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: Matthew Wilcox (Oracle) <willy@infradead.org>
This commit is contained in:
Matthew Wilcox (Oracle) 2022-01-29 16:16:54 -05:00
parent 2f031c6f04
commit 84fbbe2189
5 changed files with 13 additions and 13 deletions

View file

@ -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)
{
}

View file

@ -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 */

View file

@ -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;

View file

@ -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);

View file

@ -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);