diff options
| -rw-r--r-- | mm/swap.c | 31 |
1 files changed, 29 insertions, 2 deletions
@@ -31,6 +31,7 @@ #include <linux/backing-dev.h> #include <linux/memcontrol.h> #include <linux/gfp.h> +#include <linux/hugetlb.h> #include "internal.h" @@ -69,13 +70,26 @@ static void __put_compound_page(struct page *page) { compound_page_dtor *dtor; - __page_cache_release(page); + if (!PageHuge(page)) + __page_cache_release(page); dtor = get_compound_page_dtor(page); (*dtor)(page); } static void put_compound_page(struct page *page) { + /* + * hugetlbfs pages cannot be split from under us. If this is a + * hugetlbfs page, check refcount on head page and release the page if + * the refcount becomes zero. + */ + if (PageHuge(page)) { + page = compound_head(page); + if (put_page_testzero(page)) + __put_compound_page(page); + return; + } + if (unlikely(PageTail(page))) { /* __split_huge_page_refcount can run under us */ struct page *page_head = compound_trans_head(page); @@ -160,8 +174,20 @@ bool __get_page_tail(struct page *page) */ unsigned long flags; bool got = false; - struct page *page_head = compound_trans_head(page); + struct page *page_head; + + /* + * If this is a hugetlbfs page it cannot be split under us. Simply + * increment refcount for the head page. + */ + if (PageHuge(page)) { + page_head = compound_head(page); + atomic_inc(&page_head->_count); + got = true; + goto out; + } + page_head = compound_trans_head(page); if (likely(page != page_head && get_page_unless_zero(page_head))) { /* * page_head wasn't a dangling pointer but it @@ -179,6 +205,7 @@ bool __get_page_tail(struct page *page) if (unlikely(!got)) put_page(page_head); } +out: return got; } EXPORT_SYMBOL(__get_page_tail); |