diff options
| -rw-r--r-- | include/linux/migrate.h | 3 | ||||
| -rw-r--r-- | mm/internal.h | 2 | ||||
| -rw-r--r-- | mm/memory_hotplug.c | 3 | ||||
| -rw-r--r-- | mm/mempolicy.c | 9 | ||||
| -rw-r--r-- | mm/migrate.c | 34 | ||||
| -rw-r--r-- | mm/vmscan.c | 45 |
6 files changed, 59 insertions, 37 deletions
diff --git a/include/linux/migrate.h b/include/linux/migrate.h index 03aea61..3f34005 100644 --- a/include/linux/migrate.h +++ b/include/linux/migrate.h @@ -7,7 +7,6 @@ typedef struct page *new_page_t(struct page *, unsigned long private, int **); #ifdef CONFIG_MIGRATION -extern int isolate_lru_page(struct page *p, struct list_head *pagelist); extern int putback_lru_pages(struct list_head *l); extern int migrate_page(struct address_space *, struct page *, struct page *); @@ -21,8 +20,6 @@ extern int migrate_vmas(struct mm_struct *mm, const nodemask_t *from, const nodemask_t *to, unsigned long flags); #else -static inline int isolate_lru_page(struct page *p, struct list_head *list) - { return -ENOSYS; } static inline int putback_lru_pages(struct list_head *l) { return 0; } static inline int migrate_pages(struct list_head *l, new_page_t x, unsigned long private) { return -ENOSYS; } diff --git a/mm/internal.h b/mm/internal.h index 1f43f74..4e8e78b 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -39,6 +39,8 @@ static inline void __put_page(struct page *page) atomic_dec(&page->_count); } +extern int isolate_lru_page(struct page *page); + extern void __free_pages_bootmem(struct page *page, unsigned int order); /* diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index c299d08..3b49758 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -658,8 +658,9 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) * We can skip free pages. And we can only deal with pages on * LRU. */ - ret = isolate_lru_page(page, &source); + ret = isolate_lru_page(page); if (!ret) { /* Success */ + list_add_tail(&page->lru, &source); move_pages--; } else { /* Becasue we don't have big zone->lock. we should diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 8336905..71b4749 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -93,6 +93,8 @@ #include <asm/tlbflush.h> #include <asm/uaccess.h> +#include "internal.h" + /* Internal flags */ #define MPOL_MF_DISCONTIG_OK (MPOL_MF_INTERNAL << 0) /* Skip checks for continuous vmas */ #define MPOL_MF_INVERT (MPOL_MF_INTERNAL << 1) /* Invert check for nodemask */ @@ -762,8 +764,11 @@ static void migrate_page_add(struct page *page, struct list_head *pagelist, /* * Avoid migrating a page that is shared with others. */ - if ((flags & MPOL_MF_MOVE_ALL) || page_mapcount(page) == 1) - isolate_lru_page(page, pagelist); + if ((flags & MPOL_MF_MOVE_ALL) || page_mapcount(page) == 1) { + if (!isolate_lru_page(page)) { + list_add_tail(&page->lru, pagelist); + } + } } static struct page *new_node_page(struct page *page, unsigned long node, int **x) diff --git a/mm/migrate.c b/mm/migrate.c index 2a80136..da73742 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -37,36 +37,6 @@ #define lru_to_page(_head) (list_entry((_head)->prev, struct page, lru)) /* - * Isolate one page from the LRU lists. If successful put it onto - * the indicated list with elevated page count. - * - * Result: - * -EBUSY: page not on LRU list - * 0: page removed from LRU list and added to the specified list. - */ -int isolate_lru_page(struct page *page, struct list_head *pagelist) -{ - int ret = -EBUSY; - - if (PageLRU(page)) { - struct zone *zone = page_zone(page); - - spin_lock_irq(&zone->lru_lock); - if (PageLRU(page) && get_page_unless_zero(page)) { - ret = 0; - ClearPageLRU(page); - if (PageActive(page)) - del_page_from_active_list(zone, page); - else - del_page_from_inactive_list(zone, page); - list_add_tail(&page->lru, pagelist); - } - spin_unlock_irq(&zone->lru_lock); - } - return ret; -} - -/* * migrate_prep() needs to be called before we start compiling a list of pages * to be migrated using isolate_lru_page(). */ @@ -914,7 +884,9 @@ static int do_move_pages(struct mm_struct *mm, struct page_to_node *pm, !migrate_all) goto put_and_set; - err = isolate_lru_page(page, &pagelist); + err = isolate_lru_page(page); + if (!err) + list_add_tail(&page->lru, &pagelist); put_and_set: /* * Either remove the duplicate refcount from diff --git a/mm/vmscan.c b/mm/vmscan.c index 1ff1a58..1fd4912 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -844,6 +844,51 @@ static unsigned long clear_active_flags(struct list_head *page_list) return nr_active; } +/** + * isolate_lru_page - tries to isolate a page from its LRU list + * @page: page to isolate from its LRU list + * + * Isolates a @page from an LRU list, clears PageLRU and adjusts the + * vmstat statistic corresponding to whatever LRU list the page was on. + * + * Returns 0 if the page was removed from an LRU list. + * Returns -EBUSY if the page was not on an LRU list. + * + * The returned page will have PageLRU() cleared. If it was found on + * the active list, it will have PageActive set. That flag may need + * to be cleared by the caller before letting the page go. + * + * The vmstat statistic corresponding to the list on which the page was + * found will be decremented. + * + * Restrictions: + * (1) Must be called with an elevated refcount on the page. This is a + * fundamentnal difference from isolate_lru_pages (which is called + * without a stable reference). + * (2) the lru_lock must not be held. + * (3) interrupts must be enabled. + */ +int isolate_lru_page(struct page *page) +{ + int ret = -EBUSY; + + if (PageLRU(page)) { + struct zone *zone = page_zone(page); + + spin_lock_irq(&zone->lru_lock); + if (PageLRU(page) && get_page_unless_zero(page)) { + ret = 0; + ClearPageLRU(page); + if (PageActive(page)) + del_page_from_active_list(zone, page); + else + del_page_from_inactive_list(zone, page); + } + spin_unlock_irq(&zone->lru_lock); + } + return ret; +} + /* * shrink_inactive_list() is a helper for shrink_zone(). It returns the number * of reclaimed pages |