#include <linux/vmalloc.h>
#include <linux/security.h>
#include <linux/backing-dev.h>
+#include <linux/compaction.h>
#include <linux/syscalls.h>
#include <linux/hugetlb.h>
#include <linux/hugetlb_cgroup.h>
return 0;
}
+bool isolate_movable_page(struct page *page, isolate_mode_t mode)
+{
+ struct address_space *mapping;
+
+ /*
+ * Avoid burning cycles with pages that are yet under __free_pages(),
+ * or just got freed under us.
+ *
+ * In case we 'win' a race for a movable page being freed under us and
+ * raise its refcount preventing __free_pages() from doing its job
+ * the put_page() at the end of this block will take care of
+ * release this page, thus avoiding a nasty leakage.
+ */
+ if (unlikely(!get_page_unless_zero(page)))
+ goto out;
+
+ /*
+ * Check PageMovable before holding a PG_lock because page's owner
+ * assumes anybody doesn't touch PG_lock of newly allocated page
+ * so unconditionally grapping the lock ruins page's owner side.
+ */
+ if (unlikely(!__PageMovable(page)))
+ goto out_putpage;
+ /*
+ * As movable pages are not isolated from LRU lists, concurrent
+ * compaction threads can race against page migration functions
+ * as well as race against the releasing a page.
+ *
+ * In order to avoid having an already isolated movable page
+ * being (wrongly) re-isolated while it is under migration,
+ * or to avoid attempting to isolate pages being released,
+ * lets be sure we have the page lock
+ * before proceeding with the movable page isolation steps.
+ */
+ if (unlikely(!trylock_page(page)))
+ goto out_putpage;
+
+ if (!PageMovable(page) || PageIsolated(page))
+ goto out_no_isolated;
+
+ mapping = page_mapping(page);
+ VM_BUG_ON_PAGE(!mapping, page);
+
+ if (!mapping->a_ops->isolate_page(page, mode))
+ goto out_no_isolated;
+
+ /* Driver shouldn't use PG_isolated bit of page->flags */
+ WARN_ON_ONCE(PageIsolated(page));
+ __SetPageIsolated(page);
+ unlock_page(page);
+
+ return true;
+
+out_no_isolated:
+ unlock_page(page);
+out_putpage:
+ put_page(page);
+out:
+ return false;
+}
+
+/* It should be called on page which is PG_movable */
+void putback_movable_page(struct page *page)
+{
+ struct address_space *mapping;
+
+ VM_BUG_ON_PAGE(!PageLocked(page), page);
+ VM_BUG_ON_PAGE(!PageMovable(page), page);
+ VM_BUG_ON_PAGE(!PageIsolated(page), page);
+
+ mapping = page_mapping(page);
+ mapping->a_ops->putback_page(page);
+ __ClearPageIsolated(page);
+}
+
/*
* Put previously isolated pages back onto the appropriate lists
* from where they were once taken off for compaction/migration.
continue;
}
list_del(&page->lru);
- dec_zone_page_state(page, NR_ISOLATED_ANON +
+ dec_node_page_state(page, NR_ISOLATED_ANON +
page_is_file_cache(page));
- if (unlikely(isolated_balloon_page(page)))
- balloon_page_putback(page);
- else
+ /*
+ * We isolated non-lru movable page so here we can use
+ * __PageMovable because LRU page's mapping cannot have
+ * PAGE_MAPPING_MOVABLE.
+ */
+ if (unlikely(__PageMovable(page))) {
+ VM_BUG_ON_PAGE(!PageIsolated(page), page);
+ lock_page(page);
+ if (PageMovable(page))
+ putback_movable_page(page);
+ else
+ __ClearPageIsolated(page);
+ unlock_page(page);
+ put_page(page);
+ } else {
putback_lru_page(page);
+ }
}
}
} else if (PageAnon(new))
page_add_anon_rmap(new, vma, addr, false);
else
- page_add_file_rmap(new);
+ page_add_file_rmap(new, false);
if (vma->vm_flags & VM_LOCKED && !PageTransCompound(new))
mlock_vma_page(new);
* 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
+ * via NR_FILE_PAGES and NR_ANON_MAPPED if they
* are mapped to swap space.
*/
if (newzone != oldzone) {
- __dec_zone_state(oldzone, NR_FILE_PAGES);
- __inc_zone_state(newzone, NR_FILE_PAGES);
+ __dec_node_state(oldzone->zone_pgdat, NR_FILE_PAGES);
+ __inc_node_state(newzone->zone_pgdat, NR_FILE_PAGES);
if (PageSwapBacked(page) && !PageSwapCache(page)) {
- __dec_zone_state(oldzone, NR_SHMEM);
- __inc_zone_state(newzone, NR_SHMEM);
+ __dec_node_state(oldzone->zone_pgdat, NR_SHMEM);
+ __inc_node_state(newzone->zone_pgdat, NR_SHMEM);
}
if (dirty && mapping_cap_account_dirty(mapping)) {
- __dec_zone_state(oldzone, NR_FILE_DIRTY);
- __inc_zone_state(newzone, NR_FILE_DIRTY);
+ __dec_node_state(oldzone->zone_pgdat, NR_FILE_DIRTY);
+ __dec_zone_state(oldzone, NR_ZONE_WRITE_PENDING);
+ __inc_node_state(newzone->zone_pgdat, NR_FILE_DIRTY);
+ __inc_zone_state(newzone, NR_ZONE_WRITE_PENDING);
}
}
local_irq_enable();
***********************************************************/
/*
- * Common logic to directly migrate a single page suitable for
+ * Common logic to directly migrate a single LRU page suitable for
* pages that do not use PagePrivate/PagePrivate2.
*
* Pages are locked upon entry and exit.
enum migrate_mode mode)
{
struct address_space *mapping;
- int rc;
+ int rc = -EAGAIN;
+ bool is_lru = !__PageMovable(page);
VM_BUG_ON_PAGE(!PageLocked(page), page);
VM_BUG_ON_PAGE(!PageLocked(newpage), newpage);
mapping = page_mapping(page);
- if (!mapping)
- rc = migrate_page(mapping, newpage, page, mode);
- else if (mapping->a_ops->migratepage)
+
+ if (likely(is_lru)) {
+ if (!mapping)
+ rc = migrate_page(mapping, newpage, page, mode);
+ else if (mapping->a_ops->migratepage)
+ /*
+ * Most pages have a mapping and most filesystems
+ * provide a migratepage callback. Anonymous pages
+ * are part of swap space which also has its own
+ * migratepage callback. This is the most common path
+ * for page migration.
+ */
+ rc = mapping->a_ops->migratepage(mapping, newpage,
+ page, mode);
+ else
+ rc = fallback_migrate_page(mapping, newpage,
+ page, mode);
+ } else {
/*
- * Most pages have a mapping and most filesystems provide a
- * migratepage callback. Anonymous pages are part of swap
- * space which also has its own migratepage callback. This
- * is the most common path for page migration.
+ * In case of non-lru page, it could be released after
+ * isolation step. In that case, we shouldn't try migration.
*/
- rc = mapping->a_ops->migratepage(mapping, newpage, page, mode);
- else
- rc = fallback_migrate_page(mapping, newpage, page, mode);
+ VM_BUG_ON_PAGE(!PageIsolated(page), page);
+ if (!PageMovable(page)) {
+ rc = MIGRATEPAGE_SUCCESS;
+ __ClearPageIsolated(page);
+ goto out;
+ }
+
+ rc = mapping->a_ops->migratepage(mapping, newpage,
+ page, mode);
+ WARN_ON_ONCE(rc == MIGRATEPAGE_SUCCESS &&
+ !PageIsolated(page));
+ }
/*
* When successful, old pagecache page->mapping must be cleared before
* page is freed; but stats require that PageAnon be left as PageAnon.
*/
if (rc == MIGRATEPAGE_SUCCESS) {
- if (!PageAnon(page))
+ if (__PageMovable(page)) {
+ VM_BUG_ON_PAGE(!PageIsolated(page), page);
+
+ /*
+ * We clear PG_movable under page_lock so any compactor
+ * cannot try to migrate this page.
+ */
+ __ClearPageIsolated(page);
+ }
+
+ /*
+ * Anonymous and movable page->mapping will be cleard by
+ * free_pages_prepare so don't reset it here for keeping
+ * the type to work PageAnon, for example.
+ */
+ if (!PageMappingFlags(page))
page->mapping = NULL;
}
+out:
return rc;
}
int rc = -EAGAIN;
int page_was_mapped = 0;
struct anon_vma *anon_vma = NULL;
+ bool is_lru = !__PageMovable(page);
if (!trylock_page(page)) {
if (!force || mode == MIGRATE_ASYNC)
if (unlikely(!trylock_page(newpage)))
goto out_unlock;
- if (unlikely(isolated_balloon_page(page))) {
- /*
- * A ballooned page does not need any special attention from
- * physical to virtual reverse mapping procedures.
- * Skip any attempt to unmap PTEs or to remap swap cache,
- * in order to avoid burning cycles at rmap level, and perform
- * the page migration right away (proteced by page lock).
- */
- rc = balloon_page_migrate(newpage, page, mode);
+ if (unlikely(!is_lru)) {
+ rc = move_to_new_page(newpage, page, mode);
goto out_unlock_both;
}
put_anon_vma(anon_vma);
unlock_page(page);
out:
+ /*
+ * If migration is successful, decrease refcount of the newpage
+ * which will not free the page because new page owner increased
+ * refcounter. As well, if it is LRU page, add the page to LRU
+ * list in here.
+ */
+ if (rc == MIGRATEPAGE_SUCCESS) {
+ if (unlikely(__PageMovable(newpage)))
+ put_page(newpage);
+ else
+ putback_lru_page(newpage);
+ }
+
return rc;
}
if (page_count(page) == 1) {
/* page was freed from under us. So we are done. */
+ ClearPageActive(page);
+ ClearPageUnevictable(page);
+ if (unlikely(__PageMovable(page))) {
+ lock_page(page);
+ if (!PageMovable(page))
+ __ClearPageIsolated(page);
+ unlock_page(page);
+ }
+ if (put_new_page)
+ put_new_page(newpage, private);
+ else
+ put_page(newpage);
goto out;
}
}
rc = __unmap_and_move(page, newpage, force, mode);
- if (rc == MIGRATEPAGE_SUCCESS) {
- put_new_page = NULL;
+ if (rc == MIGRATEPAGE_SUCCESS)
set_page_owner_migrate_reason(newpage, reason);
- }
out:
if (rc != -EAGAIN) {
* restored.
*/
list_del(&page->lru);
- dec_zone_page_state(page, NR_ISOLATED_ANON +
+ dec_node_page_state(page, NR_ISOLATED_ANON +
page_is_file_cache(page));
- /* Soft-offlined page shouldn't go through lru cache list */
- if (reason == MR_MEMORY_FAILURE && rc == MIGRATEPAGE_SUCCESS) {
+ }
+
+ /*
+ * If migration is successful, releases reference grabbed during
+ * isolation. Otherwise, restore the page to right list unless
+ * we want to retry.
+ */
+ if (rc == MIGRATEPAGE_SUCCESS) {
+ put_page(page);
+ if (reason == MR_MEMORY_FAILURE) {
/*
- * With this release, we free successfully migrated
- * page and set PG_HWPoison on just freed page
- * intentionally. Although it's rather weird, it's how
- * HWPoison flag works at the moment.
+ * Set PG_HWPoison on just freed page
+ * intentionally. Although it's rather weird,
+ * it's how HWPoison flag works at the moment.
*/
- put_page(page);
if (!test_set_page_hwpoison(page))
num_poisoned_pages_inc();
- } else
- putback_lru_page(page);
- }
+ }
+ } else {
+ if (rc != -EAGAIN) {
+ if (likely(!__PageMovable(page))) {
+ putback_lru_page(page);
+ goto put_new;
+ }
- /*
- * If migration was not successful and there's a freeing callback, use
- * it. Otherwise, putback_lru_page() will drop the reference grabbed
- * during isolation.
- */
- if (put_new_page)
- put_new_page(newpage, private);
- else if (unlikely(__is_movable_balloon_page(newpage))) {
- /* drop our reference, page already in the balloon */
- put_page(newpage);
- } else
- putback_lru_page(newpage);
+ lock_page(page);
+ if (PageMovable(page))
+ putback_movable_page(page);
+ else
+ __ClearPageIsolated(page);
+ unlock_page(page);
+ put_page(page);
+ }
+put_new:
+ if (put_new_page)
+ put_new_page(newpage, private);
+ else
+ put_page(newpage);
+ }
if (result) {
if (rc)
err = isolate_lru_page(page);
if (!err) {
list_add_tail(&page->lru, &pagelist);
- inc_zone_page_state(page, NR_ISOLATED_ANON +
+ inc_node_page_state(page, NR_ISOLATED_ANON +
page_is_file_cache(page));
}
put_and_set:
unsigned long nr_migrate_pages)
{
int z;
+
+ if (!pgdat_reclaimable(pgdat))
+ return false;
+
for (z = pgdat->nr_zones - 1; z >= 0; z--) {
struct zone *zone = pgdat->node_zones + z;
if (!populated_zone(zone))
continue;
- if (!zone_reclaimable(zone))
- continue;
-
/* Avoid waking kswapd by allocating pages_to_migrate pages. */
if (!zone_watermark_ok(zone, 0,
high_wmark_pages(zone) +
}
page_lru = page_is_file_cache(page);
- mod_zone_page_state(page_zone(page), NR_ISOLATED_ANON + page_lru,
+ mod_node_page_state(page_pgdat(page), NR_ISOLATED_ANON + page_lru,
hpage_nr_pages(page));
/*
if (nr_remaining) {
if (!list_empty(&migratepages)) {
list_del(&page->lru);
- dec_zone_page_state(page, NR_ISOLATED_ANON +
+ dec_node_page_state(page, NR_ISOLATED_ANON +
page_is_file_cache(page));
putback_lru_page(page);
}
goto out_dropref;
new_page = alloc_pages_node(node,
- (GFP_TRANSHUGE | __GFP_THISNODE) & ~__GFP_RECLAIM,
+ (GFP_TRANSHUGE_LIGHT | __GFP_THISNODE),
HPAGE_PMD_ORDER);
if (!new_page)
goto out_fail;
/* Retake the callers reference and putback on LRU */
get_page(page);
putback_lru_page(page);
- mod_zone_page_state(page_zone(page),
+ mod_node_page_state(page_pgdat(page),
NR_ISOLATED_ANON + page_lru, -HPAGE_PMD_NR);
goto out_unlock;
}
orig_entry = *pmd;
- entry = mk_pmd(new_page, vma->vm_page_prot);
- entry = pmd_mkhuge(entry);
+ entry = mk_huge_pmd(new_page, vma->vm_page_prot);
entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
/*
count_vm_events(PGMIGRATE_SUCCESS, HPAGE_PMD_NR);
count_vm_numa_events(NUMA_PAGE_MIGRATE, HPAGE_PMD_NR);
- mod_zone_page_state(page_zone(page),
+ mod_node_page_state(page_pgdat(page),
NR_ISOLATED_ANON + page_lru,
-HPAGE_PMD_NR);
return isolated;
projects / cascardo / linux.git / blobdiff