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: David Hildenbrand <david@redhat.com>
Acked-by: Vlastimil 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: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
David Hildenbrand 2022-05-09 18:20:43 -07:00 committed by akpm
parent fb3d824d1a
commit 14f9135d54
3 changed files with 25 additions and 10 deletions

View File

@ -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 *,

View File

@ -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);

View File

@ -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);