* When racing with an mlock or AS_UNEVICTABLE clearing
* (page is unlocked) make sure that if the other thread
* does not observe our setting of PG_lru and fails
- * isolation/check_move_unevictable_page,
+ * isolation/check_move_unevictable_pages,
* we see PG_mlocked/AS_UNEVICTABLE cleared below and move
* the page back to the evictable list.
*
return PAGEREF_RECLAIM;
if (referenced_ptes) {
- if (PageAnon(page))
+ if (PageSwapBacked(page))
return PAGEREF_ACTIVATE;
/*
* All mapped pages start out with page table
*/
SetPageReferenced(page);
- if (referenced_page)
+ if (referenced_page || referenced_ptes > 1)
+ return PAGEREF_ACTIVATE;
+
+ /*
+ * Activate file-backed executable pages after first usage.
+ */
+ if (vm_flags & VM_EXEC)
return PAGEREF_ACTIVATE;
return PAGEREF_KEEP;
return PAGEREF_RECLAIM;
}
-static noinline_for_stack void free_page_list(struct list_head *free_pages)
-{
- struct pagevec freed_pvec;
- struct page *page, *tmp;
-
- pagevec_init(&freed_pvec, 1);
-
- list_for_each_entry_safe(page, tmp, free_pages, lru) {
- list_del(&page->lru);
- if (!pagevec_add(&freed_pvec, page)) {
- __pagevec_free(&freed_pvec);
- pagevec_reinit(&freed_pvec);
- }
- }
-
- pagevec_free(&freed_pvec);
-}
-
/*
* shrink_page_list() returns the number of reclaimed pages
*/
if (nr_dirty && nr_dirty == nr_congested && scanning_global_lru(sc))
zone_set_flag(zone, ZONE_CONGESTED);
- free_page_list(&free_pages);
+ free_hot_cold_page_list(&free_pages, 1);
list_splice(&ret_pages, page_list);
count_vm_events(PGACTIVATE, pgactivate);
ret = -EBUSY;
- if ((mode & ISOLATE_CLEAN) && (PageDirty(page) || PageWriteback(page)))
- return ret;
+ /*
+ * To minimise LRU disruption, the caller can indicate that it only
+ * wants to isolate pages it will be able to operate on without
+ * blocking - clean pages for the most part.
+ *
+ * ISOLATE_CLEAN means that only clean pages should be isolated. This
+ * is used by reclaim when it is cannot write to backing storage
+ *
+ * ISOLATE_ASYNC_MIGRATE is used to indicate that it only wants to pages
+ * that it is possible to migrate without blocking
+ */
+ if (mode & (ISOLATE_CLEAN|ISOLATE_ASYNC_MIGRATE)) {
+ /* All the caller can do on PageWriteback is block */
+ if (PageWriteback(page))
+ return ret;
+
+ if (PageDirty(page)) {
+ struct address_space *mapping;
+
+ /* ISOLATE_CLEAN means only clean pages */
+ if (mode & ISOLATE_CLEAN)
+ return ret;
+
+ /*
+ * Only pages without mappings or that have a
+ * ->migratepage callback are possible to migrate
+ * without blocking
+ */
+ mapping = page_mapping(page);
+ if (mapping && !mapping->a_ops->migratepage)
+ return ret;
+ }
+ }
if ((mode & ISOLATE_UNMAPPED) && page_mapped(page))
return ret;
* anon page which don't already have a swap slot is
* pointless.
*/
- if (nr_swap_pages <= 0 && PageAnon(cursor_page) &&
+ if (nr_swap_pages <= 0 && PageSwapBacked(cursor_page) &&
!PageSwapCache(cursor_page))
break;
* latencies, so it's better to scan a minimum amount there as
* well.
*/
- if (scanning_global_lru(sc) && current_is_kswapd())
+ if (scanning_global_lru(sc) && current_is_kswapd() &&
+ zone->all_unreclaimable)
force_scan = true;
if (!scanning_global_lru(sc))
force_scan = true;
* proportional to the fraction of recently scanned pages on
* each list that were recently referenced and in active use.
*/
- ap = (anon_prio + 1) * (reclaim_stat->recent_scanned[0] + 1);
+ ap = anon_prio * (reclaim_stat->recent_scanned[0] + 1);
ap /= reclaim_stat->recent_rotated[0] + 1;
- fp = (file_prio + 1) * (reclaim_stat->recent_scanned[1] + 1);
+ fp = file_prio * (reclaim_stat->recent_scanned[1] + 1);
fp /= reclaim_stat->recent_rotated[1] + 1;
spin_unlock_irq(&zone->lru_lock);
unsigned long scan;
scan = zone_nr_lru_pages(zone, sc, l);
- if (priority || noswap) {
+ if (priority || noswap || !vmscan_swappiness(sc)) {
scan >>= priority;
if (!scan && force_scan)
scan = SWAP_CLUSTER_MAX;
* inactive lists are large enough, continue reclaiming
*/
pages_for_compaction = (2UL << sc->order);
- inactive_lru_pages = zone_nr_lru_pages(zone, sc, LRU_INACTIVE_ANON) +
- zone_nr_lru_pages(zone, sc, LRU_INACTIVE_FILE);
+ inactive_lru_pages = zone_nr_lru_pages(zone, sc, LRU_INACTIVE_FILE);
+ if (nr_swap_pages > 0)
+ inactive_lru_pages += zone_nr_lru_pages(zone, sc, LRU_INACTIVE_ANON);
if (sc->nr_reclaimed < pages_for_compaction &&
inactive_lru_pages > pages_for_compaction)
return true;
throttle_vm_writeout(sc->gfp_mask);
}
+/* Returns true if compaction should go ahead for a high-order request */
+static inline bool compaction_ready(struct zone *zone, struct scan_control *sc)
+{
+ unsigned long balance_gap, watermark;
+ bool watermark_ok;
+
+ /* Do not consider compaction for orders reclaim is meant to satisfy */
+ if (sc->order <= PAGE_ALLOC_COSTLY_ORDER)
+ return false;
+
+ /*
+ * Compaction takes time to run and there are potentially other
+ * callers using the pages just freed. Continue reclaiming until
+ * there is a buffer of free pages available to give compaction
+ * a reasonable chance of completing and allocating the page
+ */
+ balance_gap = min(low_wmark_pages(zone),
+ (zone->present_pages + KSWAPD_ZONE_BALANCE_GAP_RATIO-1) /
+ KSWAPD_ZONE_BALANCE_GAP_RATIO);
+ watermark = high_wmark_pages(zone) + balance_gap + (2UL << sc->order);
+ watermark_ok = zone_watermark_ok_safe(zone, 0, watermark, 0, 0);
+
+ /*
+ * If compaction is deferred, reclaim up to a point where
+ * compaction will have a chance of success when re-enabled
+ */
+ if (compaction_deferred(zone))
+ return watermark_ok;
+
+ /* If compaction is not ready to start, keep reclaiming */
+ if (!compaction_suitable(zone, sc->order))
+ return false;
+
+ return watermark_ok;
+}
+
/*
* This is the direct reclaim path, for page-allocating processes. We only
* try to reclaim pages from zones which will satisfy the caller's allocation
* scan then give up on it.
*
* This function returns true if a zone is being reclaimed for a costly
- * high-order allocation and compaction is either ready to begin or deferred.
- * This indicates to the caller that it should retry the allocation or fail.
+ * high-order allocation and compaction is ready to begin. This indicates to
+ * the caller that it should consider retrying the allocation instead of
+ * further reclaim.
*/
static bool shrink_zones(int priority, struct zonelist *zonelist,
struct scan_control *sc)
struct zone *zone;
unsigned long nr_soft_reclaimed;
unsigned long nr_soft_scanned;
- bool should_abort_reclaim = false;
+ bool aborted_reclaim = false;
for_each_zone_zonelist_nodemask(zone, z, zonelist,
gfp_zone(sc->gfp_mask), sc->nodemask) {
* noticable problem, like transparent huge page
* allocations.
*/
- if (sc->order > PAGE_ALLOC_COSTLY_ORDER &&
- (compaction_suitable(zone, sc->order) ||
- compaction_deferred(zone))) {
- should_abort_reclaim = true;
+ if (compaction_ready(zone, sc)) {
+ aborted_reclaim = true;
continue;
}
}
shrink_zone(priority, zone, sc);
}
- return should_abort_reclaim;
+ return aborted_reclaim;
}
static bool zone_reclaimable(struct zone *zone)
struct zoneref *z;
struct zone *zone;
unsigned long writeback_threshold;
+ bool aborted_reclaim;
- get_mems_allowed();
delayacct_freepages_start();
if (scanning_global_lru(sc))
sc->nr_scanned = 0;
if (!priority)
disable_swap_token(sc->mem_cgroup);
- if (shrink_zones(priority, zonelist, sc))
- break;
+ aborted_reclaim = shrink_zones(priority, zonelist, sc);
/*
* Don't shrink slabs when reclaiming memory from
out:
delayacct_freepages_end();
- put_mems_allowed();
if (sc->nr_reclaimed)
return sc->nr_reclaimed;
if (oom_killer_disabled)
return 0;
+ /* Aborted reclaim to try compaction? don't OOM, then */
+ if (aborted_reclaim)
+ return 1;
+
/* top priority shrink_zones still had more to do? don't OOM, then */
if (scanning_global_lru(sc) && !all_unreclaimable(zonelist, sc))
return 1;
* them before going back to sleep.
*/
set_pgdat_percpu_threshold(pgdat, calculate_normal_threshold);
- schedule();
+
+ if (!kthread_should_stop())
+ schedule();
+
set_pgdat_percpu_threshold(pgdat, calculate_pressure_threshold);
} else {
if (remaining)
&balanced_classzone_idx);
}
}
+
+ current->reclaim_state = NULL;
return 0;
}
}
/*
- * Called by memory hotplug when all memory in a node is offlined.
+ * Called by memory hotplug when all memory in a node is offlined. Caller must
+ * hold lock_memory_hotplug().
*/
void kswapd_stop(int nid)
{
struct task_struct *kswapd = NODE_DATA(nid)->kswapd;
- if (kswapd)
+ if (kswapd) {
kthread_stop(kswapd);
+ NODE_DATA(nid)->kswapd = NULL;
+ }
}
static int __init kswapd_init(void)
return 1;
}
+#ifdef CONFIG_SHMEM
/**
- * check_move_unevictable_page - check page for evictability and move to appropriate zone lru list
- * @page: page to check evictability and move to appropriate lru list
- * @zone: zone page is in
+ * check_move_unevictable_pages - check pages for evictability and move to appropriate zone lru list
+ * @pages: array of pages to check
+ * @nr_pages: number of pages to check
*
- * Checks a page for evictability and moves the page to the appropriate
- * zone lru list.
+ * Checks pages for evictability and moves them to the appropriate lru list.
*
- * Restrictions: zone->lru_lock must be held, page must be on LRU and must
- * have PageUnevictable set.
+ * This function is only used for SysV IPC SHM_UNLOCK.
*/
-static void check_move_unevictable_page(struct page *page, struct zone *zone)
+void check_move_unevictable_pages(struct page **pages, int nr_pages)
{
- VM_BUG_ON(PageActive(page));
-
-retry:
- ClearPageUnevictable(page);
- if (page_evictable(page, NULL)) {
- enum lru_list l = page_lru_base_type(page);
+ struct zone *zone = NULL;
+ int pgscanned = 0;
+ int pgrescued = 0;
+ int i;
- __dec_zone_state(zone, NR_UNEVICTABLE);
- list_move(&page->lru, &zone->lru[l].list);
- mem_cgroup_move_lists(page, LRU_UNEVICTABLE, l);
- __inc_zone_state(zone, NR_INACTIVE_ANON + l);
- __count_vm_event(UNEVICTABLE_PGRESCUED);
- } else {
- /*
- * rotate unevictable list
- */
- SetPageUnevictable(page);
- list_move(&page->lru, &zone->lru[LRU_UNEVICTABLE].list);
- mem_cgroup_rotate_lru_list(page, LRU_UNEVICTABLE);
- if (page_evictable(page, NULL))
- goto retry;
- }
-}
+ for (i = 0; i < nr_pages; i++) {
+ struct page *page = pages[i];
+ struct zone *pagezone;
-/**
- * scan_mapping_unevictable_pages - scan an address space for evictable pages
- * @mapping: struct address_space to scan for evictable pages
- *
- * Scan all pages in mapping. Check unevictable pages for
- * evictability and move them to the appropriate zone lru list.
- */
-void scan_mapping_unevictable_pages(struct address_space *mapping)
-{
- pgoff_t next = 0;
- pgoff_t end = (i_size_read(mapping->host) + PAGE_CACHE_SIZE - 1) >>
- PAGE_CACHE_SHIFT;
- struct zone *zone;
- struct pagevec pvec;
+ pgscanned++;
+ pagezone = page_zone(page);
+ if (pagezone != zone) {
+ if (zone)
+ spin_unlock_irq(&zone->lru_lock);
+ zone = pagezone;
+ spin_lock_irq(&zone->lru_lock);
+ }
- if (mapping->nrpages == 0)
- return;
+ if (!PageLRU(page) || !PageUnevictable(page))
+ continue;
- pagevec_init(&pvec, 0);
- while (next < end &&
- pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) {
- int i;
- int pg_scanned = 0;
-
- zone = NULL;
-
- for (i = 0; i < pagevec_count(&pvec); i++) {
- struct page *page = pvec.pages[i];
- pgoff_t page_index = page->index;
- struct zone *pagezone = page_zone(page);
-
- pg_scanned++;
- if (page_index > next)
- next = page_index;
- next++;
-
- if (pagezone != zone) {
- if (zone)
- spin_unlock_irq(&zone->lru_lock);
- zone = pagezone;
- spin_lock_irq(&zone->lru_lock);
- }
+ if (page_evictable(page, NULL)) {
+ enum lru_list lru = page_lru_base_type(page);
- if (PageLRU(page) && PageUnevictable(page))
- check_move_unevictable_page(page, zone);
+ VM_BUG_ON(PageActive(page));
+ ClearPageUnevictable(page);
+ __dec_zone_state(zone, NR_UNEVICTABLE);
+ list_move(&page->lru, &zone->lru[lru].list);
+ mem_cgroup_move_lists(page, LRU_UNEVICTABLE, lru);
+ __inc_zone_state(zone, NR_INACTIVE_ANON + lru);
+ pgrescued++;
}
- if (zone)
- spin_unlock_irq(&zone->lru_lock);
- pagevec_release(&pvec);
-
- count_vm_events(UNEVICTABLE_PGSCANNED, pg_scanned);
}
+ if (zone) {
+ __count_vm_events(UNEVICTABLE_PGRESCUED, pgrescued);
+ __count_vm_events(UNEVICTABLE_PGSCANNED, pgscanned);
+ spin_unlock_irq(&zone->lru_lock);
+ }
}
+#endif /* CONFIG_SHMEM */
static void warn_scan_unevictable_pages(void)
{
* a specified node's per zone unevictable lists for evictable pages.
*/
-static ssize_t read_scan_unevictable_node(struct sys_device *dev,
- struct sysdev_attribute *attr,
+static ssize_t read_scan_unevictable_node(struct device *dev,
+ struct device_attribute *attr,
char *buf)
{
warn_scan_unevictable_pages();
return sprintf(buf, "0\n"); /* always zero; should fit... */
}
-static ssize_t write_scan_unevictable_node(struct sys_device *dev,
- struct sysdev_attribute *attr,
+static ssize_t write_scan_unevictable_node(struct device *dev,
+ struct device_attribute *attr,
const char *buf, size_t count)
{
warn_scan_unevictable_pages();
}
-static SYSDEV_ATTR(scan_unevictable_pages, S_IRUGO | S_IWUSR,
+static DEVICE_ATTR(scan_unevictable_pages, S_IRUGO | S_IWUSR,
read_scan_unevictable_node,
write_scan_unevictable_node);
int scan_unevictable_register_node(struct node *node)
{
- return sysdev_create_file(&node->sysdev, &attr_scan_unevictable_pages);
+ return device_create_file(&node->dev, &dev_attr_scan_unevictable_pages);
}
void scan_unevictable_unregister_node(struct node *node)
{
- sysdev_remove_file(&node->sysdev, &attr_scan_unevictable_pages);
+ device_remove_file(&node->dev, &dev_attr_scan_unevictable_pages);
}
#endif
git.openpandora.org / pandora-kernel.git / blobdiff