8. LRU
Each memcg has its own private LRU. Now, its handling is under global
- VM's control (means that it's handled under global zone_lru_lock).
+ VM's control (means that it's handled under global pgdat->lru_lock).
Almost all routines around memcg's LRU is called by global LRU's
- list management functions under zone_lru_lock().
+ list management functions under pgdat->lru_lock.
A special function is mem_cgroup_isolate_pages(). This scans
memcg's private LRU and call __isolate_lru_page() to extract a page
Other lock order is following:
PG_locked.
mm->page_table_lock
- zone_lru_lock
+ pgdat->lru_lock
lock_page_cgroup.
In many cases, just lock_page_cgroup() is called.
per-zone-per-cgroup LRU (cgroup's private LRU) is just guarded by
- zone_lru_lock, it has no lock of its own.
+ pgdat->lru_lock, it has no lock of its own.
2.7 Kernel Memory Extension (CONFIG_MEMCG_KMEM)
struct { /* Page cache and anonymous pages */
/**
* @lru: Pageout list, eg. active_list protected by
- * zone_lru_lock. Sometimes used as a generic list
+ * pgdat->lru_lock. Sometimes used as a generic list
* by the page owner.
*/
struct list_head lru;
#define node_start_pfn(nid) (NODE_DATA(nid)->node_start_pfn)
#define node_end_pfn(nid) pgdat_end_pfn(NODE_DATA(nid))
-static inline spinlock_t *zone_lru_lock(struct zone *zone)
-{
- return &zone->zone_pgdat->lru_lock;
-}
static inline struct lruvec *node_lruvec(struct pglist_data *pgdat)
{
unsigned long end_pfn, isolate_mode_t isolate_mode)
{
struct zone *zone = cc->zone;
+ pg_data_t *pgdat = zone->zone_pgdat;
unsigned long nr_scanned = 0, nr_isolated = 0;
struct lruvec *lruvec;
unsigned long flags = 0;
* if contended.
*/
if (!(low_pfn % SWAP_CLUSTER_MAX)
- && compact_unlock_should_abort(zone_lru_lock(zone), flags,
- &locked, cc))
+ && compact_unlock_should_abort(&pgdat->lru_lock,
+ flags, &locked, cc))
break;
if (!pfn_valid_within(low_pfn))
if (unlikely(__PageMovable(page)) &&
!PageIsolated(page)) {
if (locked) {
- spin_unlock_irqrestore(zone_lru_lock(zone),
+ spin_unlock_irqrestore(&pgdat->lru_lock,
flags);
locked = false;
}
/* If we already hold the lock, we can skip some rechecking */
if (!locked) {
- locked = compact_lock_irqsave(zone_lru_lock(zone),
+ locked = compact_lock_irqsave(&pgdat->lru_lock,
&flags, cc);
/* Try get exclusive access under lock */
}
}
- lruvec = mem_cgroup_page_lruvec(page, zone->zone_pgdat);
+ lruvec = mem_cgroup_page_lruvec(page, pgdat);
/* Try isolate the page */
if (__isolate_lru_page(page, isolate_mode) != 0)
*/
if (nr_isolated) {
if (locked) {
- spin_unlock_irqrestore(zone_lru_lock(zone), flags);
+ spin_unlock_irqrestore(&pgdat->lru_lock, flags);
locked = false;
}
putback_movable_pages(&cc->migratepages);
isolate_abort:
if (locked)
- spin_unlock_irqrestore(zone_lru_lock(zone), flags);
+ spin_unlock_irqrestore(&pgdat->lru_lock, flags);
/*
* Updated the cached scanner pfn once the pageblock has been scanned
* ->swap_lock (try_to_unmap_one)
* ->private_lock (try_to_unmap_one)
* ->i_pages lock (try_to_unmap_one)
- * ->zone_lru_lock(zone) (follow_page->mark_page_accessed)
- * ->zone_lru_lock(zone) (check_pte_range->isolate_lru_page)
+ * ->pgdat->lru_lock (follow_page->mark_page_accessed)
+ * ->pgdat->lru_lock (check_pte_range->isolate_lru_page)
* ->private_lock (page_remove_rmap->set_page_dirty)
* ->i_pages lock (page_remove_rmap->set_page_dirty)
* bdi.wb->list_lock (page_remove_rmap->set_page_dirty)
pgoff_t end, unsigned long flags)
{
struct page *head = compound_head(page);
- struct zone *zone = page_zone(head);
+ pg_data_t *pgdat = page_pgdat(head);
struct lruvec *lruvec;
int i;
- lruvec = mem_cgroup_page_lruvec(head, zone->zone_pgdat);
+ lruvec = mem_cgroup_page_lruvec(head, pgdat);
/* complete memcg works before add pages to LRU */
mem_cgroup_split_huge_fixup(head);
xa_unlock(&head->mapping->i_pages);
}
- spin_unlock_irqrestore(zone_lru_lock(page_zone(head)), flags);
+ spin_unlock_irqrestore(&pgdat->lru_lock, flags);
remap_page(head);
lru_add_drain();
/* prevent PageLRU to go away from under us, and freeze lru stats */
- spin_lock_irqsave(zone_lru_lock(page_zone(head)), flags);
+ spin_lock_irqsave(&pgdata->lru_lock, flags);
if (mapping) {
XA_STATE(xas, &mapping->i_pages, page_index(head));
spin_unlock(&pgdata->split_queue_lock);
fail: if (mapping)
xa_unlock(&mapping->i_pages);
- spin_unlock_irqrestore(zone_lru_lock(page_zone(head)), flags);
+ spin_unlock_irqrestore(&pgdata->lru_lock, flags);
remap_page(head);
ret = -EBUSY;
}
static void lock_page_lru(struct page *page, int *isolated)
{
- struct zone *zone = page_zone(page);
+ pg_data_t *pgdat = page_pgdat(page);
- spin_lock_irq(zone_lru_lock(zone));
+ spin_lock_irq(&pgdat->lru_lock);
if (PageLRU(page)) {
struct lruvec *lruvec;
- lruvec = mem_cgroup_page_lruvec(page, zone->zone_pgdat);
+ lruvec = mem_cgroup_page_lruvec(page, pgdat);
ClearPageLRU(page);
del_page_from_lru_list(page, lruvec, page_lru(page));
*isolated = 1;
static void unlock_page_lru(struct page *page, int isolated)
{
- struct zone *zone = page_zone(page);
+ pg_data_t *pgdat = page_pgdat(page);
if (isolated) {
struct lruvec *lruvec;
- lruvec = mem_cgroup_page_lruvec(page, zone->zone_pgdat);
+ lruvec = mem_cgroup_page_lruvec(page, pgdat);
VM_BUG_ON_PAGE(PageLRU(page), page);
SetPageLRU(page);
add_page_to_lru_list(page, lruvec, page_lru(page));
}
- spin_unlock_irq(zone_lru_lock(zone));
+ spin_unlock_irq(&pgdat->lru_lock);
}
static void commit_charge(struct page *page, struct mem_cgroup *memcg,
/*
* Because tail pages are not marked as "used", set it. We're under
- * zone_lru_lock and migration entries setup in all page mappings.
+ * pgdat->lru_lock and migration entries setup in all page mappings.
*/
void mem_cgroup_split_huge_fixup(struct page *head)
{
unsigned int munlock_vma_page(struct page *page)
{
int nr_pages;
- struct zone *zone = page_zone(page);
+ pg_data_t *pgdat = page_pgdat(page);
/* For try_to_munlock() and to serialize with page migration */
BUG_ON(!PageLocked(page));
* might otherwise copy PageMlocked to part of the tail pages before
* we clear it in the head page. It also stabilizes hpage_nr_pages().
*/
- spin_lock_irq(zone_lru_lock(zone));
+ spin_lock_irq(&pgdat->lru_lock);
if (!TestClearPageMlocked(page)) {
/* Potentially, PTE-mapped THP: do not skip the rest PTEs */
}
nr_pages = hpage_nr_pages(page);
- __mod_zone_page_state(zone, NR_MLOCK, -nr_pages);
+ __mod_zone_page_state(page_zone(page), NR_MLOCK, -nr_pages);
if (__munlock_isolate_lru_page(page, true)) {
- spin_unlock_irq(zone_lru_lock(zone));
+ spin_unlock_irq(&pgdat->lru_lock);
__munlock_isolated_page(page);
goto out;
}
__munlock_isolation_failed(page);
unlock_out:
- spin_unlock_irq(zone_lru_lock(zone));
+ spin_unlock_irq(&pgdat->lru_lock);
out:
return nr_pages - 1;
pagevec_init(&pvec_putback);
/* Phase 1: page isolation */
- spin_lock_irq(zone_lru_lock(zone));
+ spin_lock_irq(&zone->zone_pgdat->lru_lock);
for (i = 0; i < nr; i++) {
struct page *page = pvec->pages[i];
pvec->pages[i] = NULL;
}
__mod_zone_page_state(zone, NR_MLOCK, delta_munlocked);
- spin_unlock_irq(zone_lru_lock(zone));
+ spin_unlock_irq(&zone->zone_pgdat->lru_lock);
/* Now we can release pins of pages that we are not munlocking */
pagevec_release(&pvec_putback);
static struct page *page_idle_get_page(unsigned long pfn)
{
struct page *page;
- struct zone *zone;
+ pg_data_t *pgdat;
if (!pfn_valid(pfn))
return NULL;
!get_page_unless_zero(page))
return NULL;
- zone = page_zone(page);
- spin_lock_irq(zone_lru_lock(zone));
+ pgdat = page_pgdat(page);
+ spin_lock_irq(&pgdat->lru_lock);
if (unlikely(!PageLRU(page))) {
put_page(page);
page = NULL;
}
- spin_unlock_irq(zone_lru_lock(zone));
+ spin_unlock_irq(&pgdat->lru_lock);
return page;
}
* mapping->i_mmap_rwsem
* anon_vma->rwsem
* mm->page_table_lock or pte_lock
- * zone_lru_lock (in mark_page_accessed, isolate_lru_page)
+ * pgdat->lru_lock (in mark_page_accessed, isolate_lru_page)
* swap_lock (in swap_duplicate, swap_info_get)
* mmlist_lock (in mmput, drain_mmlist and others)
* mapping->private_lock (in __set_page_dirty_buffers)
static void __page_cache_release(struct page *page)
{
if (PageLRU(page)) {
- struct zone *zone = page_zone(page);
+ pg_data_t *pgdat = page_pgdat(page);
struct lruvec *lruvec;
unsigned long flags;
- spin_lock_irqsave(zone_lru_lock(zone), flags);
- lruvec = mem_cgroup_page_lruvec(page, zone->zone_pgdat);
+ spin_lock_irqsave(&pgdat->lru_lock, flags);
+ lruvec = mem_cgroup_page_lruvec(page, pgdat);
VM_BUG_ON_PAGE(!PageLRU(page), page);
__ClearPageLRU(page);
del_page_from_lru_list(page, lruvec, page_off_lru(page));
- spin_unlock_irqrestore(zone_lru_lock(zone), flags);
+ spin_unlock_irqrestore(&pgdat->lru_lock, flags);
}
__ClearPageWaiters(page);
mem_cgroup_uncharge(page);
void activate_page(struct page *page)
{
- struct zone *zone = page_zone(page);
+ pg_data_t *pgdat = page_pgdat(page);
page = compound_head(page);
- spin_lock_irq(zone_lru_lock(zone));
- __activate_page(page, mem_cgroup_page_lruvec(page, zone->zone_pgdat), NULL);
- spin_unlock_irq(zone_lru_lock(zone));
+ spin_lock_irq(&pgdat->lru_lock);
+ __activate_page(page, mem_cgroup_page_lruvec(page, pgdat), NULL);
+ spin_unlock_irq(&pgdat->lru_lock);
}
#endif
}
-/*
- * zone_lru_lock is heavily contended. Some of the functions that
+/**
+ * pgdat->lru_lock is heavily contended. Some of the functions that
* shrink the lists perform better by taking out a batch of pages
* and working on them outside the LRU lock.
*
WARN_RATELIMIT(PageTail(page), "trying to isolate tail page");
if (PageLRU(page)) {
- struct zone *zone = page_zone(page);
+ pg_data_t *pgdat = page_pgdat(page);
struct lruvec *lruvec;
- spin_lock_irq(zone_lru_lock(zone));
- lruvec = mem_cgroup_page_lruvec(page, zone->zone_pgdat);
+ spin_lock_irq(&pgdat->lru_lock);
+ lruvec = mem_cgroup_page_lruvec(page, pgdat);
if (PageLRU(page)) {
int lru = page_lru(page);
get_page(page);
del_page_from_lru_list(page, lruvec, lru);
ret = 0;
}
- spin_unlock_irq(zone_lru_lock(zone));
+ spin_unlock_irq(&pgdat->lru_lock);
}
return ret;
}
* processes, from rmap.
*
* If the pages are mostly unmapped, the processing is fast and it is
- * appropriate to hold zone_lru_lock across the whole operation. But if
+ * appropriate to hold pgdat->lru_lock across the whole operation. But if
* the pages are mapped, the processing is slow (page_referenced()) so we
- * should drop zone_lru_lock around each page. It's impossible to balance
+ * should drop pgdat->lru_lock around each page. It's impossible to balance
* this, so instead we remove the pages from the LRU while processing them.
* It is safe to rely on PG_active against the non-LRU pages in here because
* nobody will play with that bit on a non-LRU page.