mempolicy.c 63.2 KB
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/*
 * Simple NUMA memory policy for the Linux kernel.
 *
 * Copyright 2003,2004 Andi Kleen, SuSE Labs.
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 * (C) Copyright 2005 Christoph Lameter, Silicon Graphics, Inc.
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 * Subject to the GNU Public License, version 2.
 *
 * NUMA policy allows the user to give hints in which node(s) memory should
 * be allocated.
 *
 * Support four policies per VMA and per process:
 *
 * The VMA policy has priority over the process policy for a page fault.
 *
 * interleave     Allocate memory interleaved over a set of nodes,
 *                with normal fallback if it fails.
 *                For VMA based allocations this interleaves based on the
 *                offset into the backing object or offset into the mapping
 *                for anonymous memory. For process policy an process counter
 *                is used.
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 *
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 * bind           Only allocate memory on a specific set of nodes,
 *                no fallback.
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 *                FIXME: memory is allocated starting with the first node
 *                to the last. It would be better if bind would truly restrict
 *                the allocation to memory nodes instead
 *
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 * preferred       Try a specific node first before normal fallback.
 *                As a special case node -1 here means do the allocation
 *                on the local CPU. This is normally identical to default,
 *                but useful to set in a VMA when you have a non default
 *                process policy.
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 *
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 * default        Allocate on the local node first, or when on a VMA
 *                use the process policy. This is what Linux always did
 *		  in a NUMA aware kernel and still does by, ahem, default.
 *
 * The process policy is applied for most non interrupt memory allocations
 * in that process' context. Interrupts ignore the policies and always
 * try to allocate on the local CPU. The VMA policy is only applied for memory
 * allocations for a VMA in the VM.
 *
 * Currently there are a few corner cases in swapping where the policy
 * is not applied, but the majority should be handled. When process policy
 * is used it is not remembered over swap outs/swap ins.
 *
 * Only the highest zone in the zone hierarchy gets policied. Allocations
 * requesting a lower zone just use default policy. This implies that
 * on systems with highmem kernel lowmem allocation don't get policied.
 * Same with GFP_DMA allocations.
 *
 * For shmfs/tmpfs/hugetlbfs shared memory the policy is shared between
 * all users and remembered even when nobody has memory mapped.
 */

/* Notebook:
   fix mmap readahead to honour policy and enable policy for any page cache
   object
   statistics for bigpages
   global policy for page cache? currently it uses process policy. Requires
   first item above.
   handle mremap for shared memory (currently ignored for the policy)
   grows down?
   make bind policy root only? It can trigger oom much faster and the
   kernel is not always grateful with that.
*/

#include <linux/mempolicy.h>
#include <linux/mm.h>
#include <linux/highmem.h>
#include <linux/hugetlb.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/nodemask.h>
#include <linux/cpuset.h>
#include <linux/gfp.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/module.h>
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#include <linux/nsproxy.h>
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#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/compat.h>
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#include <linux/swap.h>
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#include <linux/seq_file.h>
#include <linux/proc_fs.h>
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#include <linux/migrate.h>
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#include <linux/ksm.h>
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#include <linux/rmap.h>
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#include <linux/security.h>
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#include <linux/syscalls.h>
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#include <linux/ctype.h>
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#include <linux/mm_inline.h>
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#include <asm/tlbflush.h>
#include <asm/uaccess.h>

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#include "internal.h"

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/* Internal flags */
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#define MPOL_MF_DISCONTIG_OK (MPOL_MF_INTERNAL << 0)	/* Skip checks for continuous vmas */
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#define MPOL_MF_INVERT (MPOL_MF_INTERNAL << 1)		/* Invert check for nodemask */
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#define MPOL_MF_STATS (MPOL_MF_INTERNAL << 2)		/* Gather statistics */
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static struct kmem_cache *policy_cache;
static struct kmem_cache *sn_cache;
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/* Highest zone. An specific allocation for a zone below that is not
   policied. */
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enum zone_type policy_zone = 0;
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/*
 * run-time system-wide default policy => local allocation
 */
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struct mempolicy default_policy = {
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	.refcnt = ATOMIC_INIT(1), /* never free it */
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	.mode = MPOL_PREFERRED,
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	.flags = MPOL_F_LOCAL,
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};

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static const struct mempolicy_operations {
	int (*create)(struct mempolicy *pol, const nodemask_t *nodes);
	void (*rebind)(struct mempolicy *pol, const nodemask_t *nodes);
} mpol_ops[MPOL_MAX];

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/* Check that the nodemask contains at least one populated zone */
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static int is_valid_nodemask(const nodemask_t *nodemask)
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{
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	int nd, k;
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	/* Check that there is something useful in this mask */
	k = policy_zone;

	for_each_node_mask(nd, *nodemask) {
		struct zone *z;

		for (k = 0; k <= policy_zone; k++) {
			z = &NODE_DATA(nd)->node_zones[k];
			if (z->present_pages > 0)
				return 1;
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		}
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	}
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	return 0;
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}

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static inline int mpol_store_user_nodemask(const struct mempolicy *pol)
{
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	return pol->flags & (MPOL_F_STATIC_NODES | MPOL_F_RELATIVE_NODES);
}

static void mpol_relative_nodemask(nodemask_t *ret, const nodemask_t *orig,
				   const nodemask_t *rel)
{
	nodemask_t tmp;
	nodes_fold(tmp, *orig, nodes_weight(*rel));
	nodes_onto(*ret, tmp, *rel);
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}

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static int mpol_new_interleave(struct mempolicy *pol, const nodemask_t *nodes)
{
	if (nodes_empty(*nodes))
		return -EINVAL;
	pol->v.nodes = *nodes;
	return 0;
}

static int mpol_new_preferred(struct mempolicy *pol, const nodemask_t *nodes)
{
	if (!nodes)
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		pol->flags |= MPOL_F_LOCAL;	/* local allocation */
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	else if (nodes_empty(*nodes))
		return -EINVAL;			/*  no allowed nodes */
	else
		pol->v.preferred_node = first_node(*nodes);
	return 0;
}

static int mpol_new_bind(struct mempolicy *pol, const nodemask_t *nodes)
{
	if (!is_valid_nodemask(nodes))
		return -EINVAL;
	pol->v.nodes = *nodes;
	return 0;
}

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/*
 * mpol_set_nodemask is called after mpol_new() to set up the nodemask, if
 * any, for the new policy.  mpol_new() has already validated the nodes
 * parameter with respect to the policy mode and flags.  But, we need to
 * handle an empty nodemask with MPOL_PREFERRED here.
 *
 * Must be called holding task's alloc_lock to protect task's mems_allowed
 * and mempolicy.  May also be called holding the mmap_semaphore for write.
 */
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static int mpol_set_nodemask(struct mempolicy *pol,
		     const nodemask_t *nodes, struct nodemask_scratch *nsc)
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{
	int ret;

	/* if mode is MPOL_DEFAULT, pol is NULL. This is right. */
	if (pol == NULL)
		return 0;
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	/* Check N_HIGH_MEMORY */
	nodes_and(nsc->mask1,
		  cpuset_current_mems_allowed, node_states[N_HIGH_MEMORY]);
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	VM_BUG_ON(!nodes);
	if (pol->mode == MPOL_PREFERRED && nodes_empty(*nodes))
		nodes = NULL;	/* explicit local allocation */
	else {
		if (pol->flags & MPOL_F_RELATIVE_NODES)
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			mpol_relative_nodemask(&nsc->mask2, nodes,&nsc->mask1);
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		else
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			nodes_and(nsc->mask2, *nodes, nsc->mask1);

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		if (mpol_store_user_nodemask(pol))
			pol->w.user_nodemask = *nodes;
		else
			pol->w.cpuset_mems_allowed =
						cpuset_current_mems_allowed;
	}

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	if (nodes)
		ret = mpol_ops[pol->mode].create(pol, &nsc->mask2);
	else
		ret = mpol_ops[pol->mode].create(pol, NULL);
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	return ret;
}

/*
 * This function just creates a new policy, does some check and simple
 * initialization. You must invoke mpol_set_nodemask() to set nodes.
 */
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static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags,
				  nodemask_t *nodes)
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{
	struct mempolicy *policy;

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	pr_debug("setting mode %d flags %d nodes[0] %lx\n",
		 mode, flags, nodes ? nodes_addr(*nodes)[0] : -1);
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	if (mode == MPOL_DEFAULT) {
		if (nodes && !nodes_empty(*nodes))
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			return ERR_PTR(-EINVAL);
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		return NULL;	/* simply delete any existing policy */
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	}
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	VM_BUG_ON(!nodes);

	/*
	 * MPOL_PREFERRED cannot be used with MPOL_F_STATIC_NODES or
	 * MPOL_F_RELATIVE_NODES if the nodemask is empty (local allocation).
	 * All other modes require a valid pointer to a non-empty nodemask.
	 */
	if (mode == MPOL_PREFERRED) {
		if (nodes_empty(*nodes)) {
			if (((flags & MPOL_F_STATIC_NODES) ||
			     (flags & MPOL_F_RELATIVE_NODES)))
				return ERR_PTR(-EINVAL);
		}
	} else if (nodes_empty(*nodes))
		return ERR_PTR(-EINVAL);
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	policy = kmem_cache_alloc(policy_cache, GFP_KERNEL);
	if (!policy)
		return ERR_PTR(-ENOMEM);
	atomic_set(&policy->refcnt, 1);
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	policy->mode = mode;
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	policy->flags = flags;
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	return policy;
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}

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/* Slow path of a mpol destructor. */
void __mpol_put(struct mempolicy *p)
{
	if (!atomic_dec_and_test(&p->refcnt))
		return;
	kmem_cache_free(policy_cache, p);
}

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static void mpol_rebind_default(struct mempolicy *pol, const nodemask_t *nodes)
{
}

static void mpol_rebind_nodemask(struct mempolicy *pol,
				 const nodemask_t *nodes)
{
	nodemask_t tmp;

	if (pol->flags & MPOL_F_STATIC_NODES)
		nodes_and(tmp, pol->w.user_nodemask, *nodes);
	else if (pol->flags & MPOL_F_RELATIVE_NODES)
		mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes);
	else {
		nodes_remap(tmp, pol->v.nodes, pol->w.cpuset_mems_allowed,
			    *nodes);
		pol->w.cpuset_mems_allowed = *nodes;
	}
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	pol->v.nodes = tmp;
	if (!node_isset(current->il_next, tmp)) {
		current->il_next = next_node(current->il_next, tmp);
		if (current->il_next >= MAX_NUMNODES)
			current->il_next = first_node(tmp);
		if (current->il_next >= MAX_NUMNODES)
			current->il_next = numa_node_id();
	}
}

static void mpol_rebind_preferred(struct mempolicy *pol,
				  const nodemask_t *nodes)
{
	nodemask_t tmp;

	if (pol->flags & MPOL_F_STATIC_NODES) {
		int node = first_node(pol->w.user_nodemask);

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		if (node_isset(node, *nodes)) {
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			pol->v.preferred_node = node;
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			pol->flags &= ~MPOL_F_LOCAL;
		} else
			pol->flags |= MPOL_F_LOCAL;
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	} else if (pol->flags & MPOL_F_RELATIVE_NODES) {
		mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes);
		pol->v.preferred_node = first_node(tmp);
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	} else if (!(pol->flags & MPOL_F_LOCAL)) {
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		pol->v.preferred_node = node_remap(pol->v.preferred_node,
						   pol->w.cpuset_mems_allowed,
						   *nodes);
		pol->w.cpuset_mems_allowed = *nodes;
	}
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}

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/* Migrate a policy to a different set of nodes */
static void mpol_rebind_policy(struct mempolicy *pol,
			       const nodemask_t *newmask)
{
	if (!pol)
		return;
	if (!mpol_store_user_nodemask(pol) &&
	    nodes_equal(pol->w.cpuset_mems_allowed, *newmask))
		return;
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	mpol_ops[pol->mode].rebind(pol, newmask);
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}

/*
 * Wrapper for mpol_rebind_policy() that just requires task
 * pointer, and updates task mempolicy.
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 *
 * Called with task's alloc_lock held.
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 */

void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new)
{
	mpol_rebind_policy(tsk->mempolicy, new);
}

/*
 * Rebind each vma in mm to new nodemask.
 *
 * Call holding a reference to mm.  Takes mm->mmap_sem during call.
 */

void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new)
{
	struct vm_area_struct *vma;

	down_write(&mm->mmap_sem);
	for (vma = mm->mmap; vma; vma = vma->vm_next)
		mpol_rebind_policy(vma->vm_policy, new);
	up_write(&mm->mmap_sem);
}

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static const struct mempolicy_operations mpol_ops[MPOL_MAX] = {
	[MPOL_DEFAULT] = {
		.rebind = mpol_rebind_default,
	},
	[MPOL_INTERLEAVE] = {
		.create = mpol_new_interleave,
		.rebind = mpol_rebind_nodemask,
	},
	[MPOL_PREFERRED] = {
		.create = mpol_new_preferred,
		.rebind = mpol_rebind_preferred,
	},
	[MPOL_BIND] = {
		.create = mpol_new_bind,
		.rebind = mpol_rebind_nodemask,
	},
};

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static void gather_stats(struct page *, void *, int pte_dirty);
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static void migrate_page_add(struct page *page, struct list_head *pagelist,
				unsigned long flags);
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/* Scan through pages checking if pages follow certain conditions. */
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static int check_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
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		unsigned long addr, unsigned long end,
		const nodemask_t *nodes, unsigned long flags,
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		void *private)
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{
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	pte_t *orig_pte;
	pte_t *pte;
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	spinlock_t *ptl;
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	orig_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
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	do {
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		struct page *page;
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		int nid;
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		if (!pte_present(*pte))
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			continue;
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		page = vm_normal_page(vma, addr, *pte);
		if (!page)
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			continue;
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		/*
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		 * vm_normal_page() filters out zero pages, but there might
		 * still be PageReserved pages to skip, perhaps in a VDSO.
		 * And we cannot move PageKsm pages sensibly or safely yet.
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		 */
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		if (PageReserved(page) || PageKsm(page))
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			continue;
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		nid = page_to_nid(page);
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		if (node_isset(nid, *nodes) == !!(flags & MPOL_MF_INVERT))
			continue;

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		if (flags & MPOL_MF_STATS)
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			gather_stats(page, private, pte_dirty(*pte));
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		else if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
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			migrate_page_add(page, private, flags);
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		else
			break;
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	} while (pte++, addr += PAGE_SIZE, addr != end);
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	pte_unmap_unlock(orig_pte, ptl);
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	return addr != end;
}

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static inline int check_pmd_range(struct vm_area_struct *vma, pud_t *pud,
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		unsigned long addr, unsigned long end,
		const nodemask_t *nodes, unsigned long flags,
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		void *private)
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{
	pmd_t *pmd;
	unsigned long next;

	pmd = pmd_offset(pud, addr);
	do {
		next = pmd_addr_end(addr, end);
		if (pmd_none_or_clear_bad(pmd))
			continue;
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		if (check_pte_range(vma, pmd, addr, next, nodes,
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				    flags, private))
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			return -EIO;
	} while (pmd++, addr = next, addr != end);
	return 0;
}

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static inline int check_pud_range(struct vm_area_struct *vma, pgd_t *pgd,
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		unsigned long addr, unsigned long end,
		const nodemask_t *nodes, unsigned long flags,
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		void *private)
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{
	pud_t *pud;
	unsigned long next;

	pud = pud_offset(pgd, addr);
	do {
		next = pud_addr_end(addr, end);
		if (pud_none_or_clear_bad(pud))
			continue;
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		if (check_pmd_range(vma, pud, addr, next, nodes,
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				    flags, private))
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			return -EIO;
	} while (pud++, addr = next, addr != end);
	return 0;
}

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static inline int check_pgd_range(struct vm_area_struct *vma,
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		unsigned long addr, unsigned long end,
		const nodemask_t *nodes, unsigned long flags,
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		void *private)
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{
	pgd_t *pgd;
	unsigned long next;

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	pgd = pgd_offset(vma->vm_mm, addr);
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	do {
		next = pgd_addr_end(addr, end);
		if (pgd_none_or_clear_bad(pgd))
			continue;
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		if (check_pud_range(vma, pgd, addr, next, nodes,
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				    flags, private))
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			return -EIO;
	} while (pgd++, addr = next, addr != end);
	return 0;
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}

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/*
 * Check if all pages in a range are on a set of nodes.
 * If pagelist != NULL then isolate pages from the LRU and
 * put them on the pagelist.
 */
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static struct vm_area_struct *
check_range(struct mm_struct *mm, unsigned long start, unsigned long end,
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		const nodemask_t *nodes, unsigned long flags, void *private)
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{
	int err;
	struct vm_area_struct *first, *vma, *prev;

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	first = find_vma(mm, start);
	if (!first)
		return ERR_PTR(-EFAULT);
	prev = NULL;
	for (vma = first; vma && vma->vm_start < end; vma = vma->vm_next) {
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		if (!(flags & MPOL_MF_DISCONTIG_OK)) {
			if (!vma->vm_next && vma->vm_end < end)
				return ERR_PTR(-EFAULT);
			if (prev && prev->vm_end < vma->vm_start)
				return ERR_PTR(-EFAULT);
		}
		if (!is_vm_hugetlb_page(vma) &&
		    ((flags & MPOL_MF_STRICT) ||
		     ((flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) &&
				vma_migratable(vma)))) {
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			unsigned long endvma = vma->vm_end;
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			if (endvma > end)
				endvma = end;
			if (vma->vm_start > start)
				start = vma->vm_start;
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			err = check_pgd_range(vma, start, endvma, nodes,
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						flags, private);
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			if (err) {
				first = ERR_PTR(err);
				break;
			}
		}
		prev = vma;
	}
	return first;
}

/* Apply policy to a single VMA */
static int policy_vma(struct vm_area_struct *vma, struct mempolicy *new)
{
	int err = 0;
	struct mempolicy *old = vma->vm_policy;

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	pr_debug("vma %lx-%lx/%lx vm_ops %p vm_file %p set_policy %p\n",
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		 vma->vm_start, vma->vm_end, vma->vm_pgoff,
		 vma->vm_ops, vma->vm_file,
		 vma->vm_ops ? vma->vm_ops->set_policy : NULL);

	if (vma->vm_ops && vma->vm_ops->set_policy)
		err = vma->vm_ops->set_policy(vma, new);
	if (!err) {
		mpol_get(new);
		vma->vm_policy = new;
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		mpol_put(old);
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	}
	return err;
}

/* Step 2: apply policy to a range and do splits. */
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static int mbind_range(struct mm_struct *mm, unsigned long start,
		       unsigned long end, struct mempolicy *new_pol)
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{
	struct vm_area_struct *next;
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	struct vm_area_struct *prev;
	struct vm_area_struct *vma;
	int err = 0;
	pgoff_t pgoff;
	unsigned long vmstart;
	unsigned long vmend;
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	vma = find_vma_prev(mm, start, &prev);
	if (!vma || vma->vm_start > start)
		return -EFAULT;

	for (; vma && vma->vm_start < end; prev = vma, vma = next) {
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		next = vma->vm_next;
583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604
		vmstart = max(start, vma->vm_start);
		vmend   = min(end, vma->vm_end);

		pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
		prev = vma_merge(mm, prev, vmstart, vmend, vma->vm_flags,
				  vma->anon_vma, vma->vm_file, pgoff, new_pol);
		if (prev) {
			vma = prev;
			next = vma->vm_next;
			continue;
		}
		if (vma->vm_start != vmstart) {
			err = split_vma(vma->vm_mm, vma, vmstart, 1);
			if (err)
				goto out;
		}
		if (vma->vm_end != vmend) {
			err = split_vma(vma->vm_mm, vma, vmend, 0);
			if (err)
				goto out;
		}
		err = policy_vma(vma, new_pol);
L
Linus Torvalds 已提交
605
		if (err)
606
			goto out;
L
Linus Torvalds 已提交
607
	}
608 609

 out:
L
Linus Torvalds 已提交
610 611 612
	return err;
}

613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642
/*
 * Update task->flags PF_MEMPOLICY bit: set iff non-default
 * mempolicy.  Allows more rapid checking of this (combined perhaps
 * with other PF_* flag bits) on memory allocation hot code paths.
 *
 * If called from outside this file, the task 'p' should -only- be
 * a newly forked child not yet visible on the task list, because
 * manipulating the task flags of a visible task is not safe.
 *
 * The above limitation is why this routine has the funny name
 * mpol_fix_fork_child_flag().
 *
 * It is also safe to call this with a task pointer of current,
 * which the static wrapper mpol_set_task_struct_flag() does,
 * for use within this file.
 */

void mpol_fix_fork_child_flag(struct task_struct *p)
{
	if (p->mempolicy)
		p->flags |= PF_MEMPOLICY;
	else
		p->flags &= ~PF_MEMPOLICY;
}

static void mpol_set_task_struct_flag(void)
{
	mpol_fix_fork_child_flag(current);
}

L
Linus Torvalds 已提交
643
/* Set the process memory policy */
644 645
static long do_set_mempolicy(unsigned short mode, unsigned short flags,
			     nodemask_t *nodes)
L
Linus Torvalds 已提交
646
{
647
	struct mempolicy *new, *old;
648
	struct mm_struct *mm = current->mm;
649
	NODEMASK_SCRATCH(scratch);
650
	int ret;
L
Linus Torvalds 已提交
651

652 653
	if (!scratch)
		return -ENOMEM;
654

655 656 657 658 659
	new = mpol_new(mode, flags, nodes);
	if (IS_ERR(new)) {
		ret = PTR_ERR(new);
		goto out;
	}
660 661 662 663 664 665 666 667
	/*
	 * prevent changing our mempolicy while show_numa_maps()
	 * is using it.
	 * Note:  do_set_mempolicy() can be called at init time
	 * with no 'mm'.
	 */
	if (mm)
		down_write(&mm->mmap_sem);
668
	task_lock(current);
669
	ret = mpol_set_nodemask(new, nodes, scratch);
670 671 672 673 674
	if (ret) {
		task_unlock(current);
		if (mm)
			up_write(&mm->mmap_sem);
		mpol_put(new);
675
		goto out;
676 677
	}
	old = current->mempolicy;
L
Linus Torvalds 已提交
678
	current->mempolicy = new;
679
	mpol_set_task_struct_flag();
680
	if (new && new->mode == MPOL_INTERLEAVE &&
681
	    nodes_weight(new->v.nodes))
682
		current->il_next = first_node(new->v.nodes);
683
	task_unlock(current);
684 685 686
	if (mm)
		up_write(&mm->mmap_sem);

687
	mpol_put(old);
688 689 690 691
	ret = 0;
out:
	NODEMASK_SCRATCH_FREE(scratch);
	return ret;
L
Linus Torvalds 已提交
692 693
}

694 695
/*
 * Return nodemask for policy for get_mempolicy() query
696 697
 *
 * Called with task's alloc_lock held
698 699
 */
static void get_policy_nodemask(struct mempolicy *p, nodemask_t *nodes)
L
Linus Torvalds 已提交
700
{
701
	nodes_clear(*nodes);
702 703 704
	if (p == &default_policy)
		return;

705
	switch (p->mode) {
706 707
	case MPOL_BIND:
		/* Fall through */
L
Linus Torvalds 已提交
708
	case MPOL_INTERLEAVE:
709
		*nodes = p->v.nodes;
L
Linus Torvalds 已提交
710 711
		break;
	case MPOL_PREFERRED:
712
		if (!(p->flags & MPOL_F_LOCAL))
713
			node_set(p->v.preferred_node, *nodes);
714
		/* else return empty node mask for local allocation */
L
Linus Torvalds 已提交
715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734
		break;
	default:
		BUG();
	}
}

static int lookup_node(struct mm_struct *mm, unsigned long addr)
{
	struct page *p;
	int err;

	err = get_user_pages(current, mm, addr & PAGE_MASK, 1, 0, 0, &p, NULL);
	if (err >= 0) {
		err = page_to_nid(p);
		put_page(p);
	}
	return err;
}

/* Retrieve NUMA policy */
A
Adrian Bunk 已提交
735 736
static long do_get_mempolicy(int *policy, nodemask_t *nmask,
			     unsigned long addr, unsigned long flags)
L
Linus Torvalds 已提交
737
{
738
	int err;
L
Linus Torvalds 已提交
739 740 741 742
	struct mm_struct *mm = current->mm;
	struct vm_area_struct *vma = NULL;
	struct mempolicy *pol = current->mempolicy;

743 744
	if (flags &
		~(unsigned long)(MPOL_F_NODE|MPOL_F_ADDR|MPOL_F_MEMS_ALLOWED))
L
Linus Torvalds 已提交
745
		return -EINVAL;
746 747 748 749 750

	if (flags & MPOL_F_MEMS_ALLOWED) {
		if (flags & (MPOL_F_NODE|MPOL_F_ADDR))
			return -EINVAL;
		*policy = 0;	/* just so it's initialized */
751
		task_lock(current);
752
		*nmask  = cpuset_current_mems_allowed;
753
		task_unlock(current);
754 755 756
		return 0;
	}

L
Linus Torvalds 已提交
757
	if (flags & MPOL_F_ADDR) {
758 759 760 761 762
		/*
		 * Do NOT fall back to task policy if the
		 * vma/shared policy at addr is NULL.  We
		 * want to return MPOL_DEFAULT in this case.
		 */
L
Linus Torvalds 已提交
763 764 765 766 767 768 769 770 771 772 773 774 775 776
		down_read(&mm->mmap_sem);
		vma = find_vma_intersection(mm, addr, addr+1);
		if (!vma) {
			up_read(&mm->mmap_sem);
			return -EFAULT;
		}
		if (vma->vm_ops && vma->vm_ops->get_policy)
			pol = vma->vm_ops->get_policy(vma, addr);
		else
			pol = vma->vm_policy;
	} else if (addr)
		return -EINVAL;

	if (!pol)
777
		pol = &default_policy;	/* indicates default behavior */
L
Linus Torvalds 已提交
778 779 780 781 782 783

	if (flags & MPOL_F_NODE) {
		if (flags & MPOL_F_ADDR) {
			err = lookup_node(mm, addr);
			if (err < 0)
				goto out;
784
			*policy = err;
L
Linus Torvalds 已提交
785
		} else if (pol == current->mempolicy &&
786
				pol->mode == MPOL_INTERLEAVE) {
787
			*policy = current->il_next;
L
Linus Torvalds 已提交
788 789 790 791
		} else {
			err = -EINVAL;
			goto out;
		}
792 793 794
	} else {
		*policy = pol == &default_policy ? MPOL_DEFAULT :
						pol->mode;
795 796 797 798 799
		/*
		 * Internal mempolicy flags must be masked off before exposing
		 * the policy to userspace.
		 */
		*policy |= (pol->flags & MPOL_MODE_FLAGS);
800
	}
L
Linus Torvalds 已提交
801 802 803 804 805 806 807

	if (vma) {
		up_read(&current->mm->mmap_sem);
		vma = NULL;
	}

	err = 0;
808 809
	if (nmask) {
		task_lock(current);
810
		get_policy_nodemask(pol, nmask);
811 812
		task_unlock(current);
	}
L
Linus Torvalds 已提交
813 814

 out:
815
	mpol_cond_put(pol);
L
Linus Torvalds 已提交
816 817 818 819 820
	if (vma)
		up_read(&current->mm->mmap_sem);
	return err;
}

C
Christoph Lameter 已提交
821
#ifdef CONFIG_MIGRATION
822 823 824
/*
 * page migration
 */
825 826
static void migrate_page_add(struct page *page, struct list_head *pagelist,
				unsigned long flags)
827 828
{
	/*
829
	 * Avoid migrating a page that is shared with others.
830
	 */
831 832 833
	if ((flags & MPOL_MF_MOVE_ALL) || page_mapcount(page) == 1) {
		if (!isolate_lru_page(page)) {
			list_add_tail(&page->lru, pagelist);
834 835
			inc_zone_page_state(page, NR_ISOLATED_ANON +
					    page_is_file_cache(page));
836 837
		}
	}
838
}
839

840
static struct page *new_node_page(struct page *page, unsigned long node, int **x)
841
{
842
	return alloc_pages_exact_node(node, GFP_HIGHUSER_MOVABLE, 0);
843 844
}

845 846 847 848
/*
 * Migrate pages from one node to a target node.
 * Returns error or the number of pages not migrated.
 */
A
Adrian Bunk 已提交
849 850
static int migrate_to_node(struct mm_struct *mm, int source, int dest,
			   int flags)
851 852 853 854 855 856 857
{
	nodemask_t nmask;
	LIST_HEAD(pagelist);
	int err = 0;

	nodes_clear(nmask);
	node_set(source, nmask);
858

859 860 861
	check_range(mm, mm->mmap->vm_start, TASK_SIZE, &nmask,
			flags | MPOL_MF_DISCONTIG_OK, &pagelist);

862
	if (!list_empty(&pagelist))
863
		err = migrate_pages(&pagelist, new_node_page, dest, 0);
864

865
	return err;
866 867
}

868
/*
869 870
 * Move pages between the two nodesets so as to preserve the physical
 * layout as much as possible.
871 872 873 874 875 876
 *
 * Returns the number of page that could not be moved.
 */
int do_migrate_pages(struct mm_struct *mm,
	const nodemask_t *from_nodes, const nodemask_t *to_nodes, int flags)
{
877
	int busy = 0;
878
	int err;
879
	nodemask_t tmp;
880

881 882 883 884
	err = migrate_prep();
	if (err)
		return err;

885
	down_read(&mm->mmap_sem);
886

887 888 889 890
	err = migrate_vmas(mm, from_nodes, to_nodes, flags);
	if (err)
		goto out;

891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920
	/*
	 * Find a 'source' bit set in 'tmp' whose corresponding 'dest'
	 * bit in 'to' is not also set in 'tmp'.  Clear the found 'source'
	 * bit in 'tmp', and return that <source, dest> pair for migration.
	 * The pair of nodemasks 'to' and 'from' define the map.
	 *
	 * If no pair of bits is found that way, fallback to picking some
	 * pair of 'source' and 'dest' bits that are not the same.  If the
	 * 'source' and 'dest' bits are the same, this represents a node
	 * that will be migrating to itself, so no pages need move.
	 *
	 * If no bits are left in 'tmp', or if all remaining bits left
	 * in 'tmp' correspond to the same bit in 'to', return false
	 * (nothing left to migrate).
	 *
	 * This lets us pick a pair of nodes to migrate between, such that
	 * if possible the dest node is not already occupied by some other
	 * source node, minimizing the risk of overloading the memory on a
	 * node that would happen if we migrated incoming memory to a node
	 * before migrating outgoing memory source that same node.
	 *
	 * A single scan of tmp is sufficient.  As we go, we remember the
	 * most recent <s, d> pair that moved (s != d).  If we find a pair
	 * that not only moved, but what's better, moved to an empty slot
	 * (d is not set in tmp), then we break out then, with that pair.
	 * Otherwise when we finish scannng from_tmp, we at least have the
	 * most recent <s, d> pair that moved.  If we get all the way through
	 * the scan of tmp without finding any node that moved, much less
	 * moved to an empty node, then there is nothing left worth migrating.
	 */
921

922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948
	tmp = *from_nodes;
	while (!nodes_empty(tmp)) {
		int s,d;
		int source = -1;
		int dest = 0;

		for_each_node_mask(s, tmp) {
			d = node_remap(s, *from_nodes, *to_nodes);
			if (s == d)
				continue;

			source = s;	/* Node moved. Memorize */
			dest = d;

			/* dest not in remaining from nodes? */
			if (!node_isset(dest, tmp))
				break;
		}
		if (source == -1)
			break;

		node_clear(source, tmp);
		err = migrate_to_node(mm, source, dest, flags);
		if (err > 0)
			busy += err;
		if (err < 0)
			break;
949
	}
950
out:
951
	up_read(&mm->mmap_sem);
952 953 954
	if (err < 0)
		return err;
	return busy;
C
Christoph Lameter 已提交
955 956 957

}

958 959 960 961 962 963 964
/*
 * Allocate a new page for page migration based on vma policy.
 * Start assuming that page is mapped by vma pointed to by @private.
 * Search forward from there, if not.  N.B., this assumes that the
 * list of pages handed to migrate_pages()--which is how we get here--
 * is in virtual address order.
 */
965
static struct page *new_vma_page(struct page *page, unsigned long private, int **x)
966 967
{
	struct vm_area_struct *vma = (struct vm_area_struct *)private;
968
	unsigned long uninitialized_var(address);
969

970 971 972 973 974 975 976 977 978 979 980
	while (vma) {
		address = page_address_in_vma(page, vma);
		if (address != -EFAULT)
			break;
		vma = vma->vm_next;
	}

	/*
	 * if !vma, alloc_page_vma() will use task or system default policy
	 */
	return alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
981
}
C
Christoph Lameter 已提交
982 983 984 985 986
#else

static void migrate_page_add(struct page *page, struct list_head *pagelist,
				unsigned long flags)
{
987 988
}

C
Christoph Lameter 已提交
989 990 991 992 993
int do_migrate_pages(struct mm_struct *mm,
	const nodemask_t *from_nodes, const nodemask_t *to_nodes, int flags)
{
	return -ENOSYS;
}
994

995
static struct page *new_vma_page(struct page *page, unsigned long private, int **x)
996 997 998
{
	return NULL;
}
C
Christoph Lameter 已提交
999 1000
#endif

A
Adrian Bunk 已提交
1001
static long do_mbind(unsigned long start, unsigned long len,
1002 1003
		     unsigned short mode, unsigned short mode_flags,
		     nodemask_t *nmask, unsigned long flags)
1004 1005 1006 1007 1008 1009 1010 1011
{
	struct vm_area_struct *vma;
	struct mm_struct *mm = current->mm;
	struct mempolicy *new;
	unsigned long end;
	int err;
	LIST_HEAD(pagelist);

1012 1013
	if (flags & ~(unsigned long)(MPOL_MF_STRICT |
				     MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
1014
		return -EINVAL;
1015
	if ((flags & MPOL_MF_MOVE_ALL) && !capable(CAP_SYS_NICE))
1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031
		return -EPERM;

	if (start & ~PAGE_MASK)
		return -EINVAL;

	if (mode == MPOL_DEFAULT)
		flags &= ~MPOL_MF_STRICT;

	len = (len + PAGE_SIZE - 1) & PAGE_MASK;
	end = start + len;

	if (end < start)
		return -EINVAL;
	if (end == start)
		return 0;

1032
	new = mpol_new(mode, mode_flags, nmask);
1033 1034 1035 1036 1037 1038 1039 1040 1041 1042
	if (IS_ERR(new))
		return PTR_ERR(new);

	/*
	 * If we are using the default policy then operation
	 * on discontinuous address spaces is okay after all
	 */
	if (!new)
		flags |= MPOL_MF_DISCONTIG_OK;

1043 1044 1045
	pr_debug("mbind %lx-%lx mode:%d flags:%d nodes:%lx\n",
		 start, start + len, mode, mode_flags,
		 nmask ? nodes_addr(*nmask)[0] : -1);
1046

1047 1048 1049 1050
	if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) {

		err = migrate_prep();
		if (err)
K
KOSAKI Motohiro 已提交
1051
			goto mpol_out;
1052
	}
1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065
	{
		NODEMASK_SCRATCH(scratch);
		if (scratch) {
			down_write(&mm->mmap_sem);
			task_lock(current);
			err = mpol_set_nodemask(new, nmask, scratch);
			task_unlock(current);
			if (err)
				up_write(&mm->mmap_sem);
		} else
			err = -ENOMEM;
		NODEMASK_SCRATCH_FREE(scratch);
	}
K
KOSAKI Motohiro 已提交
1066 1067 1068
	if (err)
		goto mpol_out;

1069 1070 1071 1072 1073 1074 1075
	vma = check_range(mm, start, end, nmask,
			  flags | MPOL_MF_INVERT, &pagelist);

	err = PTR_ERR(vma);
	if (!IS_ERR(vma)) {
		int nr_failed = 0;

1076
		err = mbind_range(mm, start, end, new);
1077

1078
		if (!list_empty(&pagelist))
1079
			nr_failed = migrate_pages(&pagelist, new_vma_page,
1080
						(unsigned long)vma, 0);
1081 1082 1083

		if (!err && nr_failed && (flags & MPOL_MF_STRICT))
			err = -EIO;
1084 1085
	} else
		putback_lru_pages(&pagelist);
C
Christoph Lameter 已提交
1086

1087
	up_write(&mm->mmap_sem);
K
KOSAKI Motohiro 已提交
1088
 mpol_out:
1089
	mpol_put(new);
1090 1091 1092
	return err;
}

1093 1094 1095 1096 1097
/*
 * User space interface with variable sized bitmaps for nodelists.
 */

/* Copy a node mask from user space. */
1098
static int get_nodes(nodemask_t *nodes, const unsigned long __user *nmask,
1099 1100 1101 1102 1103 1104 1105 1106 1107 1108
		     unsigned long maxnode)
{
	unsigned long k;
	unsigned long nlongs;
	unsigned long endmask;

	--maxnode;
	nodes_clear(*nodes);
	if (maxnode == 0 || !nmask)
		return 0;
A
Andi Kleen 已提交
1109
	if (maxnode > PAGE_SIZE*BITS_PER_BYTE)
C
Chris Wright 已提交
1110
		return -EINVAL;
1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159

	nlongs = BITS_TO_LONGS(maxnode);
	if ((maxnode % BITS_PER_LONG) == 0)
		endmask = ~0UL;
	else
		endmask = (1UL << (maxnode % BITS_PER_LONG)) - 1;

	/* When the user specified more nodes than supported just check
	   if the non supported part is all zero. */
	if (nlongs > BITS_TO_LONGS(MAX_NUMNODES)) {
		if (nlongs > PAGE_SIZE/sizeof(long))
			return -EINVAL;
		for (k = BITS_TO_LONGS(MAX_NUMNODES); k < nlongs; k++) {
			unsigned long t;
			if (get_user(t, nmask + k))
				return -EFAULT;
			if (k == nlongs - 1) {
				if (t & endmask)
					return -EINVAL;
			} else if (t)
				return -EINVAL;
		}
		nlongs = BITS_TO_LONGS(MAX_NUMNODES);
		endmask = ~0UL;
	}

	if (copy_from_user(nodes_addr(*nodes), nmask, nlongs*sizeof(unsigned long)))
		return -EFAULT;
	nodes_addr(*nodes)[nlongs-1] &= endmask;
	return 0;
}

/* Copy a kernel node mask to user space */
static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode,
			      nodemask_t *nodes)
{
	unsigned long copy = ALIGN(maxnode-1, 64) / 8;
	const int nbytes = BITS_TO_LONGS(MAX_NUMNODES) * sizeof(long);

	if (copy > nbytes) {
		if (copy > PAGE_SIZE)
			return -EINVAL;
		if (clear_user((char __user *)mask + nbytes, copy - nbytes))
			return -EFAULT;
		copy = nbytes;
	}
	return copy_to_user(mask, nodes_addr(*nodes), copy) ? -EFAULT : 0;
}

1160 1161 1162
SYSCALL_DEFINE6(mbind, unsigned long, start, unsigned long, len,
		unsigned long, mode, unsigned long __user *, nmask,
		unsigned long, maxnode, unsigned, flags)
1163 1164 1165
{
	nodemask_t nodes;
	int err;
1166
	unsigned short mode_flags;
1167

1168 1169
	mode_flags = mode & MPOL_MODE_FLAGS;
	mode &= ~MPOL_MODE_FLAGS;
1170 1171
	if (mode >= MPOL_MAX)
		return -EINVAL;
1172 1173 1174
	if ((mode_flags & MPOL_F_STATIC_NODES) &&
	    (mode_flags & MPOL_F_RELATIVE_NODES))
		return -EINVAL;
1175 1176 1177
	err = get_nodes(&nodes, nmask, maxnode);
	if (err)
		return err;
1178
	return do_mbind(start, len, mode, mode_flags, &nodes, flags);
1179 1180 1181
}

/* Set the process memory policy */
1182 1183
SYSCALL_DEFINE3(set_mempolicy, int, mode, unsigned long __user *, nmask,
		unsigned long, maxnode)
1184 1185 1186
{
	int err;
	nodemask_t nodes;
1187
	unsigned short flags;
1188

1189 1190 1191
	flags = mode & MPOL_MODE_FLAGS;
	mode &= ~MPOL_MODE_FLAGS;
	if ((unsigned int)mode >= MPOL_MAX)
1192
		return -EINVAL;
1193 1194
	if ((flags & MPOL_F_STATIC_NODES) && (flags & MPOL_F_RELATIVE_NODES))
		return -EINVAL;
1195 1196 1197
	err = get_nodes(&nodes, nmask, maxnode);
	if (err)
		return err;
1198
	return do_set_mempolicy(mode, flags, &nodes);
1199 1200
}

1201 1202 1203
SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode,
		const unsigned long __user *, old_nodes,
		const unsigned long __user *, new_nodes)
1204
{
1205
	const struct cred *cred = current_cred(), *tcred;
1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222
	struct mm_struct *mm;
	struct task_struct *task;
	nodemask_t old;
	nodemask_t new;
	nodemask_t task_nodes;
	int err;

	err = get_nodes(&old, old_nodes, maxnode);
	if (err)
		return err;

	err = get_nodes(&new, new_nodes, maxnode);
	if (err)
		return err;

	/* Find the mm_struct */
	read_lock(&tasklist_lock);
1223
	task = pid ? find_task_by_vpid(pid) : current;
1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236
	if (!task) {
		read_unlock(&tasklist_lock);
		return -ESRCH;
	}
	mm = get_task_mm(task);
	read_unlock(&tasklist_lock);

	if (!mm)
		return -EINVAL;

	/*
	 * Check if this process has the right to modify the specified
	 * process. The right exists if the process has administrative
A
Alexey Dobriyan 已提交
1237
	 * capabilities, superuser privileges or the same
1238 1239
	 * userid as the target process.
	 */
1240 1241
	rcu_read_lock();
	tcred = __task_cred(task);
1242 1243
	if (cred->euid != tcred->suid && cred->euid != tcred->uid &&
	    cred->uid  != tcred->suid && cred->uid  != tcred->uid &&
1244
	    !capable(CAP_SYS_NICE)) {
1245
		rcu_read_unlock();
1246 1247 1248
		err = -EPERM;
		goto out;
	}
1249
	rcu_read_unlock();
1250 1251 1252

	task_nodes = cpuset_mems_allowed(task);
	/* Is the user allowed to access the target nodes? */
1253
	if (!nodes_subset(new, task_nodes) && !capable(CAP_SYS_NICE)) {
1254 1255 1256 1257
		err = -EPERM;
		goto out;
	}

1258
	if (!nodes_subset(new, node_states[N_HIGH_MEMORY])) {
1259 1260 1261 1262
		err = -EINVAL;
		goto out;
	}

1263 1264 1265 1266
	err = security_task_movememory(task);
	if (err)
		goto out;

1267
	err = do_migrate_pages(mm, &old, &new,
1268
		capable(CAP_SYS_NICE) ? MPOL_MF_MOVE_ALL : MPOL_MF_MOVE);
1269 1270 1271 1272 1273 1274
out:
	mmput(mm);
	return err;
}


1275
/* Retrieve NUMA policy */
1276 1277 1278
SYSCALL_DEFINE5(get_mempolicy, int __user *, policy,
		unsigned long __user *, nmask, unsigned long, maxnode,
		unsigned long, addr, unsigned long, flags)
1279
{
A
Adrian Bunk 已提交
1280 1281
	int err;
	int uninitialized_var(pval);
1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300
	nodemask_t nodes;

	if (nmask != NULL && maxnode < MAX_NUMNODES)
		return -EINVAL;

	err = do_get_mempolicy(&pval, &nodes, addr, flags);

	if (err)
		return err;

	if (policy && put_user(pval, policy))
		return -EFAULT;

	if (nmask)
		err = copy_nodes_to_user(nmask, maxnode, &nodes);

	return err;
}

L
Linus Torvalds 已提交
1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360
#ifdef CONFIG_COMPAT

asmlinkage long compat_sys_get_mempolicy(int __user *policy,
				     compat_ulong_t __user *nmask,
				     compat_ulong_t maxnode,
				     compat_ulong_t addr, compat_ulong_t flags)
{
	long err;
	unsigned long __user *nm = NULL;
	unsigned long nr_bits, alloc_size;
	DECLARE_BITMAP(bm, MAX_NUMNODES);

	nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
	alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;

	if (nmask)
		nm = compat_alloc_user_space(alloc_size);

	err = sys_get_mempolicy(policy, nm, nr_bits+1, addr, flags);

	if (!err && nmask) {
		err = copy_from_user(bm, nm, alloc_size);
		/* ensure entire bitmap is zeroed */
		err |= clear_user(nmask, ALIGN(maxnode-1, 8) / 8);
		err |= compat_put_bitmap(nmask, bm, nr_bits);
	}

	return err;
}

asmlinkage long compat_sys_set_mempolicy(int mode, compat_ulong_t __user *nmask,
				     compat_ulong_t maxnode)
{
	long err = 0;
	unsigned long __user *nm = NULL;
	unsigned long nr_bits, alloc_size;
	DECLARE_BITMAP(bm, MAX_NUMNODES);

	nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
	alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;

	if (nmask) {
		err = compat_get_bitmap(bm, nmask, nr_bits);
		nm = compat_alloc_user_space(alloc_size);
		err |= copy_to_user(nm, bm, alloc_size);
	}

	if (err)
		return -EFAULT;

	return sys_set_mempolicy(mode, nm, nr_bits+1);
}

asmlinkage long compat_sys_mbind(compat_ulong_t start, compat_ulong_t len,
			     compat_ulong_t mode, compat_ulong_t __user *nmask,
			     compat_ulong_t maxnode, compat_ulong_t flags)
{
	long err = 0;
	unsigned long __user *nm = NULL;
	unsigned long nr_bits, alloc_size;
1361
	nodemask_t bm;
L
Linus Torvalds 已提交
1362 1363 1364 1365 1366

	nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
	alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;

	if (nmask) {
1367
		err = compat_get_bitmap(nodes_addr(bm), nmask, nr_bits);
L
Linus Torvalds 已提交
1368
		nm = compat_alloc_user_space(alloc_size);
1369
		err |= copy_to_user(nm, nodes_addr(bm), alloc_size);
L
Linus Torvalds 已提交
1370 1371 1372 1373 1374 1375 1376 1377 1378 1379
	}

	if (err)
		return -EFAULT;

	return sys_mbind(start, len, mode, nm, nr_bits+1, flags);
}

#endif

1380 1381 1382 1383 1384 1385 1386 1387
/*
 * get_vma_policy(@task, @vma, @addr)
 * @task - task for fallback if vma policy == default
 * @vma   - virtual memory area whose policy is sought
 * @addr  - address in @vma for shared policy lookup
 *
 * Returns effective policy for a VMA at specified address.
 * Falls back to @task or system default policy, as necessary.
1388 1389 1390 1391 1392 1393 1394
 * Current or other task's task mempolicy and non-shared vma policies
 * are protected by the task's mmap_sem, which must be held for read by
 * the caller.
 * Shared policies [those marked as MPOL_F_SHARED] require an extra reference
 * count--added by the get_policy() vm_op, as appropriate--to protect against
 * freeing by another task.  It is the caller's responsibility to free the
 * extra reference for shared policies.
1395
 */
1396
static struct mempolicy *get_vma_policy(struct task_struct *task,
1397
		struct vm_area_struct *vma, unsigned long addr)
L
Linus Torvalds 已提交
1398
{
1399
	struct mempolicy *pol = task->mempolicy;
L
Linus Torvalds 已提交
1400 1401

	if (vma) {
1402
		if (vma->vm_ops && vma->vm_ops->get_policy) {
1403 1404 1405 1406
			struct mempolicy *vpol = vma->vm_ops->get_policy(vma,
									addr);
			if (vpol)
				pol = vpol;
1407
		} else if (vma->vm_policy)
L
Linus Torvalds 已提交
1408 1409 1410 1411 1412 1413 1414
			pol = vma->vm_policy;
	}
	if (!pol)
		pol = &default_policy;
	return pol;
}

1415 1416 1417 1418 1419
/*
 * Return a nodemask representing a mempolicy for filtering nodes for
 * page allocation
 */
static nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy)
1420 1421
{
	/* Lower zones don't get a nodemask applied for MPOL_BIND */
1422
	if (unlikely(policy->mode == MPOL_BIND) &&
1423 1424 1425 1426 1427 1428 1429
			gfp_zone(gfp) >= policy_zone &&
			cpuset_nodemask_valid_mems_allowed(&policy->v.nodes))
		return &policy->v.nodes;

	return NULL;
}

1430 1431
/* Return a zonelist indicated by gfp for node representing a mempolicy */
static struct zonelist *policy_zonelist(gfp_t gfp, struct mempolicy *policy)
L
Linus Torvalds 已提交
1432
{
1433
	int nd = numa_node_id();
L
Linus Torvalds 已提交
1434

1435
	switch (policy->mode) {
L
Linus Torvalds 已提交
1436
	case MPOL_PREFERRED:
1437 1438
		if (!(policy->flags & MPOL_F_LOCAL))
			nd = policy->v.preferred_node;
L
Linus Torvalds 已提交
1439 1440
		break;
	case MPOL_BIND:
1441
		/*
1442 1443 1444 1445
		 * Normally, MPOL_BIND allocations are node-local within the
		 * allowed nodemask.  However, if __GFP_THISNODE is set and the
		 * current node is part of the mask, we use the zonelist for
		 * the first node in the mask instead.
1446 1447 1448 1449 1450
		 */
		if (unlikely(gfp & __GFP_THISNODE) &&
				unlikely(!node_isset(nd, policy->v.nodes)))
			nd = first_node(policy->v.nodes);
		break;
L
Linus Torvalds 已提交
1451 1452 1453 1454 1455
	case MPOL_INTERLEAVE: /* should not happen */
		break;
	default:
		BUG();
	}
1456
	return node_zonelist(nd, gfp);
L
Linus Torvalds 已提交
1457 1458 1459 1460 1461 1462 1463 1464 1465
}

/* Do dynamic interleaving for a process */
static unsigned interleave_nodes(struct mempolicy *policy)
{
	unsigned nid, next;
	struct task_struct *me = current;

	nid = me->il_next;
1466
	next = next_node(nid, policy->v.nodes);
L
Linus Torvalds 已提交
1467
	if (next >= MAX_NUMNODES)
1468
		next = first_node(policy->v.nodes);
1469 1470
	if (next < MAX_NUMNODES)
		me->il_next = next;
L
Linus Torvalds 已提交
1471 1472 1473
	return nid;
}

1474 1475 1476
/*
 * Depending on the memory policy provide a node from which to allocate the
 * next slab entry.
1477 1478 1479 1480
 * @policy must be protected by freeing by the caller.  If @policy is
 * the current task's mempolicy, this protection is implicit, as only the
 * task can change it's policy.  The system default policy requires no
 * such protection.
1481 1482 1483
 */
unsigned slab_node(struct mempolicy *policy)
{
1484
	if (!policy || policy->flags & MPOL_F_LOCAL)
1485 1486 1487 1488
		return numa_node_id();

	switch (policy->mode) {
	case MPOL_PREFERRED:
1489 1490 1491 1492
		/*
		 * handled MPOL_F_LOCAL above
		 */
		return policy->v.preferred_node;
1493

1494 1495 1496
	case MPOL_INTERLEAVE:
		return interleave_nodes(policy);

1497
	case MPOL_BIND: {
1498 1499 1500 1501
		/*
		 * Follow bind policy behavior and start allocation at the
		 * first node.
		 */
1502 1503 1504 1505 1506 1507 1508 1509
		struct zonelist *zonelist;
		struct zone *zone;
		enum zone_type highest_zoneidx = gfp_zone(GFP_KERNEL);
		zonelist = &NODE_DATA(numa_node_id())->node_zonelists[0];
		(void)first_zones_zonelist(zonelist, highest_zoneidx,
							&policy->v.nodes,
							&zone);
		return zone->node;
1510
	}
1511 1512

	default:
1513
		BUG();
1514 1515 1516
	}
}

L
Linus Torvalds 已提交
1517 1518 1519 1520
/* Do static interleaving for a VMA with known offset. */
static unsigned offset_il_node(struct mempolicy *pol,
		struct vm_area_struct *vma, unsigned long off)
{
1521
	unsigned nnodes = nodes_weight(pol->v.nodes);
1522
	unsigned target;
L
Linus Torvalds 已提交
1523 1524 1525
	int c;
	int nid = -1;

1526 1527 1528
	if (!nnodes)
		return numa_node_id();
	target = (unsigned int)off % nnodes;
L
Linus Torvalds 已提交
1529 1530
	c = 0;
	do {
1531
		nid = next_node(nid, pol->v.nodes);
L
Linus Torvalds 已提交
1532 1533 1534 1535 1536
		c++;
	} while (c <= target);
	return nid;
}

1537 1538 1539 1540 1541 1542 1543
/* Determine a node number for interleave */
static inline unsigned interleave_nid(struct mempolicy *pol,
		 struct vm_area_struct *vma, unsigned long addr, int shift)
{
	if (vma) {
		unsigned long off;

1544 1545 1546 1547 1548 1549 1550 1551 1552
		/*
		 * for small pages, there is no difference between
		 * shift and PAGE_SHIFT, so the bit-shift is safe.
		 * for huge pages, since vm_pgoff is in units of small
		 * pages, we need to shift off the always 0 bits to get
		 * a useful offset.
		 */
		BUG_ON(shift < PAGE_SHIFT);
		off = vma->vm_pgoff >> (shift - PAGE_SHIFT);
1553 1554 1555 1556 1557 1558
		off += (addr - vma->vm_start) >> shift;
		return offset_il_node(pol, vma, off);
	} else
		return interleave_nodes(pol);
}

1559
#ifdef CONFIG_HUGETLBFS
1560 1561 1562 1563 1564
/*
 * huge_zonelist(@vma, @addr, @gfp_flags, @mpol)
 * @vma = virtual memory area whose policy is sought
 * @addr = address in @vma for shared policy lookup and interleave policy
 * @gfp_flags = for requested zone
1565 1566
 * @mpol = pointer to mempolicy pointer for reference counted mempolicy
 * @nodemask = pointer to nodemask pointer for MPOL_BIND nodemask
1567
 *
1568 1569 1570 1571
 * Returns a zonelist suitable for a huge page allocation and a pointer
 * to the struct mempolicy for conditional unref after allocation.
 * If the effective policy is 'BIND, returns a pointer to the mempolicy's
 * @nodemask for filtering the zonelist.
1572
 */
1573
struct zonelist *huge_zonelist(struct vm_area_struct *vma, unsigned long addr,
1574 1575
				gfp_t gfp_flags, struct mempolicy **mpol,
				nodemask_t **nodemask)
1576
{
1577
	struct zonelist *zl;
1578

1579
	*mpol = get_vma_policy(current, vma, addr);
1580
	*nodemask = NULL;	/* assume !MPOL_BIND */
1581

1582 1583
	if (unlikely((*mpol)->mode == MPOL_INTERLEAVE)) {
		zl = node_zonelist(interleave_nid(*mpol, vma, addr,
1584
				huge_page_shift(hstate_vma(vma))), gfp_flags);
1585 1586 1587 1588
	} else {
		zl = policy_zonelist(gfp_flags, *mpol);
		if ((*mpol)->mode == MPOL_BIND)
			*nodemask = &(*mpol)->v.nodes;
1589 1590
	}
	return zl;
1591
}
1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638

/*
 * init_nodemask_of_mempolicy
 *
 * If the current task's mempolicy is "default" [NULL], return 'false'
 * to indicate default policy.  Otherwise, extract the policy nodemask
 * for 'bind' or 'interleave' policy into the argument nodemask, or
 * initialize the argument nodemask to contain the single node for
 * 'preferred' or 'local' policy and return 'true' to indicate presence
 * of non-default mempolicy.
 *
 * We don't bother with reference counting the mempolicy [mpol_get/put]
 * because the current task is examining it's own mempolicy and a task's
 * mempolicy is only ever changed by the task itself.
 *
 * N.B., it is the caller's responsibility to free a returned nodemask.
 */
bool init_nodemask_of_mempolicy(nodemask_t *mask)
{
	struct mempolicy *mempolicy;
	int nid;

	if (!(mask && current->mempolicy))
		return false;

	mempolicy = current->mempolicy;
	switch (mempolicy->mode) {
	case MPOL_PREFERRED:
		if (mempolicy->flags & MPOL_F_LOCAL)
			nid = numa_node_id();
		else
			nid = mempolicy->v.preferred_node;
		init_nodemask_of_node(mask, nid);
		break;

	case MPOL_BIND:
		/* Fall through */
	case MPOL_INTERLEAVE:
		*mask =  mempolicy->v.nodes;
		break;

	default:
		BUG();
	}

	return true;
}
1639
#endif
1640

L
Linus Torvalds 已提交
1641 1642
/* Allocate a page in interleaved policy.
   Own path because it needs to do special accounting. */
1643 1644
static struct page *alloc_page_interleave(gfp_t gfp, unsigned order,
					unsigned nid)
L
Linus Torvalds 已提交
1645 1646 1647 1648
{
	struct zonelist *zl;
	struct page *page;

1649
	zl = node_zonelist(nid, gfp);
L
Linus Torvalds 已提交
1650
	page = __alloc_pages(gfp, order, zl);
1651
	if (page && page_zone(page) == zonelist_zone(&zl->_zonerefs[0]))
1652
		inc_zone_page_state(page, NUMA_INTERLEAVE_HIT);
L
Linus Torvalds 已提交
1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678
	return page;
}

/**
 * 	alloc_page_vma	- Allocate a page for a VMA.
 *
 * 	@gfp:
 *      %GFP_USER    user allocation.
 *      %GFP_KERNEL  kernel allocations,
 *      %GFP_HIGHMEM highmem/user allocations,
 *      %GFP_FS      allocation should not call back into a file system.
 *      %GFP_ATOMIC  don't sleep.
 *
 * 	@vma:  Pointer to VMA or NULL if not available.
 *	@addr: Virtual Address of the allocation. Must be inside the VMA.
 *
 * 	This function allocates a page from the kernel page pool and applies
 *	a NUMA policy associated with the VMA or the current process.
 *	When VMA is not NULL caller must hold down_read on the mmap_sem of the
 *	mm_struct of the VMA to prevent it from going away. Should be used for
 *	all allocations for pages that will be mapped into
 * 	user space. Returns NULL when no page can be allocated.
 *
 *	Should be called with the mm_sem of the vma hold.
 */
struct page *
A
Al Viro 已提交
1679
alloc_page_vma(gfp_t gfp, struct vm_area_struct *vma, unsigned long addr)
L
Linus Torvalds 已提交
1680
{
1681
	struct mempolicy *pol = get_vma_policy(current, vma, addr);
1682
	struct zonelist *zl;
L
Linus Torvalds 已提交
1683

1684
	if (unlikely(pol->mode == MPOL_INTERLEAVE)) {
L
Linus Torvalds 已提交
1685
		unsigned nid;
1686 1687

		nid = interleave_nid(pol, vma, addr, PAGE_SHIFT);
1688
		mpol_cond_put(pol);
L
Linus Torvalds 已提交
1689 1690
		return alloc_page_interleave(gfp, 0, nid);
	}
1691 1692
	zl = policy_zonelist(gfp, pol);
	if (unlikely(mpol_needs_cond_ref(pol))) {
1693
		/*
1694
		 * slow path: ref counted shared policy
1695
		 */
1696
		struct page *page =  __alloc_pages_nodemask(gfp, 0,
1697
						zl, policy_nodemask(gfp, pol));
1698
		__mpol_put(pol);
1699 1700 1701 1702 1703
		return page;
	}
	/*
	 * fast path:  default or task policy
	 */
1704
	return __alloc_pages_nodemask(gfp, 0, zl, policy_nodemask(gfp, pol));
L
Linus Torvalds 已提交
1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721
}

/**
 * 	alloc_pages_current - Allocate pages.
 *
 *	@gfp:
 *		%GFP_USER   user allocation,
 *      	%GFP_KERNEL kernel allocation,
 *      	%GFP_HIGHMEM highmem allocation,
 *      	%GFP_FS     don't call back into a file system.
 *      	%GFP_ATOMIC don't sleep.
 *	@order: Power of two of allocation size in pages. 0 is a single page.
 *
 *	Allocate a page from the kernel page pool.  When not in
 *	interrupt context and apply the current process NUMA policy.
 *	Returns NULL when no page can be allocated.
 *
1722
 *	Don't call cpuset_update_task_memory_state() unless
L
Linus Torvalds 已提交
1723 1724 1725
 *	1) it's ok to take cpuset_sem (can WAIT), and
 *	2) allocating for current task (not interrupt).
 */
A
Al Viro 已提交
1726
struct page *alloc_pages_current(gfp_t gfp, unsigned order)
L
Linus Torvalds 已提交
1727 1728 1729
{
	struct mempolicy *pol = current->mempolicy;

1730
	if (!pol || in_interrupt() || (gfp & __GFP_THISNODE))
L
Linus Torvalds 已提交
1731
		pol = &default_policy;
1732 1733 1734 1735 1736

	/*
	 * No reference counting needed for current->mempolicy
	 * nor system default_policy
	 */
1737
	if (pol->mode == MPOL_INTERLEAVE)
L
Linus Torvalds 已提交
1738
		return alloc_page_interleave(gfp, order, interleave_nodes(pol));
1739
	return __alloc_pages_nodemask(gfp, order,
1740
			policy_zonelist(gfp, pol), policy_nodemask(gfp, pol));
L
Linus Torvalds 已提交
1741 1742 1743
}
EXPORT_SYMBOL(alloc_pages_current);

1744
/*
1745
 * If mpol_dup() sees current->cpuset == cpuset_being_rebound, then it
1746 1747 1748 1749 1750 1751
 * rebinds the mempolicy its copying by calling mpol_rebind_policy()
 * with the mems_allowed returned by cpuset_mems_allowed().  This
 * keeps mempolicies cpuset relative after its cpuset moves.  See
 * further kernel/cpuset.c update_nodemask().
 */

1752 1753
/* Slow path of a mempolicy duplicate */
struct mempolicy *__mpol_dup(struct mempolicy *old)
L
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{
	struct mempolicy *new = kmem_cache_alloc(policy_cache, GFP_KERNEL);

	if (!new)
		return ERR_PTR(-ENOMEM);
1759
	rcu_read_lock();
1760 1761 1762 1763
	if (current_cpuset_is_being_rebound()) {
		nodemask_t mems = cpuset_mems_allowed(current);
		mpol_rebind_policy(old, &mems);
	}
1764
	rcu_read_unlock();
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	*new = *old;
	atomic_set(&new->refcnt, 1);
	return new;
}

1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791
/*
 * If *frompol needs [has] an extra ref, copy *frompol to *tompol ,
 * eliminate the * MPOL_F_* flags that require conditional ref and
 * [NOTE!!!] drop the extra ref.  Not safe to reference *frompol directly
 * after return.  Use the returned value.
 *
 * Allows use of a mempolicy for, e.g., multiple allocations with a single
 * policy lookup, even if the policy needs/has extra ref on lookup.
 * shmem_readahead needs this.
 */
struct mempolicy *__mpol_cond_copy(struct mempolicy *tompol,
						struct mempolicy *frompol)
{
	if (!mpol_needs_cond_ref(frompol))
		return frompol;

	*tompol = *frompol;
	tompol->flags &= ~MPOL_F_SHARED;	/* copy doesn't need unref */
	__mpol_put(frompol);
	return tompol;
}

1792 1793 1794 1795 1796 1797 1798 1799 1800 1801
static int mpol_match_intent(const struct mempolicy *a,
			     const struct mempolicy *b)
{
	if (a->flags != b->flags)
		return 0;
	if (!mpol_store_user_nodemask(a))
		return 1;
	return nodes_equal(a->w.user_nodemask, b->w.user_nodemask);
}

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1802 1803 1804 1805 1806
/* Slow path of a mempolicy comparison */
int __mpol_equal(struct mempolicy *a, struct mempolicy *b)
{
	if (!a || !b)
		return 0;
1807
	if (a->mode != b->mode)
L
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1808
		return 0;
1809
	if (a->mode != MPOL_DEFAULT && !mpol_match_intent(a, b))
1810
		return 0;
1811
	switch (a->mode) {
1812 1813
	case MPOL_BIND:
		/* Fall through */
L
Linus Torvalds 已提交
1814
	case MPOL_INTERLEAVE:
1815
		return nodes_equal(a->v.nodes, b->v.nodes);
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	case MPOL_PREFERRED:
1817 1818
		return a->v.preferred_node == b->v.preferred_node &&
			a->flags == b->flags;
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1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885
	default:
		BUG();
		return 0;
	}
}

/*
 * Shared memory backing store policy support.
 *
 * Remember policies even when nobody has shared memory mapped.
 * The policies are kept in Red-Black tree linked from the inode.
 * They are protected by the sp->lock spinlock, which should be held
 * for any accesses to the tree.
 */

/* lookup first element intersecting start-end */
/* Caller holds sp->lock */
static struct sp_node *
sp_lookup(struct shared_policy *sp, unsigned long start, unsigned long end)
{
	struct rb_node *n = sp->root.rb_node;

	while (n) {
		struct sp_node *p = rb_entry(n, struct sp_node, nd);

		if (start >= p->end)
			n = n->rb_right;
		else if (end <= p->start)
			n = n->rb_left;
		else
			break;
	}
	if (!n)
		return NULL;
	for (;;) {
		struct sp_node *w = NULL;
		struct rb_node *prev = rb_prev(n);
		if (!prev)
			break;
		w = rb_entry(prev, struct sp_node, nd);
		if (w->end <= start)
			break;
		n = prev;
	}
	return rb_entry(n, struct sp_node, nd);
}

/* Insert a new shared policy into the list. */
/* Caller holds sp->lock */
static void sp_insert(struct shared_policy *sp, struct sp_node *new)
{
	struct rb_node **p = &sp->root.rb_node;
	struct rb_node *parent = NULL;
	struct sp_node *nd;

	while (*p) {
		parent = *p;
		nd = rb_entry(parent, struct sp_node, nd);
		if (new->start < nd->start)
			p = &(*p)->rb_left;
		else if (new->end > nd->end)
			p = &(*p)->rb_right;
		else
			BUG();
	}
	rb_link_node(&new->nd, parent, p);
	rb_insert_color(&new->nd, &sp->root);
1886
	pr_debug("inserting %lx-%lx: %d\n", new->start, new->end,
1887
		 new->policy ? new->policy->mode : 0);
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1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910
}

/* Find shared policy intersecting idx */
struct mempolicy *
mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx)
{
	struct mempolicy *pol = NULL;
	struct sp_node *sn;

	if (!sp->root.rb_node)
		return NULL;
	spin_lock(&sp->lock);
	sn = sp_lookup(sp, idx, idx+1);
	if (sn) {
		mpol_get(sn->policy);
		pol = sn->policy;
	}
	spin_unlock(&sp->lock);
	return pol;
}

static void sp_delete(struct shared_policy *sp, struct sp_node *n)
{
1911
	pr_debug("deleting %lx-l%lx\n", n->start, n->end);
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Linus Torvalds 已提交
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	rb_erase(&n->nd, &sp->root);
1913
	mpol_put(n->policy);
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1914 1915 1916
	kmem_cache_free(sn_cache, n);
}

A
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1917 1918
static struct sp_node *sp_alloc(unsigned long start, unsigned long end,
				struct mempolicy *pol)
L
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1919 1920 1921 1922 1923 1924 1925 1926
{
	struct sp_node *n = kmem_cache_alloc(sn_cache, GFP_KERNEL);

	if (!n)
		return NULL;
	n->start = start;
	n->end = end;
	mpol_get(pol);
1927
	pol->flags |= MPOL_F_SHARED;	/* for unref */
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1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973
	n->policy = pol;
	return n;
}

/* Replace a policy range. */
static int shared_policy_replace(struct shared_policy *sp, unsigned long start,
				 unsigned long end, struct sp_node *new)
{
	struct sp_node *n, *new2 = NULL;

restart:
	spin_lock(&sp->lock);
	n = sp_lookup(sp, start, end);
	/* Take care of old policies in the same range. */
	while (n && n->start < end) {
		struct rb_node *next = rb_next(&n->nd);
		if (n->start >= start) {
			if (n->end <= end)
				sp_delete(sp, n);
			else
				n->start = end;
		} else {
			/* Old policy spanning whole new range. */
			if (n->end > end) {
				if (!new2) {
					spin_unlock(&sp->lock);
					new2 = sp_alloc(end, n->end, n->policy);
					if (!new2)
						return -ENOMEM;
					goto restart;
				}
				n->end = start;
				sp_insert(sp, new2);
				new2 = NULL;
				break;
			} else
				n->end = start;
		}
		if (!next)
			break;
		n = rb_entry(next, struct sp_node, nd);
	}
	if (new)
		sp_insert(sp, new);
	spin_unlock(&sp->lock);
	if (new2) {
1974
		mpol_put(new2->policy);
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1975 1976 1977 1978 1979
		kmem_cache_free(sn_cache, new2);
	}
	return 0;
}

1980 1981 1982 1983 1984 1985 1986 1987
/**
 * mpol_shared_policy_init - initialize shared policy for inode
 * @sp: pointer to inode shared policy
 * @mpol:  struct mempolicy to install
 *
 * Install non-NULL @mpol in inode's shared policy rb-tree.
 * On entry, the current task has a reference on a non-NULL @mpol.
 * This must be released on exit.
1988
 * This is called at get_inode() calls and we can use GFP_KERNEL.
1989 1990 1991
 */
void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol)
{
1992 1993
	int ret;

1994 1995 1996 1997 1998 1999
	sp->root = RB_ROOT;		/* empty tree == default mempolicy */
	spin_lock_init(&sp->lock);

	if (mpol) {
		struct vm_area_struct pvma;
		struct mempolicy *new;
2000
		NODEMASK_SCRATCH(scratch);
2001

2002 2003
		if (!scratch)
			return;
2004 2005
		/* contextualize the tmpfs mount point mempolicy */
		new = mpol_new(mpol->mode, mpol->flags, &mpol->w.user_nodemask);
2006 2007
		if (IS_ERR(new)) {
			mpol_put(mpol);	/* drop our ref on sb mpol */
2008
			NODEMASK_SCRATCH_FREE(scratch);
2009
			return;		/* no valid nodemask intersection */
2010 2011 2012
		}

		task_lock(current);
2013
		ret = mpol_set_nodemask(new, &mpol->w.user_nodemask, scratch);
2014 2015 2016
		task_unlock(current);
		mpol_put(mpol);	/* drop our ref on sb mpol */
		if (ret) {
2017
			NODEMASK_SCRATCH_FREE(scratch);
2018 2019 2020
			mpol_put(new);
			return;
		}
2021 2022 2023 2024 2025 2026

		/* Create pseudo-vma that contains just the policy */
		memset(&pvma, 0, sizeof(struct vm_area_struct));
		pvma.vm_end = TASK_SIZE;	/* policy covers entire file */
		mpol_set_shared_policy(sp, &pvma, new); /* adds ref */
		mpol_put(new);			/* drop initial ref */
2027
		NODEMASK_SCRATCH_FREE(scratch);
2028 2029 2030
	}
}

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Linus Torvalds 已提交
2031 2032 2033 2034 2035 2036 2037
int mpol_set_shared_policy(struct shared_policy *info,
			struct vm_area_struct *vma, struct mempolicy *npol)
{
	int err;
	struct sp_node *new = NULL;
	unsigned long sz = vma_pages(vma);

2038
	pr_debug("set_shared_policy %lx sz %lu %d %d %lx\n",
L
Linus Torvalds 已提交
2039
		 vma->vm_pgoff,
2040
		 sz, npol ? npol->mode : -1,
2041
		 npol ? npol->flags : -1,
2042
		 npol ? nodes_addr(npol->v.nodes)[0] : -1);
L
Linus Torvalds 已提交
2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067

	if (npol) {
		new = sp_alloc(vma->vm_pgoff, vma->vm_pgoff + sz, npol);
		if (!new)
			return -ENOMEM;
	}
	err = shared_policy_replace(info, vma->vm_pgoff, vma->vm_pgoff+sz, new);
	if (err && new)
		kmem_cache_free(sn_cache, new);
	return err;
}

/* Free a backing policy store on inode delete. */
void mpol_free_shared_policy(struct shared_policy *p)
{
	struct sp_node *n;
	struct rb_node *next;

	if (!p->root.rb_node)
		return;
	spin_lock(&p->lock);
	next = rb_first(&p->root);
	while (next) {
		n = rb_entry(next, struct sp_node, nd);
		next = rb_next(&n->nd);
2068
		rb_erase(&n->nd, &p->root);
2069
		mpol_put(n->policy);
L
Linus Torvalds 已提交
2070 2071 2072 2073 2074 2075 2076 2077
		kmem_cache_free(sn_cache, n);
	}
	spin_unlock(&p->lock);
}

/* assumes fs == KERNEL_DS */
void __init numa_policy_init(void)
{
2078 2079 2080 2081
	nodemask_t interleave_nodes;
	unsigned long largest = 0;
	int nid, prefer = 0;

L
Linus Torvalds 已提交
2082 2083
	policy_cache = kmem_cache_create("numa_policy",
					 sizeof(struct mempolicy),
2084
					 0, SLAB_PANIC, NULL);
L
Linus Torvalds 已提交
2085 2086 2087

	sn_cache = kmem_cache_create("shared_policy_node",
				     sizeof(struct sp_node),
2088
				     0, SLAB_PANIC, NULL);
L
Linus Torvalds 已提交
2089

2090 2091 2092 2093 2094 2095
	/*
	 * Set interleaving policy for system init. Interleaving is only
	 * enabled across suitably sized nodes (default is >= 16MB), or
	 * fall back to the largest node if they're all smaller.
	 */
	nodes_clear(interleave_nodes);
2096
	for_each_node_state(nid, N_HIGH_MEMORY) {
2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112
		unsigned long total_pages = node_present_pages(nid);

		/* Preserve the largest node */
		if (largest < total_pages) {
			largest = total_pages;
			prefer = nid;
		}

		/* Interleave this node? */
		if ((total_pages << PAGE_SHIFT) >= (16 << 20))
			node_set(nid, interleave_nodes);
	}

	/* All too small, use the largest */
	if (unlikely(nodes_empty(interleave_nodes)))
		node_set(prefer, interleave_nodes);
L
Linus Torvalds 已提交
2113

2114
	if (do_set_mempolicy(MPOL_INTERLEAVE, 0, &interleave_nodes))
L
Linus Torvalds 已提交
2115 2116 2117
		printk("numa_policy_init: interleaving failed\n");
}

2118
/* Reset policy of current process to default */
L
Linus Torvalds 已提交
2119 2120
void numa_default_policy(void)
{
2121
	do_set_mempolicy(MPOL_DEFAULT, 0, NULL);
L
Linus Torvalds 已提交
2122
}
2123

2124 2125 2126 2127
/*
 * Parse and format mempolicy from/to strings
 */

2128
/*
2129
 * "local" is pseudo-policy:  MPOL_PREFERRED with MPOL_F_LOCAL flag
2130
 * Used only for mpol_parse_str() and mpol_to_str()
2131
 */
2132
#define MPOL_LOCAL (MPOL_INTERLEAVE + 1)
2133
static const char * const policy_types[] =
2134
	{ "default", "prefer", "bind", "interleave", "local" };
2135

2136 2137 2138 2139 2140

#ifdef CONFIG_TMPFS
/**
 * mpol_parse_str - parse string to mempolicy
 * @str:  string containing mempolicy to parse
2141 2142
 * @mpol:  pointer to struct mempolicy pointer, returned on success.
 * @no_context:  flag whether to "contextualize" the mempolicy
2143 2144 2145 2146
 *
 * Format of input:
 *	<mode>[=<flags>][:<nodelist>]
 *
2147 2148 2149 2150 2151 2152 2153 2154
 * if @no_context is true, save the input nodemask in w.user_nodemask in
 * the returned mempolicy.  This will be used to "clone" the mempolicy in
 * a specific context [cpuset] at a later time.  Used to parse tmpfs mpol
 * mount option.  Note that if 'static' or 'relative' mode flags were
 * specified, the input nodemask will already have been saved.  Saving
 * it again is redundant, but safe.
 *
 * On success, returns 0, else 1
2155
 */
2156
int mpol_parse_str(char *str, struct mempolicy **mpol, int no_context)
2157
{
2158 2159 2160 2161
	struct mempolicy *new = NULL;
	unsigned short uninitialized_var(mode);
	unsigned short uninitialized_var(mode_flags);
	nodemask_t nodes;
2162 2163 2164 2165 2166 2167 2168 2169
	char *nodelist = strchr(str, ':');
	char *flags = strchr(str, '=');
	int i;
	int err = 1;

	if (nodelist) {
		/* NUL-terminate mode or flags string */
		*nodelist++ = '\0';
2170
		if (nodelist_parse(nodelist, nodes))
2171
			goto out;
2172
		if (!nodes_subset(nodes, node_states[N_HIGH_MEMORY]))
2173
			goto out;
2174 2175 2176
	} else
		nodes_clear(nodes);

2177 2178 2179
	if (flags)
		*flags++ = '\0';	/* terminate mode string */

2180
	for (i = 0; i <= MPOL_LOCAL; i++) {
2181
		if (!strcmp(str, policy_types[i])) {
2182
			mode = i;
2183 2184 2185
			break;
		}
	}
2186
	if (i > MPOL_LOCAL)
2187 2188
		goto out;

2189
	switch (mode) {
2190
	case MPOL_PREFERRED:
2191 2192 2193
		/*
		 * Insist on a nodelist of one node only
		 */
2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206
		if (nodelist) {
			char *rest = nodelist;
			while (isdigit(*rest))
				rest++;
			if (!*rest)
				err = 0;
		}
		break;
	case MPOL_INTERLEAVE:
		/*
		 * Default to online nodes with memory if no nodelist
		 */
		if (!nodelist)
2207
			nodes = node_states[N_HIGH_MEMORY];
2208
		err = 0;
2209
		break;
2210
	case MPOL_LOCAL:
2211
		/*
2212
		 * Don't allow a nodelist;  mpol_new() checks flags
2213
		 */
2214
		if (nodelist)
2215
			goto out;
2216
		mode = MPOL_PREFERRED;
2217
		break;
2218 2219 2220 2221 2222 2223 2224
	case MPOL_DEFAULT:
		/*
		 * Insist on a empty nodelist
		 */
		if (!nodelist)
			err = 0;
		goto out;
2225 2226 2227
	/*
	 * case MPOL_BIND:    mpol_new() enforces non-empty nodemask.
	 */
2228 2229
	}

2230
	mode_flags = 0;
2231 2232 2233 2234 2235 2236
	if (flags) {
		/*
		 * Currently, we only support two mutually exclusive
		 * mode flags.
		 */
		if (!strcmp(flags, "static"))
2237
			mode_flags |= MPOL_F_STATIC_NODES;
2238
		else if (!strcmp(flags, "relative"))
2239
			mode_flags |= MPOL_F_RELATIVE_NODES;
2240 2241 2242
		else
			err = 1;
	}
2243 2244 2245 2246

	new = mpol_new(mode, mode_flags, &nodes);
	if (IS_ERR(new))
		err = 1;
2247 2248
	else {
		int ret;
2249 2250 2251 2252 2253 2254 2255 2256 2257
		NODEMASK_SCRATCH(scratch);
		if (scratch) {
			task_lock(current);
			ret = mpol_set_nodemask(new, &nodes, scratch);
			task_unlock(current);
		} else
			ret = -ENOMEM;
		NODEMASK_SCRATCH_FREE(scratch);
		if (ret) {
2258
			err = 1;
2259 2260
			mpol_put(new);
		} else if (no_context) {
2261 2262 2263 2264
			/* save for contextualization */
			new->w.user_nodemask = nodes;
		}
	}
2265

2266 2267 2268 2269 2270 2271
out:
	/* Restore string for error message */
	if (nodelist)
		*--nodelist = ':';
	if (flags)
		*--flags = '=';
2272 2273
	if (!err)
		*mpol = new;
2274 2275 2276 2277
	return err;
}
#endif /* CONFIG_TMPFS */

2278 2279 2280 2281 2282 2283 2284
/**
 * mpol_to_str - format a mempolicy structure for printing
 * @buffer:  to contain formatted mempolicy string
 * @maxlen:  length of @buffer
 * @pol:  pointer to mempolicy to be formatted
 * @no_context:  "context free" mempolicy - use nodemask in w.user_nodemask
 *
2285 2286 2287 2288
 * Convert a mempolicy into a string.
 * Returns the number of characters in buffer (if positive)
 * or an error (negative)
 */
2289
int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol, int no_context)
2290 2291 2292 2293
{
	char *p = buffer;
	int l;
	nodemask_t nodes;
2294
	unsigned short mode;
2295
	unsigned short flags = pol ? pol->flags : 0;
2296

2297 2298 2299 2300 2301
	/*
	 * Sanity check:  room for longest mode, flag and some nodes
	 */
	VM_BUG_ON(maxlen < strlen("interleave") + strlen("relative") + 16);

2302 2303 2304 2305 2306
	if (!pol || pol == &default_policy)
		mode = MPOL_DEFAULT;
	else
		mode = pol->mode;

2307 2308 2309 2310 2311 2312 2313
	switch (mode) {
	case MPOL_DEFAULT:
		nodes_clear(nodes);
		break;

	case MPOL_PREFERRED:
		nodes_clear(nodes);
2314
		if (flags & MPOL_F_LOCAL)
2315 2316
			mode = MPOL_LOCAL;	/* pseudo-policy */
		else
2317
			node_set(pol->v.preferred_node, nodes);
2318 2319 2320
		break;

	case MPOL_BIND:
2321
		/* Fall through */
2322
	case MPOL_INTERLEAVE:
2323 2324 2325 2326
		if (no_context)
			nodes = pol->w.user_nodemask;
		else
			nodes = pol->v.nodes;
2327 2328 2329 2330 2331 2332 2333
		break;

	default:
		BUG();
	}

	l = strlen(policy_types[mode]);
2334 2335
	if (buffer + maxlen < p + l + 1)
		return -ENOSPC;
2336 2337 2338 2339

	strcpy(p, policy_types[mode]);
	p += l;

2340
	if (flags & MPOL_MODE_FLAGS) {
2341 2342 2343 2344
		if (buffer + maxlen < p + 2)
			return -ENOSPC;
		*p++ = '=';

2345 2346 2347
		/*
		 * Currently, the only defined flags are mutually exclusive
		 */
2348
		if (flags & MPOL_F_STATIC_NODES)
2349 2350 2351
			p += snprintf(p, buffer + maxlen - p, "static");
		else if (flags & MPOL_F_RELATIVE_NODES)
			p += snprintf(p, buffer + maxlen - p, "relative");
2352 2353
	}

2354 2355 2356
	if (!nodes_empty(nodes)) {
		if (buffer + maxlen < p + 2)
			return -ENOSPC;
2357
		*p++ = ':';
2358 2359 2360 2361 2362 2363 2364 2365
	 	p += nodelist_scnprintf(p, buffer + maxlen - p, nodes);
	}
	return p - buffer;
}

struct numa_maps {
	unsigned long pages;
	unsigned long anon;
C
Christoph Lameter 已提交
2366 2367
	unsigned long active;
	unsigned long writeback;
2368
	unsigned long mapcount_max;
C
Christoph Lameter 已提交
2369 2370
	unsigned long dirty;
	unsigned long swapcache;
2371 2372 2373
	unsigned long node[MAX_NUMNODES];
};

C
Christoph Lameter 已提交
2374
static void gather_stats(struct page *page, void *private, int pte_dirty)
2375 2376 2377 2378
{
	struct numa_maps *md = private;
	int count = page_mapcount(page);

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Christoph Lameter 已提交
2379 2380 2381
	md->pages++;
	if (pte_dirty || PageDirty(page))
		md->dirty++;
2382

C
Christoph Lameter 已提交
2383 2384
	if (PageSwapCache(page))
		md->swapcache++;
2385

L
Lee Schermerhorn 已提交
2386
	if (PageActive(page) || PageUnevictable(page))
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Christoph Lameter 已提交
2387 2388 2389 2390
		md->active++;

	if (PageWriteback(page))
		md->writeback++;
2391 2392 2393 2394

	if (PageAnon(page))
		md->anon++;

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Christoph Lameter 已提交
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	if (count > md->mapcount_max)
		md->mapcount_max = count;

2398 2399 2400
	md->node[page_to_nid(page)]++;
}

A
Andrew Morton 已提交
2401
#ifdef CONFIG_HUGETLB_PAGE
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static void check_huge_range(struct vm_area_struct *vma,
		unsigned long start, unsigned long end,
		struct numa_maps *md)
{
	unsigned long addr;
	struct page *page;
2408 2409
	struct hstate *h = hstate_vma(vma);
	unsigned long sz = huge_page_size(h);
C
Christoph Lameter 已提交
2410

2411 2412 2413
	for (addr = start; addr < end; addr += sz) {
		pte_t *ptep = huge_pte_offset(vma->vm_mm,
						addr & huge_page_mask(h));
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Christoph Lameter 已提交
2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429
		pte_t pte;

		if (!ptep)
			continue;

		pte = *ptep;
		if (pte_none(pte))
			continue;

		page = pte_page(pte);
		if (!page)
			continue;

		gather_stats(page, md, pte_dirty(*ptep));
	}
}
A
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2430 2431 2432 2433 2434 2435 2436
#else
static inline void check_huge_range(struct vm_area_struct *vma,
		unsigned long start, unsigned long end,
		struct numa_maps *md)
{
}
#endif
C
Christoph Lameter 已提交
2437

2438 2439 2440
/*
 * Display pages allocated per node and memory policy via /proc.
 */
2441 2442
int show_numa_map(struct seq_file *m, void *v)
{
2443
	struct proc_maps_private *priv = m->private;
2444 2445
	struct vm_area_struct *vma = v;
	struct numa_maps *md;
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	struct file *file = vma->vm_file;
	struct mm_struct *mm = vma->vm_mm;
2448
	struct mempolicy *pol;
2449 2450 2451
	int n;
	char buffer[50];

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2452
	if (!mm)
2453 2454 2455 2456 2457 2458
		return 0;

	md = kzalloc(sizeof(struct numa_maps), GFP_KERNEL);
	if (!md)
		return 0;

2459
	pol = get_vma_policy(priv->task, vma, vma->vm_start);
2460
	mpol_to_str(buffer, sizeof(buffer), pol, 0);
2461
	mpol_cond_put(pol);
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	seq_printf(m, "%08lx %s", vma->vm_start, buffer);

	if (file) {
		seq_printf(m, " file=");
2467
		seq_path(m, &file->f_path, "\n\t= ");
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Christoph Lameter 已提交
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	} else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) {
		seq_printf(m, " heap");
	} else if (vma->vm_start <= mm->start_stack &&
			vma->vm_end >= mm->start_stack) {
		seq_printf(m, " stack");
	}

	if (is_vm_hugetlb_page(vma)) {
		check_huge_range(vma, vma->vm_start, vma->vm_end, md);
		seq_printf(m, " huge");
	} else {
2479
		check_pgd_range(vma, vma->vm_start, vma->vm_end,
2480
			&node_states[N_HIGH_MEMORY], MPOL_MF_STATS, md);
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2481 2482 2483 2484
	}

	if (!md->pages)
		goto out;
2485

C
Christoph Lameter 已提交
2486 2487
	if (md->anon)
		seq_printf(m," anon=%lu",md->anon);
2488

C
Christoph Lameter 已提交
2489 2490
	if (md->dirty)
		seq_printf(m," dirty=%lu",md->dirty);
2491

C
Christoph Lameter 已提交
2492 2493
	if (md->pages != md->anon && md->pages != md->dirty)
		seq_printf(m, " mapped=%lu", md->pages);
2494

C
Christoph Lameter 已提交
2495 2496
	if (md->mapcount_max > 1)
		seq_printf(m, " mapmax=%lu", md->mapcount_max);
2497

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2498 2499 2500 2501 2502 2503 2504 2505 2506
	if (md->swapcache)
		seq_printf(m," swapcache=%lu", md->swapcache);

	if (md->active < md->pages && !is_vm_hugetlb_page(vma))
		seq_printf(m," active=%lu", md->active);

	if (md->writeback)
		seq_printf(m," writeback=%lu", md->writeback);

2507
	for_each_node_state(n, N_HIGH_MEMORY)
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Christoph Lameter 已提交
2508 2509 2510 2511
		if (md->node[n])
			seq_printf(m, " N%d=%lu", n, md->node[n]);
out:
	seq_putc(m, '\n');
2512 2513 2514
	kfree(md);

	if (m->count < m->size)
2515
		m->version = (vma != priv->tail_vma) ? vma->vm_start : 0;
2516 2517
	return 0;
}