mm: use folio more widely in __split_huge_page

We already have a folio; use it instead of the head page where reasonable.
Saves a couple of calls to compound_head() and elimimnates a few
references to page->mapping.

Link: https://lkml.kernel.org/r/20240228164326.1355045-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Matthew Wilcox (Oracle) 2024-02-28 16:42:36 +00:00 committed by Andrew Morton
parent d3246b6ee4
commit 435a755481

View File

@ -2919,7 +2919,7 @@ static void __split_huge_page(struct page *page, struct list_head *list,
if (head[i].index >= end) {
struct folio *tail = page_folio(head + i);
if (shmem_mapping(head->mapping))
if (shmem_mapping(folio->mapping))
nr_dropped++;
else if (folio_test_clear_dirty(tail))
folio_account_cleaned(tail,
@ -2927,7 +2927,7 @@ static void __split_huge_page(struct page *page, struct list_head *list,
__filemap_remove_folio(tail, NULL);
folio_put(tail);
} else if (!PageAnon(page)) {
__xa_store(&head->mapping->i_pages, head[i].index,
__xa_store(&folio->mapping->i_pages, head[i].index,
head + i, 0);
} else if (swap_cache) {
__xa_store(&swap_cache->i_pages, offset + i,
@ -2948,23 +2948,23 @@ static void __split_huge_page(struct page *page, struct list_head *list,
split_page_owner(head, order, new_order);
/* See comment in __split_huge_page_tail() */
if (PageAnon(head)) {
if (folio_test_anon(folio)) {
/* Additional pin to swap cache */
if (PageSwapCache(head)) {
page_ref_add(head, 1 + new_nr);
if (folio_test_swapcache(folio)) {
folio_ref_add(folio, 1 + new_nr);
xa_unlock(&swap_cache->i_pages);
} else {
page_ref_inc(head);
folio_ref_inc(folio);
}
} else {
/* Additional pin to page cache */
page_ref_add(head, 1 + new_nr);
xa_unlock(&head->mapping->i_pages);
folio_ref_add(folio, 1 + new_nr);
xa_unlock(&folio->mapping->i_pages);
}
local_irq_enable();
if (nr_dropped)
shmem_uncharge(head->mapping->host, nr_dropped);
shmem_uncharge(folio->mapping->host, nr_dropped);
remap_page(folio, nr);
if (folio_test_swapcache(folio))
@ -2980,9 +2980,10 @@ static void __split_huge_page(struct page *page, struct list_head *list,
for (i = 0; i < nr; i += new_nr) {
struct page *subpage = head + i;
struct folio *new_folio = page_folio(subpage);
if (subpage == page)
continue;
unlock_page(subpage);
folio_unlock(new_folio);
/*
* Subpages may be freed if there wasn't any mapping