Messages in this thread | | | Date | Fri, 14 Mar 2014 15:33:11 +0200 | From | "Kirill A. Shutemov" <> | Subject | Re: [RFC 3/6] mm: support madvise(MADV_FREE) |
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On Fri, Mar 14, 2014 at 03:37:47PM +0900, Minchan Kim wrote: > diff --git a/include/linux/mm.h b/include/linux/mm.h > index c1b7414c7bef..9b048cabce27 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -933,10 +933,16 @@ void page_address_init(void); > * Please note that, confusingly, "page_mapping" refers to the inode > * address_space which maps the page from disk; whereas "page_mapped" > * refers to user virtual address space into which the page is mapped. > + * > + * PAGE_MAPPING_LZFREE bit is set along with PAGE_MAPPING_ANON bit > + * and then page->mapping points to an anon_vma. This flag is used > + * for lazy freeing the page instead of swap. > */ > #define PAGE_MAPPING_ANON 1 > #define PAGE_MAPPING_KSM 2 > -#define PAGE_MAPPING_FLAGS (PAGE_MAPPING_ANON | PAGE_MAPPING_KSM) > +#define PAGE_MAPPING_LZFREE 4 > +#define PAGE_MAPPING_FLAGS (PAGE_MAPPING_ANON | PAGE_MAPPING_KSM | \ > + PAGE_MAPPING_LZFREE)
Is it safe to use third bit in pointer everywhere?
-- Kirill A. Shutemov
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