mm: convert page_add_file_rmap() to use a folio internally

The API for page_add_file_rmap() needs to be page-based, because we can
add mappings of individual pages.  But inside the function, we want to
only call compound_head() once and then use the folio APIs instead of the
page APIs that each call compound_head().

Link: https://lkml.kernel.org/r/20230111142915.1001531-8-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Matthew Wilcox (Oracle) 2023-01-11 14:28:53 +00:00 committed by Andrew Morton
parent ee0800c2f6
commit eb01a2ad7e

View File

@ -1309,10 +1309,11 @@ void page_add_new_anon_rmap(struct page *page,
* *
* The caller needs to hold the pte lock. * The caller needs to hold the pte lock.
*/ */
void page_add_file_rmap(struct page *page, void page_add_file_rmap(struct page *page, struct vm_area_struct *vma,
struct vm_area_struct *vma, bool compound) bool compound)
{ {
atomic_t *mapped; struct folio *folio = page_folio(page);
atomic_t *mapped = &folio->_nr_pages_mapped;
int nr = 0, nr_pmdmapped = 0; int nr = 0, nr_pmdmapped = 0;
bool first; bool first;
@ -1322,20 +1323,18 @@ void page_add_file_rmap(struct page *page,
if (likely(!compound)) { if (likely(!compound)) {
first = atomic_inc_and_test(&page->_mapcount); first = atomic_inc_and_test(&page->_mapcount);
nr = first; nr = first;
if (first && PageCompound(page)) { if (first && folio_test_large(folio)) {
mapped = subpages_mapcount_ptr(compound_head(page));
nr = atomic_inc_return_relaxed(mapped); nr = atomic_inc_return_relaxed(mapped);
nr = (nr < COMPOUND_MAPPED); nr = (nr < COMPOUND_MAPPED);
} }
} else if (PageTransHuge(page)) { } else if (folio_test_pmd_mappable(folio)) {
/* That test is redundant: it's for safety or to optimize out */ /* That test is redundant: it's for safety or to optimize out */
first = atomic_inc_and_test(compound_mapcount_ptr(page)); first = atomic_inc_and_test(&folio->_entire_mapcount);
if (first) { if (first) {
mapped = subpages_mapcount_ptr(page);
nr = atomic_add_return_relaxed(COMPOUND_MAPPED, mapped); nr = atomic_add_return_relaxed(COMPOUND_MAPPED, mapped);
if (likely(nr < COMPOUND_MAPPED + COMPOUND_MAPPED)) { if (likely(nr < COMPOUND_MAPPED + COMPOUND_MAPPED)) {
nr_pmdmapped = thp_nr_pages(page); nr_pmdmapped = folio_nr_pages(folio);
nr = nr_pmdmapped - (nr & FOLIO_PAGES_MAPPED); nr = nr_pmdmapped - (nr & FOLIO_PAGES_MAPPED);
/* Raced ahead of a remove and another add? */ /* Raced ahead of a remove and another add? */
if (unlikely(nr < 0)) if (unlikely(nr < 0))
@ -1348,10 +1347,10 @@ void page_add_file_rmap(struct page *page,
} }
if (nr_pmdmapped) if (nr_pmdmapped)
__mod_lruvec_page_state(page, PageSwapBacked(page) ? __lruvec_stat_mod_folio(folio, folio_test_swapbacked(folio) ?
NR_SHMEM_PMDMAPPED : NR_FILE_PMDMAPPED, nr_pmdmapped); NR_SHMEM_PMDMAPPED : NR_FILE_PMDMAPPED, nr_pmdmapped);
if (nr) if (nr)
__mod_lruvec_page_state(page, NR_FILE_MAPPED, nr); __lruvec_stat_mod_folio(folio, NR_FILE_MAPPED, nr);
mlock_vma_page(page, vma, compound); mlock_vma_page(page, vma, compound);
} }