diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/page_alloc.c | 46 |
1 files changed, 34 insertions, 12 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 23b84c4e1a5..1731236dec3 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -140,8 +140,7 @@ static void bad_page(const char *function, struct page *page) 1 << PG_reclaim | 1 << PG_slab | 1 << PG_swapcache | - 1 << PG_writeback | - 1 << PG_reserved ); + 1 << PG_writeback ); set_page_count(page, 0); reset_page_mapcount(page); page->mapping = NULL; @@ -335,7 +334,7 @@ static inline void __free_pages_bulk (struct page *page, zone->free_area[order].nr_free++; } -static inline void free_pages_check(const char *function, struct page *page) +static inline int free_pages_check(const char *function, struct page *page) { if ( page_mapcount(page) || page->mapping != NULL || @@ -353,6 +352,12 @@ static inline void free_pages_check(const char *function, struct page *page) bad_page(function, page); if (PageDirty(page)) __ClearPageDirty(page); + /* + * For now, we report if PG_reserved was found set, but do not + * clear it, and do not free the page. But we shall soon need + * to do more, for when the ZERO_PAGE count wraps negative. + */ + return PageReserved(page); } /* @@ -392,11 +397,10 @@ void __free_pages_ok(struct page *page, unsigned int order) { LIST_HEAD(list); int i; + int reserved = 0; arch_free_page(page, order); - mod_page_state(pgfree, 1 << order); - #ifndef CONFIG_MMU if (order > 0) for (i = 1 ; i < (1 << order) ; ++i) @@ -404,8 +408,12 @@ void __free_pages_ok(struct page *page, unsigned int order) #endif for (i = 0 ; i < (1 << order) ; ++i) - free_pages_check(__FUNCTION__, page + i); + reserved += free_pages_check(__FUNCTION__, page + i); + if (reserved) + return; + list_add(&page->lru, &list); + mod_page_state(pgfree, 1 << order); kernel_map_pages(page, 1<<order, 0); free_pages_bulk(page_zone(page), 1, &list, order); } @@ -463,7 +471,7 @@ void set_page_refs(struct page *page, int order) /* * This page is about to be returned from the page allocator */ -static void prep_new_page(struct page *page, int order) +static int prep_new_page(struct page *page, int order) { if ( page_mapcount(page) || page->mapping != NULL || @@ -481,12 +489,20 @@ static void prep_new_page(struct page *page, int order) 1 << PG_reserved ))) bad_page(__FUNCTION__, page); + /* + * For now, we report if PG_reserved was found set, but do not + * clear it, and do not allocate the page: as a safety net. + */ + if (PageReserved(page)) + return 1; + page->flags &= ~(1 << PG_uptodate | 1 << PG_error | 1 << PG_referenced | 1 << PG_arch_1 | 1 << PG_checked | 1 << PG_mappedtodisk); set_page_private(page, 0); set_page_refs(page, order); kernel_map_pages(page, 1 << order, 1); + return 0; } /* @@ -669,11 +685,14 @@ static void fastcall free_hot_cold_page(struct page *page, int cold) arch_free_page(page, 0); - kernel_map_pages(page, 1, 0); - inc_page_state(pgfree); if (PageAnon(page)) page->mapping = NULL; - free_pages_check(__FUNCTION__, page); + if (free_pages_check(__FUNCTION__, page)) + return; + + inc_page_state(pgfree); + kernel_map_pages(page, 1, 0); + pcp = &zone_pcp(zone, get_cpu())->pcp[cold]; local_irq_save(flags); list_add(&page->lru, &pcp->list); @@ -712,12 +731,14 @@ static struct page * buffered_rmqueue(struct zone *zone, int order, gfp_t gfp_flags) { unsigned long flags; - struct page *page = NULL; + struct page *page; int cold = !!(gfp_flags & __GFP_COLD); +again: if (order == 0) { struct per_cpu_pages *pcp; + page = NULL; pcp = &zone_pcp(zone, get_cpu())->pcp[cold]; local_irq_save(flags); if (pcp->count <= pcp->low) @@ -739,7 +760,8 @@ buffered_rmqueue(struct zone *zone, int order, gfp_t gfp_flags) if (page != NULL) { BUG_ON(bad_range(zone, page)); mod_page_state_zone(zone, pgalloc, 1 << order); - prep_new_page(page, order); + if (prep_new_page(page, order)) + goto again; if (gfp_flags & __GFP_ZERO) prep_zero_page(page, order, gfp_flags); |