Commit 14f9135d authored by David Hildenbrand's avatar David Hildenbrand Committed by Andrew Morton
Browse files

mm/rmap: convert RMAP flags to a proper distinct rmap_t type 

We want to pass the flags to more than one anon rmap function, getting rid
of special "do_page_add_anon_rmap()".  So let's pass around a distinct
__bitwise type and refine documentation.

Link: https://lkml.kernel.org/r/20220428083441.37290-6-david@redhat.com


Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Don Dutile <ddutile@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Liang Zhang <zhangliang5@huawei.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Nadav Amit <namit@vmware.com>
Cc: Oded Gabbay <oded.gabbay@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pedro Demarchi Gomes <pedrodemargomes@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent fb3d824d

include/linux/rmap.h

+18 −4
Original line number Diff line number Diff line
@@ -160,9 +160,23 @@ static inline void anon_vma_merge(struct vm_area_struct *vma, 


struct anon_vma *page_get_anon_vma(struct page *page);



/* bitflags for do_page_add_anon_rmap() */

#define RMAP_EXCLUSIVE 0x01

#define RMAP_COMPOUND 0x02

/* RMAP flags, currently only relevant for some anon rmap operations. */

typedef int __bitwise rmap_t;



/*

 * No special request: if the page is a subpage of a compound page, it is

 * mapped via a PTE. The mapped (sub)page is possibly shared between processes.

 */

#define RMAP_NONE		((__force rmap_t)0)



/* The (sub)page is exclusive to a single process. */

#define RMAP_EXCLUSIVE		((__force rmap_t)BIT(0))



/*

 * The compound page is not mapped via PTEs, but instead via a single PMD and

 * should be accounted accordingly.

 */

#define RMAP_COMPOUND		((__force rmap_t)BIT(1))



/*

 * rmap interfaces called when adding or removing pte of page
@@ -171,7 +185,7 @@ void page_move_anon_rmap(struct page *, struct vm_area_struct *); 
void page_add_anon_rmap(struct page *, struct vm_area_struct *,

		unsigned long address, bool compound);

void do_page_add_anon_rmap(struct page *, struct vm_area_struct *,

		unsigned long address, int flags);

		unsigned long address, rmap_t flags);

void page_add_new_anon_rmap(struct page *, struct vm_area_struct *,

		unsigned long address, bool compound);

void page_add_file_rmap(struct page *, struct vm_area_struct *,

mm/memory.c

+3 −3
Original line number Diff line number Diff line
@@ -3511,10 +3511,10 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) 
	struct vm_area_struct *vma = vmf->vma;

	struct page *page = NULL, *swapcache;

	struct swap_info_struct *si = NULL;

	rmap_t rmap_flags = RMAP_NONE;

	swp_entry_t entry;

	pte_t pte;

	int locked;

	int exclusive = 0;

	vm_fault_t ret = 0;

	void *shadow = NULL;
@@ -3689,7 +3689,7 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) 
		pte = maybe_mkwrite(pte_mkdirty(pte), vma);

		vmf->flags &= ~FAULT_FLAG_WRITE;

		ret |= VM_FAULT_WRITE;

		exclusive = RMAP_EXCLUSIVE;

		rmap_flags |= RMAP_EXCLUSIVE;

	}

	flush_icache_page(vma, page);

	if (pte_swp_soft_dirty(vmf->orig_pte))
@@ -3705,7 +3705,7 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) 
		page_add_new_anon_rmap(page, vma, vmf->address, false);

		lru_cache_add_inactive_or_unevictable(page, vma);

	} else {

		do_page_add_anon_rmap(page, vma, vmf->address, exclusive);

		do_page_add_anon_rmap(page, vma, vmf->address, rmap_flags);

	}



	set_pte_at(vma->vm_mm, vmf->address, vmf->pte, pte);

mm/rmap.c

+4 −3
Original line number Diff line number Diff line
@@ -1181,7 +1181,8 @@ static void __page_check_anon_rmap(struct page *page, 
void page_add_anon_rmap(struct page *page,

	struct vm_area_struct *vma, unsigned long address, bool compound)

{

	do_page_add_anon_rmap(page, vma, address, compound ? RMAP_COMPOUND : 0);

	do_page_add_anon_rmap(page, vma, address,

			      compound ? RMAP_COMPOUND : RMAP_NONE);

}



/*
@@ -1190,7 +1191,7 @@ void page_add_anon_rmap(struct page *page, 
 * Everybody else should continue to use page_add_anon_rmap above.

 */

void do_page_add_anon_rmap(struct page *page,

	struct vm_area_struct *vma, unsigned long address, int flags)

	struct vm_area_struct *vma, unsigned long address, rmap_t flags)

{

	bool compound = flags & RMAP_COMPOUND;

	bool first;
@@ -1229,7 +1230,7 @@ void do_page_add_anon_rmap(struct page *page, 
	/* address might be in next vma when migration races vma_adjust */

	else if (first)

		__page_set_anon_rmap(page, vma, address,

				flags & RMAP_EXCLUSIVE);

				     !!(flags & RMAP_EXCLUSIVE));

	else

		__page_check_anon_rmap(page, vma, address);