*/
/*
- * This file contains the default values for the opereation of the
+ * This file contains the default values for the operation of the
* Linux VM subsystem. Fine-tuning documentation can be found in
* Documentation/sysctl/vm.txt.
* Started 18.12.91
#include <linux/module.h>
#include <linux/mm_inline.h>
#include <linux/buffer_head.h> /* for try_to_release_page() */
-#include <linux/module.h>
#include <linux/percpu_counter.h>
#include <linux/percpu.h>
#include <linux/cpu.h>
#include <linux/notifier.h>
-#include <linux/init.h>
+#include <linux/backing-dev.h>
+#include <linux/memcontrol.h>
+
+#include "internal.h"
/* How many pages do we try to swap or page in/out together? */
int page_cluster;
+static DEFINE_PER_CPU(struct pagevec[NR_LRU_LISTS], lru_add_pvecs);
+static DEFINE_PER_CPU(struct pagevec, lru_rotate_pvecs);
+
+/*
+ * This path almost never happens for VM activity - pages are normally
+ * freed via pagevecs. But it gets used by networking.
+ */
+static void __page_cache_release(struct page *page)
+{
+ if (PageLRU(page)) {
+ unsigned long flags;
+ struct zone *zone = page_zone(page);
+
+ spin_lock_irqsave(&zone->lru_lock, flags);
+ VM_BUG_ON(!PageLRU(page));
+ __ClearPageLRU(page);
+ del_page_from_lru(zone, page);
+ spin_unlock_irqrestore(&zone->lru_lock, flags);
+ }
+ free_hot_page(page);
+}
+
static void put_compound_page(struct page *page)
{
- page = (struct page *)page_private(page);
+ page = compound_head(page);
if (put_page_testzero(page)) {
- void (*dtor)(struct page *page);
+ compound_page_dtor *dtor;
- dtor = (void (*)(struct page *))page[1].lru.next;
+ dtor = get_compound_page_dtor(page);
(*dtor)(page);
}
}
}
EXPORT_SYMBOL(put_page);
+/**
+ * put_pages_list() - release a list of pages
+ * @pages: list of pages threaded on page->lru
+ *
+ * Release a list of pages which are strung together on page.lru. Currently
+ * used by read_cache_pages() and related error recovery code.
+ */
+void put_pages_list(struct list_head *pages)
+{
+ while (!list_empty(pages)) {
+ struct page *victim;
+
+ victim = list_entry(pages->prev, struct page, lru);
+ list_del(&victim->lru);
+ page_cache_release(victim);
+ }
+}
+EXPORT_SYMBOL(put_pages_list);
+
+/*
+ * pagevec_move_tail() must be called with IRQ disabled.
+ * Otherwise this may cause nasty races.
+ */
+static void pagevec_move_tail(struct pagevec *pvec)
+{
+ int i;
+ int pgmoved = 0;
+ struct zone *zone = NULL;
+
+ for (i = 0; i < pagevec_count(pvec); i++) {
+ struct page *page = pvec->pages[i];
+ struct zone *pagezone = page_zone(page);
+
+ if (pagezone != zone) {
+ if (zone)
+ spin_unlock(&zone->lru_lock);
+ zone = pagezone;
+ spin_lock(&zone->lru_lock);
+ }
+ if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) {
+ int lru = page_is_file_cache(page);
+ list_move_tail(&page->lru, &zone->lru[lru].list);
+ pgmoved++;
+ }
+ }
+ if (zone)
+ spin_unlock(&zone->lru_lock);
+ __count_vm_events(PGROTATED, pgmoved);
+ release_pages(pvec->pages, pvec->nr, pvec->cold);
+ pagevec_reinit(pvec);
+}
+
/*
* Writeback is about to end against a page which has been marked for immediate
* reclaim. If it still appears to be reclaimable, move it to the tail of the
- * inactive list. The page still has PageWriteback set, which will pin it.
- *
- * We don't expect many pages to come through here, so don't bother batching
- * things up.
- *
- * To avoid placing the page at the tail of the LRU while PG_writeback is still
- * set, this function will clear PG_writeback before performing the page
- * motion. Do that inside the lru lock because once PG_writeback is cleared
- * we may not touch the page.
- *
- * Returns zero if it cleared PG_writeback.
+ * inactive list.
*/
-int rotate_reclaimable_page(struct page *page)
+void rotate_reclaimable_page(struct page *page)
{
- struct zone *zone;
- unsigned long flags;
-
- if (PageLocked(page))
- return 1;
- if (PageDirty(page))
- return 1;
- if (PageActive(page))
- return 1;
- if (!PageLRU(page))
- return 1;
-
- zone = page_zone(page);
- spin_lock_irqsave(&zone->lru_lock, flags);
- if (PageLRU(page) && !PageActive(page)) {
- list_move_tail(&page->lru, &zone->inactive_list);
- __count_vm_event(PGROTATED);
+ if (!PageLocked(page) && !PageDirty(page) && !PageActive(page) &&
+ !PageUnevictable(page) && PageLRU(page)) {
+ struct pagevec *pvec;
+ unsigned long flags;
+
+ page_cache_get(page);
+ local_irq_save(flags);
+ pvec = &__get_cpu_var(lru_rotate_pvecs);
+ if (!pagevec_add(pvec, page))
+ pagevec_move_tail(pvec);
+ local_irq_restore(flags);
}
- if (!test_clear_page_writeback(page))
- BUG();
- spin_unlock_irqrestore(&zone->lru_lock, flags);
- return 0;
}
/*
* FIXME: speed this up?
*/
-void fastcall activate_page(struct page *page)
+void activate_page(struct page *page)
{
struct zone *zone = page_zone(page);
spin_lock_irq(&zone->lru_lock);
- if (PageLRU(page) && !PageActive(page)) {
- del_page_from_inactive_list(zone, page);
+ if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) {
+ int file = page_is_file_cache(page);
+ int lru = LRU_BASE + file;
+ del_page_from_lru_list(zone, page, lru);
+
SetPageActive(page);
- add_page_to_active_list(zone, page);
+ lru += LRU_ACTIVE;
+ add_page_to_lru_list(zone, page, lru);
__count_vm_event(PGACTIVATE);
+ mem_cgroup_move_lists(page, lru);
+
+ zone->recent_rotated[!!file]++;
+ zone->recent_scanned[!!file]++;
}
spin_unlock_irq(&zone->lru_lock);
}
* inactive,referenced -> active,unreferenced
* active,unreferenced -> active,referenced
*/
-void fastcall mark_page_accessed(struct page *page)
+void mark_page_accessed(struct page *page)
{
- if (!PageActive(page) && PageReferenced(page) && PageLRU(page)) {
+ if (!PageActive(page) && !PageUnevictable(page) &&
+ PageReferenced(page) && PageLRU(page)) {
activate_page(page);
ClearPageReferenced(page);
} else if (!PageReferenced(page)) {
EXPORT_SYMBOL(mark_page_accessed);
-/**
- * lru_cache_add: add a page to the page lists
- * @page: the page to add
- */
-static DEFINE_PER_CPU(struct pagevec, lru_add_pvecs) = { 0, };
-static DEFINE_PER_CPU(struct pagevec, lru_add_active_pvecs) = { 0, };
-
-void fastcall lru_cache_add(struct page *page)
+void __lru_cache_add(struct page *page, enum lru_list lru)
{
- struct pagevec *pvec = &get_cpu_var(lru_add_pvecs);
+ struct pagevec *pvec = &get_cpu_var(lru_add_pvecs)[lru];
page_cache_get(page);
if (!pagevec_add(pvec, page))
- __pagevec_lru_add(pvec);
+ ____pagevec_lru_add(pvec, lru);
put_cpu_var(lru_add_pvecs);
}
-void fastcall lru_cache_add_active(struct page *page)
+/**
+ * lru_cache_add_lru - add a page to a page list
+ * @page: the page to be added to the LRU.
+ * @lru: the LRU list to which the page is added.
+ */
+void lru_cache_add_lru(struct page *page, enum lru_list lru)
{
- struct pagevec *pvec = &get_cpu_var(lru_add_active_pvecs);
+ if (PageActive(page)) {
+ VM_BUG_ON(PageUnevictable(page));
+ ClearPageActive(page);
+ } else if (PageUnevictable(page)) {
+ VM_BUG_ON(PageActive(page));
+ ClearPageUnevictable(page);
+ }
- page_cache_get(page);
- if (!pagevec_add(pvec, page))
- __pagevec_lru_add_active(pvec);
- put_cpu_var(lru_add_active_pvecs);
+ VM_BUG_ON(PageLRU(page) || PageActive(page) || PageUnevictable(page));
+ __lru_cache_add(page, lru);
}
-static void __lru_add_drain(int cpu)
+/**
+ * add_page_to_unevictable_list - add a page to the unevictable list
+ * @page: the page to be added to the unevictable list
+ *
+ * Add page directly to its zone's unevictable list. To avoid races with
+ * tasks that might be making the page evictable, through eg. munlock,
+ * munmap or exit, while it's not on the lru, we want to add the page
+ * while it's locked or otherwise "invisible" to other tasks. This is
+ * difficult to do when using the pagevec cache, so bypass that.
+ */
+void add_page_to_unevictable_list(struct page *page)
{
- struct pagevec *pvec = &per_cpu(lru_add_pvecs, cpu);
-
- /* CPU is dead, so no locking needed. */
- if (pagevec_count(pvec))
- __pagevec_lru_add(pvec);
- pvec = &per_cpu(lru_add_active_pvecs, cpu);
- if (pagevec_count(pvec))
- __pagevec_lru_add_active(pvec);
-}
+ struct zone *zone = page_zone(page);
-void lru_add_drain(void)
-{
- __lru_add_drain(get_cpu());
- put_cpu();
+ spin_lock_irq(&zone->lru_lock);
+ SetPageUnevictable(page);
+ SetPageLRU(page);
+ add_page_to_lru_list(zone, page, LRU_UNEVICTABLE);
+ spin_unlock_irq(&zone->lru_lock);
}
-#ifdef CONFIG_NUMA
-static void lru_add_drain_per_cpu(void *dummy)
+/**
+ * lru_cache_add_active_or_unevictable
+ * @page: the page to be added to LRU
+ * @vma: vma in which page is mapped for determining reclaimability
+ *
+ * place @page on active or unevictable LRU list, depending on
+ * page_evictable(). Note that if the page is not evictable,
+ * it goes directly back onto it's zone's unevictable list. It does
+ * NOT use a per cpu pagevec.
+ */
+void lru_cache_add_active_or_unevictable(struct page *page,
+ struct vm_area_struct *vma)
{
- lru_add_drain();
+ if (page_evictable(page, vma))
+ lru_cache_add_lru(page, LRU_ACTIVE + page_is_file_cache(page));
+ else
+ add_page_to_unevictable_list(page);
}
/*
- * Returns 0 for success
+ * Drain pages out of the cpu's pagevecs.
+ * Either "cpu" is the current CPU, and preemption has already been
+ * disabled; or "cpu" is being hot-unplugged, and is already dead.
*/
-int lru_add_drain_all(void)
+static void drain_cpu_pagevecs(int cpu)
{
- return schedule_on_each_cpu(lru_add_drain_per_cpu, NULL);
+ struct pagevec *pvecs = per_cpu(lru_add_pvecs, cpu);
+ struct pagevec *pvec;
+ int lru;
+
+ for_each_lru(lru) {
+ pvec = &pvecs[lru - LRU_BASE];
+ if (pagevec_count(pvec))
+ ____pagevec_lru_add(pvec, lru);
+ }
+
+ pvec = &per_cpu(lru_rotate_pvecs, cpu);
+ if (pagevec_count(pvec)) {
+ unsigned long flags;
+
+ /* No harm done if a racing interrupt already did this */
+ local_irq_save(flags);
+ pagevec_move_tail(pvec);
+ local_irq_restore(flags);
+ }
}
-#else
+void lru_add_drain(void)
+{
+ drain_cpu_pagevecs(get_cpu());
+ put_cpu();
+}
-/*
- * Returns 0 for success
- */
-int lru_add_drain_all(void)
+static void lru_add_drain_per_cpu(struct work_struct *dummy)
{
lru_add_drain();
- return 0;
}
-#endif
/*
- * This path almost never happens for VM activity - pages are normally
- * freed via pagevecs. But it gets used by networking.
+ * Returns 0 for success
*/
-void fastcall __page_cache_release(struct page *page)
+int lru_add_drain_all(void)
{
- if (PageLRU(page)) {
- unsigned long flags;
- struct zone *zone = page_zone(page);
-
- spin_lock_irqsave(&zone->lru_lock, flags);
- BUG_ON(!PageLRU(page));
- __ClearPageLRU(page);
- del_page_from_lru(zone, page);
- spin_unlock_irqrestore(&zone->lru_lock, flags);
- }
- free_hot_page(page);
+ return schedule_on_each_cpu(lru_add_drain_per_cpu);
}
-EXPORT_SYMBOL(__page_cache_release);
/*
* Batched page_cache_release(). Decrement the reference count on all the
* Avoid taking zone->lru_lock if possible, but if it is taken, retain it
* for the remainder of the operation.
*
- * The locking in this function is against shrink_cache(): we recheck the
- * page count inside the lock to see whether shrink_cache grabbed the page
- * via the LRU. If it did, give up: shrink_cache will free it.
+ * The locking in this function is against shrink_inactive_list(): we recheck
+ * the page count inside the lock to see whether shrink_inactive_list()
+ * grabbed the page via the LRU. If it did, give up: shrink_inactive_list()
+ * will free it.
*/
void release_pages(struct page **pages, int nr, int cold)
{
int i;
struct pagevec pages_to_free;
struct zone *zone = NULL;
+ unsigned long uninitialized_var(flags);
pagevec_init(&pages_to_free, cold);
for (i = 0; i < nr; i++) {
if (unlikely(PageCompound(page))) {
if (zone) {
- spin_unlock_irq(&zone->lru_lock);
+ spin_unlock_irqrestore(&zone->lru_lock, flags);
zone = NULL;
}
put_compound_page(page);
if (PageLRU(page)) {
struct zone *pagezone = page_zone(page);
+
if (pagezone != zone) {
if (zone)
- spin_unlock_irq(&zone->lru_lock);
+ spin_unlock_irqrestore(&zone->lru_lock,
+ flags);
zone = pagezone;
- spin_lock_irq(&zone->lru_lock);
+ spin_lock_irqsave(&zone->lru_lock, flags);
}
- BUG_ON(!PageLRU(page));
+ VM_BUG_ON(!PageLRU(page));
__ClearPageLRU(page);
del_page_from_lru(zone, page);
}
if (!pagevec_add(&pages_to_free, page)) {
if (zone) {
- spin_unlock_irq(&zone->lru_lock);
+ spin_unlock_irqrestore(&zone->lru_lock, flags);
zone = NULL;
}
__pagevec_free(&pages_to_free);
}
}
if (zone)
- spin_unlock_irq(&zone->lru_lock);
+ spin_unlock_irqrestore(&zone->lru_lock, flags);
pagevec_free(&pages_to_free);
}
for (i = 0; i < pagevec_count(pvec); i++) {
struct page *page = pvec->pages[i];
- BUG_ON(PageLRU(page));
+ VM_BUG_ON(PageLRU(page));
if (put_page_testzero(page))
pagevec_add(&pages_to_free, page);
}
* Add the passed pages to the LRU, then drop the caller's refcount
* on them. Reinitialises the caller's pagevec.
*/
-void __pagevec_lru_add(struct pagevec *pvec)
+void ____pagevec_lru_add(struct pagevec *pvec, enum lru_list lru)
{
int i;
struct zone *zone = NULL;
+ VM_BUG_ON(is_unevictable_lru(lru));
for (i = 0; i < pagevec_count(pvec); i++) {
struct page *page = pvec->pages[i];
struct zone *pagezone = page_zone(page);
+ int file;
if (pagezone != zone) {
if (zone)
zone = pagezone;
spin_lock_irq(&zone->lru_lock);
}
- BUG_ON(PageLRU(page));
+ VM_BUG_ON(PageActive(page));
+ VM_BUG_ON(PageUnevictable(page));
+ VM_BUG_ON(PageLRU(page));
SetPageLRU(page);
- add_page_to_inactive_list(zone, page);
+ file = is_file_lru(lru);
+ zone->recent_scanned[file]++;
+ if (is_active_lru(lru)) {
+ SetPageActive(page);
+ zone->recent_rotated[file]++;
+ }
+ add_page_to_lru_list(zone, page, lru);
}
if (zone)
spin_unlock_irq(&zone->lru_lock);
pagevec_reinit(pvec);
}
-EXPORT_SYMBOL(__pagevec_lru_add);
+EXPORT_SYMBOL(____pagevec_lru_add);
-void __pagevec_lru_add_active(struct pagevec *pvec)
+/*
+ * Try to drop buffers from the pages in a pagevec
+ */
+void pagevec_strip(struct pagevec *pvec)
{
int i;
- struct zone *zone = NULL;
for (i = 0; i < pagevec_count(pvec); i++) {
struct page *page = pvec->pages[i];
- struct zone *pagezone = page_zone(page);
- if (pagezone != zone) {
- if (zone)
- spin_unlock_irq(&zone->lru_lock);
- zone = pagezone;
- spin_lock_irq(&zone->lru_lock);
+ if (PagePrivate(page) && trylock_page(page)) {
+ if (PagePrivate(page))
+ try_to_release_page(page, 0);
+ unlock_page(page);
}
- BUG_ON(PageLRU(page));
- SetPageLRU(page);
- BUG_ON(PageActive(page));
- SetPageActive(page);
- add_page_to_active_list(zone, page);
}
- if (zone)
- spin_unlock_irq(&zone->lru_lock);
- release_pages(pvec->pages, pvec->nr, pvec->cold);
- pagevec_reinit(pvec);
}
-/*
- * Try to drop buffers from the pages in a pagevec
+/**
+ * pagevec_swap_free - try to free swap space from the pages in a pagevec
+ * @pvec: pagevec with swapcache pages to free the swap space of
+ *
+ * The caller needs to hold an extra reference to each page and
+ * not hold the page lock on the pages. This function uses a
+ * trylock on the page lock so it may not always free the swap
+ * space associated with a page.
*/
-void pagevec_strip(struct pagevec *pvec)
+void pagevec_swap_free(struct pagevec *pvec)
{
int i;
for (i = 0; i < pagevec_count(pvec); i++) {
struct page *page = pvec->pages[i];
- if (PagePrivate(page) && !TestSetPageLocked(page)) {
- if (PagePrivate(page))
- try_to_release_page(page, 0);
+ if (PageSwapCache(page) && trylock_page(page)) {
+ if (PageSwapCache(page))
+ remove_exclusive_swap_page_ref(page);
unlock_page(page);
}
}
*/
#define ACCT_THRESHOLD max(16, NR_CPUS * 2)
-static DEFINE_PER_CPU(long, committed_space) = 0;
+static DEFINE_PER_CPU(long, committed_space);
void vm_acct_memory(long pages)
{
local = &__get_cpu_var(committed_space);
*local += pages;
if (*local > ACCT_THRESHOLD || *local < -ACCT_THRESHOLD) {
- atomic_add(*local, &vm_committed_space);
+ atomic_long_add(*local, &vm_committed_space);
*local = 0;
}
preempt_enable();
long *committed;
committed = &per_cpu(committed_space, (long)hcpu);
- if (action == CPU_DEAD) {
- atomic_add(*committed, &vm_committed_space);
+ if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
+ atomic_long_add(*committed, &vm_committed_space);
*committed = 0;
- __lru_add_drain((long)hcpu);
+ drain_cpu_pagevecs((long)hcpu);
}
return NOTIFY_OK;
}
{
unsigned long megs = num_physpages >> (20 - PAGE_SHIFT);
+#ifdef CONFIG_SWAP
+ bdi_init(swapper_space.backing_dev_info);
+#endif
+
/* Use a smaller cluster for small-memory machines */
if (megs < 16)
page_cluster = 2;
* Right now other parts of the system means that we
* _really_ don't want to cluster much more
*/
+#ifdef CONFIG_HOTPLUG_CPU
hotcpu_notifier(cpu_swap_callback, 0);
+#endif
}