mempolicy.c 61.4 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/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 <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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		/*
		 * The check for PageReserved here is important to avoid
		 * handling zero pages and other pages that may have been
		 * marked special by the system.
		 *
		 * If the PageReserved would not be checked here then f.e.
		 * the location of the zero page could have an influence
		 * on MPOL_MF_STRICT, zero pages would be counted for
		 * the per node stats, and there would be useless attempts
		 * to put zero pages on the migration list.
		 */
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		if (PageReserved(page))
			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. */
static int mbind_range(struct vm_area_struct *vma, unsigned long start,
		       unsigned long end, struct mempolicy *new)
{
	struct vm_area_struct *next;
	int err;

	err = 0;
	for (; vma && vma->vm_start < end; vma = next) {
		next = vma->vm_next;
		if (vma->vm_start < start)
			err = split_vma(vma->vm_mm, vma, start, 1);
		if (!err && vma->vm_end > end)
			err = split_vma(vma->vm_mm, vma, end, 0);
		if (!err)
			err = policy_vma(vma, new);
		if (err)
			break;
	}
	return err;
}

591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620
/*
 * 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
621
/* Set the process memory policy */
622 623
static long do_set_mempolicy(unsigned short mode, unsigned short flags,
			     nodemask_t *nodes)
L
Linus Torvalds 已提交
624
{
625
	struct mempolicy *new, *old;
626
	struct mm_struct *mm = current->mm;
627
	NODEMASK_SCRATCH(scratch);
628
	int ret;
L
Linus Torvalds 已提交
629

630 631
	if (!scratch)
		return -ENOMEM;
632

633 634 635 636 637
	new = mpol_new(mode, flags, nodes);
	if (IS_ERR(new)) {
		ret = PTR_ERR(new);
		goto out;
	}
638 639 640 641 642 643 644 645
	/*
	 * 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);
646
	task_lock(current);
647
	ret = mpol_set_nodemask(new, nodes, scratch);
648 649 650 651 652
	if (ret) {
		task_unlock(current);
		if (mm)
			up_write(&mm->mmap_sem);
		mpol_put(new);
653
		goto out;
654 655
	}
	old = current->mempolicy;
L
Linus Torvalds 已提交
656
	current->mempolicy = new;
657
	mpol_set_task_struct_flag();
658
	if (new && new->mode == MPOL_INTERLEAVE &&
659
	    nodes_weight(new->v.nodes))
660
		current->il_next = first_node(new->v.nodes);
661
	task_unlock(current);
662 663 664
	if (mm)
		up_write(&mm->mmap_sem);

665
	mpol_put(old);
666 667 668 669
	ret = 0;
out:
	NODEMASK_SCRATCH_FREE(scratch);
	return ret;
L
Linus Torvalds 已提交
670 671
}

672 673
/*
 * Return nodemask for policy for get_mempolicy() query
674 675
 *
 * Called with task's alloc_lock held
676 677
 */
static void get_policy_nodemask(struct mempolicy *p, nodemask_t *nodes)
L
Linus Torvalds 已提交
678
{
679
	nodes_clear(*nodes);
680 681 682
	if (p == &default_policy)
		return;

683
	switch (p->mode) {
684 685
	case MPOL_BIND:
		/* Fall through */
L
Linus Torvalds 已提交
686
	case MPOL_INTERLEAVE:
687
		*nodes = p->v.nodes;
L
Linus Torvalds 已提交
688 689
		break;
	case MPOL_PREFERRED:
690
		if (!(p->flags & MPOL_F_LOCAL))
691
			node_set(p->v.preferred_node, *nodes);
692
		/* else return empty node mask for local allocation */
L
Linus Torvalds 已提交
693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712
		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
713 714
static long do_get_mempolicy(int *policy, nodemask_t *nmask,
			     unsigned long addr, unsigned long flags)
L
Linus Torvalds 已提交
715
{
716
	int err;
L
Linus Torvalds 已提交
717 718 719 720
	struct mm_struct *mm = current->mm;
	struct vm_area_struct *vma = NULL;
	struct mempolicy *pol = current->mempolicy;

721 722
	if (flags &
		~(unsigned long)(MPOL_F_NODE|MPOL_F_ADDR|MPOL_F_MEMS_ALLOWED))
L
Linus Torvalds 已提交
723
		return -EINVAL;
724 725 726 727 728

	if (flags & MPOL_F_MEMS_ALLOWED) {
		if (flags & (MPOL_F_NODE|MPOL_F_ADDR))
			return -EINVAL;
		*policy = 0;	/* just so it's initialized */
729
		task_lock(current);
730
		*nmask  = cpuset_current_mems_allowed;
731
		task_unlock(current);
732 733 734
		return 0;
	}

L
Linus Torvalds 已提交
735
	if (flags & MPOL_F_ADDR) {
736 737 738 739 740
		/*
		 * 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
741 742 743 744 745 746 747 748 749 750 751 752 753 754
		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)
755
		pol = &default_policy;	/* indicates default behavior */
L
Linus Torvalds 已提交
756 757 758 759 760 761

	if (flags & MPOL_F_NODE) {
		if (flags & MPOL_F_ADDR) {
			err = lookup_node(mm, addr);
			if (err < 0)
				goto out;
762
			*policy = err;
L
Linus Torvalds 已提交
763
		} else if (pol == current->mempolicy &&
764
				pol->mode == MPOL_INTERLEAVE) {
765
			*policy = current->il_next;
L
Linus Torvalds 已提交
766 767 768 769
		} else {
			err = -EINVAL;
			goto out;
		}
770 771 772
	} else {
		*policy = pol == &default_policy ? MPOL_DEFAULT :
						pol->mode;
773 774 775 776 777
		/*
		 * Internal mempolicy flags must be masked off before exposing
		 * the policy to userspace.
		 */
		*policy |= (pol->flags & MPOL_MODE_FLAGS);
778
	}
L
Linus Torvalds 已提交
779 780 781 782 783 784 785

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

	err = 0;
786 787
	if (nmask) {
		task_lock(current);
788
		get_policy_nodemask(pol, nmask);
789 790
		task_unlock(current);
	}
L
Linus Torvalds 已提交
791 792

 out:
793
	mpol_cond_put(pol);
L
Linus Torvalds 已提交
794 795 796 797 798
	if (vma)
		up_read(&current->mm->mmap_sem);
	return err;
}

C
Christoph Lameter 已提交
799
#ifdef CONFIG_MIGRATION
800 801 802
/*
 * page migration
 */
803 804
static void migrate_page_add(struct page *page, struct list_head *pagelist,
				unsigned long flags)
805 806
{
	/*
807
	 * Avoid migrating a page that is shared with others.
808
	 */
809 810 811 812 813
	if ((flags & MPOL_MF_MOVE_ALL) || page_mapcount(page) == 1) {
		if (!isolate_lru_page(page)) {
			list_add_tail(&page->lru, pagelist);
		}
	}
814
}
815

816
static struct page *new_node_page(struct page *page, unsigned long node, int **x)
817
{
818
	return alloc_pages_exact_node(node, GFP_HIGHUSER_MOVABLE, 0);
819 820
}

821 822 823 824
/*
 * Migrate pages from one node to a target node.
 * Returns error or the number of pages not migrated.
 */
A
Adrian Bunk 已提交
825 826
static int migrate_to_node(struct mm_struct *mm, int source, int dest,
			   int flags)
827 828 829 830 831 832 833
{
	nodemask_t nmask;
	LIST_HEAD(pagelist);
	int err = 0;

	nodes_clear(nmask);
	node_set(source, nmask);
834

835 836 837
	check_range(mm, mm->mmap->vm_start, TASK_SIZE, &nmask,
			flags | MPOL_MF_DISCONTIG_OK, &pagelist);

838
	if (!list_empty(&pagelist))
839 840
		err = migrate_pages(&pagelist, new_node_page, dest);

841
	return err;
842 843
}

844
/*
845 846
 * Move pages between the two nodesets so as to preserve the physical
 * layout as much as possible.
847 848 849 850 851 852
 *
 * 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)
{
853
	int busy = 0;
854
	int err;
855
	nodemask_t tmp;
856

857 858 859 860
	err = migrate_prep();
	if (err)
		return err;

861
	down_read(&mm->mmap_sem);
862

863 864 865 866
	err = migrate_vmas(mm, from_nodes, to_nodes, flags);
	if (err)
		goto out;

867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896
/*
 * 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.
 */
897

898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924
	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;
925
	}
926
out:
927
	up_read(&mm->mmap_sem);
928 929 930
	if (err < 0)
		return err;
	return busy;
C
Christoph Lameter 已提交
931 932 933

}

934 935 936 937 938 939 940
/*
 * 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.
 */
941
static struct page *new_vma_page(struct page *page, unsigned long private, int **x)
942 943
{
	struct vm_area_struct *vma = (struct vm_area_struct *)private;
944
	unsigned long uninitialized_var(address);
945

946 947 948 949 950 951 952 953 954 955 956
	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);
957
}
C
Christoph Lameter 已提交
958 959 960 961 962
#else

static void migrate_page_add(struct page *page, struct list_head *pagelist,
				unsigned long flags)
{
963 964
}

C
Christoph Lameter 已提交
965 966 967 968 969
int do_migrate_pages(struct mm_struct *mm,
	const nodemask_t *from_nodes, const nodemask_t *to_nodes, int flags)
{
	return -ENOSYS;
}
970

971
static struct page *new_vma_page(struct page *page, unsigned long private, int **x)
972 973 974
{
	return NULL;
}
C
Christoph Lameter 已提交
975 976
#endif

A
Adrian Bunk 已提交
977
static long do_mbind(unsigned long start, unsigned long len,
978 979
		     unsigned short mode, unsigned short mode_flags,
		     nodemask_t *nmask, unsigned long flags)
980 981 982 983 984 985 986 987
{
	struct vm_area_struct *vma;
	struct mm_struct *mm = current->mm;
	struct mempolicy *new;
	unsigned long end;
	int err;
	LIST_HEAD(pagelist);

988 989
	if (flags & ~(unsigned long)(MPOL_MF_STRICT |
				     MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
990
		return -EINVAL;
991
	if ((flags & MPOL_MF_MOVE_ALL) && !capable(CAP_SYS_NICE))
992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007
		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;

1008
	new = mpol_new(mode, mode_flags, nmask);
1009 1010 1011 1012 1013 1014 1015 1016 1017 1018
	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;

1019 1020 1021
	pr_debug("mbind %lx-%lx mode:%d flags:%d nodes:%lx\n",
		 start, start + len, mode, mode_flags,
		 nmask ? nodes_addr(*nmask)[0] : -1);
1022

1023 1024 1025 1026 1027 1028
	if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) {

		err = migrate_prep();
		if (err)
			return err;
	}
1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041
	{
		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);
	}
1042 1043 1044 1045
	if (err) {
		mpol_put(new);
		return err;
	}
1046 1047 1048 1049 1050 1051 1052 1053
	vma = check_range(mm, start, end, nmask,
			  flags | MPOL_MF_INVERT, &pagelist);

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

		err = mbind_range(vma, start, end, new);
1054

1055
		if (!list_empty(&pagelist))
1056 1057
			nr_failed = migrate_pages(&pagelist, new_vma_page,
						(unsigned long)vma);
1058 1059 1060

		if (!err && nr_failed && (flags & MPOL_MF_STRICT))
			err = -EIO;
1061 1062
	} else
		putback_lru_pages(&pagelist);
C
Christoph Lameter 已提交
1063

1064
	up_write(&mm->mmap_sem);
1065
	mpol_put(new);
1066 1067 1068
	return err;
}

1069 1070 1071 1072 1073
/*
 * User space interface with variable sized bitmaps for nodelists.
 */

/* Copy a node mask from user space. */
1074
static int get_nodes(nodemask_t *nodes, const unsigned long __user *nmask,
1075 1076 1077 1078 1079 1080 1081 1082 1083 1084
		     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
1085
	if (maxnode > PAGE_SIZE*BITS_PER_BYTE)
C
Chris Wright 已提交
1086
		return -EINVAL;
1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 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

	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;
}

1136 1137 1138
SYSCALL_DEFINE6(mbind, unsigned long, start, unsigned long, len,
		unsigned long, mode, unsigned long __user *, nmask,
		unsigned long, maxnode, unsigned, flags)
1139 1140 1141
{
	nodemask_t nodes;
	int err;
1142
	unsigned short mode_flags;
1143

1144 1145
	mode_flags = mode & MPOL_MODE_FLAGS;
	mode &= ~MPOL_MODE_FLAGS;
1146 1147
	if (mode >= MPOL_MAX)
		return -EINVAL;
1148 1149 1150
	if ((mode_flags & MPOL_F_STATIC_NODES) &&
	    (mode_flags & MPOL_F_RELATIVE_NODES))
		return -EINVAL;
1151 1152 1153
	err = get_nodes(&nodes, nmask, maxnode);
	if (err)
		return err;
1154
	return do_mbind(start, len, mode, mode_flags, &nodes, flags);
1155 1156 1157
}

/* Set the process memory policy */
1158 1159
SYSCALL_DEFINE3(set_mempolicy, int, mode, unsigned long __user *, nmask,
		unsigned long, maxnode)
1160 1161 1162
{
	int err;
	nodemask_t nodes;
1163
	unsigned short flags;
1164

1165 1166 1167
	flags = mode & MPOL_MODE_FLAGS;
	mode &= ~MPOL_MODE_FLAGS;
	if ((unsigned int)mode >= MPOL_MAX)
1168
		return -EINVAL;
1169 1170
	if ((flags & MPOL_F_STATIC_NODES) && (flags & MPOL_F_RELATIVE_NODES))
		return -EINVAL;
1171 1172 1173
	err = get_nodes(&nodes, nmask, maxnode);
	if (err)
		return err;
1174
	return do_set_mempolicy(mode, flags, &nodes);
1175 1176
}

1177 1178 1179
SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode,
		const unsigned long __user *, old_nodes,
		const unsigned long __user *, new_nodes)
1180
{
1181
	const struct cred *cred = current_cred(), *tcred;
1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198
	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);
1199
	task = pid ? find_task_by_vpid(pid) : current;
1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212
	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
1213
	 * capabilities, superuser privileges or the same
1214 1215
	 * userid as the target process.
	 */
1216 1217
	rcu_read_lock();
	tcred = __task_cred(task);
1218 1219
	if (cred->euid != tcred->suid && cred->euid != tcred->uid &&
	    cred->uid  != tcred->suid && cred->uid  != tcred->uid &&
1220
	    !capable(CAP_SYS_NICE)) {
1221
		rcu_read_unlock();
1222 1223 1224
		err = -EPERM;
		goto out;
	}
1225
	rcu_read_unlock();
1226 1227 1228

	task_nodes = cpuset_mems_allowed(task);
	/* Is the user allowed to access the target nodes? */
1229
	if (!nodes_subset(new, task_nodes) && !capable(CAP_SYS_NICE)) {
1230 1231 1232 1233
		err = -EPERM;
		goto out;
	}

1234
	if (!nodes_subset(new, node_states[N_HIGH_MEMORY])) {
1235 1236 1237 1238
		err = -EINVAL;
		goto out;
	}

1239 1240 1241 1242
	err = security_task_movememory(task);
	if (err)
		goto out;

1243
	err = do_migrate_pages(mm, &old, &new,
1244
		capable(CAP_SYS_NICE) ? MPOL_MF_MOVE_ALL : MPOL_MF_MOVE);
1245 1246 1247 1248 1249 1250
out:
	mmput(mm);
	return err;
}


1251
/* Retrieve NUMA policy */
1252 1253 1254
SYSCALL_DEFINE5(get_mempolicy, int __user *, policy,
		unsigned long __user *, nmask, unsigned long, maxnode,
		unsigned long, addr, unsigned long, flags)
1255
{
A
Adrian Bunk 已提交
1256 1257
	int err;
	int uninitialized_var(pval);
1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276
	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
1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 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
#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;
1337
	nodemask_t bm;
L
Linus Torvalds 已提交
1338 1339 1340 1341 1342

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

	if (nmask) {
1343
		err = compat_get_bitmap(nodes_addr(bm), nmask, nr_bits);
L
Linus Torvalds 已提交
1344
		nm = compat_alloc_user_space(alloc_size);
1345
		err |= copy_to_user(nm, nodes_addr(bm), alloc_size);
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1346 1347 1348 1349 1350 1351 1352 1353 1354 1355
	}

	if (err)
		return -EFAULT;

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

#endif

1356 1357 1358 1359 1360 1361 1362 1363
/*
 * 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.
1364 1365 1366 1367 1368 1369 1370
 * 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.
1371
 */
1372
static struct mempolicy *get_vma_policy(struct task_struct *task,
1373
		struct vm_area_struct *vma, unsigned long addr)
L
Linus Torvalds 已提交
1374
{
1375
	struct mempolicy *pol = task->mempolicy;
L
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1376 1377

	if (vma) {
1378
		if (vma->vm_ops && vma->vm_ops->get_policy) {
1379 1380 1381 1382
			struct mempolicy *vpol = vma->vm_ops->get_policy(vma,
									addr);
			if (vpol)
				pol = vpol;
1383
		} else if (vma->vm_policy)
L
Linus Torvalds 已提交
1384 1385 1386 1387 1388 1389 1390
			pol = vma->vm_policy;
	}
	if (!pol)
		pol = &default_policy;
	return pol;
}

1391 1392 1393 1394 1395
/*
 * Return a nodemask representing a mempolicy for filtering nodes for
 * page allocation
 */
static nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy)
1396 1397
{
	/* Lower zones don't get a nodemask applied for MPOL_BIND */
1398
	if (unlikely(policy->mode == MPOL_BIND) &&
1399 1400 1401 1402 1403 1404 1405
			gfp_zone(gfp) >= policy_zone &&
			cpuset_nodemask_valid_mems_allowed(&policy->v.nodes))
		return &policy->v.nodes;

	return NULL;
}

1406 1407
/* 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
1408
{
1409
	int nd = numa_node_id();
L
Linus Torvalds 已提交
1410

1411
	switch (policy->mode) {
L
Linus Torvalds 已提交
1412
	case MPOL_PREFERRED:
1413 1414
		if (!(policy->flags & MPOL_F_LOCAL))
			nd = policy->v.preferred_node;
L
Linus Torvalds 已提交
1415 1416
		break;
	case MPOL_BIND:
1417
		/*
1418 1419 1420 1421
		 * 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.
1422 1423 1424 1425 1426
		 */
		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
1427 1428 1429 1430 1431
	case MPOL_INTERLEAVE: /* should not happen */
		break;
	default:
		BUG();
	}
1432
	return node_zonelist(nd, gfp);
L
Linus Torvalds 已提交
1433 1434 1435 1436 1437 1438 1439 1440 1441
}

/* 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;
1442
	next = next_node(nid, policy->v.nodes);
L
Linus Torvalds 已提交
1443
	if (next >= MAX_NUMNODES)
1444
		next = first_node(policy->v.nodes);
1445 1446
	if (next < MAX_NUMNODES)
		me->il_next = next;
L
Linus Torvalds 已提交
1447 1448 1449
	return nid;
}

1450 1451 1452
/*
 * Depending on the memory policy provide a node from which to allocate the
 * next slab entry.
1453 1454 1455 1456
 * @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.
1457 1458 1459
 */
unsigned slab_node(struct mempolicy *policy)
{
1460
	if (!policy || policy->flags & MPOL_F_LOCAL)
1461 1462 1463 1464
		return numa_node_id();

	switch (policy->mode) {
	case MPOL_PREFERRED:
1465 1466 1467 1468
		/*
		 * handled MPOL_F_LOCAL above
		 */
		return policy->v.preferred_node;
1469

1470 1471 1472
	case MPOL_INTERLEAVE:
		return interleave_nodes(policy);

1473
	case MPOL_BIND: {
1474 1475 1476 1477
		/*
		 * Follow bind policy behavior and start allocation at the
		 * first node.
		 */
1478 1479 1480 1481 1482 1483 1484 1485
		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;
1486
	}
1487 1488

	default:
1489
		BUG();
1490 1491 1492
	}
}

L
Linus Torvalds 已提交
1493 1494 1495 1496
/* 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)
{
1497
	unsigned nnodes = nodes_weight(pol->v.nodes);
1498
	unsigned target;
L
Linus Torvalds 已提交
1499 1500 1501
	int c;
	int nid = -1;

1502 1503 1504
	if (!nnodes)
		return numa_node_id();
	target = (unsigned int)off % nnodes;
L
Linus Torvalds 已提交
1505 1506
	c = 0;
	do {
1507
		nid = next_node(nid, pol->v.nodes);
L
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1508 1509 1510 1511 1512
		c++;
	} while (c <= target);
	return nid;
}

1513 1514 1515 1516 1517 1518 1519
/* 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;

1520 1521 1522 1523 1524 1525 1526 1527 1528
		/*
		 * 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);
1529 1530 1531 1532 1533 1534
		off += (addr - vma->vm_start) >> shift;
		return offset_il_node(pol, vma, off);
	} else
		return interleave_nodes(pol);
}

1535
#ifdef CONFIG_HUGETLBFS
1536 1537 1538 1539 1540
/*
 * 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
1541 1542
 * @mpol = pointer to mempolicy pointer for reference counted mempolicy
 * @nodemask = pointer to nodemask pointer for MPOL_BIND nodemask
1543
 *
1544 1545 1546 1547
 * 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.
1548
 */
1549
struct zonelist *huge_zonelist(struct vm_area_struct *vma, unsigned long addr,
1550 1551
				gfp_t gfp_flags, struct mempolicy **mpol,
				nodemask_t **nodemask)
1552
{
1553
	struct zonelist *zl;
1554

1555
	*mpol = get_vma_policy(current, vma, addr);
1556
	*nodemask = NULL;	/* assume !MPOL_BIND */
1557

1558 1559
	if (unlikely((*mpol)->mode == MPOL_INTERLEAVE)) {
		zl = node_zonelist(interleave_nid(*mpol, vma, addr,
1560
				huge_page_shift(hstate_vma(vma))), gfp_flags);
1561 1562 1563 1564
	} else {
		zl = policy_zonelist(gfp_flags, *mpol);
		if ((*mpol)->mode == MPOL_BIND)
			*nodemask = &(*mpol)->v.nodes;
1565 1566
	}
	return zl;
1567
}
1568
#endif
1569

L
Linus Torvalds 已提交
1570 1571
/* Allocate a page in interleaved policy.
   Own path because it needs to do special accounting. */
1572 1573
static struct page *alloc_page_interleave(gfp_t gfp, unsigned order,
					unsigned nid)
L
Linus Torvalds 已提交
1574 1575 1576 1577
{
	struct zonelist *zl;
	struct page *page;

1578
	zl = node_zonelist(nid, gfp);
L
Linus Torvalds 已提交
1579
	page = __alloc_pages(gfp, order, zl);
1580
	if (page && page_zone(page) == zonelist_zone(&zl->_zonerefs[0]))
1581
		inc_zone_page_state(page, NUMA_INTERLEAVE_HIT);
L
Linus Torvalds 已提交
1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607
	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
1608
alloc_page_vma(gfp_t gfp, struct vm_area_struct *vma, unsigned long addr)
L
Linus Torvalds 已提交
1609
{
1610
	struct mempolicy *pol = get_vma_policy(current, vma, addr);
1611
	struct zonelist *zl;
L
Linus Torvalds 已提交
1612

1613
	if (unlikely(pol->mode == MPOL_INTERLEAVE)) {
L
Linus Torvalds 已提交
1614
		unsigned nid;
1615 1616

		nid = interleave_nid(pol, vma, addr, PAGE_SHIFT);
1617
		mpol_cond_put(pol);
L
Linus Torvalds 已提交
1618 1619
		return alloc_page_interleave(gfp, 0, nid);
	}
1620 1621
	zl = policy_zonelist(gfp, pol);
	if (unlikely(mpol_needs_cond_ref(pol))) {
1622
		/*
1623
		 * slow path: ref counted shared policy
1624
		 */
1625
		struct page *page =  __alloc_pages_nodemask(gfp, 0,
1626
						zl, policy_nodemask(gfp, pol));
1627
		__mpol_put(pol);
1628 1629 1630 1631 1632
		return page;
	}
	/*
	 * fast path:  default or task policy
	 */
1633
	return __alloc_pages_nodemask(gfp, 0, zl, policy_nodemask(gfp, pol));
L
Linus Torvalds 已提交
1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650
}

/**
 * 	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.
 *
1651
 *	Don't call cpuset_update_task_memory_state() unless
L
Linus Torvalds 已提交
1652 1653 1654
 *	1) it's ok to take cpuset_sem (can WAIT), and
 *	2) allocating for current task (not interrupt).
 */
A
Al Viro 已提交
1655
struct page *alloc_pages_current(gfp_t gfp, unsigned order)
L
Linus Torvalds 已提交
1656 1657 1658
{
	struct mempolicy *pol = current->mempolicy;

1659
	if (!pol || in_interrupt() || (gfp & __GFP_THISNODE))
L
Linus Torvalds 已提交
1660
		pol = &default_policy;
1661 1662 1663 1664 1665

	/*
	 * No reference counting needed for current->mempolicy
	 * nor system default_policy
	 */
1666
	if (pol->mode == MPOL_INTERLEAVE)
L
Linus Torvalds 已提交
1667
		return alloc_page_interleave(gfp, order, interleave_nodes(pol));
1668
	return __alloc_pages_nodemask(gfp, order,
1669
			policy_zonelist(gfp, pol), policy_nodemask(gfp, pol));
L
Linus Torvalds 已提交
1670 1671 1672
}
EXPORT_SYMBOL(alloc_pages_current);

1673
/*
1674
 * If mpol_dup() sees current->cpuset == cpuset_being_rebound, then it
1675 1676 1677 1678 1679 1680
 * 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().
 */

1681 1682
/* Slow path of a mempolicy duplicate */
struct mempolicy *__mpol_dup(struct mempolicy *old)
L
Linus Torvalds 已提交
1683 1684 1685 1686 1687
{
	struct mempolicy *new = kmem_cache_alloc(policy_cache, GFP_KERNEL);

	if (!new)
		return ERR_PTR(-ENOMEM);
1688 1689 1690 1691
	if (current_cpuset_is_being_rebound()) {
		nodemask_t mems = cpuset_mems_allowed(current);
		mpol_rebind_policy(old, &mems);
	}
L
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1692 1693 1694 1695 1696
	*new = *old;
	atomic_set(&new->refcnt, 1);
	return new;
}

1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718
/*
 * 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;
}

1719 1720 1721 1722 1723 1724 1725 1726 1727 1728
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);
}

L
Linus Torvalds 已提交
1729 1730 1731 1732 1733
/* Slow path of a mempolicy comparison */
int __mpol_equal(struct mempolicy *a, struct mempolicy *b)
{
	if (!a || !b)
		return 0;
1734
	if (a->mode != b->mode)
L
Linus Torvalds 已提交
1735
		return 0;
1736
	if (a->mode != MPOL_DEFAULT && !mpol_match_intent(a, b))
1737
		return 0;
1738
	switch (a->mode) {
1739 1740
	case MPOL_BIND:
		/* Fall through */
L
Linus Torvalds 已提交
1741
	case MPOL_INTERLEAVE:
1742
		return nodes_equal(a->v.nodes, b->v.nodes);
L
Linus Torvalds 已提交
1743
	case MPOL_PREFERRED:
1744 1745
		return a->v.preferred_node == b->v.preferred_node &&
			a->flags == b->flags;
L
Linus Torvalds 已提交
1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812
	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);
1813
	pr_debug("inserting %lx-%lx: %d\n", new->start, new->end,
1814
		 new->policy ? new->policy->mode : 0);
L
Linus Torvalds 已提交
1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837
}

/* 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)
{
1838
	pr_debug("deleting %lx-l%lx\n", n->start, n->end);
L
Linus Torvalds 已提交
1839
	rb_erase(&n->nd, &sp->root);
1840
	mpol_put(n->policy);
L
Linus Torvalds 已提交
1841 1842 1843
	kmem_cache_free(sn_cache, n);
}

A
Adrian Bunk 已提交
1844 1845
static struct sp_node *sp_alloc(unsigned long start, unsigned long end,
				struct mempolicy *pol)
L
Linus Torvalds 已提交
1846 1847 1848 1849 1850 1851 1852 1853
{
	struct sp_node *n = kmem_cache_alloc(sn_cache, GFP_KERNEL);

	if (!n)
		return NULL;
	n->start = start;
	n->end = end;
	mpol_get(pol);
1854
	pol->flags |= MPOL_F_SHARED;	/* for unref */
L
Linus Torvalds 已提交
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 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900
	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) {
1901
		mpol_put(new2->policy);
L
Linus Torvalds 已提交
1902 1903 1904 1905 1906
		kmem_cache_free(sn_cache, new2);
	}
	return 0;
}

1907 1908 1909 1910 1911 1912 1913 1914
/**
 * 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.
1915
 * This is called at get_inode() calls and we can use GFP_KERNEL.
1916 1917 1918
 */
void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol)
{
1919 1920
	int ret;

1921 1922 1923 1924 1925 1926
	sp->root = RB_ROOT;		/* empty tree == default mempolicy */
	spin_lock_init(&sp->lock);

	if (mpol) {
		struct vm_area_struct pvma;
		struct mempolicy *new;
1927
		NODEMASK_SCRATCH(scratch);
1928

1929 1930
		if (!scratch)
			return;
1931 1932
		/* contextualize the tmpfs mount point mempolicy */
		new = mpol_new(mpol->mode, mpol->flags, &mpol->w.user_nodemask);
1933 1934
		if (IS_ERR(new)) {
			mpol_put(mpol);	/* drop our ref on sb mpol */
1935
			NODEMASK_SCRATCH_FREE(scratch);
1936
			return;		/* no valid nodemask intersection */
1937 1938 1939
		}

		task_lock(current);
1940
		ret = mpol_set_nodemask(new, &mpol->w.user_nodemask, scratch);
1941 1942 1943
		task_unlock(current);
		mpol_put(mpol);	/* drop our ref on sb mpol */
		if (ret) {
1944
			NODEMASK_SCRATCH_FREE(scratch);
1945 1946 1947
			mpol_put(new);
			return;
		}
1948 1949 1950 1951 1952 1953

		/* 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 */
1954
		NODEMASK_SCRATCH_FREE(scratch);
1955 1956 1957
	}
}

L
Linus Torvalds 已提交
1958 1959 1960 1961 1962 1963 1964
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);

1965
	pr_debug("set_shared_policy %lx sz %lu %d %d %lx\n",
L
Linus Torvalds 已提交
1966
		 vma->vm_pgoff,
1967
		 sz, npol ? npol->mode : -1,
1968
		 npol ? npol->flags : -1,
1969
		 npol ? nodes_addr(npol->v.nodes)[0] : -1);
L
Linus Torvalds 已提交
1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994

	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);
1995
		rb_erase(&n->nd, &p->root);
1996
		mpol_put(n->policy);
L
Linus Torvalds 已提交
1997 1998 1999 2000 2001 2002 2003 2004
		kmem_cache_free(sn_cache, n);
	}
	spin_unlock(&p->lock);
}

/* assumes fs == KERNEL_DS */
void __init numa_policy_init(void)
{
2005 2006 2007 2008
	nodemask_t interleave_nodes;
	unsigned long largest = 0;
	int nid, prefer = 0;

L
Linus Torvalds 已提交
2009 2010
	policy_cache = kmem_cache_create("numa_policy",
					 sizeof(struct mempolicy),
2011
					 0, SLAB_PANIC, NULL);
L
Linus Torvalds 已提交
2012 2013 2014

	sn_cache = kmem_cache_create("shared_policy_node",
				     sizeof(struct sp_node),
2015
				     0, SLAB_PANIC, NULL);
L
Linus Torvalds 已提交
2016

2017 2018 2019 2020 2021 2022
	/*
	 * 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);
2023
	for_each_node_state(nid, N_HIGH_MEMORY) {
2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039
		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
2040

2041
	if (do_set_mempolicy(MPOL_INTERLEAVE, 0, &interleave_nodes))
L
Linus Torvalds 已提交
2042 2043 2044
		printk("numa_policy_init: interleaving failed\n");
}

2045
/* Reset policy of current process to default */
L
Linus Torvalds 已提交
2046 2047
void numa_default_policy(void)
{
2048
	do_set_mempolicy(MPOL_DEFAULT, 0, NULL);
L
Linus Torvalds 已提交
2049
}
2050

2051 2052 2053 2054
/*
 * Parse and format mempolicy from/to strings
 */

2055
/*
2056
 * "local" is pseudo-policy:  MPOL_PREFERRED with MPOL_F_LOCAL flag
2057
 * Used only for mpol_parse_str() and mpol_to_str()
2058
 */
2059
#define MPOL_LOCAL (MPOL_INTERLEAVE + 1)
2060
static const char * const policy_types[] =
2061
	{ "default", "prefer", "bind", "interleave", "local" };
2062

2063 2064 2065 2066 2067

#ifdef CONFIG_TMPFS
/**
 * mpol_parse_str - parse string to mempolicy
 * @str:  string containing mempolicy to parse
2068 2069
 * @mpol:  pointer to struct mempolicy pointer, returned on success.
 * @no_context:  flag whether to "contextualize" the mempolicy
2070 2071 2072 2073
 *
 * Format of input:
 *	<mode>[=<flags>][:<nodelist>]
 *
2074 2075 2076 2077 2078 2079 2080 2081
 * 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
2082
 */
2083
int mpol_parse_str(char *str, struct mempolicy **mpol, int no_context)
2084
{
2085 2086 2087 2088
	struct mempolicy *new = NULL;
	unsigned short uninitialized_var(mode);
	unsigned short uninitialized_var(mode_flags);
	nodemask_t nodes;
2089 2090 2091 2092 2093 2094 2095 2096
	char *nodelist = strchr(str, ':');
	char *flags = strchr(str, '=');
	int i;
	int err = 1;

	if (nodelist) {
		/* NUL-terminate mode or flags string */
		*nodelist++ = '\0';
2097
		if (nodelist_parse(nodelist, nodes))
2098
			goto out;
2099
		if (!nodes_subset(nodes, node_states[N_HIGH_MEMORY]))
2100
			goto out;
2101 2102 2103
	} else
		nodes_clear(nodes);

2104 2105 2106
	if (flags)
		*flags++ = '\0';	/* terminate mode string */

2107
	for (i = 0; i <= MPOL_LOCAL; i++) {
2108
		if (!strcmp(str, policy_types[i])) {
2109
			mode = i;
2110 2111 2112
			break;
		}
	}
2113
	if (i > MPOL_LOCAL)
2114 2115
		goto out;

2116
	switch (mode) {
2117
	case MPOL_PREFERRED:
2118 2119 2120
		/*
		 * Insist on a nodelist of one node only
		 */
2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133
		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)
2134
			nodes = node_states[N_HIGH_MEMORY];
2135
		err = 0;
2136
		break;
2137
	case MPOL_LOCAL:
2138
		/*
2139
		 * Don't allow a nodelist;  mpol_new() checks flags
2140
		 */
2141
		if (nodelist)
2142
			goto out;
2143
		mode = MPOL_PREFERRED;
2144
		break;
2145 2146 2147 2148 2149

	/*
	 * case MPOL_BIND:    mpol_new() enforces non-empty nodemask.
	 * case MPOL_DEFAULT: mpol_new() enforces empty nodemask, ignores flags.
	 */
2150 2151
	}

2152
	mode_flags = 0;
2153 2154 2155 2156 2157 2158
	if (flags) {
		/*
		 * Currently, we only support two mutually exclusive
		 * mode flags.
		 */
		if (!strcmp(flags, "static"))
2159
			mode_flags |= MPOL_F_STATIC_NODES;
2160
		else if (!strcmp(flags, "relative"))
2161
			mode_flags |= MPOL_F_RELATIVE_NODES;
2162 2163 2164
		else
			err = 1;
	}
2165 2166 2167 2168

	new = mpol_new(mode, mode_flags, &nodes);
	if (IS_ERR(new))
		err = 1;
2169 2170
	else {
		int ret;
2171 2172 2173 2174 2175 2176 2177 2178 2179
		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) {
2180
			err = 1;
2181 2182
			mpol_put(new);
		} else if (no_context) {
2183 2184 2185 2186
			/* save for contextualization */
			new->w.user_nodemask = nodes;
		}
	}
2187

2188 2189 2190 2191 2192 2193
out:
	/* Restore string for error message */
	if (nodelist)
		*--nodelist = ':';
	if (flags)
		*--flags = '=';
2194 2195
	if (!err)
		*mpol = new;
2196 2197 2198 2199
	return err;
}
#endif /* CONFIG_TMPFS */

2200 2201 2202 2203 2204 2205 2206
/**
 * 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
 *
2207 2208 2209 2210
 * Convert a mempolicy into a string.
 * Returns the number of characters in buffer (if positive)
 * or an error (negative)
 */
2211
int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol, int no_context)
2212 2213 2214 2215
{
	char *p = buffer;
	int l;
	nodemask_t nodes;
2216
	unsigned short mode;
2217
	unsigned short flags = pol ? pol->flags : 0;
2218

2219 2220 2221 2222 2223
	/*
	 * Sanity check:  room for longest mode, flag and some nodes
	 */
	VM_BUG_ON(maxlen < strlen("interleave") + strlen("relative") + 16);

2224 2225 2226 2227 2228
	if (!pol || pol == &default_policy)
		mode = MPOL_DEFAULT;
	else
		mode = pol->mode;

2229 2230 2231 2232 2233 2234 2235
	switch (mode) {
	case MPOL_DEFAULT:
		nodes_clear(nodes);
		break;

	case MPOL_PREFERRED:
		nodes_clear(nodes);
2236
		if (flags & MPOL_F_LOCAL)
2237 2238
			mode = MPOL_LOCAL;	/* pseudo-policy */
		else
2239
			node_set(pol->v.preferred_node, nodes);
2240 2241 2242
		break;

	case MPOL_BIND:
2243
		/* Fall through */
2244
	case MPOL_INTERLEAVE:
2245 2246 2247 2248
		if (no_context)
			nodes = pol->w.user_nodemask;
		else
			nodes = pol->v.nodes;
2249 2250 2251 2252 2253 2254 2255
		break;

	default:
		BUG();
	}

	l = strlen(policy_types[mode]);
2256 2257
	if (buffer + maxlen < p + l + 1)
		return -ENOSPC;
2258 2259 2260 2261

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

2262
	if (flags & MPOL_MODE_FLAGS) {
2263 2264 2265 2266
		if (buffer + maxlen < p + 2)
			return -ENOSPC;
		*p++ = '=';

2267 2268 2269
		/*
		 * Currently, the only defined flags are mutually exclusive
		 */
2270
		if (flags & MPOL_F_STATIC_NODES)
2271 2272 2273
			p += snprintf(p, buffer + maxlen - p, "static");
		else if (flags & MPOL_F_RELATIVE_NODES)
			p += snprintf(p, buffer + maxlen - p, "relative");
2274 2275
	}

2276 2277 2278
	if (!nodes_empty(nodes)) {
		if (buffer + maxlen < p + 2)
			return -ENOSPC;
2279
		*p++ = ':';
2280 2281 2282 2283 2284 2285 2286 2287
	 	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
2288 2289
	unsigned long active;
	unsigned long writeback;
2290
	unsigned long mapcount_max;
C
Christoph Lameter 已提交
2291 2292
	unsigned long dirty;
	unsigned long swapcache;
2293 2294 2295
	unsigned long node[MAX_NUMNODES];
};

C
Christoph Lameter 已提交
2296
static void gather_stats(struct page *page, void *private, int pte_dirty)
2297 2298 2299 2300
{
	struct numa_maps *md = private;
	int count = page_mapcount(page);

C
Christoph Lameter 已提交
2301 2302 2303
	md->pages++;
	if (pte_dirty || PageDirty(page))
		md->dirty++;
2304

C
Christoph Lameter 已提交
2305 2306
	if (PageSwapCache(page))
		md->swapcache++;
2307

L
Lee Schermerhorn 已提交
2308
	if (PageActive(page) || PageUnevictable(page))
C
Christoph Lameter 已提交
2309 2310 2311 2312
		md->active++;

	if (PageWriteback(page))
		md->writeback++;
2313 2314 2315 2316

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

C
Christoph Lameter 已提交
2317 2318 2319
	if (count > md->mapcount_max)
		md->mapcount_max = count;

2320 2321 2322
	md->node[page_to_nid(page)]++;
}

A
Andrew Morton 已提交
2323
#ifdef CONFIG_HUGETLB_PAGE
C
Christoph Lameter 已提交
2324 2325 2326 2327 2328 2329
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;
2330 2331
	struct hstate *h = hstate_vma(vma);
	unsigned long sz = huge_page_size(h);
C
Christoph Lameter 已提交
2332

2333 2334 2335
	for (addr = start; addr < end; addr += sz) {
		pte_t *ptep = huge_pte_offset(vma->vm_mm,
						addr & huge_page_mask(h));
C
Christoph Lameter 已提交
2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351
		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
Andrew Morton 已提交
2352 2353 2354 2355 2356 2357 2358
#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
2359

2360 2361 2362
/*
 * Display pages allocated per node and memory policy via /proc.
 */
2363 2364
int show_numa_map(struct seq_file *m, void *v)
{
2365
	struct proc_maps_private *priv = m->private;
2366 2367
	struct vm_area_struct *vma = v;
	struct numa_maps *md;
C
Christoph Lameter 已提交
2368 2369
	struct file *file = vma->vm_file;
	struct mm_struct *mm = vma->vm_mm;
2370
	struct mempolicy *pol;
2371 2372 2373
	int n;
	char buffer[50];

C
Christoph Lameter 已提交
2374
	if (!mm)
2375 2376 2377 2378 2379 2380
		return 0;

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

2381
	pol = get_vma_policy(priv->task, vma, vma->vm_start);
2382
	mpol_to_str(buffer, sizeof(buffer), pol, 0);
2383
	mpol_cond_put(pol);
C
Christoph Lameter 已提交
2384 2385 2386 2387 2388

	seq_printf(m, "%08lx %s", vma->vm_start, buffer);

	if (file) {
		seq_printf(m, " file=");
2389
		seq_path(m, &file->f_path, "\n\t= ");
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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 {
2401
		check_pgd_range(vma, vma->vm_start, vma->vm_end,
2402
			&node_states[N_HIGH_MEMORY], MPOL_MF_STATS, md);
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	}

	if (!md->pages)
		goto out;
2407

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2408 2409
	if (md->anon)
		seq_printf(m," anon=%lu",md->anon);
2410

C
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	if (md->dirty)
		seq_printf(m," dirty=%lu",md->dirty);
2413

C
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	if (md->pages != md->anon && md->pages != md->dirty)
		seq_printf(m, " mapped=%lu", md->pages);
2416

C
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	if (md->mapcount_max > 1)
		seq_printf(m, " mapmax=%lu", md->mapcount_max);
2419

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2420 2421 2422 2423 2424 2425 2426 2427 2428
	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);

2429
	for_each_node_state(n, N_HIGH_MEMORY)
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2430 2431 2432 2433
		if (md->node[n])
			seq_printf(m, " N%d=%lu", n, md->node[n]);
out:
	seq_putc(m, '\n');
2434 2435 2436
	kfree(md);

	if (m->count < m->size)
2437
		m->version = (vma != priv->tail_vma) ? vma->vm_start : 0;
2438 2439
	return 0;
}