mempolicy.c 47.0 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.
   could replace all the switch()es with a mempolicy_ops structure.
*/

#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/mm.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>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/compat.h>
#include <linux/mempolicy.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 <asm/tlbflush.h>
#include <asm/uaccess.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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#define PDprintk(fmt...)

/* Highest zone. An specific allocation for a zone below that is not
   policied. */
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enum zone_type policy_zone = ZONE_DMA;
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struct mempolicy default_policy = {
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	.refcnt = ATOMIC_INIT(1), /* never free it */
	.policy = MPOL_DEFAULT,
};

/* Do sanity checking on a policy */
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static int mpol_check_policy(int mode, nodemask_t *nodes)
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{
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	int empty = nodes_empty(*nodes);
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	switch (mode) {
	case MPOL_DEFAULT:
		if (!empty)
			return -EINVAL;
		break;
	case MPOL_BIND:
	case MPOL_INTERLEAVE:
		/* Preferred will only use the first bit, but allow
		   more for now. */
		if (empty)
			return -EINVAL;
		break;
	}
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	return nodes_subset(*nodes, node_online_map) ? 0 : -EINVAL;
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}
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/* Generate a custom zonelist for the BIND policy. */
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static struct zonelist *bind_zonelist(nodemask_t *nodes)
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{
	struct zonelist *zl;
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	int num, max, nd;
	enum zone_type k;
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	max = 1 + MAX_NR_ZONES * nodes_weight(*nodes);
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	zl = kmalloc(sizeof(struct zone *) * max, GFP_KERNEL);
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	if (!zl)
		return NULL;
	num = 0;
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	/* First put in the highest zones from all nodes, then all the next 
	   lower zones etc. Avoid empty zones because the memory allocator
	   doesn't like them. If you implement node hot removal you
	   have to fix that. */
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	k = policy_zone;
	while (1) {
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		for_each_node_mask(nd, *nodes) { 
			struct zone *z = &NODE_DATA(nd)->node_zones[k];
			if (z->present_pages > 0) 
				zl->zones[num++] = z;
		}
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		if (k == 0)
			break;
		k--;
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	}
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	zl->zones[num] = NULL;
	return zl;
}

/* Create a new policy */
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static struct mempolicy *mpol_new(int mode, nodemask_t *nodes)
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{
	struct mempolicy *policy;

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	PDprintk("setting mode %d nodes[0] %lx\n", mode, nodes_addr(*nodes)[0]);
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	if (mode == MPOL_DEFAULT)
		return NULL;
	policy = kmem_cache_alloc(policy_cache, GFP_KERNEL);
	if (!policy)
		return ERR_PTR(-ENOMEM);
	atomic_set(&policy->refcnt, 1);
	switch (mode) {
	case MPOL_INTERLEAVE:
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		policy->v.nodes = *nodes;
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		if (nodes_weight(*nodes) == 0) {
			kmem_cache_free(policy_cache, policy);
			return ERR_PTR(-EINVAL);
		}
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		break;
	case MPOL_PREFERRED:
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		policy->v.preferred_node = first_node(*nodes);
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		if (policy->v.preferred_node >= MAX_NUMNODES)
			policy->v.preferred_node = -1;
		break;
	case MPOL_BIND:
		policy->v.zonelist = bind_zonelist(nodes);
		if (policy->v.zonelist == NULL) {
			kmem_cache_free(policy_cache, policy);
			return ERR_PTR(-ENOMEM);
		}
		break;
	}
	policy->policy = mode;
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	policy->cpuset_mems_allowed = cpuset_mems_allowed(current);
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	return policy;
}

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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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		unsigned int nid;

		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 a vma is migratable */
static inline int vma_migratable(struct vm_area_struct *vma)
{
	if (vma->vm_flags & (
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		VM_LOCKED|VM_IO|VM_HUGETLB|VM_PFNMAP|VM_RESERVED))
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		return 0;
	return 1;
}

/*
 * 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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	if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) {

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		err = migrate_prep();
		if (err)
			return ERR_PTR(err);
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	}
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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;

	PDprintk("vma %lx-%lx/%lx vm_ops %p vm_file %p set_policy %p\n",
		 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;
		mpol_free(old);
	}
	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;
}

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static int contextualize_policy(int mode, nodemask_t *nodes)
{
	if (!nodes)
		return 0;

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	cpuset_update_task_memory_state();
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	if (!cpuset_nodes_subset_current_mems_allowed(*nodes))
		return -EINVAL;
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	return mpol_check_policy(mode, nodes);
}

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/*
 * 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);
}

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/* Set the process memory policy */
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long do_set_mempolicy(int mode, nodemask_t *nodes)
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{
	struct mempolicy *new;

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	if (contextualize_policy(mode, nodes))
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		return -EINVAL;
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	new = mpol_new(mode, nodes);
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	if (IS_ERR(new))
		return PTR_ERR(new);
	mpol_free(current->mempolicy);
	current->mempolicy = new;
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	mpol_set_task_struct_flag();
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	if (new && new->policy == MPOL_INTERLEAVE)
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		current->il_next = first_node(new->v.nodes);
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	return 0;
}

/* Fill a zone bitmap for a policy */
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static void get_zonemask(struct mempolicy *p, nodemask_t *nodes)
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{
	int i;

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	nodes_clear(*nodes);
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	switch (p->policy) {
	case MPOL_BIND:
		for (i = 0; p->v.zonelist->zones[i]; i++)
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			node_set(zone_to_nid(p->v.zonelist->zones[i]),
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				*nodes);
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		break;
	case MPOL_DEFAULT:
		break;
	case MPOL_INTERLEAVE:
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		*nodes = p->v.nodes;
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		break;
	case MPOL_PREFERRED:
		/* or use current node instead of online map? */
		if (p->v.preferred_node < 0)
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			*nodes = node_online_map;
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		else
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			node_set(p->v.preferred_node, *nodes);
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		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 */
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long do_get_mempolicy(int *policy, nodemask_t *nmask,
			unsigned long addr, unsigned long flags)
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{
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	int err;
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	struct mm_struct *mm = current->mm;
	struct vm_area_struct *vma = NULL;
	struct mempolicy *pol = current->mempolicy;

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	cpuset_update_task_memory_state();
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	if (flags & ~(unsigned long)(MPOL_F_NODE|MPOL_F_ADDR))
		return -EINVAL;
	if (flags & MPOL_F_ADDR) {
		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)
		pol = &default_policy;

	if (flags & MPOL_F_NODE) {
		if (flags & MPOL_F_ADDR) {
			err = lookup_node(mm, addr);
			if (err < 0)
				goto out;
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			*policy = err;
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		} else if (pol == current->mempolicy &&
				pol->policy == MPOL_INTERLEAVE) {
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			*policy = current->il_next;
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		} else {
			err = -EINVAL;
			goto out;
		}
	} else
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		*policy = pol->policy;
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	if (vma) {
		up_read(&current->mm->mmap_sem);
		vma = NULL;
	}

	err = 0;
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	if (nmask)
		get_zonemask(pol, nmask);
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 out:
	if (vma)
		up_read(&current->mm->mmap_sem);
	return err;
}

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#ifdef CONFIG_MIGRATION
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/*
 * page migration
 */
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static void migrate_page_add(struct page *page, struct list_head *pagelist,
				unsigned long flags)
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{
	/*
591
	 * Avoid migrating a page that is shared with others.
592
	 */
C
Christoph Lameter 已提交
593 594
	if ((flags & MPOL_MF_MOVE_ALL) || page_mapcount(page) == 1)
		isolate_lru_page(page, pagelist);
595
}
596

597
static struct page *new_node_page(struct page *page, unsigned long node, int **x)
598 599 600 601
{
	return alloc_pages_node(node, GFP_HIGHUSER, 0);
}

602 603 604 605 606 607 608 609 610 611 612 613
/*
 * Migrate pages from one node to a target node.
 * Returns error or the number of pages not migrated.
 */
int migrate_to_node(struct mm_struct *mm, int source, int dest, int flags)
{
	nodemask_t nmask;
	LIST_HEAD(pagelist);
	int err = 0;

	nodes_clear(nmask);
	node_set(source, nmask);
614

615 616 617
	check_range(mm, mm->mmap->vm_start, TASK_SIZE, &nmask,
			flags | MPOL_MF_DISCONTIG_OK, &pagelist);

618
	if (!list_empty(&pagelist))
619 620
		err = migrate_pages(&pagelist, new_node_page, dest);

621
	return err;
622 623
}

624
/*
625 626
 * Move pages between the two nodesets so as to preserve the physical
 * layout as much as possible.
627 628 629 630 631 632 633
 *
 * 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)
{
	LIST_HEAD(pagelist);
634 635 636
	int busy = 0;
	int err = 0;
	nodemask_t tmp;
637

638
  	down_read(&mm->mmap_sem);
639

640 641 642 643
	err = migrate_vmas(mm, from_nodes, to_nodes, flags);
	if (err)
		goto out;

644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673
/*
 * 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.
 */
674

675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701
	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;
702
	}
703
out:
704
	up_read(&mm->mmap_sem);
705 706 707
	if (err < 0)
		return err;
	return busy;
C
Christoph Lameter 已提交
708 709 710

}

711
static struct page *new_vma_page(struct page *page, unsigned long private, int **x)
712 713 714 715 716
{
	struct vm_area_struct *vma = (struct vm_area_struct *)private;

	return alloc_page_vma(GFP_HIGHUSER, vma, page_address_in_vma(page, vma));
}
C
Christoph Lameter 已提交
717 718 719 720 721
#else

static void migrate_page_add(struct page *page, struct list_head *pagelist,
				unsigned long flags)
{
722 723
}

C
Christoph Lameter 已提交
724 725 726 727 728
int do_migrate_pages(struct mm_struct *mm,
	const nodemask_t *from_nodes, const nodemask_t *to_nodes, int flags)
{
	return -ENOSYS;
}
729

730
static struct page *new_vma_page(struct page *page, unsigned long private, int **x)
731 732 733
{
	return NULL;
}
C
Christoph Lameter 已提交
734 735
#endif

736 737 738 739 740 741 742 743 744 745 746 747 748 749
long do_mbind(unsigned long start, unsigned long len,
		unsigned long mode, nodemask_t *nmask, unsigned long flags)
{
	struct vm_area_struct *vma;
	struct mm_struct *mm = current->mm;
	struct mempolicy *new;
	unsigned long end;
	int err;
	LIST_HEAD(pagelist);

	if ((flags & ~(unsigned long)(MPOL_MF_STRICT |
				      MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
	    || mode > MPOL_MAX)
		return -EINVAL;
750
	if ((flags & MPOL_MF_MOVE_ALL) && !capable(CAP_SYS_NICE))
751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792
		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;

	if (mpol_check_policy(mode, nmask))
		return -EINVAL;

	new = mpol_new(mode, nmask);
	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;

	PDprintk("mbind %lx-%lx mode:%ld nodes:%lx\n",start,start+len,
			mode,nodes_addr(nodes)[0]);

	down_write(&mm->mmap_sem);
	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);
793

794
		if (!list_empty(&pagelist))
795 796
			nr_failed = migrate_pages(&pagelist, new_vma_page,
						(unsigned long)vma);
797 798 799 800

		if (!err && nr_failed && (flags & MPOL_MF_STRICT))
			err = -EIO;
	}
C
Christoph Lameter 已提交
801

802 803 804 805 806
	up_write(&mm->mmap_sem);
	mpol_free(new);
	return err;
}

807 808 809 810 811
/*
 * User space interface with variable sized bitmaps for nodelists.
 */

/* Copy a node mask from user space. */
812
static int get_nodes(nodemask_t *nodes, const unsigned long __user *nmask,
813 814 815 816 817 818 819 820 821 822
		     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
823
	if (maxnode > PAGE_SIZE*BITS_PER_BYTE)
C
Chris Wright 已提交
824
		return -EINVAL;
825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902

	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;
}

asmlinkage long sys_mbind(unsigned long start, unsigned long len,
			unsigned long mode,
			unsigned long __user *nmask, unsigned long maxnode,
			unsigned flags)
{
	nodemask_t nodes;
	int err;

	err = get_nodes(&nodes, nmask, maxnode);
	if (err)
		return err;
	return do_mbind(start, len, mode, &nodes, flags);
}

/* Set the process memory policy */
asmlinkage long sys_set_mempolicy(int mode, unsigned long __user *nmask,
		unsigned long maxnode)
{
	int err;
	nodemask_t nodes;

	if (mode < 0 || mode > MPOL_MAX)
		return -EINVAL;
	err = get_nodes(&nodes, nmask, maxnode);
	if (err)
		return err;
	return do_set_mempolicy(mode, &nodes);
}

903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937
asmlinkage long sys_migrate_pages(pid_t pid, unsigned long maxnode,
		const unsigned long __user *old_nodes,
		const unsigned long __user *new_nodes)
{
	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);
	task = pid ? find_task_by_pid(pid) : current;
	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
938
	 * capabilities, superuser privileges or the same
939 940 941 942
	 * userid as the target process.
	 */
	if ((current->euid != task->suid) && (current->euid != task->uid) &&
	    (current->uid != task->suid) && (current->uid != task->uid) &&
943
	    !capable(CAP_SYS_NICE)) {
944 945 946 947 948 949
		err = -EPERM;
		goto out;
	}

	task_nodes = cpuset_mems_allowed(task);
	/* Is the user allowed to access the target nodes? */
950
	if (!nodes_subset(new, task_nodes) && !capable(CAP_SYS_NICE)) {
951 952 953 954
		err = -EPERM;
		goto out;
	}

955 956 957 958
	err = security_task_movememory(task);
	if (err)
		goto out;

959
	err = do_migrate_pages(mm, &old, &new,
960
		capable(CAP_SYS_NICE) ? MPOL_MF_MOVE_ALL : MPOL_MF_MOVE);
961 962 963 964 965 966
out:
	mmput(mm);
	return err;
}


967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992
/* Retrieve NUMA policy */
asmlinkage long sys_get_mempolicy(int __user *policy,
				unsigned long __user *nmask,
				unsigned long maxnode,
				unsigned long addr, unsigned long flags)
{
	int err, pval;
	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
993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052
#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;
1053
	nodemask_t bm;
L
Linus Torvalds 已提交
1054 1055 1056 1057 1058

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

	if (nmask) {
1059
		err = compat_get_bitmap(nodes_addr(bm), nmask, nr_bits);
L
Linus Torvalds 已提交
1060
		nm = compat_alloc_user_space(alloc_size);
1061
		err |= copy_to_user(nm, nodes_addr(bm), alloc_size);
L
Linus Torvalds 已提交
1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072
	}

	if (err)
		return -EFAULT;

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

#endif

/* Return effective policy for a VMA */
1073 1074
static struct mempolicy * get_vma_policy(struct task_struct *task,
		struct vm_area_struct *vma, unsigned long addr)
L
Linus Torvalds 已提交
1075
{
1076
	struct mempolicy *pol = task->mempolicy;
L
Linus Torvalds 已提交
1077 1078 1079

	if (vma) {
		if (vma->vm_ops && vma->vm_ops->get_policy)
1080
			pol = vma->vm_ops->get_policy(vma, addr);
L
Linus Torvalds 已提交
1081 1082 1083 1084 1085 1086 1087 1088 1089 1090
		else if (vma->vm_policy &&
				vma->vm_policy->policy != MPOL_DEFAULT)
			pol = vma->vm_policy;
	}
	if (!pol)
		pol = &default_policy;
	return pol;
}

/* Return a zonelist representing a mempolicy */
A
Al Viro 已提交
1091
static struct zonelist *zonelist_policy(gfp_t gfp, struct mempolicy *policy)
L
Linus Torvalds 已提交
1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103
{
	int nd;

	switch (policy->policy) {
	case MPOL_PREFERRED:
		nd = policy->v.preferred_node;
		if (nd < 0)
			nd = numa_node_id();
		break;
	case MPOL_BIND:
		/* Lower zones don't get a policy applied */
		/* Careful: current->mems_allowed might have moved */
1104
		if (gfp_zone(gfp) >= policy_zone)
L
Linus Torvalds 已提交
1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115
			if (cpuset_zonelist_valid_mems_allowed(policy->v.zonelist))
				return policy->v.zonelist;
		/*FALL THROUGH*/
	case MPOL_INTERLEAVE: /* should not happen */
	case MPOL_DEFAULT:
		nd = numa_node_id();
		break;
	default:
		nd = 0;
		BUG();
	}
A
Al Viro 已提交
1116
	return NODE_DATA(nd)->node_zonelists + gfp_zone(gfp);
L
Linus Torvalds 已提交
1117 1118 1119 1120 1121 1122 1123 1124 1125
}

/* 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;
1126
	next = next_node(nid, policy->v.nodes);
L
Linus Torvalds 已提交
1127
	if (next >= MAX_NUMNODES)
1128
		next = first_node(policy->v.nodes);
L
Linus Torvalds 已提交
1129 1130 1131 1132
	me->il_next = next;
	return nid;
}

1133 1134 1135 1136 1137 1138
/*
 * Depending on the memory policy provide a node from which to allocate the
 * next slab entry.
 */
unsigned slab_node(struct mempolicy *policy)
{
1139 1140 1141
	int pol = policy ? policy->policy : MPOL_DEFAULT;

	switch (pol) {
1142 1143 1144 1145 1146 1147 1148 1149
	case MPOL_INTERLEAVE:
		return interleave_nodes(policy);

	case MPOL_BIND:
		/*
		 * Follow bind policy behavior and start allocation at the
		 * first node.
		 */
1150
		return zone_to_nid(policy->v.zonelist->zones[0]);
1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161

	case MPOL_PREFERRED:
		if (policy->v.preferred_node >= 0)
			return policy->v.preferred_node;
		/* Fall through */

	default:
		return numa_node_id();
	}
}

L
Linus Torvalds 已提交
1162 1163 1164 1165
/* 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)
{
1166
	unsigned nnodes = nodes_weight(pol->v.nodes);
L
Linus Torvalds 已提交
1167 1168 1169 1170 1171 1172
	unsigned target = (unsigned)off % nnodes;
	int c;
	int nid = -1;

	c = 0;
	do {
1173
		nid = next_node(nid, pol->v.nodes);
L
Linus Torvalds 已提交
1174 1175 1176 1177 1178
		c++;
	} while (c <= target);
	return nid;
}

1179 1180 1181 1182 1183 1184 1185
/* 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;

1186 1187 1188 1189 1190 1191 1192 1193 1194
		/*
		 * 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);
1195 1196 1197 1198 1199 1200
		off += (addr - vma->vm_start) >> shift;
		return offset_il_node(pol, vma, off);
	} else
		return interleave_nodes(pol);
}

1201
#ifdef CONFIG_HUGETLBFS
1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214
/* Return a zonelist suitable for a huge page allocation. */
struct zonelist *huge_zonelist(struct vm_area_struct *vma, unsigned long addr)
{
	struct mempolicy *pol = get_vma_policy(current, vma, addr);

	if (pol->policy == MPOL_INTERLEAVE) {
		unsigned nid;

		nid = interleave_nid(pol, vma, addr, HPAGE_SHIFT);
		return NODE_DATA(nid)->node_zonelists + gfp_zone(GFP_HIGHUSER);
	}
	return zonelist_policy(GFP_HIGHUSER, pol);
}
1215
#endif
1216

L
Linus Torvalds 已提交
1217 1218
/* Allocate a page in interleaved policy.
   Own path because it needs to do special accounting. */
1219 1220
static struct page *alloc_page_interleave(gfp_t gfp, unsigned order,
					unsigned nid)
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{
	struct zonelist *zl;
	struct page *page;

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	zl = NODE_DATA(nid)->node_zonelists + gfp_zone(gfp);
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	page = __alloc_pages(gfp, order, zl);
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	if (page && page_zone(page) == zl->zones[0])
		inc_zone_page_state(page, NUMA_INTERLEAVE_HIT);
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	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 *
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alloc_page_vma(gfp_t gfp, struct vm_area_struct *vma, unsigned long addr)
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{
1257
	struct mempolicy *pol = get_vma_policy(current, vma, addr);
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	cpuset_update_task_memory_state();
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	if (unlikely(pol->policy == MPOL_INTERLEAVE)) {
		unsigned nid;
1263 1264

		nid = interleave_nid(pol, vma, addr, PAGE_SHIFT);
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		return alloc_page_interleave(gfp, 0, nid);
	}
	return __alloc_pages(gfp, 0, zonelist_policy(gfp, pol));
}

/**
 * 	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.
 *
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 *	Don't call cpuset_update_task_memory_state() unless
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 *	1) it's ok to take cpuset_sem (can WAIT), and
 *	2) allocating for current task (not interrupt).
 */
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struct page *alloc_pages_current(gfp_t gfp, unsigned order)
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{
	struct mempolicy *pol = current->mempolicy;

	if ((gfp & __GFP_WAIT) && !in_interrupt())
1294
		cpuset_update_task_memory_state();
1295
	if (!pol || in_interrupt() || (gfp & __GFP_THISNODE))
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		pol = &default_policy;
	if (pol->policy == MPOL_INTERLEAVE)
		return alloc_page_interleave(gfp, order, interleave_nodes(pol));
	return __alloc_pages(gfp, order, zonelist_policy(gfp, pol));
}
EXPORT_SYMBOL(alloc_pages_current);

1303 1304 1305 1306 1307 1308 1309 1310 1311
/*
 * If mpol_copy() sees current->cpuset == cpuset_being_rebound, then it
 * 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().
 */
void *cpuset_being_rebound;

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/* Slow path of a mempolicy copy */
struct mempolicy *__mpol_copy(struct mempolicy *old)
{
	struct mempolicy *new = kmem_cache_alloc(policy_cache, GFP_KERNEL);

	if (!new)
		return ERR_PTR(-ENOMEM);
1319 1320 1321 1322
	if (current_cpuset_is_being_rebound()) {
		nodemask_t mems = cpuset_mems_allowed(current);
		mpol_rebind_policy(old, &mems);
	}
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	*new = *old;
	atomic_set(&new->refcnt, 1);
	if (new->policy == MPOL_BIND) {
		int sz = ksize(old->v.zonelist);
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		new->v.zonelist = kmemdup(old->v.zonelist, sz, SLAB_KERNEL);
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		if (!new->v.zonelist) {
			kmem_cache_free(policy_cache, new);
			return ERR_PTR(-ENOMEM);
		}
	}
	return new;
}

/* Slow path of a mempolicy comparison */
int __mpol_equal(struct mempolicy *a, struct mempolicy *b)
{
	if (!a || !b)
		return 0;
	if (a->policy != b->policy)
		return 0;
	switch (a->policy) {
	case MPOL_DEFAULT:
		return 1;
	case MPOL_INTERLEAVE:
1347
		return nodes_equal(a->v.nodes, b->v.nodes);
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	case MPOL_PREFERRED:
		return a->v.preferred_node == b->v.preferred_node;
	case MPOL_BIND: {
		int i;
		for (i = 0; a->v.zonelist->zones[i]; i++)
			if (a->v.zonelist->zones[i] != b->v.zonelist->zones[i])
				return 0;
		return b->v.zonelist->zones[i] == NULL;
	}
	default:
		BUG();
		return 0;
	}
}

/* Slow path of a mpol destructor. */
void __mpol_free(struct mempolicy *p)
{
	if (!atomic_dec_and_test(&p->refcnt))
		return;
	if (p->policy == MPOL_BIND)
		kfree(p->v.zonelist);
	p->policy = MPOL_DEFAULT;
	kmem_cache_free(policy_cache, p);
}

/*
 * 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);
	PDprintk("inserting %lx-%lx: %d\n", new->start, new->end,
		 new->policy ? new->policy->policy : 0);
}

/* 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)
{
	PDprintk("deleting %lx-l%x\n", n->start, n->end);
	rb_erase(&n->nd, &sp->root);
	mpol_free(n->policy);
	kmem_cache_free(sn_cache, n);
}

struct sp_node *
sp_alloc(unsigned long start, unsigned long end, struct mempolicy *pol)
{
	struct sp_node *n = kmem_cache_alloc(sn_cache, GFP_KERNEL);

	if (!n)
		return NULL;
	n->start = start;
	n->end = end;
	mpol_get(pol);
	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) {
		mpol_free(new2->policy);
		kmem_cache_free(sn_cache, new2);
	}
	return 0;
}

1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551
void mpol_shared_policy_init(struct shared_policy *info, int policy,
				nodemask_t *policy_nodes)
{
	info->root = RB_ROOT;
	spin_lock_init(&info->lock);

	if (policy != MPOL_DEFAULT) {
		struct mempolicy *newpol;

		/* Falls back to MPOL_DEFAULT on any error */
		newpol = mpol_new(policy, policy_nodes);
		if (!IS_ERR(newpol)) {
			/* Create pseudo-vma that contains just the policy */
			struct vm_area_struct pvma;

			memset(&pvma, 0, sizeof(struct vm_area_struct));
			/* Policy covers entire file */
			pvma.vm_end = TASK_SIZE;
			mpol_set_shared_policy(info, &pvma, newpol);
			mpol_free(newpol);
		}
	}
}

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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);

	PDprintk("set_shared_policy %lx sz %lu %d %lx\n",
		 vma->vm_pgoff,
		 sz, npol? npol->policy : -1,
1562
		npol ? nodes_addr(npol->v.nodes)[0] : -1);
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	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);
1588
		rb_erase(&n->nd, &p->root);
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		mpol_free(n->policy);
		kmem_cache_free(sn_cache, n);
	}
	spin_unlock(&p->lock);
}

/* assumes fs == KERNEL_DS */
void __init numa_policy_init(void)
{
	policy_cache = kmem_cache_create("numa_policy",
					 sizeof(struct mempolicy),
					 0, SLAB_PANIC, NULL, NULL);

	sn_cache = kmem_cache_create("shared_policy_node",
				     sizeof(struct sp_node),
				     0, SLAB_PANIC, NULL, NULL);

	/* Set interleaving policy for system init. This way not all
	   the data structures allocated at system boot end up in node zero. */

1609
	if (do_set_mempolicy(MPOL_INTERLEAVE, &node_online_map))
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		printk("numa_policy_init: interleaving failed\n");
}

1613
/* Reset policy of current process to default */
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void numa_default_policy(void)
{
1616
	do_set_mempolicy(MPOL_DEFAULT, NULL);
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}
1618 1619

/* Migrate a policy to a different set of nodes */
1620
void mpol_rebind_policy(struct mempolicy *pol, const nodemask_t *newmask)
1621
{
1622
	nodemask_t *mpolmask;
1623 1624 1625 1626
	nodemask_t tmp;

	if (!pol)
		return;
1627 1628 1629
	mpolmask = &pol->cpuset_mems_allowed;
	if (nodes_equal(*mpolmask, *newmask))
		return;
1630 1631 1632 1633 1634

	switch (pol->policy) {
	case MPOL_DEFAULT:
		break;
	case MPOL_INTERLEAVE:
1635
		nodes_remap(tmp, pol->v.nodes, *mpolmask, *newmask);
1636
		pol->v.nodes = tmp;
1637 1638 1639
		*mpolmask = *newmask;
		current->il_next = node_remap(current->il_next,
						*mpolmask, *newmask);
1640 1641 1642
		break;
	case MPOL_PREFERRED:
		pol->v.preferred_node = node_remap(pol->v.preferred_node,
1643 1644
						*mpolmask, *newmask);
		*mpolmask = *newmask;
1645 1646 1647 1648 1649 1650 1651 1652
		break;
	case MPOL_BIND: {
		nodemask_t nodes;
		struct zone **z;
		struct zonelist *zonelist;

		nodes_clear(nodes);
		for (z = pol->v.zonelist->zones; *z; z++)
1653
			node_set(zone_to_nid(*z), nodes);
1654
		nodes_remap(tmp, nodes, *mpolmask, *newmask);
1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668
		nodes = tmp;

		zonelist = bind_zonelist(&nodes);

		/* If no mem, then zonelist is NULL and we keep old zonelist.
		 * If that old zonelist has no remaining mems_allowed nodes,
		 * then zonelist_policy() will "FALL THROUGH" to MPOL_DEFAULT.
		 */

		if (zonelist) {
			/* Good - got mem - substitute new zonelist */
			kfree(pol->v.zonelist);
			pol->v.zonelist = zonelist;
		}
1669
		*mpolmask = *newmask;
1670 1671 1672 1673 1674 1675 1676 1677 1678
		break;
	}
	default:
		BUG();
		break;
	}
}

/*
1679 1680
 * Wrapper for mpol_rebind_policy() that just requires task
 * pointer, and updates task mempolicy.
1681
 */
1682 1683

void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new)
1684
{
1685
	mpol_rebind_policy(tsk->mempolicy, new);
1686
}
1687

1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703
/*
 * 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);
}

1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764
/*
 * Display pages allocated per node and memory policy via /proc.
 */

static const char *policy_types[] = { "default", "prefer", "bind",
				      "interleave" };

/*
 * Convert a mempolicy into a string.
 * Returns the number of characters in buffer (if positive)
 * or an error (negative)
 */
static inline int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol)
{
	char *p = buffer;
	int l;
	nodemask_t nodes;
	int mode = pol ? pol->policy : MPOL_DEFAULT;

	switch (mode) {
	case MPOL_DEFAULT:
		nodes_clear(nodes);
		break;

	case MPOL_PREFERRED:
		nodes_clear(nodes);
		node_set(pol->v.preferred_node, nodes);
		break;

	case MPOL_BIND:
		get_zonemask(pol, &nodes);
		break;

	case MPOL_INTERLEAVE:
		nodes = pol->v.nodes;
		break;

	default:
		BUG();
		return -EFAULT;
	}

	l = strlen(policy_types[mode]);
 	if (buffer + maxlen < p + l + 1)
 		return -ENOSPC;

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

	if (!nodes_empty(nodes)) {
		if (buffer + maxlen < p + 2)
			return -ENOSPC;
		*p++ = '=';
	 	p += nodelist_scnprintf(p, buffer + maxlen - p, nodes);
	}
	return p - buffer;
}

struct numa_maps {
	unsigned long pages;
	unsigned long anon;
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	unsigned long active;
	unsigned long writeback;
1767
	unsigned long mapcount_max;
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	unsigned long dirty;
	unsigned long swapcache;
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	unsigned long node[MAX_NUMNODES];
};

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static void gather_stats(struct page *page, void *private, int pte_dirty)
1774 1775 1776 1777
{
	struct numa_maps *md = private;
	int count = page_mapcount(page);

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	md->pages++;
	if (pte_dirty || PageDirty(page))
		md->dirty++;
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	if (PageSwapCache(page))
		md->swapcache++;
1784

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	if (PageActive(page))
		md->active++;

	if (PageWriteback(page))
		md->writeback++;
1790 1791 1792 1793

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

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	if (count > md->mapcount_max)
		md->mapcount_max = count;

1797 1798 1799
	md->node[page_to_nid(page)]++;
}

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#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;

	for (addr = start; addr < end; addr += HPAGE_SIZE) {
		pte_t *ptep = huge_pte_offset(vma->vm_mm, addr & HPAGE_MASK);
		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));
	}
}
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#else
static inline void check_huge_range(struct vm_area_struct *vma,
		unsigned long start, unsigned long end,
		struct numa_maps *md)
{
}
#endif
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int show_numa_map(struct seq_file *m, void *v)
{
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	struct proc_maps_private *priv = m->private;
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	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;
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	int n;
	char buffer[50];

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	if (!mm)
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		return 0;

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

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	mpol_to_str(buffer, sizeof(buffer),
1852
			    get_vma_policy(priv->task, vma, vma->vm_start));
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	seq_printf(m, "%08lx %s", vma->vm_start, buffer);

	if (file) {
		seq_printf(m, " file=");
		seq_path(m, file->f_vfsmnt, file->f_dentry, "\n\t= ");
	} 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 {
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		check_pgd_range(vma, vma->vm_start, vma->vm_end,
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				&node_online_map, MPOL_MF_STATS, md);
	}

	if (!md->pages)
		goto out;
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	if (md->anon)
		seq_printf(m," anon=%lu",md->anon);
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	if (md->dirty)
		seq_printf(m," dirty=%lu",md->dirty);
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	if (md->pages != md->anon && md->pages != md->dirty)
		seq_printf(m, " mapped=%lu", md->pages);
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	if (md->mapcount_max > 1)
		seq_printf(m, " mapmax=%lu", md->mapcount_max);
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	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);

	for_each_online_node(n)
		if (md->node[n])
			seq_printf(m, " N%d=%lu", n, md->node[n]);
out:
	seq_putc(m, '\n');
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	kfree(md);

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