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.

Matthew Wilcox (Oracle) committed 4 years ago

Commit 84fbbe21 parent 2f031c65 files · +13 −13Browse files

Unified · Split

5 files

include/linux/ksm.h +2 −2
include/linux/rmap.h +2 −2
mm/ksm.c +1 −1
mm/page_idle.c +1 −1
mm/rmap.c +7 −7

include/linux/ksm.h+2−2

@@ -51,7 +51,7 @@ static inline void ksm_exit(struct mm_struct *mm) · 50 unmodified lines
51	struct page ksm_might_need_to_copy(struct page page,	51	struct page ksm_might_need_to_copy(struct page page,
52	struct vm_area_struct *vma, unsigned long address);	52	struct vm_area_struct *vma, unsigned long address);
53		53
54	void rmap_walk_ksm(struct folio folio, struct rmap_walk_control rwc);	54	void rmap_walk_ksm(struct folio folio, const struct rmap_walk_control rwc);
55	void folio_migrate_ksm(struct folio newfolio, struct folio folio);	55	void folio_migrate_ksm(struct folio newfolio, struct folio folio);
56		56
57	#else /* !CONFIG_KSM */	57	#else /* !CONFIG_KSM */
@@ -79,7 +79,7 @@ static inline struct page ksm_might_need_to_copy(struct page page, · 21 unmodified lines
79	}	79	}
80		80
81	static inline void rmap_walk_ksm(struct folio *folio,	81	static inline void rmap_walk_ksm(struct folio *folio,
82	struct rmap_walk_control *rwc)	82	const struct rmap_walk_control *rwc)
83	{	83	{
84	}	84	}
85		85

include/linux/rmap.h+2−2

@@ -292,8 +292,8 @@ struct rmap_walk_control { · 291 unmodified lines
292	bool (invalid_vma)(struct vm_area_struct vma, void *arg);	292	bool (invalid_vma)(struct vm_area_struct vma, void *arg);
293	};	293	};
294		294
295	void rmap_walk(struct folio folio, struct rmap_walk_control rwc);	295	void rmap_walk(struct folio folio, const struct rmap_walk_control rwc);
296	void rmap_walk_locked(struct folio folio, struct rmap_walk_control rwc);	296	void rmap_walk_locked(struct folio folio, const struct rmap_walk_control rwc);
297		297
298	#else /* !CONFIG_MMU */	298	#else /* !CONFIG_MMU */
299		299

mm/ksm.c+1−1

@@ -2588,7 +2588,7 @@ struct page ksm_might_need_to_copy(struct page page, · 2587 unmodified lines
2588	return new_page;	2588	return new_page;
2589	}	2589	}
2590		2590
2591	void rmap_walk_ksm(struct folio folio, struct rmap_walk_control rwc)	2591	void rmap_walk_ksm(struct folio folio, const struct rmap_walk_control rwc)
2592	{	2592	{
2593	struct stable_node *stable_node;	2593	struct stable_node *stable_node;
2594	struct rmap_item *rmap_item;	2594	struct rmap_item *rmap_item;

mm/page_idle.c+1−1

@@ -103,7 +103,7 @@ static void page_idle_clear_pte_refs(struct page *page) · 102 unmodified lines
103	if (need_lock && !folio_trylock(folio))	103	if (need_lock && !folio_trylock(folio))
104	return;	104	return;
105		105
106	rmap_walk(folio, (struct rmap_walk_control *)&rwc);	106	rmap_walk(folio, &rwc);
107		107
108	if (need_lock)	108	if (need_lock)
109	folio_unlock(folio);	109	folio_unlock(folio);

mm/rmap.c+7−7

@@ -2173,7 +2173,7 @@ void __put_anon_vma(struct anon_vma *anon_vma) · 2172 unmodified lines
2173	}	2173	}
2174		2174
2175	static struct anon_vma rmap_walk_anon_lock(struct folio folio,	2175	static struct anon_vma rmap_walk_anon_lock(struct folio folio,
2176	struct rmap_walk_control *rwc)	2176	const struct rmap_walk_control *rwc)
2177	{	2177	{
2178	struct anon_vma *anon_vma;	2178	struct anon_vma *anon_vma;
2179		2179
@@ -2203,8 +2203,8 @@ static struct anon_vma rmap_walk_anon_lock(struct folio folio, · 23 unmodified lines
2203	* Find all the mappings of a page using the mapping pointer and the vma chains	2203	* Find all the mappings of a page using the mapping pointer and the vma chains
2204	* contained in the anon_vma struct it points to.	2204	* contained in the anon_vma struct it points to.
2205	*/	2205	*/
2206	static void rmap_walk_anon(struct folio folio, struct rmap_walk_control rwc,	2206	static void rmap_walk_anon(struct folio *folio,
2207	bool locked)	2207	const struct rmap_walk_control *rwc, bool locked)
2208	{	2208	{
2209	struct anon_vma *anon_vma;	2209	struct anon_vma *anon_vma;
2210	pgoff_t pgoff_start, pgoff_end;	2210	pgoff_t pgoff_start, pgoff_end;
@@ -2251,8 +2251,8 @@ static void rmap_walk_anon(struct folio folio, struct rmap_walk_control rwc, · 40 unmodified lines
2251	* Find all the mappings of a page using the mapping pointer and the vma chains	2251	* Find all the mappings of a page using the mapping pointer and the vma chains
2252	* contained in the address_space struct it points to.	2252	* contained in the address_space struct it points to.
2253	*/	2253	*/
2254	static void rmap_walk_file(struct folio folio, struct rmap_walk_control rwc,	2254	static void rmap_walk_file(struct folio *folio,
2255	bool locked)	2255	const struct rmap_walk_control *rwc, bool locked)
2256	{	2256	{
2257	struct address_space *mapping = folio_mapping(folio);	2257	struct address_space *mapping = folio_mapping(folio);
2258	pgoff_t pgoff_start, pgoff_end;	2258	pgoff_t pgoff_start, pgoff_end;
@@ -2294,7 +2294,7 @@ done: · 35 unmodified lines
2294	i_mmap_unlock_read(mapping);	2294	i_mmap_unlock_read(mapping);
2295	}	2295	}
2296		2296
2297	void rmap_walk(struct folio folio, struct rmap_walk_control rwc)	2297	void rmap_walk(struct folio folio, const struct rmap_walk_control rwc)
2298	{	2298	{
2299	if (unlikely(folio_test_ksm(folio)))	2299	if (unlikely(folio_test_ksm(folio)))
2300	rmap_walk_ksm(folio, rwc);	2300	rmap_walk_ksm(folio, rwc);
@@ -2305,7 +2305,7 @@ void rmap_walk(struct folio folio, struct rmap_walk_control rwc) · 4 unmodified lines
2305	}	2305	}
2306		2306
2307	/* Like rmap_walk, but caller holds relevant rmap lock */	2307	/* Like rmap_walk, but caller holds relevant rmap lock */
2308	void rmap_walk_locked(struct folio folio, struct rmap_walk_control rwc)	2308	void rmap_walk_locked(struct folio folio, const struct rmap_walk_control rwc)
2309	{	2309	{
2310	/* no ksm support for now */	2310	/* no ksm support for now */
2311	VM_BUG_ON_FOLIO(folio_test_ksm(folio), folio);	2311	VM_BUG_ON_FOLIO(folio_test_ksm(folio), folio);

mm/rmap: Constify the rmap_walk_control argument

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