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rmap: add folio_add_file_rmap_range()

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folio_add_file_rmap_range() allows to add pte mapping to a specific range
of file folio.  Comparing to page_add_file_rmap(), it batched updates
__lruvec_stat for large folio.

Link: https://lkml.kernel.org/r/20230802151406.3735276-36-willy@infradead.org
Signed-off-by: Yin Fengwei <fengwei.yin@intel.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Yin Fengwei 2023-08-02 16:14:03 +01:00 committed by Andrew Morton
parent de74976eb6
commit 86f35f69db
2 changed files with 48 additions and 14 deletions
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2
include/linux/rmap.h
View File

@ -198,6 +198,8 @@ void folio_add_new_anon_rmap(struct folio *, struct vm_area_struct *,
unsigned long address);
void page_add_file_rmap(struct page *, struct vm_area_struct *,
bool compound);
void folio_add_file_rmap_range(struct folio *, struct page *, unsigned int nr,
struct vm_area_struct *, bool compound);
void page_remove_rmap(struct page *, struct vm_area_struct *,
bool compound);

52
mm/rmap.c
View File

@ -1294,31 +1294,39 @@ void folio_add_new_anon_rmap(struct folio *folio, struct vm_area_struct *vma,
}
/**
* page_add_file_rmap - add pte mapping to a file page
* @page: the page to add the mapping to
* folio_add_file_rmap_range - add pte mapping to page range of a folio
* @folio: The folio to add the mapping to
* @page: The first page to add
* @nr_pages: The number of pages which will be mapped
* @vma: the vm area in which the mapping is added
* @compound: charge the page as compound or small page
*
* The page range of folio is defined by [first_page, first_page + nr_pages)
*
* The caller needs to hold the pte lock.
*/
void page_add_file_rmap(struct page *page, struct vm_area_struct *vma,
void folio_add_file_rmap_range(struct folio *folio, struct page *page,
unsigned int nr_pages, struct vm_area_struct *vma,
bool compound)
{
struct folio *folio = page_folio(page);
atomic_t *mapped = &folio->_nr_pages_mapped;
int nr = 0, nr_pmdmapped = 0;
bool first;
unsigned int nr_pmdmapped = 0, first;
int nr = 0;
VM_BUG_ON_PAGE(compound && !PageTransHuge(page), page);
VM_WARN_ON_FOLIO(compound && !folio_test_pmd_mappable(folio), folio);
/* Is page being mapped by PTE? Is this its first map to be added? */
if (likely(!compound)) {
do {
first = atomic_inc_and_test(&page->_mapcount);
nr = first;
if (first && folio_test_large(folio)) {
nr = atomic_inc_return_relaxed(mapped);
nr = (nr < COMPOUND_MAPPED);
first = atomic_inc_return_relaxed(mapped);
first = (first < COMPOUND_MAPPED);
}
if (first)
nr++;
} while (page++, --nr_pages > 0);
} else if (folio_test_pmd_mappable(folio)) {
/* That test is redundant: it's for safety or to optimize out */
@ -1347,6 +1355,30 @@ void page_add_file_rmap(struct page *page, struct vm_area_struct *vma,
mlock_vma_folio(folio, vma, compound);
}
/**
* page_add_file_rmap - add pte mapping to a file page
* @page: the page to add the mapping to
* @vma: the vm area in which the mapping is added
* @compound: charge the page as compound or small page
*
* The caller needs to hold the pte lock.
*/
void page_add_file_rmap(struct page *page, struct vm_area_struct *vma,
bool compound)
{
struct folio *folio = page_folio(page);
unsigned int nr_pages;
VM_WARN_ON_ONCE_PAGE(compound && !PageTransHuge(page), page);
if (likely(!compound))
nr_pages = 1;
else
nr_pages = folio_nr_pages(folio);
folio_add_file_rmap_range(folio, page, nr_pages, vma, compound);
}
/**
* page_remove_rmap - take down pte mapping from a page
* @page: page to remove mapping from