linux/mm/mempolicy.c
Christoph Lameter 6e21c8f145 [PATCH] /proc/<pid>/numa_maps to show on which nodes pages reside
This patch was recently discussed on linux-mm:
http://marc.theaimsgroup.com/?t=112085728500002&r=1&w=2

I inherited a large code base from Ray for page migration.  There was a
small patch in there that I find to be very useful since it allows the
display of the locality of the pages in use by a process.  I reworked that
patch and came up with a /proc/<pid>/numa_maps that gives more information
about the vma's of a process.  numa_maps is indexes by the start address
found in /proc/<pid>/maps.  F.e.  with this patch you can see the page use
of the "getty" process:

margin:/proc/12008 # cat maps
00000000-00004000 r--p 00000000 00:00 0
2000000000000000-200000000002c000 r-xp 00000000 08:04 516                /lib/ld-2.3.3.so
2000000000038000-2000000000040000 rw-p 00028000 08:04 516                /lib/ld-2.3.3.so
2000000000040000-2000000000044000 rw-p 2000000000040000 00:00 0
2000000000058000-2000000000260000 r-xp 00000000 08:04 54707842           /lib/tls/libc.so.6.1
2000000000260000-2000000000268000 ---p 00208000 08:04 54707842           /lib/tls/libc.so.6.1
2000000000268000-2000000000274000 rw-p 00200000 08:04 54707842           /lib/tls/libc.so.6.1
2000000000274000-2000000000280000 rw-p 2000000000274000 00:00 0
2000000000280000-20000000002b4000 r--p 00000000 08:04 9126923            /usr/lib/locale/en_US.utf8/LC_CTYPE
2000000000300000-2000000000308000 r--s 00000000 08:04 60071467           /usr/lib/gconv/gconv-modules.cache
2000000000318000-2000000000328000 rw-p 2000000000318000 00:00 0
4000000000000000-4000000000008000 r-xp 00000000 08:04 29576399           /sbin/mingetty
6000000000004000-6000000000008000 rw-p 00004000 08:04 29576399           /sbin/mingetty
6000000000008000-600000000002c000 rw-p 6000000000008000 00:00 0          [heap]
60000fff7fffc000-60000fff80000000 rw-p 60000fff7fffc000 00:00 0
60000ffffff44000-60000ffffff98000 rw-p 60000ffffff44000 00:00 0          [stack]
a000000000000000-a000000000020000 ---p 00000000 00:00 0                  [vdso]

cat numa_maps
2000000000000000 default MaxRef=43 Pages=11 Mapped=11 N0=4 N1=3 N2=2 N3=2
2000000000038000 default MaxRef=1 Pages=2 Mapped=2 Anon=2 N0=2
2000000000040000 default MaxRef=1 Pages=1 Mapped=1 Anon=1 N0=1
2000000000058000 default MaxRef=43 Pages=61 Mapped=61 N0=14 N1=15 N2=16 N3=16
2000000000268000 default MaxRef=1 Pages=2 Mapped=2 Anon=2 N0=2
2000000000274000 default MaxRef=1 Pages=3 Mapped=3 Anon=3 N0=3
2000000000280000 default MaxRef=8 Pages=3 Mapped=3 N0=3
2000000000300000 default MaxRef=8 Pages=2 Mapped=2 N0=2
2000000000318000 default MaxRef=1 Pages=1 Mapped=1 Anon=1 N2=1
4000000000000000 default MaxRef=6 Pages=2 Mapped=2 N1=2
6000000000004000 default MaxRef=1 Pages=1 Mapped=1 Anon=1 N0=1
6000000000008000 default MaxRef=1 Pages=1 Mapped=1 Anon=1 N0=1
60000fff7fffc000 default MaxRef=1 Pages=1 Mapped=1 Anon=1 N0=1
60000ffffff44000 default MaxRef=1 Pages=1 Mapped=1 Anon=1 N0=1

getty uses ld.so.  The first vma is the code segment which is used by 43
other processes and the pages are evenly distributed over the 4 nodes.

The second vma is the process specific data portion for ld.so.  This is
only one page.

The display format is:

<startaddress>	 Links to information in /proc/<pid>/map
<memory policy>  This can be "default" "interleave={}", "prefer=<node>" or "bind={<zones>}"
MaxRef=		<maximum reference to a page in this vma>
Pages=		<Nr of pages in use>
Mapped=		<Nr of pages with mapcount >
Anon=		<nr of anonymous pages>
Nx=		<Nr of pages on Node x>

The content of the proc-file is self-evident.  If this would be tied into
the sparsemem system then the contents of this file would not be too
useful.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:05:43 -07:00

1173 lines
30 KiB
C

/*
* Simple NUMA memory policy for the Linux kernel.
*
* Copyright 2003,2004 Andi Kleen, SuSE Labs.
* 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.
* 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 <asm/tlbflush.h>
#include <asm/uaccess.h>
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. */
static int policy_zone;
static struct mempolicy default_policy = {
.refcnt = ATOMIC_INIT(1), /* never free it */
.policy = MPOL_DEFAULT,
};
/* Check if all specified nodes are online */
static int nodes_online(unsigned long *nodes)
{
DECLARE_BITMAP(online2, MAX_NUMNODES);
bitmap_copy(online2, nodes_addr(node_online_map), MAX_NUMNODES);
if (bitmap_empty(online2, MAX_NUMNODES))
set_bit(0, online2);
if (!bitmap_subset(nodes, online2, MAX_NUMNODES))
return -EINVAL;
return 0;
}
/* Do sanity checking on a policy */
static int mpol_check_policy(int mode, unsigned long *nodes)
{
int empty = bitmap_empty(nodes, MAX_NUMNODES);
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_online(nodes);
}
/* Copy a node mask from user space. */
static int get_nodes(unsigned long *nodes, unsigned long __user *nmask,
unsigned long maxnode, int mode)
{
unsigned long k;
unsigned long nlongs;
unsigned long endmask;
--maxnode;
bitmap_zero(nodes, MAX_NUMNODES);
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, nmask, nlongs*sizeof(unsigned long)))
return -EFAULT;
nodes[nlongs-1] &= endmask;
/* Update current mems_allowed */
cpuset_update_current_mems_allowed();
/* Ignore nodes not set in current->mems_allowed */
cpuset_restrict_to_mems_allowed(nodes);
return mpol_check_policy(mode, nodes);
}
/* Generate a custom zonelist for the BIND policy. */
static struct zonelist *bind_zonelist(unsigned long *nodes)
{
struct zonelist *zl;
int num, max, nd;
max = 1 + MAX_NR_ZONES * bitmap_weight(nodes, MAX_NUMNODES);
zl = kmalloc(sizeof(void *) * max, GFP_KERNEL);
if (!zl)
return NULL;
num = 0;
for (nd = find_first_bit(nodes, MAX_NUMNODES);
nd < MAX_NUMNODES;
nd = find_next_bit(nodes, MAX_NUMNODES, 1+nd)) {
int k;
for (k = MAX_NR_ZONES-1; k >= 0; k--) {
struct zone *z = &NODE_DATA(nd)->node_zones[k];
if (!z->present_pages)
continue;
zl->zones[num++] = z;
if (k > policy_zone)
policy_zone = k;
}
}
BUG_ON(num >= max);
zl->zones[num] = NULL;
return zl;
}
/* Create a new policy */
static struct mempolicy *mpol_new(int mode, unsigned long *nodes)
{
struct mempolicy *policy;
PDprintk("setting mode %d nodes[0] %lx\n", mode, 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:
bitmap_copy(policy->v.nodes, nodes, MAX_NUMNODES);
break;
case MPOL_PREFERRED:
policy->v.preferred_node = find_first_bit(nodes, MAX_NUMNODES);
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;
return policy;
}
/* Ensure all existing pages follow the policy. */
static int check_pte_range(struct mm_struct *mm, pmd_t *pmd,
unsigned long addr, unsigned long end, unsigned long *nodes)
{
pte_t *orig_pte;
pte_t *pte;
spin_lock(&mm->page_table_lock);
orig_pte = pte = pte_offset_map(pmd, addr);
do {
unsigned long pfn;
unsigned int nid;
if (!pte_present(*pte))
continue;
pfn = pte_pfn(*pte);
if (!pfn_valid(pfn))
continue;
nid = pfn_to_nid(pfn);
if (!test_bit(nid, nodes))
break;
} while (pte++, addr += PAGE_SIZE, addr != end);
pte_unmap(orig_pte);
spin_unlock(&mm->page_table_lock);
return addr != end;
}
static inline int check_pmd_range(struct mm_struct *mm, pud_t *pud,
unsigned long addr, unsigned long end, unsigned long *nodes)
{
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(mm, pmd, addr, next, nodes))
return -EIO;
} while (pmd++, addr = next, addr != end);
return 0;
}
static inline int check_pud_range(struct mm_struct *mm, pgd_t *pgd,
unsigned long addr, unsigned long end, unsigned long *nodes)
{
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(mm, pud, addr, next, nodes))
return -EIO;
} while (pud++, addr = next, addr != end);
return 0;
}
static inline int check_pgd_range(struct mm_struct *mm,
unsigned long addr, unsigned long end, unsigned long *nodes)
{
pgd_t *pgd;
unsigned long next;
pgd = pgd_offset(mm, addr);
do {
next = pgd_addr_end(addr, end);
if (pgd_none_or_clear_bad(pgd))
continue;
if (check_pud_range(mm, pgd, addr, next, nodes))
return -EIO;
} while (pgd++, addr = next, addr != end);
return 0;
}
/* Step 1: check the range */
static struct vm_area_struct *
check_range(struct mm_struct *mm, unsigned long start, unsigned long end,
unsigned long *nodes, unsigned long flags)
{
int err;
struct vm_area_struct *first, *vma, *prev;
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 (!vma->vm_next && vma->vm_end < end)
return ERR_PTR(-EFAULT);
if (prev && prev->vm_end < vma->vm_start)
return ERR_PTR(-EFAULT);
if ((flags & MPOL_MF_STRICT) && !is_vm_hugetlb_page(vma)) {
err = check_pgd_range(vma->vm_mm,
vma->vm_start, vma->vm_end, nodes);
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;
}
/* Change policy for a memory range */
asmlinkage long sys_mbind(unsigned long start, unsigned long len,
unsigned long mode,
unsigned long __user *nmask, unsigned long maxnode,
unsigned flags)
{
struct vm_area_struct *vma;
struct mm_struct *mm = current->mm;
struct mempolicy *new;
unsigned long end;
DECLARE_BITMAP(nodes, MAX_NUMNODES);
int err;
if ((flags & ~(unsigned long)(MPOL_MF_STRICT)) || mode > MPOL_MAX)
return -EINVAL;
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;
err = get_nodes(nodes, nmask, maxnode, mode);
if (err)
return err;
new = mpol_new(mode, nodes);
if (IS_ERR(new))
return PTR_ERR(new);
PDprintk("mbind %lx-%lx mode:%ld nodes:%lx\n",start,start+len,
mode,nodes[0]);
down_write(&mm->mmap_sem);
vma = check_range(mm, start, end, nodes, flags);
err = PTR_ERR(vma);
if (!IS_ERR(vma))
err = mbind_range(vma, start, end, new);
up_write(&mm->mmap_sem);
mpol_free(new);
return err;
}
/* Set the process memory policy */
asmlinkage long sys_set_mempolicy(int mode, unsigned long __user *nmask,
unsigned long maxnode)
{
int err;
struct mempolicy *new;
DECLARE_BITMAP(nodes, MAX_NUMNODES);
if (mode < 0 || mode > MPOL_MAX)
return -EINVAL;
err = get_nodes(nodes, nmask, maxnode, mode);
if (err)
return err;
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 = find_first_bit(new->v.nodes, MAX_NUMNODES);
return 0;
}
/* Fill a zone bitmap for a policy */
static void get_zonemask(struct mempolicy *p, unsigned long *nodes)
{
int i;
bitmap_zero(nodes, MAX_NUMNODES);
switch (p->policy) {
case MPOL_BIND:
for (i = 0; p->v.zonelist->zones[i]; i++)
__set_bit(p->v.zonelist->zones[i]->zone_pgdat->node_id, nodes);
break;
case MPOL_DEFAULT:
break;
case MPOL_INTERLEAVE:
bitmap_copy(nodes, p->v.nodes, MAX_NUMNODES);
break;
case MPOL_PREFERRED:
/* or use current node instead of online map? */
if (p->v.preferred_node < 0)
bitmap_copy(nodes, nodes_addr(node_online_map), MAX_NUMNODES);
else
__set_bit(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;
}
/* Copy a kernel node mask to user space */
static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode,
void *nodes, unsigned nbytes)
{
unsigned long copy = ALIGN(maxnode-1, 64) / 8;
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, copy) ? -EFAULT : 0;
}
/* 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;
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma = NULL;
struct mempolicy *pol = current->mempolicy;
if (flags & ~(unsigned long)(MPOL_F_NODE|MPOL_F_ADDR))
return -EINVAL;
if (nmask != NULL && maxnode < MAX_NUMNODES)
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;
pval = err;
} else if (pol == current->mempolicy &&
pol->policy == MPOL_INTERLEAVE) {
pval = current->il_next;
} else {
err = -EINVAL;
goto out;
}
} else
pval = pol->policy;
if (vma) {
up_read(&current->mm->mmap_sem);
vma = NULL;
}
if (policy && put_user(pval, policy))
return -EFAULT;
err = 0;
if (nmask) {
DECLARE_BITMAP(nodes, MAX_NUMNODES);
get_zonemask(pol, nodes);
err = copy_nodes_to_user(nmask, maxnode, nodes, sizeof(nodes));
}
out:
if (vma)
up_read(&current->mm->mmap_sem);
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);
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;
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_mbind(start, len, mode, nm, nr_bits+1, flags);
}
#endif
/* Return effective policy for a VMA */
struct mempolicy *
get_vma_policy(struct task_struct *task, struct vm_area_struct *vma, unsigned long addr)
{
struct mempolicy *pol = task->mempolicy;
if (vma) {
if (vma->vm_ops && vma->vm_ops->get_policy)
pol = vma->vm_ops->get_policy(vma, addr);
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 */
static struct zonelist *zonelist_policy(unsigned int __nocast gfp, struct mempolicy *policy)
{
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 */
if ((gfp & GFP_ZONEMASK) >= policy_zone)
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();
}
return NODE_DATA(nd)->node_zonelists + (gfp & GFP_ZONEMASK);
}
/* 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;
BUG_ON(nid >= MAX_NUMNODES);
next = find_next_bit(policy->v.nodes, MAX_NUMNODES, 1+nid);
if (next >= MAX_NUMNODES)
next = find_first_bit(policy->v.nodes, MAX_NUMNODES);
me->il_next = next;
return nid;
}
/* 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)
{
unsigned nnodes = bitmap_weight(pol->v.nodes, MAX_NUMNODES);
unsigned target = (unsigned)off % nnodes;
int c;
int nid = -1;
c = 0;
do {
nid = find_next_bit(pol->v.nodes, MAX_NUMNODES, nid+1);
c++;
} while (c <= target);
BUG_ON(nid >= MAX_NUMNODES);
BUG_ON(!test_bit(nid, pol->v.nodes));
return nid;
}
/* Allocate a page in interleaved policy.
Own path because it needs to do special accounting. */
static struct page *alloc_page_interleave(unsigned int __nocast gfp, unsigned order, unsigned nid)
{
struct zonelist *zl;
struct page *page;
BUG_ON(!node_online(nid));
zl = NODE_DATA(nid)->node_zonelists + (gfp & GFP_ZONEMASK);
page = __alloc_pages(gfp, order, zl);
if (page && page_zone(page) == zl->zones[0]) {
zone_pcp(zl->zones[0],get_cpu())->interleave_hit++;
put_cpu();
}
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 *
alloc_page_vma(unsigned int __nocast gfp, struct vm_area_struct *vma, unsigned long addr)
{
struct mempolicy *pol = get_vma_policy(current, vma, addr);
cpuset_update_current_mems_allowed();
if (unlikely(pol->policy == MPOL_INTERLEAVE)) {
unsigned nid;
if (vma) {
unsigned long off;
BUG_ON(addr >= vma->vm_end);
BUG_ON(addr < vma->vm_start);
off = vma->vm_pgoff;
off += (addr - vma->vm_start) >> PAGE_SHIFT;
nid = offset_il_node(pol, vma, off);
} else {
/* fall back to process interleaving */
nid = interleave_nodes(pol);
}
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.
*
* Don't call cpuset_update_current_mems_allowed() unless
* 1) it's ok to take cpuset_sem (can WAIT), and
* 2) allocating for current task (not interrupt).
*/
struct page *alloc_pages_current(unsigned int __nocast gfp, unsigned order)
{
struct mempolicy *pol = current->mempolicy;
if ((gfp & __GFP_WAIT) && !in_interrupt())
cpuset_update_current_mems_allowed();
if (!pol || in_interrupt())
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);
/* 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);
*new = *old;
atomic_set(&new->refcnt, 1);
if (new->policy == MPOL_BIND) {
int sz = ksize(old->v.zonelist);
new->v.zonelist = kmalloc(sz, SLAB_KERNEL);
if (!new->v.zonelist) {
kmem_cache_free(policy_cache, new);
return ERR_PTR(-ENOMEM);
}
memcpy(new->v.zonelist, old->v.zonelist, sz);
}
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:
return bitmap_equal(a->v.nodes, b->v.nodes, MAX_NUMNODES);
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);
}
/*
* Hugetlb policy. Same as above, just works with node numbers instead of
* zonelists.
*/
/* Find first node suitable for an allocation */
int mpol_first_node(struct vm_area_struct *vma, unsigned long addr)
{
struct mempolicy *pol = get_vma_policy(current, vma, addr);
switch (pol->policy) {
case MPOL_DEFAULT:
return numa_node_id();
case MPOL_BIND:
return pol->v.zonelist->zones[0]->zone_pgdat->node_id;
case MPOL_INTERLEAVE:
return interleave_nodes(pol);
case MPOL_PREFERRED:
return pol->v.preferred_node >= 0 ?
pol->v.preferred_node : numa_node_id();
}
BUG();
return 0;
}
/* Find secondary valid nodes for an allocation */
int mpol_node_valid(int nid, struct vm_area_struct *vma, unsigned long addr)
{
struct mempolicy *pol = get_vma_policy(current, vma, addr);
switch (pol->policy) {
case MPOL_PREFERRED:
case MPOL_DEFAULT:
case MPOL_INTERLEAVE:
return 1;
case MPOL_BIND: {
struct zone **z;
for (z = pol->v.zonelist->zones; *z; z++)
if ((*z)->zone_pgdat->node_id == nid)
return 1;
return 0;
}
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);
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;
}
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,
npol ? npol->v.nodes[0] : -1);
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);
rb_erase(&n->nd, &p->root);
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. */
if (sys_set_mempolicy(MPOL_INTERLEAVE, nodes_addr(node_online_map),
MAX_NUMNODES) < 0)
printk("numa_policy_init: interleaving failed\n");
}
/* Reset policy of current process to default.
* Assumes fs == KERNEL_DS */
void numa_default_policy(void)
{
sys_set_mempolicy(MPOL_DEFAULT, NULL, 0);
}