#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/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);
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 (!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.
*/
/* 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;
* 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;
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff