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mempolicy.c
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mempolicy.c
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/*
* Simple NUMA memory policy for the Linux kernel.
*
* Copyright 2003,2004 Andi Kleen, SuSE Labs.
* (C) Copyright 2005 Christoph Lameter, Silicon Graphics, Inc.
* 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.
*
* bind Only allocate memory on a specific set of nodes,
* no fallback.
* 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
*
* 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.
*
* 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>
#include <linux/swap.h>
#include <linux/seq_file.h>
#include <linux/proc_fs.h>
#include <asm/tlbflush.h>
#include <asm/uaccess.h>
/* Internal flags */
#define MPOL_MF_DISCONTIG_OK (MPOL_MF_INTERNAL << 0) /* Skip checks for continuous vmas */
#define MPOL_MF_INVERT (MPOL_MF_INTERNAL << 1) /* Invert check for nodemask */
#define MPOL_MF_STATS (MPOL_MF_INTERNAL << 2) /* Gather statistics */
/* The number of pages to migrate per call to migrate_pages() */
#define MIGRATE_CHUNK_SIZE 256
static kmem_cache_t *policy_cache;
static kmem_cache_t *sn_cache;
#define PDprintk(fmt...)
/* Highest zone. An specific allocation for a zone below that is not
policied. */
int policy_zone = ZONE_DMA;
struct mempolicy default_policy = {
.refcnt = ATOMIC_INIT(1), /* never free it */
.policy = MPOL_DEFAULT,
};
/* Do sanity checking on a policy */
static int mpol_check_policy(int mode, nodemask_t *nodes)
{
int empty = nodes_empty(*nodes);
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;
}
return nodes_subset(*nodes, node_online_map) ? 0 : -EINVAL;
}
/* Generate a custom zonelist for the BIND policy. */
static struct zonelist *bind_zonelist(nodemask_t *nodes)
{
struct zonelist *zl;
int num, max, nd;
max = 1 + MAX_NR_ZONES * nodes_weight(*nodes);
zl = kmalloc(sizeof(void *) * max, GFP_KERNEL);
if (!zl)
return NULL;
num = 0;
for_each_node_mask(nd, *nodes)
zl->zones[num++] = &NODE_DATA(nd)->node_zones[policy_zone];
zl->zones[num] = NULL;
return zl;
}
/* Create a new policy */
static struct mempolicy *mpol_new(int mode, nodemask_t *nodes)
{
struct mempolicy *policy;
PDprintk("setting mode %d nodes[0] %lx\n", mode, nodes_addr(*nodes)[0]);
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:
policy->v.nodes = *nodes;
if (nodes_weight(*nodes) == 0) {
kmem_cache_free(policy_cache, policy);
return ERR_PTR(-EINVAL);
}
break;
case MPOL_PREFERRED:
policy->v.preferred_node = first_node(*nodes);
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;
policy->cpuset_mems_allowed = cpuset_mems_allowed(current);
return policy;
}
static void gather_stats(struct page *, void *);
static void migrate_page_add(struct page *page, struct list_head *pagelist,
unsigned long flags);
/* Scan through pages checking if pages follow certain conditions. */
static int check_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
unsigned long addr, unsigned long end,
const nodemask_t *nodes, unsigned long flags,
void *private)
{
pte_t *orig_pte;
pte_t *pte;
spinlock_t *ptl;
orig_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
do {
struct page *page;
unsigned int nid;
if (!pte_present(*pte))
continue;
page = vm_normal_page(vma, addr, *pte);
if (!page)
continue;
/*
* 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.
*/
if (PageReserved(page))
continue;
nid = page_to_nid(page);
if (node_isset(nid, *nodes) == !!(flags & MPOL_MF_INVERT))
continue;
if (flags & MPOL_MF_STATS)
gather_stats(page, private);
else if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
migrate_page_add(page, private, flags);
else
break;
} while (pte++, addr += PAGE_SIZE, addr != end);
pte_unmap_unlock(orig_pte, ptl);
return addr != end;
}
static inline int check_pmd_range(struct vm_area_struct *vma, pud_t *pud,
unsigned long addr, unsigned long end,
const nodemask_t *nodes, unsigned long flags,
void *private)
{
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;
if (check_pte_range(vma, pmd, addr, next, nodes,
flags, private))
return -EIO;
} while (pmd++, addr = next, addr != end);
return 0;
}
static inline int check_pud_range(struct vm_area_struct *vma, pgd_t *pgd,
unsigned long addr, unsigned long end,
const nodemask_t *nodes, unsigned long flags,
void *private)
{
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;
if (check_pmd_range(vma, pud, addr, next, nodes,
flags, private))
return -EIO;
} while (pud++, addr = next, addr != end);
return 0;
}
static inline int check_pgd_range(struct vm_area_struct *vma,
unsigned long addr, unsigned long end,
const nodemask_t *nodes, unsigned long flags,
void *private)
{
pgd_t *pgd;
unsigned long next;
pgd = pgd_offset(vma->vm_mm, addr);
do {
next = pgd_addr_end(addr, end);
if (pgd_none_or_clear_bad(pgd))
continue;
if (check_pud_range(vma, pgd, addr, next, nodes,
flags, private))
return -EIO;
} while (pgd++, addr = next, addr != end);
return 0;
}
/* Check if a vma is migratable */
static inline int vma_migratable(struct vm_area_struct *vma)
{
if (vma->vm_flags & (
VM_LOCKED|VM_IO|VM_HUGETLB|VM_PFNMAP|VM_RESERVED))
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.
*/
static struct vm_area_struct *
check_range(struct mm_struct *mm, unsigned long start, unsigned long end,
const nodemask_t *nodes, unsigned long flags, void *private)
{
int err;
struct vm_area_struct *first, *vma, *prev;
/* Clear the LRU lists so pages can be isolated */
if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
lru_add_drain_all();
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) {
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)))) {
unsigned long endvma = vma->vm_end;
if (endvma > end)
endvma = end;
if (vma->vm_start > start)
start = vma->vm_start;
err = check_pgd_range(vma, start, endvma, nodes,
flags, private);
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;
}
static int contextualize_policy(int mode, nodemask_t *nodes)
{
if (!nodes)
return 0;
cpuset_update_task_memory_state();
if (!cpuset_nodes_subset_current_mems_allowed(*nodes))
return -EINVAL;
return mpol_check_policy(mode, nodes);
}
/* Set the process memory policy */
long do_set_mempolicy(int mode, nodemask_t *nodes)
{
struct mempolicy *new;
if (contextualize_policy(mode, nodes))
return -EINVAL;
new = mpol_new(mode, nodes);
if (IS_ERR(new))
return PTR_ERR(new);
mpol_free(current->mempolicy);
current->mempolicy = new;
if (new && new->policy == MPOL_INTERLEAVE)
current->il_next = first_node(new->v.nodes);
return 0;
}
/* Fill a zone bitmap for a policy */
static void get_zonemask(struct mempolicy *p, nodemask_t *nodes)
{
int i;
nodes_clear(*nodes);
switch (p->policy) {
case MPOL_BIND:
for (i = 0; p->v.zonelist->zones[i]; i++)
node_set(p->v.zonelist->zones[i]->zone_pgdat->node_id,
*nodes);
break;
case MPOL_DEFAULT:
break;
case MPOL_INTERLEAVE:
*nodes = p->v.nodes;
break;
case MPOL_PREFERRED:
/* or use current node instead of online map? */
if (p->v.preferred_node < 0)
*nodes = node_online_map;
else
node_set(p->v.preferred_node, *nodes);
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 */
long do_get_mempolicy(int *policy, nodemask_t *nmask,
unsigned long addr, unsigned long flags)
{
int err;
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma = NULL;
struct mempolicy *pol = current->mempolicy;
cpuset_update_task_memory_state();
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;
*policy = err;
} else if (pol == current->mempolicy &&
pol->policy == MPOL_INTERLEAVE) {
*policy = current->il_next;
} else {
err = -EINVAL;
goto out;
}
} else
*policy = pol->policy;
if (vma) {
up_read(¤t->mm->mmap_sem);
vma = NULL;
}
err = 0;
if (nmask)
get_zonemask(pol, nmask);
out:
if (vma)
up_read(¤t->mm->mmap_sem);
return err;
}
/*
* page migration
*/
static void migrate_page_add(struct page *page, struct list_head *pagelist,
unsigned long flags)
{
/*
* Avoid migrating a page that is shared with others.
*/
if ((flags & MPOL_MF_MOVE_ALL) || page_mapcount(page) == 1) {
if (isolate_lru_page(page))
list_add(&page->lru, pagelist);
}
}
/*
* Migrate the list 'pagelist' of pages to a certain destination.
*
* Specify destination with either non-NULL vma or dest_node >= 0
* Return the number of pages not migrated or error code
*/
static int migrate_pages_to(struct list_head *pagelist,
struct vm_area_struct *vma, int dest)
{
LIST_HEAD(newlist);
LIST_HEAD(moved);
LIST_HEAD(failed);
int err = 0;
int nr_pages;
struct page *page;
struct list_head *p;
redo:
nr_pages = 0;
list_for_each(p, pagelist) {
if (vma)
page = alloc_page_vma(GFP_HIGHUSER, vma, vma->vm_start);
else
page = alloc_pages_node(dest, GFP_HIGHUSER, 0);
if (!page) {
err = -ENOMEM;
goto out;
}
list_add(&page->lru, &newlist);
nr_pages++;
if (nr_pages > MIGRATE_CHUNK_SIZE);
break;
}
err = migrate_pages(pagelist, &newlist, &moved, &failed);
putback_lru_pages(&moved); /* Call release pages instead ?? */
if (err >= 0 && list_empty(&newlist) && !list_empty(pagelist))
goto redo;
out:
/* Return leftover allocated pages */
while (!list_empty(&newlist)) {
page = list_entry(newlist.next, struct page, lru);
list_del(&page->lru);
__free_page(page);
}
list_splice(&failed, pagelist);
if (err < 0)
return err;
/* Calculate number of leftover pages */
nr_pages = 0;
list_for_each(p, pagelist)
nr_pages++;
return nr_pages;
}
/*
* 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);
check_range(mm, mm->mmap->vm_start, TASK_SIZE, &nmask,
flags | MPOL_MF_DISCONTIG_OK, &pagelist);
if (!list_empty(&pagelist)) {
err = migrate_pages_to(&pagelist, NULL, dest);
if (!list_empty(&pagelist))
putback_lru_pages(&pagelist);
}
return err;
}
/*
* Move pages between the two nodesets so as to preserve the physical
* layout as much as possible.
*
* 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);
int busy = 0;
int err = 0;
nodemask_t tmp;
down_read(&mm->mmap_sem);
/*
* 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.
*/
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;
}
up_read(&mm->mmap_sem);
if (err < 0)
return err;
return busy;
}
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;
if ((flags & MPOL_MF_MOVE_ALL) && !capable(CAP_SYS_RESOURCE))
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);
if (!list_empty(&pagelist))
nr_failed = migrate_pages_to(&pagelist, vma, -1);
if (!err && nr_failed && (flags & MPOL_MF_STRICT))
err = -EIO;
}
if (!list_empty(&pagelist))
putback_lru_pages(&pagelist);
up_write(&mm->mmap_sem);
mpol_free(new);
return err;
}
/*
* User space interface with variable sized bitmaps for nodelists.
*/
/* Copy a node mask from user space. */
static int get_nodes(nodemask_t *nodes, const unsigned long __user *nmask,
unsigned long maxnode)
{
unsigned long k;
unsigned long nlongs;
unsigned long endmask;
--maxnode;
nodes_clear(*nodes);
if (maxnode == 0 || !nmask)
return 0;
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);
}
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
* capabilities, superuser priviledges or the same
* userid as the target process.
*/
if ((current->euid != task->suid) && (current->euid != task->uid) &&
(current->uid != task->suid) && (current->uid != task->uid) &&
!capable(CAP_SYS_ADMIN)) {
err = -EPERM;
goto out;
}
task_nodes = cpuset_mems_allowed(task);
/* Is the user allowed to access the target nodes? */
if (!nodes_subset(new, task_nodes) && !capable(CAP_SYS_ADMIN)) {
err = -EPERM;
goto out;
}
err = do_migrate_pages(mm, &old, &new, MPOL_MF_MOVE);
out:
mmput(mm);
return err;
}
/* 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;
}
#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);