#include <linux/pagemap.h>
#include <linux/buffer_head.h>
#include <linux/mm_inline.h>
+#include <linux/nsproxy.h>
#include <linux/pagevec.h>
#include <linux/rmap.h>
#include <linux/topology.h>
#include <linux/writeback.h>
#include <linux/mempolicy.h>
#include <linux/vmalloc.h>
+#include <linux/security.h>
+#include <linux/memcontrol.h>
#include "internal.h"
struct zone *zone = page_zone(page);
spin_lock_irq(&zone->lru_lock);
- if (PageLRU(page)) {
+ if (PageLRU(page) && get_page_unless_zero(page)) {
ret = 0;
- get_page(page);
ClearPageLRU(page);
if (PageActive(page))
del_page_from_active_list(zone, page);
return count;
}
-static inline int is_swap_pte(pte_t pte)
-{
- return !pte_none(pte) && !pte_present(pte) && !pte_file(pte);
-}
-
/*
* Restore a potential migration pte to a working pte entry
*/
return;
}
+ if (mem_cgroup_charge(new, mm, GFP_KERNEL)) {
+ pte_unmap(ptep);
+ return;
+ }
+
ptl = pte_lockptr(mm, pmd);
spin_lock(ptl);
pte = *ptep;
pte = pte_mkold(mk_pte(new, vma->vm_page_prot));
if (is_write_migration_entry(entry))
pte = pte_mkwrite(pte);
+ flush_cache_page(vma, addr, pte_pfn(pte));
set_pte_at(mm, addr, ptep, pte);
if (PageAnon(new))
/* No need to invalidate - it was non-present before */
update_mmu_cache(vma, addr, pte);
- lazy_mmu_prot_update(pte);
out:
pte_unmap_unlock(ptep, ptl);
static int migrate_page_move_mapping(struct address_space *mapping,
struct page *newpage, struct page *page)
{
- struct page **radix_pointer;
+ void **pslot;
if (!mapping) {
- /* Anonymous page */
+ /* Anonymous page without mapping */
if (page_count(page) != 1)
return -EAGAIN;
return 0;
write_lock_irq(&mapping->tree_lock);
- radix_pointer = (struct page **)radix_tree_lookup_slot(
- &mapping->page_tree,
- page_index(page));
+ pslot = radix_tree_lookup_slot(&mapping->page_tree,
+ page_index(page));
if (page_count(page) != 2 + !!PagePrivate(page) ||
- *radix_pointer != page) {
+ (struct page *)radix_tree_deref_slot(pslot) != page) {
write_unlock_irq(&mapping->tree_lock);
return -EAGAIN;
}
/*
* Now we know that no one else is looking at the page.
*/
- get_page(newpage);
+ get_page(newpage); /* add cache reference */
#ifdef CONFIG_SWAP
if (PageSwapCache(page)) {
SetPageSwapCache(newpage);
}
#endif
- *radix_pointer = newpage;
+ radix_tree_replace_slot(pslot, newpage);
+
+ /*
+ * Drop cache reference from old page.
+ * We know this isn't the last reference.
+ */
__put_page(page);
+
+ /*
+ * If moved to a different zone then also account
+ * the page for that zone. Other VM counters will be
+ * taken care of when we establish references to the
+ * new page and drop references to the old page.
+ *
+ * Note that anonymous pages are accounted for
+ * via NR_FILE_PAGES and NR_ANON_PAGES if they
+ * are mapped to swap space.
+ */
+ __dec_zone_page_state(page, NR_FILE_PAGES);
+ __inc_zone_page_state(newpage, NR_FILE_PAGES);
+
write_unlock_irq(&mapping->tree_lock);
return 0;
}
EXPORT_SYMBOL(migrate_page);
+#ifdef CONFIG_BLOCK
/*
* Migration function for pages with buffers. This function can only be used
* if the underlying filesystem guarantees that no other references to "page"
return 0;
}
EXPORT_SYMBOL(buffer_migrate_page);
+#endif
/*
* Writeback a page to clean the dirty state
* Buffers may be managed in a filesystem specific way.
* We must have no buffers or drop them.
*/
- if (page_has_buffers(page) &&
+ if (PagePrivate(page) &&
!try_to_release_page(page, GFP_KERNEL))
return -EAGAIN;
int rc = 0;
int *result = NULL;
struct page *newpage = get_new_page(page, private, &result);
+ int rcu_locked = 0;
if (!newpage)
return -ENOMEM;
goto unlock;
wait_on_page_writeback(page);
}
+ /*
+ * By try_to_unmap(), page->mapcount goes down to 0 here. In this case,
+ * we cannot notice that anon_vma is freed while we migrates a page.
+ * This rcu_read_lock() delays freeing anon_vma pointer until the end
+ * of migration. File cache pages are no problem because of page_lock()
+ * File Caches may use write_page() or lock_page() in migration, then,
+ * just care Anon page here.
+ */
+ if (PageAnon(page)) {
+ rcu_read_lock();
+ rcu_locked = 1;
+ }
/*
- * Establish migration ptes or remove ptes
+ * Corner case handling:
+ * 1. When a new swap-cache page is read into, it is added to the LRU
+ * and treated as swapcache but it has no rmap yet.
+ * Calling try_to_unmap() against a page->mapping==NULL page will
+ * trigger a BUG. So handle it here.
+ * 2. An orphaned page (see truncate_complete_page) might have
+ * fs-private metadata. The page can be picked up due to memory
+ * offlining. Everywhere else except page reclaim, the page is
+ * invisible to the vm, so the page can not be migrated. So try to
+ * free the metadata, so the page can be freed.
*/
- if (try_to_unmap(page, 1) != SWAP_FAIL) {
- if (!page_mapped(page))
- rc = move_to_new_page(newpage, page);
- } else
- /* A vma has VM_LOCKED set -> permanent failure */
- rc = -EPERM;
+ if (!page->mapping) {
+ if (!PageAnon(page) && PagePrivate(page)) {
+ /*
+ * Go direct to try_to_free_buffers() here because
+ * a) that's what try_to_release_page() would do anyway
+ * b) we may be under rcu_read_lock() here, so we can't
+ * use GFP_KERNEL which is what try_to_release_page()
+ * needs to be effective.
+ */
+ try_to_free_buffers(page);
+ }
+ goto rcu_unlock;
+ }
+
+ /* Establish migration ptes or remove ptes */
+ try_to_unmap(page, 1);
+
+ if (!page_mapped(page))
+ rc = move_to_new_page(newpage, page);
if (rc)
remove_migration_ptes(page, page);
+rcu_unlock:
+ if (rcu_locked)
+ rcu_read_unlock();
+
unlock:
+
unlock_page(page);
if (rc != -EAGAIN) {
* The function returns after 10 attempts or if no pages
* are movable anymore because to has become empty
* or no retryable pages exist anymore. All pages will be
- * retruned to the LRU or freed.
+ * returned to the LRU or freed.
*
* Return: Number of pages not migrated or error code.
*/
*result = &pm->status;
- return alloc_pages_node(pm->node, GFP_HIGHUSER, 0);
+ return alloc_pages_node(pm->node,
+ GFP_HIGHUSER_MOVABLE | GFP_THISNODE, 0);
}
/*
err = -EFAULT;
vma = find_vma(mm, pp->addr);
- if (!vma)
+ if (!vma || !vma_migratable(vma))
goto set_status;
page = follow_page(vma, pp->addr, FOLL_GET);
/* Find the mm_struct */
read_lock(&tasklist_lock);
- task = pid ? find_task_by_pid(pid) : current;
+ task = pid ? find_task_by_vpid(pid) : current;
if (!task) {
read_unlock(&tasklist_lock);
return -ESRCH;
goto out2;
}
+ err = security_task_movememory(task);
+ if (err)
+ goto out2;
+
+
task_nodes = cpuset_mems_allowed(task);
/* Limit nr_pages so that the multiplication may not overflow */
* array. Return various errors if the user did something wrong.
*/
for (i = 0; i < nr_pages; i++) {
- const void *p;
+ const void __user *p;
err = -EFAULT;
if (get_user(p, pages + i))
goto out;
err = -ENODEV;
- if (!node_online(node))
+ if (!node_state(node, N_HIGH_MEMORY))
goto out;
err = -EACCES;
goto out;
pm[i].node = node;
- }
+ } else
+ pm[i].node = 0; /* anything to not match MAX_NUMNODES */
}
/* End marker */
pm[nr_pages].node = MAX_NUMNODES;
}
#endif
+/*
+ * Call migration functions in the vma_ops that may prepare
+ * memory in a vm for migration. migration functions may perform
+ * the migration for vmas that do not have an underlying page struct.
+ */
+int migrate_vmas(struct mm_struct *mm, const nodemask_t *to,
+ const nodemask_t *from, unsigned long flags)
+{
+ struct vm_area_struct *vma;
+ int err = 0;
+
+ for(vma = mm->mmap; vma->vm_next && !err; vma = vma->vm_next) {
+ if (vma->vm_ops && vma->vm_ops->migrate) {
+ err = vma->vm_ops->migrate(vma, to, from, flags);
+ if (err)
+ break;
+ }
+ }
+ return err;
+}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff