Commit 84fbbe21 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle)
Browse files

mm/rmap: Constify the rmap_walk_control argument 



The rmap walking functions do not modify the rmap_walk_control, and
page_idle_clear_pte_refs() takes advantage of that to move construction
of the rmap_walk_control to compile time.  This lets us remove an
unclean cast.

Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
parent 2f031c6f

include/linux/ksm.h

+2 −2
Original line number Diff line number Diff line
@@ -51,7 +51,7 @@ static inline void ksm_exit(struct mm_struct *mm) 
struct page *ksm_might_need_to_copy(struct page *page,

			struct vm_area_struct *vma, unsigned long address);



void rmap_walk_ksm(struct folio *folio, struct rmap_walk_control *rwc);

void rmap_walk_ksm(struct folio *folio, const struct rmap_walk_control *rwc);

void folio_migrate_ksm(struct folio *newfolio, struct folio *folio);



#else  /* !CONFIG_KSM */
@@ -79,7 +79,7 @@ static inline struct page *ksm_might_need_to_copy(struct page *page, 
}



static inline void rmap_walk_ksm(struct folio *folio,

			struct rmap_walk_control *rwc)

			const struct rmap_walk_control *rwc)

{

}

include/linux/rmap.h

+2 −2
Original line number Diff line number Diff line
@@ -292,8 +292,8 @@ struct rmap_walk_control { 
	bool (*invalid_vma)(struct vm_area_struct *vma, void *arg);

};



void rmap_walk(struct folio *folio, struct rmap_walk_control *rwc);

void rmap_walk_locked(struct folio *folio, struct rmap_walk_control *rwc);

void rmap_walk(struct folio *folio, const struct rmap_walk_control *rwc);

void rmap_walk_locked(struct folio *folio, const struct rmap_walk_control *rwc);



#else	/* !CONFIG_MMU */

mm/ksm.c

+1 −1
Original line number Diff line number Diff line
@@ -2588,7 +2588,7 @@ struct page *ksm_might_need_to_copy(struct page *page, 
	return new_page;

}



void rmap_walk_ksm(struct folio *folio, struct rmap_walk_control *rwc)

void rmap_walk_ksm(struct folio *folio, const struct rmap_walk_control *rwc)

{

	struct stable_node *stable_node;

	struct rmap_item *rmap_item;

mm/page_idle.c

+1 −1
Original line number Diff line number Diff line
@@ -103,7 +103,7 @@ static void page_idle_clear_pte_refs(struct page *page) 
	if (need_lock && !folio_trylock(folio))

		return;



	rmap_walk(folio, (struct rmap_walk_control *)&rwc);

	rmap_walk(folio, &rwc);



	if (need_lock)

		folio_unlock(folio);

mm/rmap.c

+7 −7
Original line number Diff line number Diff line
@@ -2173,7 +2173,7 @@ void __put_anon_vma(struct anon_vma *anon_vma) 
}



static struct anon_vma *rmap_walk_anon_lock(struct folio *folio,

					struct rmap_walk_control *rwc)

					const struct rmap_walk_control *rwc)

{

	struct anon_vma *anon_vma;
@@ -2203,8 +2203,8 @@ static struct anon_vma *rmap_walk_anon_lock(struct folio *folio, 
 * Find all the mappings of a page using the mapping pointer and the vma chains

 * contained in the anon_vma struct it points to.

 */

static void rmap_walk_anon(struct folio *folio, struct rmap_walk_control *rwc,

		bool locked)

static void rmap_walk_anon(struct folio *folio,

		const struct rmap_walk_control *rwc, bool locked)

{

	struct anon_vma *anon_vma;

	pgoff_t pgoff_start, pgoff_end;
@@ -2251,8 +2251,8 @@ static void rmap_walk_anon(struct folio *folio, struct rmap_walk_control *rwc, 
 * Find all the mappings of a page using the mapping pointer and the vma chains

 * contained in the address_space struct it points to.

 */

static void rmap_walk_file(struct folio *folio, struct rmap_walk_control *rwc,

		bool locked)

static void rmap_walk_file(struct folio *folio,

		const struct rmap_walk_control *rwc, bool locked)

{

	struct address_space *mapping = folio_mapping(folio);

	pgoff_t pgoff_start, pgoff_end;
@@ -2294,7 +2294,7 @@ static void rmap_walk_file(struct folio *folio, struct rmap_walk_control *rwc, 
		i_mmap_unlock_read(mapping);

}



void rmap_walk(struct folio *folio, struct rmap_walk_control *rwc)

void rmap_walk(struct folio *folio, const struct rmap_walk_control *rwc)

{

	if (unlikely(folio_test_ksm(folio)))

		rmap_walk_ksm(folio, rwc);
@@ -2305,7 +2305,7 @@ void rmap_walk(struct folio *folio, struct rmap_walk_control *rwc) 
}



/* Like rmap_walk, but caller holds relevant rmap lock */

void rmap_walk_locked(struct folio *folio, struct rmap_walk_control *rwc)

void rmap_walk_locked(struct folio *folio, const struct rmap_walk_control *rwc)

{

	/* no ksm support for now */

	VM_BUG_ON_FOLIO(folio_test_ksm(folio), folio);