From 6326fec1122cde256bd2a8c63f2606e08e44ce1d Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Sun, 25 Dec 2016 13:00:29 +1000 Subject: mm: Use owner_priv bit for PageSwapCache, valid when PageSwapBacked A page is not added to the swap cache without being swap backed, so PageSwapBacked mappings can use PG_owner_priv_1 for PageSwapCache. Signed-off-by: Nicholas Piggin Acked-by: Hugh Dickins Cc: Dave Hansen Cc: Bob Peterson Cc: Steven Whitehouse Cc: Andrew Lutomirski Cc: Andreas Gruenbacher Cc: Peter Zijlstra Cc: Mel Gorman Signed-off-by: Linus Torvalds --- include/linux/page-flags.h | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) (limited to 'include/linux') diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 74e4dda91238..a57c909a15e4 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -87,7 +87,6 @@ enum pageflags { PG_private_2, /* If pagecache, has fs aux data */ PG_writeback, /* Page is under writeback */ PG_head, /* A head page */ - PG_swapcache, /* Swap page: swp_entry_t in private */ PG_mappedtodisk, /* Has blocks allocated on-disk */ PG_reclaim, /* To be reclaimed asap */ PG_swapbacked, /* Page is backed by RAM/swap */ @@ -110,6 +109,9 @@ enum pageflags { /* Filesystems */ PG_checked = PG_owner_priv_1, + /* SwapBacked */ + PG_swapcache = PG_owner_priv_1, /* Swap page: swp_entry_t in private */ + /* Two page bits are conscripted by FS-Cache to maintain local caching * state. These bits are set on pages belonging to the netfs's inodes * when those inodes are being locally cached. @@ -314,7 +316,13 @@ PAGEFLAG_FALSE(HighMem) #endif #ifdef CONFIG_SWAP -PAGEFLAG(SwapCache, swapcache, PF_NO_COMPOUND) +static __always_inline int PageSwapCache(struct page *page) +{ + return PageSwapBacked(page) && test_bit(PG_swapcache, &page->flags); + +} +SETPAGEFLAG(SwapCache, swapcache, PF_NO_COMPOUND) +CLEARPAGEFLAG(SwapCache, swapcache, PF_NO_COMPOUND) #else PAGEFLAG_FALSE(SwapCache) #endif @@ -701,12 +709,12 @@ static inline void ClearPageSlabPfmemalloc(struct page *page) * Flags checked when a page is freed. Pages being freed should not have * these flags set. It they are, there is a problem. */ -#define PAGE_FLAGS_CHECK_AT_FREE \ - (1UL << PG_lru | 1UL << PG_locked | \ - 1UL << PG_private | 1UL << PG_private_2 | \ - 1UL << PG_writeback | 1UL << PG_reserved | \ - 1UL << PG_slab | 1UL << PG_swapcache | 1UL << PG_active | \ - 1UL << PG_unevictable | __PG_MLOCKED) +#define PAGE_FLAGS_CHECK_AT_FREE \ + (1UL << PG_lru | 1UL << PG_locked | \ + 1UL << PG_private | 1UL << PG_private_2 | \ + 1UL << PG_writeback | 1UL << PG_reserved | \ + 1UL << PG_slab | 1UL << PG_active | \ + 1UL << PG_unevictable | __PG_MLOCKED) /* * Flags checked when a page is prepped for return by the page allocator. -- cgit v1.2.3