diff options
Diffstat (limited to 'mm/vmscan.c')
| -rw-r--r-- | mm/vmscan.c | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c index e5aaaad159ef..ca64e3e0c518 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -39,6 +39,7 @@ #include <linux/freezer.h> #include <linux/memcontrol.h> #include <linux/delayacct.h> +#include <linux/sysctl.h> #include <asm/tlbflush.h> #include <asm/div64.h> @@ -2363,6 +2364,39 @@ int page_evictable(struct page *page, struct vm_area_struct *vma) return 1; } +static void show_page_path(struct page *page) +{ + char buf[256]; + if (page_is_file_cache(page)) { + struct address_space *mapping = page->mapping; + struct dentry *dentry; + pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT); + + spin_lock(&mapping->i_mmap_lock); + dentry = d_find_alias(mapping->host); + printk(KERN_INFO "rescued: %s %lu\n", + dentry_path(dentry, buf, 256), pgoff); + spin_unlock(&mapping->i_mmap_lock); + } else { +#if defined(CONFIG_MM_OWNER) && defined(CONFIG_MMU) + struct anon_vma *anon_vma; + struct vm_area_struct *vma; + + anon_vma = page_lock_anon_vma(page); + if (!anon_vma) + return; + + list_for_each_entry(vma, &anon_vma->head, anon_vma_node) { + printk(KERN_INFO "rescued: anon %s\n", + vma->vm_mm->owner->comm); + break; + } + page_unlock_anon_vma(anon_vma); +#endif + } +} + + /** * 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 @@ -2382,6 +2416,9 @@ retry: ClearPageUnevictable(page); if (page_evictable(page, NULL)) { enum lru_list l = LRU_INACTIVE_ANON + page_is_file_cache(page); + + show_page_path(page); + __dec_zone_state(zone, NR_UNEVICTABLE); list_move(&page->lru, &zone->lru[l].list); __inc_zone_state(zone, NR_INACTIVE_ANON + l); @@ -2451,4 +2488,133 @@ void scan_mapping_unevictable_pages(struct address_space *mapping) } } + +/** + * scan_zone_unevictable_pages - check unevictable list for evictable pages + * @zone - zone of which to scan the unevictable list + * + * Scan @zone's unevictable LRU lists to check for pages that have become + * evictable. Move those that have to @zone's inactive list where they + * become candidates for reclaim, unless shrink_inactive_zone() decides + * to reactivate them. Pages that are still unevictable are rotated + * back onto @zone's unevictable list. + */ +#define SCAN_UNEVICTABLE_BATCH_SIZE 16UL /* arbitrary lock hold batch size */ +void scan_zone_unevictable_pages(struct zone *zone) +{ + struct list_head *l_unevictable = &zone->lru[LRU_UNEVICTABLE].list; + unsigned long scan; + unsigned long nr_to_scan = zone_page_state(zone, NR_UNEVICTABLE); + + while (nr_to_scan > 0) { + unsigned long batch_size = min(nr_to_scan, + SCAN_UNEVICTABLE_BATCH_SIZE); + + spin_lock_irq(&zone->lru_lock); + for (scan = 0; scan < batch_size; scan++) { + struct page *page = lru_to_page(l_unevictable); + + if (!trylock_page(page)) + continue; + + prefetchw_prev_lru_page(page, l_unevictable, flags); + + if (likely(PageLRU(page) && PageUnevictable(page))) + check_move_unevictable_page(page, zone); + + unlock_page(page); + } + spin_unlock_irq(&zone->lru_lock); + + nr_to_scan -= batch_size; + } +} + + +/** + * scan_all_zones_unevictable_pages - scan all unevictable lists for evictable pages + * + * A really big hammer: scan all zones' unevictable LRU lists to check for + * pages that have become evictable. Move those back to the zones' + * inactive list where they become candidates for reclaim. + * This occurs when, e.g., we have unswappable pages on the unevictable lists, + * and we add swap to the system. As such, it runs in the context of a task + * that has possibly/probably made some previously unevictable pages + * evictable. + */ +void scan_all_zones_unevictable_pages(void) +{ + struct zone *zone; + + for_each_zone(zone) { + scan_zone_unevictable_pages(zone); + } +} + +/* + * scan_unevictable_pages [vm] sysctl handler. On demand re-scan of + * all nodes' unevictable lists for evictable pages + */ +unsigned long scan_unevictable_pages; + +int scan_unevictable_handler(struct ctl_table *table, int write, + struct file *file, void __user *buffer, + size_t *length, loff_t *ppos) +{ + proc_doulongvec_minmax(table, write, file, buffer, length, ppos); + + if (write && *(unsigned long *)table->data) + scan_all_zones_unevictable_pages(); + + scan_unevictable_pages = 0; + return 0; +} + +/* + * per node 'scan_unevictable_pages' attribute. On demand re-scan of + * 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, + char *buf) +{ + return sprintf(buf, "0\n"); /* always zero; should fit... */ +} + +static ssize_t write_scan_unevictable_node(struct sys_device *dev, + struct sysdev_attribute *attr, + const char *buf, size_t count) +{ + struct zone *node_zones = NODE_DATA(dev->id)->node_zones; + struct zone *zone; + unsigned long res; + unsigned long req = strict_strtoul(buf, 10, &res); + + if (!req) + return 1; /* zero is no-op */ + + for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) { + if (!populated_zone(zone)) + continue; + scan_zone_unevictable_pages(zone); + } + return 1; +} + + +static SYSDEV_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); +} + +void scan_unevictable_unregister_node(struct node *node) +{ + sysdev_remove_file(&node->sysdev, &attr_scan_unevictable_pages); +} + #endif |