Commit 1480a540 authored by Christoph Lameter's avatar Christoph Lameter Committed by Linus Torvalds
Browse files

[PATCH] SwapMig: add_to_swap() avoid atomic allocations 



Add gfp_mask to add_to_swap

add_to_swap does allocations with GFP_ATOMIC in order not to interfere with
swapping.  During migration we may have use add_to_swap extensively which may
lead to out of memory errors.

This patch makes add_to_swap take a parameter that specifies the gfp mask.
The page migration code can then make add_to_swap use GFP_KERNEL.

Signed-off-by: default avatarHirokazu Takahashi <taka@valinux.co.jp>
Signed-off-by: default avatarDave Hansen <haveblue@us.ibm.com>
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 8419c318

include/linux/swap.h

+1 −1
Original line number Diff line number Diff line
@@ -198,7 +198,7 @@ extern int rw_swap_page_sync(int, swp_entry_t, struct page *); 
extern struct address_space swapper_space;

#define total_swapcache_pages  swapper_space.nrpages

extern void show_swap_cache_info(void);

extern int add_to_swap(struct page *);

extern int add_to_swap(struct page *, gfp_t);

extern void __delete_from_swap_cache(struct page *);

extern void delete_from_swap_cache(struct page *);

extern int move_to_swap_cache(struct page *, swp_entry_t);

mm/swap_state.c

+2 −2
Original line number Diff line number Diff line
@@ -141,7 +141,7 @@ void __delete_from_swap_cache(struct page *page) 
 * Allocate swap space for the page and add the page to the

 * swap cache.  Caller needs to hold the page lock. 

 */

int add_to_swap(struct page * page)

int add_to_swap(struct page * page, gfp_t gfp_mask)

{

	swp_entry_t entry;

	int err;
@@ -166,7 +166,7 @@ int add_to_swap(struct page * page) 
		 * Add it to the swap cache and mark it dirty

		 */

		err = __add_to_swap_cache(page, entry,

				GFP_ATOMIC|__GFP_NOMEMALLOC|__GFP_NOWARN);

				gfp_mask|__GFP_NOMEMALLOC|__GFP_NOWARN);



		switch (err) {

		case 0:				/* Success */

mm/vmscan.c

+2 −2
Original line number Diff line number Diff line
@@ -458,7 +458,7 @@ static int shrink_list(struct list_head *page_list, struct scan_control *sc) 
		 * Try to allocate it some swap space here.

		 */

		if (PageAnon(page) && !PageSwapCache(page)) {

			if (!add_to_swap(page))

			if (!add_to_swap(page, GFP_ATOMIC))

				goto activate_locked;

		}

#endif /* CONFIG_SWAP */
@@ -715,7 +715,7 @@ redo: 
		}



		if (PageAnon(page) && !PageSwapCache(page)) {

			if (!add_to_swap(page)) {

			if (!add_to_swap(page, GFP_KERNEL)) {

				unlock_page(page);

				list_move(&page->lru, &failed);

				nr_failed++;

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