#include <linux/sched.h>
#include <linux/nodemask.h>
#include <linux/cpuset.h>
-#include <linux/gfp.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/module.h>
#include <linux/seq_file.h>
#include <linux/proc_fs.h>
#include <linux/migrate.h>
+#include <linux/ksm.h>
#include <linux/rmap.h>
#include <linux/security.h>
#include <linux/syscalls.h>
+#include <linux/ctype.h>
+#include <linux/mm_inline.h>
#include <asm/tlbflush.h>
#include <asm/uaccess.h>
+#include "internal.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 */
policied. */
enum zone_type policy_zone = 0;
+/*
+ * run-time system-wide default policy => local allocation
+ */
struct mempolicy default_policy = {
.refcnt = ATOMIC_INIT(1), /* never free it */
- .mode = MPOL_DEFAULT,
+ .mode = MPOL_PREFERRED,
+ .flags = MPOL_F_LOCAL,
};
static const struct mempolicy_operations {
static int mpol_new_preferred(struct mempolicy *pol, const nodemask_t *nodes)
{
if (!nodes)
- pol->v.preferred_node = -1; /* local allocation */
+ pol->flags |= MPOL_F_LOCAL; /* local allocation */
else if (nodes_empty(*nodes))
return -EINVAL; /* no allowed nodes */
else
return 0;
}
-/* Create a new policy */
+/*
+ * mpol_set_nodemask is called after mpol_new() to set up the nodemask, if
+ * any, for the new policy. mpol_new() has already validated the nodes
+ * parameter with respect to the policy mode and flags. But, we need to
+ * handle an empty nodemask with MPOL_PREFERRED here.
+ *
+ * Must be called holding task's alloc_lock to protect task's mems_allowed
+ * and mempolicy. May also be called holding the mmap_semaphore for write.
+ */
+static int mpol_set_nodemask(struct mempolicy *pol,
+ const nodemask_t *nodes, struct nodemask_scratch *nsc)
+{
+ int ret;
+
+ /* if mode is MPOL_DEFAULT, pol is NULL. This is right. */
+ if (pol == NULL)
+ return 0;
+ /* Check N_HIGH_MEMORY */
+ nodes_and(nsc->mask1,
+ cpuset_current_mems_allowed, node_states[N_HIGH_MEMORY]);
+
+ VM_BUG_ON(!nodes);
+ if (pol->mode == MPOL_PREFERRED && nodes_empty(*nodes))
+ nodes = NULL; /* explicit local allocation */
+ else {
+ if (pol->flags & MPOL_F_RELATIVE_NODES)
+ mpol_relative_nodemask(&nsc->mask2, nodes,&nsc->mask1);
+ else
+ nodes_and(nsc->mask2, *nodes, nsc->mask1);
+
+ if (mpol_store_user_nodemask(pol))
+ pol->w.user_nodemask = *nodes;
+ else
+ pol->w.cpuset_mems_allowed =
+ cpuset_current_mems_allowed;
+ }
+
+ if (nodes)
+ ret = mpol_ops[pol->mode].create(pol, &nsc->mask2);
+ else
+ ret = mpol_ops[pol->mode].create(pol, NULL);
+ return ret;
+}
+
+/*
+ * This function just creates a new policy, does some check and simple
+ * initialization. You must invoke mpol_set_nodemask() to set nodes.
+ */
static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags,
nodemask_t *nodes)
{
struct mempolicy *policy;
- nodemask_t cpuset_context_nmask;
- int ret;
pr_debug("setting mode %d flags %d nodes[0] %lx\n",
mode, flags, nodes ? nodes_addr(*nodes)[0] : -1);
if (mode == MPOL_DEFAULT) {
if (nodes && !nodes_empty(*nodes))
return ERR_PTR(-EINVAL);
- return NULL;
+ return NULL; /* simply delete any existing policy */
}
VM_BUG_ON(!nodes);
if (((flags & MPOL_F_STATIC_NODES) ||
(flags & MPOL_F_RELATIVE_NODES)))
return ERR_PTR(-EINVAL);
- nodes = NULL; /* flag local alloc */
}
} else if (nodes_empty(*nodes))
return ERR_PTR(-EINVAL);
policy->mode = mode;
policy->flags = flags;
- if (nodes) {
- /*
- * cpuset related setup doesn't apply to local allocation
- */
- cpuset_update_task_memory_state();
- if (flags & MPOL_F_RELATIVE_NODES)
- mpol_relative_nodemask(&cpuset_context_nmask, nodes,
- &cpuset_current_mems_allowed);
- else
- nodes_and(cpuset_context_nmask, *nodes,
- cpuset_current_mems_allowed);
- if (mpol_store_user_nodemask(policy))
- policy->w.user_nodemask = *nodes;
- else
- policy->w.cpuset_mems_allowed =
- cpuset_mems_allowed(current);
- }
-
- ret = mpol_ops[mode].create(policy,
- nodes ? &cpuset_context_nmask : NULL);
- if (ret < 0) {
- kmem_cache_free(policy_cache, policy);
- return ERR_PTR(ret);
- }
return policy;
}
+/* Slow path of a mpol destructor. */
+void __mpol_put(struct mempolicy *p)
+{
+ if (!atomic_dec_and_test(&p->refcnt))
+ return;
+ kmem_cache_free(policy_cache, p);
+}
+
static void mpol_rebind_default(struct mempolicy *pol, const nodemask_t *nodes)
{
}
if (pol->flags & MPOL_F_STATIC_NODES) {
int node = first_node(pol->w.user_nodemask);
- if (node_isset(node, *nodes))
+ if (node_isset(node, *nodes)) {
pol->v.preferred_node = node;
- else
- pol->v.preferred_node = -1;
+ pol->flags &= ~MPOL_F_LOCAL;
+ } else
+ pol->flags |= MPOL_F_LOCAL;
} else if (pol->flags & MPOL_F_RELATIVE_NODES) {
mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes);
pol->v.preferred_node = first_node(tmp);
- } else if (pol->v.preferred_node != -1) {
+ } else if (!(pol->flags & MPOL_F_LOCAL)) {
pol->v.preferred_node = node_remap(pol->v.preferred_node,
pol->w.cpuset_mems_allowed,
*nodes);
/*
* Wrapper for mpol_rebind_policy() that just requires task
* pointer, and updates task mempolicy.
+ *
+ * Called with task's alloc_lock held.
*/
void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new)
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.
+ * vm_normal_page() filters out zero pages, but there might
+ * still be PageReserved pages to skip, perhaps in a VDSO.
+ * And we cannot move PageKsm pages sensibly or safely yet.
*/
- if (PageReserved(page))
+ if (PageReserved(page) || PageKsm(page))
continue;
nid = page_to_nid(page);
if (node_isset(nid, *nodes) == !!(flags & MPOL_MF_INVERT))
int err;
struct vm_area_struct *first, *vma, *prev;
- if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) {
-
- err = migrate_prep();
- if (err)
- return ERR_PTR(err);
- }
first = find_vma(mm, start);
if (!first)
}
/* 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)
+static int mbind_range(struct mm_struct *mm, unsigned long start,
+ unsigned long end, struct mempolicy *new_pol)
{
struct vm_area_struct *next;
- int err;
+ struct vm_area_struct *prev;
+ struct vm_area_struct *vma;
+ int err = 0;
+ pgoff_t pgoff;
+ unsigned long vmstart;
+ unsigned long vmend;
- err = 0;
- for (; vma && vma->vm_start < end; vma = next) {
+ vma = find_vma_prev(mm, start, &prev);
+ if (!vma || vma->vm_start > start)
+ return -EFAULT;
+
+ for (; vma && vma->vm_start < end; prev = vma, vma = next) {
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);
+ vmstart = max(start, vma->vm_start);
+ vmend = min(end, vma->vm_end);
+
+ pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
+ prev = vma_merge(mm, prev, vmstart, vmend, vma->vm_flags,
+ vma->anon_vma, vma->vm_file, pgoff, new_pol);
+ if (prev) {
+ vma = prev;
+ next = vma->vm_next;
+ continue;
+ }
+ if (vma->vm_start != vmstart) {
+ err = split_vma(vma->vm_mm, vma, vmstart, 1);
+ if (err)
+ goto out;
+ }
+ if (vma->vm_end != vmend) {
+ err = split_vma(vma->vm_mm, vma, vmend, 0);
+ if (err)
+ goto out;
+ }
+ err = policy_vma(vma, new_pol);
if (err)
- break;
+ goto out;
}
+
+ out:
return err;
}
static long do_set_mempolicy(unsigned short mode, unsigned short flags,
nodemask_t *nodes)
{
- struct mempolicy *new;
+ struct mempolicy *new, *old;
struct mm_struct *mm = current->mm;
+ NODEMASK_SCRATCH(scratch);
+ int ret;
- new = mpol_new(mode, flags, nodes);
- if (IS_ERR(new))
- return PTR_ERR(new);
+ if (!scratch)
+ return -ENOMEM;
+ new = mpol_new(mode, flags, nodes);
+ if (IS_ERR(new)) {
+ ret = PTR_ERR(new);
+ goto out;
+ }
/*
* prevent changing our mempolicy while show_numa_maps()
* is using it.
*/
if (mm)
down_write(&mm->mmap_sem);
- mpol_put(current->mempolicy);
+ task_lock(current);
+ ret = mpol_set_nodemask(new, nodes, scratch);
+ if (ret) {
+ task_unlock(current);
+ if (mm)
+ up_write(&mm->mmap_sem);
+ mpol_put(new);
+ goto out;
+ }
+ old = current->mempolicy;
current->mempolicy = new;
mpol_set_task_struct_flag();
if (new && new->mode == MPOL_INTERLEAVE &&
nodes_weight(new->v.nodes))
current->il_next = first_node(new->v.nodes);
+ task_unlock(current);
if (mm)
up_write(&mm->mmap_sem);
- return 0;
+ mpol_put(old);
+ ret = 0;
+out:
+ NODEMASK_SCRATCH_FREE(scratch);
+ return ret;
}
-/* Fill a zone bitmap for a policy */
-static void get_zonemask(struct mempolicy *p, nodemask_t *nodes)
+/*
+ * Return nodemask for policy for get_mempolicy() query
+ *
+ * Called with task's alloc_lock held
+ */
+static void get_policy_nodemask(struct mempolicy *p, nodemask_t *nodes)
{
nodes_clear(*nodes);
+ if (p == &default_policy)
+ return;
+
switch (p->mode) {
- case MPOL_DEFAULT:
- break;
case MPOL_BIND:
/* Fall through */
case MPOL_INTERLEAVE:
*nodes = p->v.nodes;
break;
case MPOL_PREFERRED:
- /* or use current node instead of memory_map? */
- if (p->v.preferred_node < 0)
- *nodes = node_states[N_HIGH_MEMORY];
- else
+ if (!(p->flags & MPOL_F_LOCAL))
node_set(p->v.preferred_node, *nodes);
+ /* else return empty node mask for local allocation */
break;
default:
BUG();
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|MPOL_F_MEMS_ALLOWED))
return -EINVAL;
if (flags & (MPOL_F_NODE|MPOL_F_ADDR))
return -EINVAL;
*policy = 0; /* just so it's initialized */
+ task_lock(current);
*nmask = cpuset_current_mems_allowed;
+ task_unlock(current);
return 0;
}
if (flags & MPOL_F_ADDR) {
+ /*
+ * Do NOT fall back to task policy if the
+ * vma/shared policy at addr is NULL. We
+ * want to return MPOL_DEFAULT in this case.
+ */
down_read(&mm->mmap_sem);
vma = find_vma_intersection(mm, addr, addr+1);
if (!vma) {
return -EINVAL;
if (!pol)
- pol = &default_policy;
+ pol = &default_policy; /* indicates default behavior */
if (flags & MPOL_F_NODE) {
if (flags & MPOL_F_ADDR) {
err = -EINVAL;
goto out;
}
- } else
- *policy = pol->mode | pol->flags;
+ } else {
+ *policy = pol == &default_policy ? MPOL_DEFAULT :
+ pol->mode;
+ /*
+ * Internal mempolicy flags must be masked off before exposing
+ * the policy to userspace.
+ */
+ *policy |= (pol->flags & MPOL_MODE_FLAGS);
+ }
if (vma) {
up_read(¤t->mm->mmap_sem);
}
err = 0;
- if (nmask)
- get_zonemask(pol, nmask);
+ if (nmask) {
+ if (mpol_store_user_nodemask(pol)) {
+ *nmask = pol->w.user_nodemask;
+ } else {
+ task_lock(current);
+ get_policy_nodemask(pol, nmask);
+ task_unlock(current);
+ }
+ }
out:
+ mpol_cond_put(pol);
if (vma)
up_read(¤t->mm->mmap_sem);
return err;
/*
* Avoid migrating a page that is shared with others.
*/
- if ((flags & MPOL_MF_MOVE_ALL) || page_mapcount(page) == 1)
- isolate_lru_page(page, pagelist);
+ if ((flags & MPOL_MF_MOVE_ALL) || page_mapcount(page) == 1) {
+ if (!isolate_lru_page(page)) {
+ list_add_tail(&page->lru, pagelist);
+ inc_zone_page_state(page, NR_ISOLATED_ANON +
+ page_is_file_cache(page));
+ }
+ }
}
static struct page *new_node_page(struct page *page, unsigned long node, int **x)
{
- return alloc_pages_node(node, GFP_HIGHUSER_MOVABLE, 0);
+ return alloc_pages_exact_node(node, GFP_HIGHUSER_MOVABLE, 0);
}
/*
flags | MPOL_MF_DISCONTIG_OK, &pagelist);
if (!list_empty(&pagelist))
- err = migrate_pages(&pagelist, new_node_page, dest);
+ err = migrate_pages(&pagelist, new_node_page, dest, 0);
return err;
}
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;
+ int err;
nodemask_t tmp;
- down_read(&mm->mmap_sem);
+ err = migrate_prep();
+ if (err)
+ return err;
+
+ down_read(&mm->mmap_sem);
err = migrate_vmas(mm, from_nodes, to_nodes, flags);
if (err)
goto out;
-/*
- * 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.
- */
+ /*
+ * 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)) {
start, start + len, mode, mode_flags,
nmask ? nodes_addr(*nmask)[0] : -1);
- down_write(&mm->mmap_sem);
+ if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) {
+
+ err = migrate_prep();
+ if (err)
+ goto mpol_out;
+ }
+ {
+ NODEMASK_SCRATCH(scratch);
+ if (scratch) {
+ down_write(&mm->mmap_sem);
+ task_lock(current);
+ err = mpol_set_nodemask(new, nmask, scratch);
+ task_unlock(current);
+ if (err)
+ up_write(&mm->mmap_sem);
+ } else
+ err = -ENOMEM;
+ NODEMASK_SCRATCH_FREE(scratch);
+ }
+ if (err)
+ goto mpol_out;
+
vma = check_range(mm, start, end, nmask,
flags | MPOL_MF_INVERT, &pagelist);
if (!IS_ERR(vma)) {
int nr_failed = 0;
- err = mbind_range(vma, start, end, new);
+ err = mbind_range(mm, start, end, new);
if (!list_empty(&pagelist))
nr_failed = migrate_pages(&pagelist, new_vma_page,
- (unsigned long)vma);
+ (unsigned long)vma, 0);
if (!err && nr_failed && (flags & MPOL_MF_STRICT))
err = -EIO;
- }
+ } else
+ putback_lru_pages(&pagelist);
up_write(&mm->mmap_sem);
+ mpol_out:
mpol_put(new);
return err;
}
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)
+SYSCALL_DEFINE6(mbind, unsigned long, start, unsigned long, len,
+ unsigned long, mode, unsigned long __user *, nmask,
+ unsigned long, maxnode, unsigned, flags)
{
nodemask_t nodes;
int err;
}
/* Set the process memory policy */
-asmlinkage long sys_set_mempolicy(int mode, unsigned long __user *nmask,
- unsigned long maxnode)
+SYSCALL_DEFINE3(set_mempolicy, int, mode, unsigned long __user *, nmask,
+ unsigned long, maxnode)
{
int err;
nodemask_t nodes;
return do_set_mempolicy(mode, flags, &nodes);
}
-asmlinkage long sys_migrate_pages(pid_t pid, unsigned long maxnode,
- const unsigned long __user *old_nodes,
- const unsigned long __user *new_nodes)
+SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode,
+ const unsigned long __user *, old_nodes,
+ const unsigned long __user *, new_nodes)
{
+ const struct cred *cred = current_cred(), *tcred;
struct mm_struct *mm;
struct task_struct *task;
nodemask_t old;
* capabilities, superuser privileges 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) &&
+ rcu_read_lock();
+ tcred = __task_cred(task);
+ if (cred->euid != tcred->suid && cred->euid != tcred->uid &&
+ cred->uid != tcred->suid && cred->uid != tcred->uid &&
!capable(CAP_SYS_NICE)) {
+ rcu_read_unlock();
err = -EPERM;
goto out;
}
+ rcu_read_unlock();
task_nodes = cpuset_mems_allowed(task);
/* Is the user allowed to access the target nodes? */
/* Retrieve NUMA policy */
-asmlinkage long sys_get_mempolicy(int __user *policy,
- unsigned long __user *nmask,
- unsigned long maxnode,
- unsigned long addr, unsigned long flags)
+SYSCALL_DEFINE5(get_mempolicy, int __user *, policy,
+ unsigned long __user *, nmask, unsigned long, maxnode,
+ unsigned long, addr, unsigned long, flags)
{
int err;
int uninitialized_var(pval);
*
* Returns effective policy for a VMA at specified address.
* Falls back to @task or system default policy, as necessary.
- * Returned policy has extra reference count if shared, vma,
- * or some other task's policy [show_numa_maps() can pass
- * @task != current]. It is the caller's responsibility to
- * free the reference in these cases.
+ * Current or other task's task mempolicy and non-shared vma policies
+ * are protected by the task's mmap_sem, which must be held for read by
+ * the caller.
+ * Shared policies [those marked as MPOL_F_SHARED] require an extra reference
+ * count--added by the get_policy() vm_op, as appropriate--to protect against
+ * freeing by another task. It is the caller's responsibility to free the
+ * extra reference for shared policies.
*/
static struct mempolicy *get_vma_policy(struct task_struct *task,
struct vm_area_struct *vma, unsigned long addr)
{
struct mempolicy *pol = task->mempolicy;
- int shared_pol = 0;
if (vma) {
if (vma->vm_ops && vma->vm_ops->get_policy) {
addr);
if (vpol)
pol = vpol;
- shared_pol = 1; /* if pol non-NULL, add ref below */
- } else if (vma->vm_policy &&
- vma->vm_policy->mode != MPOL_DEFAULT)
+ } else if (vma->vm_policy)
pol = vma->vm_policy;
}
if (!pol)
pol = &default_policy;
- else if (!shared_pol && pol != current->mempolicy)
- mpol_get(pol); /* vma or other task's policy */
return pol;
}
-/* Return a nodemask representing a mempolicy */
-static nodemask_t *nodemask_policy(gfp_t gfp, struct mempolicy *policy)
+/*
+ * Return a nodemask representing a mempolicy for filtering nodes for
+ * page allocation
+ */
+static nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy)
{
/* Lower zones don't get a nodemask applied for MPOL_BIND */
if (unlikely(policy->mode == MPOL_BIND) &&
return NULL;
}
-/* Return a zonelist representing a mempolicy */
-static struct zonelist *zonelist_policy(gfp_t gfp, struct mempolicy *policy)
+/* Return a zonelist indicated by gfp for node representing a mempolicy */
+static struct zonelist *policy_zonelist(gfp_t gfp, struct mempolicy *policy)
{
- int nd;
+ int nd = numa_node_id();
switch (policy->mode) {
case MPOL_PREFERRED:
- nd = policy->v.preferred_node;
- if (nd < 0)
- nd = numa_node_id();
+ if (!(policy->flags & MPOL_F_LOCAL))
+ nd = policy->v.preferred_node;
break;
case MPOL_BIND:
/*
- * Normally, MPOL_BIND allocations node-local are node-local
- * within the allowed nodemask. However, if __GFP_THISNODE is
- * set and the current node is part of the mask, we use the
- * the zonelist for the first node in the mask instead.
+ * Normally, MPOL_BIND allocations are node-local within the
+ * allowed nodemask. However, if __GFP_THISNODE is set and the
+ * current node is part of the mask, we use the zonelist for
+ * the first node in the mask instead.
*/
- nd = numa_node_id();
if (unlikely(gfp & __GFP_THISNODE) &&
unlikely(!node_isset(nd, policy->v.nodes)))
nd = first_node(policy->v.nodes);
break;
case MPOL_INTERLEAVE: /* should not happen */
- case MPOL_DEFAULT:
- nd = numa_node_id();
break;
default:
- nd = 0;
BUG();
}
return node_zonelist(nd, gfp);
/*
* Depending on the memory policy provide a node from which to allocate the
* next slab entry.
+ * @policy must be protected by freeing by the caller. If @policy is
+ * the current task's mempolicy, this protection is implicit, as only the
+ * task can change it's policy. The system default policy requires no
+ * such protection.
*/
unsigned slab_node(struct mempolicy *policy)
{
- unsigned short pol = policy ? policy->mode : MPOL_DEFAULT;
+ if (!policy || policy->flags & MPOL_F_LOCAL)
+ return numa_node_id();
+
+ switch (policy->mode) {
+ case MPOL_PREFERRED:
+ /*
+ * handled MPOL_F_LOCAL above
+ */
+ return policy->v.preferred_node;
- switch (pol) {
case MPOL_INTERLEAVE:
return interleave_nodes(policy);
return zone->node;
}
- case MPOL_PREFERRED:
- if (policy->v.preferred_node >= 0)
- return policy->v.preferred_node;
- /* Fall through */
-
default:
- return numa_node_id();
+ BUG();
}
}
* @mpol = pointer to mempolicy pointer for reference counted mempolicy
* @nodemask = pointer to nodemask pointer for MPOL_BIND nodemask
*
- * Returns a zonelist suitable for a huge page allocation.
- * If the effective policy is 'BIND, returns pointer to local node's zonelist,
- * and a pointer to the mempolicy's @nodemask for filtering the zonelist.
- * If it is also a policy for which get_vma_policy() returns an extra
- * reference, we must hold that reference until after the allocation.
- * In that case, return policy via @mpol so hugetlb allocation can drop
- * the reference. For non-'BIND referenced policies, we can/do drop the
- * reference here, so the caller doesn't need to know about the special case
- * for default and current task policy.
+ * Returns a zonelist suitable for a huge page allocation and a pointer
+ * to the struct mempolicy for conditional unref after allocation.
+ * If the effective policy is 'BIND, returns a pointer to the mempolicy's
+ * @nodemask for filtering the zonelist.
*/
struct zonelist *huge_zonelist(struct vm_area_struct *vma, unsigned long addr,
gfp_t gfp_flags, struct mempolicy **mpol,
nodemask_t **nodemask)
{
- struct mempolicy *pol = get_vma_policy(current, vma, addr);
struct zonelist *zl;
- *mpol = NULL; /* probably no unref needed */
+ *mpol = get_vma_policy(current, vma, addr);
*nodemask = NULL; /* assume !MPOL_BIND */
- if (pol->mode == MPOL_BIND) {
- *nodemask = &pol->v.nodes;
- } else if (pol->mode == MPOL_INTERLEAVE) {
- unsigned nid;
- nid = interleave_nid(pol, vma, addr, HPAGE_SHIFT);
- if (unlikely(pol != &default_policy &&
- pol != current->mempolicy))
- __mpol_put(pol); /* finished with pol */
- return node_zonelist(nid, gfp_flags);
+ if (unlikely((*mpol)->mode == MPOL_INTERLEAVE)) {
+ zl = node_zonelist(interleave_nid(*mpol, vma, addr,
+ huge_page_shift(hstate_vma(vma))), gfp_flags);
+ } else {
+ zl = policy_zonelist(gfp_flags, *mpol);
+ if ((*mpol)->mode == MPOL_BIND)
+ *nodemask = &(*mpol)->v.nodes;
}
+ return zl;
+}
+
+/*
+ * init_nodemask_of_mempolicy
+ *
+ * If the current task's mempolicy is "default" [NULL], return 'false'
+ * to indicate default policy. Otherwise, extract the policy nodemask
+ * for 'bind' or 'interleave' policy into the argument nodemask, or
+ * initialize the argument nodemask to contain the single node for
+ * 'preferred' or 'local' policy and return 'true' to indicate presence
+ * of non-default mempolicy.
+ *
+ * We don't bother with reference counting the mempolicy [mpol_get/put]
+ * because the current task is examining it's own mempolicy and a task's
+ * mempolicy is only ever changed by the task itself.
+ *
+ * N.B., it is the caller's responsibility to free a returned nodemask.
+ */
+bool init_nodemask_of_mempolicy(nodemask_t *mask)
+{
+ struct mempolicy *mempolicy;
+ int nid;
- zl = zonelist_policy(GFP_HIGHUSER, pol);
- if (unlikely(pol != &default_policy && pol != current->mempolicy)) {
- if (pol->mode != MPOL_BIND)
- __mpol_put(pol); /* finished with pol */
+ if (!(mask && current->mempolicy))
+ return false;
+
+ mempolicy = current->mempolicy;
+ switch (mempolicy->mode) {
+ case MPOL_PREFERRED:
+ if (mempolicy->flags & MPOL_F_LOCAL)
+ nid = numa_node_id();
else
- *mpol = pol; /* unref needed after allocation */
+ nid = mempolicy->v.preferred_node;
+ init_nodemask_of_node(mask, nid);
+ break;
+
+ case MPOL_BIND:
+ /* Fall through */
+ case MPOL_INTERLEAVE:
+ *mask = mempolicy->v.nodes;
+ break;
+
+ default:
+ BUG();
}
- return zl;
+
+ return true;
}
#endif
struct mempolicy *pol = get_vma_policy(current, vma, addr);
struct zonelist *zl;
- cpuset_update_task_memory_state();
-
if (unlikely(pol->mode == MPOL_INTERLEAVE)) {
unsigned nid;
nid = interleave_nid(pol, vma, addr, PAGE_SHIFT);
- if (unlikely(pol != &default_policy &&
- pol != current->mempolicy))
- __mpol_put(pol); /* finished with pol */
+ mpol_cond_put(pol);
return alloc_page_interleave(gfp, 0, nid);
}
- zl = zonelist_policy(gfp, pol);
- if (pol != &default_policy && pol != current->mempolicy) {
+ zl = policy_zonelist(gfp, pol);
+ if (unlikely(mpol_needs_cond_ref(pol))) {
/*
- * slow path: ref counted policy -- shared or vma
+ * slow path: ref counted shared policy
*/
struct page *page = __alloc_pages_nodemask(gfp, 0,
- zl, nodemask_policy(gfp, pol));
+ zl, policy_nodemask(gfp, pol));
__mpol_put(pol);
return page;
}
/*
* fast path: default or task policy
*/
- return __alloc_pages_nodemask(gfp, 0, zl, nodemask_policy(gfp, pol));
+ return __alloc_pages_nodemask(gfp, 0, zl, policy_nodemask(gfp, pol));
}
/**
{
struct mempolicy *pol = current->mempolicy;
- if ((gfp & __GFP_WAIT) && !in_interrupt())
- cpuset_update_task_memory_state();
if (!pol || in_interrupt() || (gfp & __GFP_THISNODE))
pol = &default_policy;
+
+ /*
+ * No reference counting needed for current->mempolicy
+ * nor system default_policy
+ */
if (pol->mode == MPOL_INTERLEAVE)
return alloc_page_interleave(gfp, order, interleave_nodes(pol));
return __alloc_pages_nodemask(gfp, order,
- zonelist_policy(gfp, pol), nodemask_policy(gfp, pol));
+ policy_zonelist(gfp, pol), policy_nodemask(gfp, pol));
}
EXPORT_SYMBOL(alloc_pages_current);
if (!new)
return ERR_PTR(-ENOMEM);
+ rcu_read_lock();
if (current_cpuset_is_being_rebound()) {
nodemask_t mems = cpuset_mems_allowed(current);
mpol_rebind_policy(old, &mems);
}
+ rcu_read_unlock();
*new = *old;
atomic_set(&new->refcnt, 1);
return new;
}
+/*
+ * If *frompol needs [has] an extra ref, copy *frompol to *tompol ,
+ * eliminate the * MPOL_F_* flags that require conditional ref and
+ * [NOTE!!!] drop the extra ref. Not safe to reference *frompol directly
+ * after return. Use the returned value.
+ *
+ * Allows use of a mempolicy for, e.g., multiple allocations with a single
+ * policy lookup, even if the policy needs/has extra ref on lookup.
+ * shmem_readahead needs this.
+ */
+struct mempolicy *__mpol_cond_copy(struct mempolicy *tompol,
+ struct mempolicy *frompol)
+{
+ if (!mpol_needs_cond_ref(frompol))
+ return frompol;
+
+ *tompol = *frompol;
+ tompol->flags &= ~MPOL_F_SHARED; /* copy doesn't need unref */
+ __mpol_put(frompol);
+ return tompol;
+}
+
static int mpol_match_intent(const struct mempolicy *a,
const struct mempolicy *b)
{
if (a->mode != MPOL_DEFAULT && !mpol_match_intent(a, b))
return 0;
switch (a->mode) {
- case MPOL_DEFAULT:
- return 1;
case MPOL_BIND:
/* Fall through */
case MPOL_INTERLEAVE:
return nodes_equal(a->v.nodes, b->v.nodes);
case MPOL_PREFERRED:
- return a->v.preferred_node == b->v.preferred_node;
+ return a->v.preferred_node == b->v.preferred_node &&
+ a->flags == b->flags;
default:
BUG();
return 0;
}
}
-/* Slow path of a mpol destructor. */
-void __mpol_put(struct mempolicy *p)
-{
- if (!atomic_dec_and_test(&p->refcnt))
- return;
- p->mode = MPOL_DEFAULT;
- kmem_cache_free(policy_cache, p);
-}
-
/*
* Shared memory backing store policy support.
*
return 0;
}
-void mpol_shared_policy_init(struct shared_policy *info, unsigned short policy,
- unsigned short flags, nodemask_t *policy_nodes)
+/**
+ * mpol_shared_policy_init - initialize shared policy for inode
+ * @sp: pointer to inode shared policy
+ * @mpol: struct mempolicy to install
+ *
+ * Install non-NULL @mpol in inode's shared policy rb-tree.
+ * On entry, the current task has a reference on a non-NULL @mpol.
+ * This must be released on exit.
+ * This is called at get_inode() calls and we can use GFP_KERNEL.
+ */
+void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol)
{
- info->root = RB_ROOT;
- spin_lock_init(&info->lock);
-
- if (policy != MPOL_DEFAULT) {
- struct mempolicy *newpol;
+ int ret;
- /* Falls back to MPOL_DEFAULT on any error */
- newpol = mpol_new(policy, flags, policy_nodes);
- if (!IS_ERR(newpol)) {
- /* Create pseudo-vma that contains just the policy */
- struct vm_area_struct pvma;
+ sp->root = RB_ROOT; /* empty tree == default mempolicy */
+ spin_lock_init(&sp->lock);
+
+ if (mpol) {
+ struct vm_area_struct pvma;
+ struct mempolicy *new;
+ NODEMASK_SCRATCH(scratch);
+
+ if (!scratch)
+ return;
+ /* contextualize the tmpfs mount point mempolicy */
+ new = mpol_new(mpol->mode, mpol->flags, &mpol->w.user_nodemask);
+ if (IS_ERR(new)) {
+ mpol_put(mpol); /* drop our ref on sb mpol */
+ NODEMASK_SCRATCH_FREE(scratch);
+ return; /* no valid nodemask intersection */
+ }
- 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_put(newpol);
+ task_lock(current);
+ ret = mpol_set_nodemask(new, &mpol->w.user_nodemask, scratch);
+ task_unlock(current);
+ mpol_put(mpol); /* drop our ref on sb mpol */
+ if (ret) {
+ NODEMASK_SCRATCH_FREE(scratch);
+ mpol_put(new);
+ return;
}
+
+ /* Create pseudo-vma that contains just the policy */
+ memset(&pvma, 0, sizeof(struct vm_area_struct));
+ pvma.vm_end = TASK_SIZE; /* policy covers entire file */
+ mpol_set_shared_policy(sp, &pvma, new); /* adds ref */
+ mpol_put(new); /* drop initial ref */
+ NODEMASK_SCRATCH_FREE(scratch);
}
}
}
/*
- * Display pages allocated per node and memory policy via /proc.
+ * Parse and format mempolicy from/to strings
*/
-static const char * const policy_types[] =
- { "default", "prefer", "bind", "interleave" };
/*
+ * "local" is pseudo-policy: MPOL_PREFERRED with MPOL_F_LOCAL flag
+ * Used only for mpol_parse_str() and mpol_to_str()
+ */
+#define MPOL_LOCAL (MPOL_INTERLEAVE + 1)
+static const char * const policy_types[] =
+ { "default", "prefer", "bind", "interleave", "local" };
+
+
+#ifdef CONFIG_TMPFS
+/**
+ * mpol_parse_str - parse string to mempolicy
+ * @str: string containing mempolicy to parse
+ * @mpol: pointer to struct mempolicy pointer, returned on success.
+ * @no_context: flag whether to "contextualize" the mempolicy
+ *
+ * Format of input:
+ * <mode>[=<flags>][:<nodelist>]
+ *
+ * if @no_context is true, save the input nodemask in w.user_nodemask in
+ * the returned mempolicy. This will be used to "clone" the mempolicy in
+ * a specific context [cpuset] at a later time. Used to parse tmpfs mpol
+ * mount option. Note that if 'static' or 'relative' mode flags were
+ * specified, the input nodemask will already have been saved. Saving
+ * it again is redundant, but safe.
+ *
+ * On success, returns 0, else 1
+ */
+int mpol_parse_str(char *str, struct mempolicy **mpol, int no_context)
+{
+ struct mempolicy *new = NULL;
+ unsigned short uninitialized_var(mode);
+ unsigned short uninitialized_var(mode_flags);
+ nodemask_t nodes;
+ char *nodelist = strchr(str, ':');
+ char *flags = strchr(str, '=');
+ int i;
+ int err = 1;
+
+ if (nodelist) {
+ /* NUL-terminate mode or flags string */
+ *nodelist++ = '\0';
+ if (nodelist_parse(nodelist, nodes))
+ goto out;
+ if (!nodes_subset(nodes, node_states[N_HIGH_MEMORY]))
+ goto out;
+ } else
+ nodes_clear(nodes);
+
+ if (flags)
+ *flags++ = '\0'; /* terminate mode string */
+
+ for (i = 0; i <= MPOL_LOCAL; i++) {
+ if (!strcmp(str, policy_types[i])) {
+ mode = i;
+ break;
+ }
+ }
+ if (i > MPOL_LOCAL)
+ goto out;
+
+ switch (mode) {
+ case MPOL_PREFERRED:
+ /*
+ * Insist on a nodelist of one node only
+ */
+ if (nodelist) {
+ char *rest = nodelist;
+ while (isdigit(*rest))
+ rest++;
+ if (*rest)
+ goto out;
+ }
+ break;
+ case MPOL_INTERLEAVE:
+ /*
+ * Default to online nodes with memory if no nodelist
+ */
+ if (!nodelist)
+ nodes = node_states[N_HIGH_MEMORY];
+ break;
+ case MPOL_LOCAL:
+ /*
+ * Don't allow a nodelist; mpol_new() checks flags
+ */
+ if (nodelist)
+ goto out;
+ mode = MPOL_PREFERRED;
+ break;
+ case MPOL_DEFAULT:
+ /*
+ * Insist on a empty nodelist
+ */
+ if (!nodelist)
+ err = 0;
+ goto out;
+ case MPOL_BIND:
+ /*
+ * Insist on a nodelist
+ */
+ if (!nodelist)
+ goto out;
+ }
+
+ mode_flags = 0;
+ if (flags) {
+ /*
+ * Currently, we only support two mutually exclusive
+ * mode flags.
+ */
+ if (!strcmp(flags, "static"))
+ mode_flags |= MPOL_F_STATIC_NODES;
+ else if (!strcmp(flags, "relative"))
+ mode_flags |= MPOL_F_RELATIVE_NODES;
+ else
+ goto out;
+ }
+
+ new = mpol_new(mode, mode_flags, &nodes);
+ if (IS_ERR(new))
+ goto out;
+
+ {
+ int ret;
+ NODEMASK_SCRATCH(scratch);
+ if (scratch) {
+ task_lock(current);
+ ret = mpol_set_nodemask(new, &nodes, scratch);
+ task_unlock(current);
+ } else
+ ret = -ENOMEM;
+ NODEMASK_SCRATCH_FREE(scratch);
+ if (ret) {
+ mpol_put(new);
+ goto out;
+ }
+ }
+ err = 0;
+ if (no_context) {
+ /* save for contextualization */
+ new->w.user_nodemask = nodes;
+ }
+
+out:
+ /* Restore string for error message */
+ if (nodelist)
+ *--nodelist = ':';
+ if (flags)
+ *--flags = '=';
+ if (!err)
+ *mpol = new;
+ return err;
+}
+#endif /* CONFIG_TMPFS */
+
+/**
+ * mpol_to_str - format a mempolicy structure for printing
+ * @buffer: to contain formatted mempolicy string
+ * @maxlen: length of @buffer
+ * @pol: pointer to mempolicy to be formatted
+ * @no_context: "context free" mempolicy - use nodemask in w.user_nodemask
+ *
* 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)
+int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol, int no_context)
{
char *p = buffer;
int l;
nodemask_t nodes;
- unsigned short mode = pol ? pol->mode : MPOL_DEFAULT;
+ unsigned short mode;
unsigned short flags = pol ? pol->flags : 0;
+ /*
+ * Sanity check: room for longest mode, flag and some nodes
+ */
+ VM_BUG_ON(maxlen < strlen("interleave") + strlen("relative") + 16);
+
+ if (!pol || pol == &default_policy)
+ mode = MPOL_DEFAULT;
+ else
+ mode = pol->mode;
+
switch (mode) {
case MPOL_DEFAULT:
nodes_clear(nodes);
case MPOL_PREFERRED:
nodes_clear(nodes);
- node_set(pol->v.preferred_node, nodes);
+ if (flags & MPOL_F_LOCAL)
+ mode = MPOL_LOCAL; /* pseudo-policy */
+ else
+ node_set(pol->v.preferred_node, nodes);
break;
case MPOL_BIND:
/* Fall through */
case MPOL_INTERLEAVE:
- nodes = pol->v.nodes;
+ if (no_context)
+ nodes = pol->w.user_nodemask;
+ else
+ nodes = pol->v.nodes;
break;
default:
BUG();
- return -EFAULT;
}
l = strlen(policy_types[mode]);
- if (buffer + maxlen < p + l + 1)
- return -ENOSPC;
+ if (buffer + maxlen < p + l + 1)
+ return -ENOSPC;
strcpy(p, policy_types[mode]);
p += l;
- if (flags) {
- int need_bar = 0;
-
+ if (flags & MPOL_MODE_FLAGS) {
if (buffer + maxlen < p + 2)
return -ENOSPC;
*p++ = '=';
+ /*
+ * Currently, the only defined flags are mutually exclusive
+ */
if (flags & MPOL_F_STATIC_NODES)
- p += sprintf(p, "%sstatic", need_bar++ ? "|" : "");
- if (flags & MPOL_F_RELATIVE_NODES)
- p += sprintf(p, "%srelative", need_bar++ ? "|" : "");
+ p += snprintf(p, buffer + maxlen - p, "static");
+ else if (flags & MPOL_F_RELATIVE_NODES)
+ p += snprintf(p, buffer + maxlen - p, "relative");
}
if (!nodes_empty(nodes)) {
if (buffer + maxlen < p + 2)
return -ENOSPC;
- *p++ = '=';
+ *p++ = ':';
p += nodelist_scnprintf(p, buffer + maxlen - p, nodes);
}
return p - buffer;
if (PageSwapCache(page))
md->swapcache++;
- if (PageActive(page))
+ if (PageActive(page) || PageUnevictable(page))
md->active++;
if (PageWriteback(page))
{
unsigned long addr;
struct page *page;
+ struct hstate *h = hstate_vma(vma);
+ unsigned long sz = huge_page_size(h);
- for (addr = start; addr < end; addr += HPAGE_SIZE) {
- pte_t *ptep = huge_pte_offset(vma->vm_mm, addr & HPAGE_MASK);
+ for (addr = start; addr < end; addr += sz) {
+ pte_t *ptep = huge_pte_offset(vma->vm_mm,
+ addr & huge_page_mask(h));
pte_t pte;
if (!ptep)
}
#endif
+/*
+ * Display pages allocated per node and memory policy via /proc.
+ */
int show_numa_map(struct seq_file *m, void *v)
{
struct proc_maps_private *priv = m->private;
return 0;
pol = get_vma_policy(priv->task, vma, vma->vm_start);
- mpol_to_str(buffer, sizeof(buffer), pol);
- /*
- * unref shared or other task's mempolicy
- */
- if (pol != &default_policy && pol != current->mempolicy)
- __mpol_put(pol);
+ mpol_to_str(buffer, sizeof(buffer), pol, 0);
+ mpol_cond_put(pol);
seq_printf(m, "%08lx %s", vma->vm_start, buffer);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff