15:31:49 -07002281
2282 task_lock(current);
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -07002283 ret = mpol_set_nodemask(new, &mpol->w.user_nodemask, scratch);
Miao Xie58568d22009-06-16 15:31:49 -07002284 task_unlock(current);
Lee Schermerhorn15d77832010-05-24 14:32:04 -07002285 if (ret)
Lee Schermerhorn5c0c1652010-06-29 15:05:30 -07002286 goto put_new;
Robin Holt7339ff82006-01-14 13:20:48 -08002287
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002288 /* Create pseudo-vma that contains just the policy */
2289 memset(&pvma, 0, sizeof(struct vm_area_struct));
2290 pvma.vm_end = TASK_SIZE; /* policy covers entire file */
2291 mpol_set_shared_policy(sp, &pvma, new); /* adds ref */
Lee Schermerhorn15d77832010-05-24 14:32:04 -07002292
Lee Schermerhorn5c0c1652010-06-29 15:05:30 -07002293put_new:
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002294 mpol_put(new); /* drop initial ref */
Dan Carpenter0cae3452010-05-25 23:42:58 -07002295free_scratch:
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -07002296 NODEMASK_SCRATCH_FREE(scratch);
Lee Schermerhorn5c0c1652010-06-29 15:05:30 -07002297put_mpol:
2298 mpol_put(mpol); /* drop our incoming ref on sb mpol */
Robin Holt7339ff82006-01-14 13:20:48 -08002299 }
2300}
2301
Linus Torvalds1da177e2005-04-16 15:20:36 -07002302int mpol_set_shared_policy(struct shared_policy *info,
2303 struct vm_area_struct *vma, struct mempolicy *npol)
2304{
2305 int err;
2306 struct sp_node *new = NULL;
2307 unsigned long sz = vma_pages(vma);
2308
David Rientjes028fec42008-04-28 02:12:25 -07002309 pr_debug("set_shared_policy %lx sz %lu %d %d %lx\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07002310 vma->vm_pgoff,
Lee Schermerhorn45c47452008-04-28 02:13:12 -07002311 sz, npol ? npol->mode : -1,
David Rientjes028fec42008-04-28 02:12:25 -07002312 npol ? npol->flags : -1,
Paul Mundt140d5a42007-07-15 23:38:16 -07002313 npol ? nodes_addr(npol->v.nodes)[0] : -1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002314
2315 if (npol) {
2316 new = sp_alloc(vma->vm_pgoff, vma->vm_pgoff + sz, npol);
2317 if (!new)
2318 return -ENOMEM;
2319 }
2320 err = shared_policy_replace(info, vma->vm_pgoff, vma->vm_pgoff+sz, new);
2321 if (err && new)
KOSAKI Motohiro63f74ca2012-10-08 16:29:19 -07002322 sp_free(new);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002323 return err;
2324}
2325
2326/* Free a backing policy store on inode delete. */
2327void mpol_free_shared_policy(struct shared_policy *p)
2328{
2329 struct sp_node *n;
2330 struct rb_node *next;
2331
2332 if (!p->root.rb_node)
2333 return;
Mel Gormanb22d1272012-10-08 16:29:17 -07002334 mutex_lock(&p->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002335 next = rb_first(&p->root);
2336 while (next) {
2337 n = rb_entry(next, struct sp_node, nd);
2338 next = rb_next(&n->nd);
KOSAKI Motohiro63f74ca2012-10-08 16:29:19 -07002339 sp_delete(p, n);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002340 }
Mel Gormanb22d1272012-10-08 16:29:17 -07002341 mutex_unlock(&p->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002342}
2343
2344/* assumes fs == KERNEL_DS */
2345void __init numa_policy_init(void)
2346{
Paul Mundtb71636e2007-07-15 23:38:15 -07002347 nodemask_t interleave_nodes;
2348 unsigned long largest = 0;
2349 int nid, prefer = 0;
2350
Linus Torvalds1da177e2005-04-16 15:20:36 -07002351 policy_cache = kmem_cache_create("numa_policy",
2352 sizeof(struct mempolicy),
Paul Mundt20c2df82007-07-20 10:11:58 +09002353 0, SLAB_PANIC, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002354
2355 sn_cache = kmem_cache_create("shared_policy_node",
2356 sizeof(struct sp_node),
Paul Mundt20c2df82007-07-20 10:11:58 +09002357 0, SLAB_PANIC, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002358
Paul Mundtb71636e2007-07-15 23:38:15 -07002359 /*
2360 * Set interleaving policy for system init. Interleaving is only
2361 * enabled across suitably sized nodes (default is >= 16MB), or
2362 * fall back to the largest node if they're all smaller.
2363 */
2364 nodes_clear(interleave_nodes);
Christoph Lameter56bbd652007-10-16 01:25:35 -07002365 for_each_node_state(nid, N_HIGH_MEMORY) {
Paul Mundtb71636e2007-07-15 23:38:15 -07002366 unsigned long total_pages = node_present_pages(nid);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002367
Paul Mundtb71636e2007-07-15 23:38:15 -07002368 /* Preserve the largest node */
2369 if (largest < total_pages) {
2370 largest = total_pages;
2371 prefer = nid;
2372 }
2373
2374 /* Interleave this node? */
2375 if ((total_pages << PAGE_SHIFT) >= (16 << 20))
2376 node_set(nid, interleave_nodes);
2377 }
2378
2379 /* All too small, use the largest */
2380 if (unlikely(nodes_empty(interleave_nodes)))
2381 node_set(prefer, interleave_nodes);
2382
David Rientjes028fec42008-04-28 02:12:25 -07002383 if (do_set_mempolicy(MPOL_INTERLEAVE, 0, &interleave_nodes))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002384 printk("numa_policy_init: interleaving failed\n");
2385}
2386
Christoph Lameter8bccd852005-10-29 18:16:59 -07002387/* Reset policy of current process to default */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002388void numa_default_policy(void)
2389{
David Rientjes028fec42008-04-28 02:12:25 -07002390 do_set_mempolicy(MPOL_DEFAULT, 0, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002391}
Paul Jackson68860ec2005-10-30 15:02:36 -08002392
Paul Jackson42253992006-01-08 01:01:59 -08002393/*
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002394 * Parse and format mempolicy from/to strings
2395 */
2396
2397/*
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -07002398 * "local" is pseudo-policy: MPOL_PREFERRED with MPOL_F_LOCAL flag
Lee Schermerhorn3f226aa2008-04-28 02:13:24 -07002399 * Used only for mpol_parse_str() and mpol_to_str()
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002400 */
Lee Schermerhorn345ace92010-05-24 14:32:04 -07002401#define MPOL_LOCAL MPOL_MAX
2402static const char * const policy_modes[] =
2403{
2404 [MPOL_DEFAULT] = "default",
2405 [MPOL_PREFERRED] = "prefer",
2406 [MPOL_BIND] = "bind",
2407 [MPOL_INTERLEAVE] = "interleave",
2408 [MPOL_LOCAL] = "local"
2409};
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002410
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002411
2412#ifdef CONFIG_TMPFS
2413/**
2414 * mpol_parse_str - parse string to mempolicy
2415 * @str: string containing mempolicy to parse
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002416 * @mpol: pointer to struct mempolicy pointer, returned on success.
2417 * @no_context: flag whether to "contextualize" the mempolicy
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002418 *
2419 * Format of input:
2420 * <mode>[=<flags>][:<nodelist>]
2421 *
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002422 * if @no_context is true, save the input nodemask in w.user_nodemask in
2423 * the returned mempolicy. This will be used to "clone" the mempolicy in
2424 * a specific context [cpuset] at a later time. Used to parse tmpfs mpol
2425 * mount option. Note that if 'static' or 'relative' mode flags were
2426 * specified, the input nodemask will already have been saved. Saving
2427 * it again is redundant, but safe.
2428 *
2429 * On success, returns 0, else 1
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002430 */
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002431int mpol_parse_str(char *str, struct mempolicy **mpol, int no_context)
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002432{
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002433 struct mempolicy *new = NULL;
Lee Schermerhornb4652e82010-05-24 14:32:03 -07002434 unsigned short mode;
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002435 unsigned short uninitialized_var(mode_flags);
2436 nodemask_t nodes;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002437 char *nodelist = strchr(str, ':');
2438 char *flags = strchr(str, '=');
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002439 int err = 1;
2440
2441 if (nodelist) {
2442 /* NUL-terminate mode or flags string */
2443 *nodelist++ = '\0';
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002444 if (nodelist_parse(nodelist, nodes))
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002445 goto out;
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002446 if (!nodes_subset(nodes, node_states[N_HIGH_MEMORY]))
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002447 goto out;
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002448 } else
2449 nodes_clear(nodes);
2450
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002451 if (flags)
2452 *flags++ = '\0'; /* terminate mode string */
2453
Lee Schermerhornb4652e82010-05-24 14:32:03 -07002454 for (mode = 0; mode <= MPOL_LOCAL; mode++) {
Lee Schermerhorn345ace92010-05-24 14:32:04 -07002455 if (!strcmp(str, policy_modes[mode])) {
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002456 break;
2457 }
2458 }
Lee Schermerhornb4652e82010-05-24 14:32:03 -07002459 if (mode > MPOL_LOCAL)
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002460 goto out;
2461
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002462 switch (mode) {
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002463 case MPOL_PREFERRED:
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002464 /*
2465 * Insist on a nodelist of one node only
2466 */
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002467 if (nodelist) {
2468 char *rest = nodelist;
2469 while (isdigit(*rest))
2470 rest++;
KOSAKI Motohiro926f2ae2010-03-23 13:35:32 -07002471 if (*rest)
2472 goto out;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002473 }
2474 break;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002475 case MPOL_INTERLEAVE:
2476 /*
2477 * Default to online nodes with memory if no nodelist
2478 */
2479 if (!nodelist)
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002480 nodes = node_states[N_HIGH_MEMORY];
Lee Schermerhorn3f226aa2008-04-28 02:13:24 -07002481 break;
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002482 case MPOL_LOCAL:
Lee Schermerhorn3f226aa2008-04-28 02:13:24 -07002483 /*
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002484 * Don't allow a nodelist; mpol_new() checks flags
Lee Schermerhorn3f226aa2008-04-28 02:13:24 -07002485 */
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002486 if (nodelist)
Lee Schermerhorn3f226aa2008-04-28 02:13:24 -07002487 goto out;
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002488 mode = MPOL_PREFERRED;
Lee Schermerhorn3f226aa2008-04-28 02:13:24 -07002489 break;
Ravikiran G Thirumalai413b43d2010-03-23 13:35:28 -07002490 case MPOL_DEFAULT:
2491 /*
2492 * Insist on a empty nodelist
2493 */
2494 if (!nodelist)
2495 err = 0;
2496 goto out;
KOSAKI Motohirod69b2e62010-03-23 13:35:30 -07002497 case MPOL_BIND:
2498 /*
2499 * Insist on a nodelist
2500 */
2501 if (!nodelist)
2502 goto out;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002503 }
2504
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002505 mode_flags = 0;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002506 if (flags) {
2507 /*
2508 * Currently, we only support two mutually exclusive
2509 * mode flags.
2510 */
2511 if (!strcmp(flags, "static"))
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002512 mode_flags |= MPOL_F_STATIC_NODES;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002513 else if (!strcmp(flags, "relative"))
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002514 mode_flags |= MPOL_F_RELATIVE_NODES;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002515 else
KOSAKI Motohiro926f2ae2010-03-23 13:35:32 -07002516 goto out;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002517 }
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002518
2519 new = mpol_new(mode, mode_flags, &nodes);
2520 if (IS_ERR(new))
KOSAKI Motohiro926f2ae2010-03-23 13:35:32 -07002521 goto out;
2522
Lee Schermerhorne17f74a2010-05-24 14:32:02 -07002523 if (no_context) {
2524 /* save for contextualization */
2525 new->w.user_nodemask = nodes;
2526 } else {
Miao Xie58568d22009-06-16 15:31:49 -07002527 int ret;
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -07002528 NODEMASK_SCRATCH(scratch);
2529 if (scratch) {
2530 task_lock(current);
2531 ret = mpol_set_nodemask(new, &nodes, scratch);
2532 task_unlock(current);
2533 } else
2534 ret = -ENOMEM;
2535 NODEMASK_SCRATCH_FREE(scratch);
2536 if (ret) {
KAMEZAWA Hiroyuki4bfc4492009-08-06 15:07:33 -07002537 mpol_put(new);
KOSAKI Motohiro926f2ae2010-03-23 13:35:32 -07002538 goto out;
Miao Xie58568d22009-06-16 15:31:49 -07002539 }
2540 }
KOSAKI Motohiro926f2ae2010-03-23 13:35:32 -07002541 err = 0;
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002542
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002543out:
2544 /* Restore string for error message */
2545 if (nodelist)
2546 *--nodelist = ':';
2547 if (flags)
2548 *--flags = '=';
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002549 if (!err)
2550 *mpol = new;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002551 return err;
2552}
2553#endif /* CONFIG_TMPFS */
2554
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002555/**
2556 * mpol_to_str - format a mempolicy structure for printing
2557 * @buffer: to contain formatted mempolicy string
2558 * @maxlen: length of @buffer
2559 * @pol: pointer to mempolicy to be formatted
2560 * @no_context: "context free" mempolicy - use nodemask in w.user_nodemask
2561 *
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002562 * Convert a mempolicy into a string.
2563 * Returns the number of characters in buffer (if positive)
2564 * or an error (negative)
2565 */
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002566int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol, int no_context)
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002567{
2568 char *p = buffer;
2569 int l;
2570 nodemask_t nodes;
Lee Schermerhornbea904d2008-04-28 02:13:18 -07002571 unsigned short mode;
David Rientjesf5b087b2008-04-28 02:12:27 -07002572 unsigned short flags = pol ? pol->flags : 0;
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002573
Lee Schermerhorn22919902008-04-28 02:13:22 -07002574 /*
2575 * Sanity check: room for longest mode, flag and some nodes
2576 */
2577 VM_BUG_ON(maxlen < strlen("interleave") + strlen("relative") + 16);
2578
Lee Schermerhornbea904d2008-04-28 02:13:18 -07002579 if (!pol || pol == &default_policy)
2580 mode = MPOL_DEFAULT;
2581 else
2582 mode = pol->mode;
2583
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002584 switch (mode) {
2585 case MPOL_DEFAULT:
2586 nodes_clear(nodes);
2587 break;
2588
2589 case MPOL_PREFERRED:
2590 nodes_clear(nodes);
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -07002591 if (flags & MPOL_F_LOCAL)
Lee Schermerhorn53f25562008-04-28 02:13:20 -07002592 mode = MPOL_LOCAL; /* pseudo-policy */
2593 else
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -07002594 node_set(pol->v.preferred_node, nodes);
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002595 break;
2596
2597 case MPOL_BIND:
Mel Gorman19770b32008-04-28 02:12:18 -07002598 /* Fall through */
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002599 case MPOL_INTERLEAVE:
Lee Schermerhorn71fe8042008-04-28 02:13:26 -07002600 if (no_context)
2601 nodes = pol->w.user_nodemask;
2602 else
2603 nodes = pol->v.nodes;
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002604 break;
2605
2606 default:
Dave Jones80de7c32012-09-06 12:01:00 -04002607 return -EINVAL;
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002608 }
2609
Lee Schermerhorn345ace92010-05-24 14:32:04 -07002610 l = strlen(policy_modes[mode]);
Lee Schermerhorn53f25562008-04-28 02:13:20 -07002611 if (buffer + maxlen < p + l + 1)
2612 return -ENOSPC;
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002613
Lee Schermerhorn345ace92010-05-24 14:32:04 -07002614 strcpy(p, policy_modes[mode]);
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002615 p += l;
2616
Lee Schermerhornfc36b8d2008-04-28 02:13:21 -07002617 if (flags & MPOL_MODE_FLAGS) {
David Rientjesf5b087b2008-04-28 02:12:27 -07002618 if (buffer + maxlen < p + 2)
2619 return -ENOSPC;
2620 *p++ = '=';
2621
Lee Schermerhorn22919902008-04-28 02:13:22 -07002622 /*
2623 * Currently, the only defined flags are mutually exclusive
2624 */
David Rientjesf5b087b2008-04-28 02:12:27 -07002625 if (flags & MPOL_F_STATIC_NODES)
Lee Schermerhorn22919902008-04-28 02:13:22 -07002626 p += snprintf(p, buffer + maxlen - p, "static");
2627 else if (flags & MPOL_F_RELATIVE_NODES)
2628 p += snprintf(p, buffer + maxlen - p, "relative");
David Rientjesf5b087b2008-04-28 02:12:27 -07002629 }
2630
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002631 if (!nodes_empty(nodes)) {
2632 if (buffer + maxlen < p + 2)
2633 return -ENOSPC;
Lee Schermerhorn095f1fc2008-04-28 02:13:23 -07002634 *p++ = ':';
Christoph Lameter1a75a6c2006-01-08 01:01:02 -08002635 p += nodelist_scnprintf(p, buffer + maxlen - p, nodes);
2636 }
2637 return p - buffer;
2638}