mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-11 12:28:41 +08:00
mm: convert page_remove_rmap() to use a folio internally
The API for page_remove_rmap() needs to be page-based, because we can remove mappings of pages individually. 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/20230111142915.1001531-6-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:
parent
b14224fbea
commit
62beb906ef
47
mm/rmap.c
47
mm/rmap.c
@ -1365,19 +1365,21 @@ void page_add_file_rmap(struct page *page,
|
||||
*
|
||||
* The caller needs to hold the pte lock.
|
||||
*/
|
||||
void page_remove_rmap(struct page *page,
|
||||
struct vm_area_struct *vma, bool compound)
|
||||
void page_remove_rmap(struct page *page, struct vm_area_struct *vma,
|
||||
bool compound)
|
||||
{
|
||||
atomic_t *mapped;
|
||||
struct folio *folio = page_folio(page);
|
||||
atomic_t *mapped = &folio->_nr_pages_mapped;
|
||||
int nr = 0, nr_pmdmapped = 0;
|
||||
bool last;
|
||||
enum node_stat_item idx;
|
||||
|
||||
VM_BUG_ON_PAGE(compound && !PageHead(page), page);
|
||||
|
||||
/* Hugetlb pages are not counted in NR_*MAPPED */
|
||||
if (unlikely(PageHuge(page))) {
|
||||
if (unlikely(folio_test_hugetlb(folio))) {
|
||||
/* hugetlb pages are always mapped with pmds */
|
||||
atomic_dec(compound_mapcount_ptr(page));
|
||||
atomic_dec(&folio->_entire_mapcount);
|
||||
return;
|
||||
}
|
||||
|
||||
@ -1385,20 +1387,18 @@ void page_remove_rmap(struct page *page,
|
||||
if (likely(!compound)) {
|
||||
last = atomic_add_negative(-1, &page->_mapcount);
|
||||
nr = last;
|
||||
if (last && PageCompound(page)) {
|
||||
mapped = subpages_mapcount_ptr(compound_head(page));
|
||||
if (last && folio_test_large(folio)) {
|
||||
nr = atomic_dec_return_relaxed(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 */
|
||||
|
||||
last = atomic_add_negative(-1, compound_mapcount_ptr(page));
|
||||
last = atomic_add_negative(-1, &folio->_entire_mapcount);
|
||||
if (last) {
|
||||
mapped = subpages_mapcount_ptr(page);
|
||||
nr = atomic_sub_return_relaxed(COMPOUND_MAPPED, mapped);
|
||||
if (likely(nr < COMPOUND_MAPPED)) {
|
||||
nr_pmdmapped = thp_nr_pages(page);
|
||||
nr_pmdmapped = folio_nr_pages(folio);
|
||||
nr = nr_pmdmapped - (nr & FOLIO_PAGES_MAPPED);
|
||||
/* Raced ahead of another remove and an add? */
|
||||
if (unlikely(nr < 0))
|
||||
@ -1411,21 +1411,26 @@ void page_remove_rmap(struct page *page,
|
||||
}
|
||||
|
||||
if (nr_pmdmapped) {
|
||||
__mod_lruvec_page_state(page, PageAnon(page) ? NR_ANON_THPS :
|
||||
(PageSwapBacked(page) ? NR_SHMEM_PMDMAPPED :
|
||||
NR_FILE_PMDMAPPED), -nr_pmdmapped);
|
||||
if (folio_test_anon(folio))
|
||||
idx = NR_ANON_THPS;
|
||||
else if (folio_test_swapbacked(folio))
|
||||
idx = NR_SHMEM_PMDMAPPED;
|
||||
else
|
||||
idx = NR_FILE_PMDMAPPED;
|
||||
__lruvec_stat_mod_folio(folio, idx, -nr_pmdmapped);
|
||||
}
|
||||
if (nr) {
|
||||
__mod_lruvec_page_state(page, PageAnon(page) ? NR_ANON_MAPPED :
|
||||
NR_FILE_MAPPED, -nr);
|
||||
idx = folio_test_anon(folio) ? NR_ANON_MAPPED : NR_FILE_MAPPED;
|
||||
__lruvec_stat_mod_folio(folio, idx, -nr);
|
||||
|
||||
/*
|
||||
* Queue anon THP for deferred split if at least one small
|
||||
* page of the compound page is unmapped, but at least one
|
||||
* small page is still mapped.
|
||||
* Queue anon THP for deferred split if at least one
|
||||
* page of the folio is unmapped and at least one page
|
||||
* is still mapped.
|
||||
*/
|
||||
if (PageTransCompound(page) && PageAnon(page))
|
||||
if (folio_test_pmd_mappable(folio) && folio_test_anon(folio))
|
||||
if (!compound || nr < nr_pmdmapped)
|
||||
deferred_split_huge_page(compound_head(page));
|
||||
deferred_split_huge_page(&folio->page);
|
||||
}
|
||||
|
||||
/*
|
||||
|
Loading…
Reference in New Issue
Block a user