Commit de53c05f authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Andrew Morton
Browse files

mm: add large_rmappable page flag 

Stored in the first tail page's flags, this flag replaces the destructor. 
That removes the last of the destructors, so remove all references to
folio_dtor and compound_dtor.

Link: https://lkml.kernel.org/r/20230816151201.3655946-9-willy@infradead.org


Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Yanteng Si <siyanteng@loongson.cn>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 9c5ccf2d

Documentation/admin-guide/kdump/vmcoreinfo.rst

+2 −2
Original line number Diff line number Diff line
@@ -141,8 +141,8 @@ nodemask_t 
The size of a nodemask_t type. Used to compute the number of online

nodes.



(page, flags|_refcount|mapping|lru|_mapcount|private|compound_dtor|compound_order|compound_head)

-------------------------------------------------------------------------------------------------

(page, flags|_refcount|mapping|lru|_mapcount|private|compound_order|compound_head)

----------------------------------------------------------------------------------



User-space tools compute their values based on the offset of these

variables. The variables are used when excluding unnecessary pages.

include/linux/mm.h

+0 −13
Original line number Diff line number Diff line
@@ -1239,19 +1239,6 @@ void folio_copy(struct folio *dst, struct folio *src); 


unsigned long nr_free_buffer_pages(void);



enum compound_dtor_id {

	COMPOUND_PAGE_DTOR,

	TRANSHUGE_PAGE_DTOR,

	NR_COMPOUND_DTORS,

};



static inline void folio_set_compound_dtor(struct folio *folio,

		enum compound_dtor_id compound_dtor)

{

	VM_BUG_ON_FOLIO(compound_dtor >= NR_COMPOUND_DTORS, folio);

	folio->_folio_dtor = compound_dtor;

}



void destroy_large_folio(struct folio *folio);



/* Returns the number of bytes in this potentially compound page. */

include/linux/mm_types.h

+0 −2
Original line number Diff line number Diff line
@@ -264,7 +264,6 @@ static inline struct page *encoded_page_ptr(struct encoded_page *page) 
 * @_refcount: Do not access this member directly.  Use folio_ref_count()

 *    to find how many references there are to this folio.

 * @memcg_data: Memory Control Group data.

 * @_folio_dtor: Which destructor to use for this folio.

 * @_folio_order: Do not use directly, call folio_order().

 * @_entire_mapcount: Do not use directly, call folio_entire_mapcount().

 * @_nr_pages_mapped: Do not use directly, call folio_mapcount().
@@ -318,7 +317,6 @@ struct folio { 
			unsigned long _flags_1;

			unsigned long _head_1;

	/* public: */

			unsigned char _folio_dtor;

			unsigned char _folio_order;

			atomic_t _entire_mapcount;

			atomic_t _nr_pages_mapped;

include/linux/page-flags.h

+6 −1
Original line number Diff line number Diff line
@@ -190,6 +190,7 @@ enum pageflags { 
	/* At least one page in this folio has the hwpoison flag set */

	PG_has_hwpoisoned = PG_error,

	PG_hugetlb = PG_active,

	PG_large_rmappable = PG_workingset, /* anon or file-backed */

};



#define PAGEFLAGS_MASK		((1UL << NR_PAGEFLAGS) - 1)
@@ -806,6 +807,9 @@ static inline void ClearPageCompound(struct page *page) 
	BUG_ON(!PageHead(page));

	ClearPageHead(page);

}

PAGEFLAG(LargeRmappable, large_rmappable, PF_SECOND)

#else

TESTPAGEFLAG_FALSE(LargeRmappable, large_rmappable)

#endif



#define PG_head_mask ((1UL << PG_head))
@@ -1077,7 +1081,8 @@ static __always_inline void __ClearPageAnonExclusive(struct page *page) 
 * the CHECK_AT_FREE flags above, so need to be cleared.

 */

#define PAGE_FLAGS_SECOND						\

	(1UL << PG_has_hwpoisoned	| 1UL << PG_hugetlb)

	(1UL << PG_has_hwpoisoned	| 1UL << PG_hugetlb |		\

	 1UL << PG_large_rmappable)



#define PAGE_FLAGS_PRIVATE				\

	(1UL << PG_private | 1UL << PG_private_2)

kernel/crash_core.c

+0 −1
Original line number Diff line number Diff line
@@ -455,7 +455,6 @@ static int __init crash_save_vmcoreinfo_init(void) 
	VMCOREINFO_OFFSET(page, lru);

	VMCOREINFO_OFFSET(page, _mapcount);

	VMCOREINFO_OFFSET(page, private);

	VMCOREINFO_OFFSET(folio, _folio_dtor);

	VMCOREINFO_OFFSET(folio, _folio_order);

	VMCOREINFO_OFFSET(page, compound_head);

	VMCOREINFO_OFFSET(pglist_data, node_zones);