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authorMatthew Wilcox <willy@infradead.org>2017-11-21 09:17:59 -0500
committerMatthew Wilcox <willy@infradead.org>2018-10-21 10:46:34 -0400
commit5c024e6a4ebc1740db9f0f075aaa476210108a97 (patch)
treeb307dce267f93c3ff7306ce39e9196e3fbc217ef /mm/filemap.c
parent74d609585d8bd6083bd9d75bc1fd2c0d3851bcc5 (diff)
page cache: Convert page deletion to XArray
The code is slightly shorter and simpler. Signed-off-by: Matthew Wilcox <willy@infradead.org>
Diffstat (limited to 'mm/filemap.c')
-rw-r--r--mm/filemap.c31
1 files changed, 13 insertions, 18 deletions
diff --git a/mm/filemap.c b/mm/filemap.c
index b63caebd1367..414efbdc95df 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -111,31 +111,26 @@
* ->tasklist_lock (memory_failure, collect_procs_ao)
*/
-static void page_cache_tree_delete(struct address_space *mapping,
+static void page_cache_delete(struct address_space *mapping,
struct page *page, void *shadow)
{
- int i, nr;
+ XA_STATE(xas, &mapping->i_pages, page->index);
+ unsigned int nr = 1;
- /* hugetlb pages are represented by one entry in the radix tree */
- nr = PageHuge(page) ? 1 : hpage_nr_pages(page);
+ mapping_set_update(&xas, mapping);
+
+ /* hugetlb pages are represented by a single entry in the xarray */
+ if (!PageHuge(page)) {
+ xas_set_order(&xas, page->index, compound_order(page));
+ nr = 1U << compound_order(page);
+ }
VM_BUG_ON_PAGE(!PageLocked(page), page);
VM_BUG_ON_PAGE(PageTail(page), page);
VM_BUG_ON_PAGE(nr != 1 && shadow, page);
- for (i = 0; i < nr; i++) {
- struct radix_tree_node *node;
- void **slot;
-
- __radix_tree_lookup(&mapping->i_pages, page->index + i,
- &node, &slot);
-
- VM_BUG_ON_PAGE(!node && nr != 1, page);
-
- radix_tree_clear_tags(&mapping->i_pages, node, slot);
- __radix_tree_replace(&mapping->i_pages, node, slot, shadow,
- workingset_lookup_update(mapping));
- }
+ xas_store(&xas, shadow);
+ xas_init_marks(&xas);
page->mapping = NULL;
/* Leave page->index set: truncation lookup relies upon it */
@@ -234,7 +229,7 @@ void __delete_from_page_cache(struct page *page, void *shadow)
trace_mm_filemap_delete_from_page_cache(page);
unaccount_page_cache_page(mapping, page);
- page_cache_tree_delete(mapping, page, shadow);
+ page_cache_delete(mapping, page, shadow);
}
static void page_cache_free_page(struct address_space *mapping,