From: Christoph Lameter Move move_to_lru, putback_lru_pages and isolate_lru in section surrounded by CONFIG_MIGRATION saving some codesize for single processor kernels. Signed-off-by: Christoph Lameter Signed-off-by: Andrew Morton --- include/linux/swap.h | 3 - mm/vmscan.c | 152 +++++++++++++++++++++++++-------------------------- 2 files changed, 77 insertions(+), 78 deletions(-) diff -puN include/linux/swap.h~swapmig-config_migration-fixes include/linux/swap.h --- devel/include/linux/swap.h~swapmig-config_migration-fixes 2005-12-22 05:08:55.000000000 -0800 +++ devel-akpm/include/linux/swap.h 2005-12-22 05:08:55.000000000 -0800 @@ -175,10 +175,9 @@ extern int try_to_free_pages(struct zone extern int shrink_all_memory(int); extern int vm_swappiness; +#ifdef CONFIG_MIGRATION extern int isolate_lru_page(struct page *p); extern int putback_lru_pages(struct list_head *l); - -#ifdef CONFIG_MIGRATION extern int migrate_pages(struct list_head *l, struct list_head *t); #endif diff -puN mm/vmscan.c~swapmig-config_migration-fixes mm/vmscan.c --- devel/mm/vmscan.c~swapmig-config_migration-fixes 2005-12-22 05:08:55.000000000 -0800 +++ devel-akpm/mm/vmscan.c 2005-12-22 05:08:55.000000000 -0800 @@ -569,6 +569,40 @@ keep: } #ifdef CONFIG_MIGRATION +static inline void move_to_lru(struct page *page) +{ + list_del(&page->lru); + if (PageActive(page)) { + /* + * lru_cache_add_active checks that + * the PG_active bit is off. + */ + ClearPageActive(page); + lru_cache_add_active(page); + } else { + lru_cache_add(page); + } + put_page(page); +} + +/* + * Add isolated pages on the list back to the LRU + * + * returns the number of pages put back. + */ +int putback_lru_pages(struct list_head *l) +{ + struct page *page; + struct page *page2; + int count = 0; + + list_for_each_entry_safe(page, page2, l, lru) { + move_to_lru(page); + count++; + } + return count; +} + /* * swapout a single page * page is locked upon entry, unlocked on exit @@ -709,6 +743,48 @@ retry_later: return nr_failed + retry; } + +static void lru_add_drain_per_cpu(void *dummy) +{ + lru_add_drain(); +} + +/* + * Isolate one page from the LRU lists and put it on the + * indicated list. Do necessary cache draining if the + * page is not on the LRU lists yet. + * + * Result: + * 0 = page not on LRU list + * 1 = page removed from LRU list and added to the specified list. + * -ENOENT = page is being freed elsewhere. + */ +int isolate_lru_page(struct page *page) +{ + int rc = 0; + struct zone *zone = page_zone(page); + +redo: + spin_lock_irq(&zone->lru_lock); + rc = __isolate_lru_page(page); + if (rc == 1) { + if (PageActive(page)) + del_page_from_active_list(zone, page); + else + del_page_from_inactive_list(zone, page); + } + spin_unlock_irq(&zone->lru_lock); + if (rc == 0) { + /* + * Maybe this page is still waiting for a cpu to drain it + * from one of the lru lists? + */ + rc = schedule_on_each_cpu(lru_add_drain_per_cpu, NULL); + if (rc == 0 && PageLRU(page)) + goto redo; + } + return rc; +} #endif /* @@ -758,48 +834,6 @@ static int isolate_lru_pages(int nr_to_s return nr_taken; } -static void lru_add_drain_per_cpu(void *dummy) -{ - lru_add_drain(); -} - -/* - * Isolate one page from the LRU lists and put it on the - * indicated list. Do necessary cache draining if the - * page is not on the LRU lists yet. - * - * Result: - * 0 = page not on LRU list - * 1 = page removed from LRU list and added to the specified list. - * -ENOENT = page is being freed elsewhere. - */ -int isolate_lru_page(struct page *page) -{ - int rc = 0; - struct zone *zone = page_zone(page); - -redo: - spin_lock_irq(&zone->lru_lock); - rc = __isolate_lru_page(page); - if (rc == 1) { - if (PageActive(page)) - del_page_from_active_list(zone, page); - else - del_page_from_inactive_list(zone, page); - } - spin_unlock_irq(&zone->lru_lock); - if (rc == 0) { - /* - * Maybe this page is still waiting for a cpu to drain it - * from one of the lru lists? - */ - rc = schedule_on_each_cpu(lru_add_drain_per_cpu, NULL); - if (rc == 0 && PageLRU(page)) - goto redo; - } - return rc; -} - /* * shrink_cache() adds the number of pages reclaimed to sc->nr_reclaimed */ @@ -865,40 +899,6 @@ done: pagevec_release(&pvec); } -static inline void move_to_lru(struct page *page) -{ - list_del(&page->lru); - if (PageActive(page)) { - /* - * lru_cache_add_active checks that - * the PG_active bit is off. - */ - ClearPageActive(page); - lru_cache_add_active(page); - } else { - lru_cache_add(page); - } - put_page(page); -} - -/* - * Add isolated pages on the list back to the LRU - * - * returns the number of pages put back. - */ -int putback_lru_pages(struct list_head *l) -{ - struct page *page; - struct page *page2; - int count = 0; - - list_for_each_entry_safe(page, page2, l, lru) { - move_to_lru(page); - count++; - } - return count; -} - /* * This moves pages from the active list to the inactive list. * _