Commit f346a947 authored by Max Kellermann's avatar Max Kellermann Committed by Andrew Morton
Browse files

mm: constify various inline functions for improved const-correctness 

We select certain test functions plus folio_migrate_refs() from
mm_inline.h which either invoke each other, functions that are already
const-ified, or no further functions.

It is therefore relatively trivial to const-ify them, which provides a
basis for further const-ification further up the call stack.

One exception is the function folio_migrate_refs() which does write to the
"new" folio pointer; there, only the "old" folio pointer is being
constified; only its "flags" field is read, but nothing written.

Link: https://lkml.kernel.org/r/20250901205021.3573313-11-max.kellermann@ionos.com


Signed-off-by: default avatarMax Kellermann <max.kellermann@ionos.com>
Reviewed-by: default avatarVishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: default avatarLorenzo Stoakes <lorenzo.stoakes@oracle.com>
Acked-by: default avatarDavid Hildenbrand <david@redhat.com>
Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
Acked-by: default avatarMike Rapoport (Microsoft) <rppt@kernel.org>
Acked-by: default avatarShakeel Butt <shakeel.butt@linux.dev>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christian Zankel <chris@zankel.net>
Cc: David Rientjes <rientjes@google.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Bottomley <james.bottomley@HansenPartnership.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jocelyn Falempe <jfalempe@redhat.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Nysal Jan K.A" <nysal@linux.ibm.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russel King <linux@armlinux.org.uk>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: Thomas Huth <thuth@redhat.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Wei Xu <weixugc@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 89bf840b

include/linux/mm_inline.h

+13 −12
Original line number Diff line number Diff line
@@ -25,7 +25,7 @@ 
 * 0 if @folio is a normal anonymous folio, a tmpfs folio or otherwise

 * ram or swap backed folio.

 */

static inline int folio_is_file_lru(struct folio *folio)

static inline int folio_is_file_lru(const struct folio *folio)

{

	return !folio_test_swapbacked(folio);

}
@@ -84,7 +84,7 @@ static __always_inline void __folio_clear_lru_flags(struct folio *folio) 
 * Return: The LRU list a folio should be on, as an index

 * into the array of LRU lists.

 */

static __always_inline enum lru_list folio_lru_list(struct folio *folio)

static __always_inline enum lru_list folio_lru_list(const struct folio *folio)

{

	enum lru_list lru;
@@ -141,7 +141,7 @@ static inline int lru_tier_from_refs(int refs, bool workingset) 
	return workingset ? MAX_NR_TIERS - 1 : order_base_2(refs);

}



static inline int folio_lru_refs(struct folio *folio)

static inline int folio_lru_refs(const struct folio *folio)

{

	unsigned long flags = READ_ONCE(folio->flags.f);
@@ -154,14 +154,14 @@ static inline int folio_lru_refs(struct folio *folio) 
	return ((flags & LRU_REFS_MASK) >> LRU_REFS_PGOFF) + 1;

}



static inline int folio_lru_gen(struct folio *folio)

static inline int folio_lru_gen(const struct folio *folio)

{

	unsigned long flags = READ_ONCE(folio->flags.f);



	return ((flags & LRU_GEN_MASK) >> LRU_GEN_PGOFF) - 1;

}



static inline bool lru_gen_is_active(struct lruvec *lruvec, int gen)

static inline bool lru_gen_is_active(const struct lruvec *lruvec, int gen)

{

	unsigned long max_seq = lruvec->lrugen.max_seq;
@@ -217,12 +217,13 @@ static inline void lru_gen_update_size(struct lruvec *lruvec, struct folio *foli 
	VM_WARN_ON_ONCE(lru_gen_is_active(lruvec, old_gen) && !lru_gen_is_active(lruvec, new_gen));

}



static inline unsigned long lru_gen_folio_seq(struct lruvec *lruvec, struct folio *folio,

static inline unsigned long lru_gen_folio_seq(const struct lruvec *lruvec,

					      const struct folio *folio,

					      bool reclaiming)

{

	int gen;

	int type = folio_is_file_lru(folio);

	struct lru_gen_folio *lrugen = &lruvec->lrugen;

	const struct lru_gen_folio *lrugen = &lruvec->lrugen;



	/*

	 * +-----------------------------------+-----------------------------------+
@@ -302,7 +303,7 @@ static inline bool lru_gen_del_folio(struct lruvec *lruvec, struct folio *folio, 
	return true;

}



static inline void folio_migrate_refs(struct folio *new, struct folio *old)

static inline void folio_migrate_refs(struct folio *new, const struct folio *old)

{

	unsigned long refs = READ_ONCE(old->flags.f) & LRU_REFS_MASK;
@@ -330,7 +331,7 @@ static inline bool lru_gen_del_folio(struct lruvec *lruvec, struct folio *folio, 
	return false;

}



static inline void folio_migrate_refs(struct folio *new, struct folio *old)

static inline void folio_migrate_refs(struct folio *new, const struct folio *old)

{



}
@@ -508,7 +509,7 @@ static inline void dec_tlb_flush_pending(struct mm_struct *mm) 
	atomic_dec(&mm->tlb_flush_pending);

}



static inline bool mm_tlb_flush_pending(struct mm_struct *mm)

static inline bool mm_tlb_flush_pending(const struct mm_struct *mm)

{

	/*

	 * Must be called after having acquired the PTL; orders against that
@@ -521,7 +522,7 @@ static inline bool mm_tlb_flush_pending(struct mm_struct *mm) 
	return atomic_read(&mm->tlb_flush_pending);

}



static inline bool mm_tlb_flush_nested(struct mm_struct *mm)

static inline bool mm_tlb_flush_nested(const struct mm_struct *mm)

{

	/*

	 * Similar to mm_tlb_flush_pending(), we must have acquired the PTL
@@ -605,7 +606,7 @@ pte_install_uffd_wp_if_needed(struct vm_area_struct *vma, unsigned long addr, 
	return false;

}



static inline bool vma_has_recency(struct vm_area_struct *vma)

static inline bool vma_has_recency(const struct vm_area_struct *vma)

{

	if (vma->vm_flags & (VM_SEQ_READ | VM_RAND_READ))

		return false;