Commit 522abd92 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Andrew Morton
Browse files

ptdesc: convert __page_flags to pt_flags 

Patch series "Some ptdesc cleanups".

The first two patches here are preparation for splitting struct ptdesc
from struct page and struct folio.  I think their only dependency is on
the memdesc_flags_t patches from August which is in mm-new.  The third
patch is just something I noticed while working on the code.


This patch (of 3):

Use the new memdesc_flags_t type to show that these are the same bits as
page/folio/slab and thesefore have the zone/node/section information in
them.  Remove a use of ptdesc_folio() by converting
pagetable_is_reserved() to use test_bit() directly.

Link: https://lkml.kernel.org/r/20250908171104.2409217-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20250908171104.2409217-2-willy@infradead.org


Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: default avatarDavid Hildenbrand <david@redhat.com>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 6106864b

include/linux/mm.h

+6 −1
Original line number Diff line number Diff line
@@ -2934,6 +2934,11 @@ static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long a 
}

#endif /* CONFIG_MMU */



enum pt_flags {

	PT_reserved = PG_reserved,

	/* High bits are used for zone/node/section */

};



static inline struct ptdesc *virt_to_ptdesc(const void *x)

{

	return page_ptdesc(virt_to_page(x));
@@ -2951,7 +2956,7 @@ static inline void *ptdesc_address(const struct ptdesc *pt) 


static inline bool pagetable_is_reserved(struct ptdesc *pt)

{

	return folio_test_reserved(ptdesc_folio(pt));

	return test_bit(PT_reserved, &pt->pt_flags.f);

}



/**

include/linux/mm_types.h

+3 −3
Original line number Diff line number Diff line
@@ -524,7 +524,7 @@ FOLIO_MATCH(compound_head, _head_3); 


/**

 * struct ptdesc -    Memory descriptor for page tables.

 * @__page_flags:     Same as page flags. Powerpc only.

 * @pt_flags: enum pt_flags plus zone/node/section.

 * @pt_rcu_head:      For freeing page table pages.

 * @pt_list:          List of used page tables. Used for s390 gmap shadow pages

 *                    (which are not linked into the user page tables) and x86
@@ -546,7 +546,7 @@ FOLIO_MATCH(compound_head, _head_3); 
 * understanding of the issues.

 */

struct ptdesc {

	unsigned long __page_flags;

	memdesc_flags_t pt_flags;



	union {

		struct rcu_head pt_rcu_head;
@@ -584,7 +584,7 @@ struct ptdesc { 


#define TABLE_MATCH(pg, pt)						\

	static_assert(offsetof(struct page, pg) == offsetof(struct ptdesc, pt))

TABLE_MATCH(flags, __page_flags);

TABLE_MATCH(flags, pt_flags);

TABLE_MATCH(compound_head, pt_list);

TABLE_MATCH(compound_head, _pt_pad_1);

TABLE_MATCH(mapping, __page_mapping);