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Commit 8419c318 authored by Christoph Lameter's avatar Christoph Lameter Committed by Linus Torvalds
Browse files

[PATCH] SwapMig: CONFIG_MIGRATION fixes 



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: default avatarChristoph Lameter <clameter@sgi.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 39743889

include/linux/swap.h

+1 −2
Original line number Diff line number Diff line
@@ -175,10 +175,9 @@ extern int try_to_free_pages(struct zone **, gfp_t); 
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

mm/vmscan.c

+76 −76
Original line number Diff line number Diff line
@@ -569,6 +569,40 @@ static int shrink_list(struct list_head *page_list, struct scan_control *sc) 
}



#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 @@ int migrate_pages(struct list_head *l, struct list_head *t) 


	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_scan, struct list_head *src, 
	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 @@ static void shrink_cache(struct zone *zone, struct scan_control *sc) 
	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.

 *