[PATCH v13 058/137] mm/swap: Add folio_mark_accessed()

Matthew Wilcox (Oracle)
2021-07-12T03:39:27Z

Convert mark_page_accessed() to folio_mark_accessed(). It already
operated on the entire compound page, but now we can avoid calling
compound_head quite so many times. Shrinks the function from 424 bytes
to 295 bytes (shrinking by 129 bytes). The compatibility wrapper is 30
bytes, plus the 8 bytes for the exported symbol means the kernel shrinks
by 91 bytes.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
include/linux/swap.h | 3 ++-
mm/folio-compat.c | 7 +++++++
mm/swap.c | 34 ++++++++++++++++------------------
3 files changed, 25 insertions(+), 19 deletions(-)

diff --git a/include/linux/swap.h b/include/linux/swap.h
index 989d8f78c256..c7a4c0a5863d 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -352,7 +352,8 @@ extern void lru_note_cost(struct lruvec *lruvec, bool file,
unsigned int nr_pages);
extern void lru_note_cost_page(struct page *);
extern void lru_cache_add(struct page *);
-extern void mark_page_accessed(struct page *);
+void mark_page_accessed(struct page *);
+void folio_mark_accessed(struct folio *);

extern atomic_t lru_disable_count;

diff --git a/mm/folio-compat.c b/mm/folio-compat.c
index 7044fcc8a8aa..a374747ae1c6 100644
--- a/mm/folio-compat.c
+++ b/mm/folio-compat.c
@@ -5,6 +5,7 @@
*/

#include <linux/pagemap.h>
+#include <linux/swap.h>

struct address_space *page_mapping(struct page *page)
{
@@ -41,3 +42,9 @@ bool page_mapped(struct page *page)
return folio_mapped(page_folio(page));
}
EXPORT_SYMBOL(page_mapped);
+
+void mark_page_accessed(struct page *page)
+{
+ folio_mark_accessed(page_folio(page));
+}
+EXPORT_SYMBOL(mark_page_accessed);
diff --git a/mm/swap.c b/mm/swap.c
index 253ac77792dc..b49e10e75af5 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -390,7 +390,7 @@ static void folio_activate(struct folio *folio)
}
#endif

-static void __lru_cache_activate_page(struct page *page)
+static void __lru_cache_activate_folio(struct folio *folio)
{
struct pagevec *pvec;
int i;
@@ -411,8 +411,8 @@ static void __lru_cache_activate_page(struct page *page)
for (i = pagevec_count(pvec) - 1; i >= 0; i--) {
struct page *pagevec_page = pvec->pages[i];

- if (pagevec_page == page) {
- SetPageActive(page);
+ if (pagevec_page == &folio->page) {
+ folio_set_active_flag(folio);
break;
}
}
@@ -430,36 +430,34 @@ static void __lru_cache_activate_page(struct page *page)
* When a newly allocated page is not yet visible, so safe for non-atomic ops,
* __SetPageReferenced(page) may be substituted for mark_page_accessed(page).
*/
-void mark_page_accessed(struct page *page)
+void folio_mark_accessed(struct folio *folio)
{
- page = compound_head(page);
-
- if (!PageReferenced(page)) {
- SetPageReferenced(page);
- } else if (PageUnevictable(page)) {
+ if (!folio_referenced(folio)) {
+ folio_set_referenced_flag(folio);
+ } else if (folio_unevictable(folio)) {
/*
* Unevictable pages are on the "LRU_UNEVICTABLE" list. But,
* this list is never rotated or maintained, so marking an
* evictable page accessed has no effect.
*/
- } else if (!PageActive(page)) {
+ } else if (!folio_active(folio)) {
/*
* If the page is on the LRU, queue it for activation via
* lru_pvecs.activate_page. Otherwise, assume the page is on a
* pagevec, mark it active and it'll be moved to the active
* LRU on the next drain.
*/
- if (PageLRU(page))
- folio_activate(page_folio(page));
+ if (folio_lru(folio))
+ folio_activate(folio);
else
- __lru_cache_activate_page(page);
- ClearPageReferenced(page);
- workingset_activation(page_folio(page));
+ __lru_cache_activate_folio(folio);
+ folio_clear_referenced_flag(folio);
+ workingset_activation(folio);
}
- if (page_is_idle(page))
- clear_page_idle(page);
+ if (folio_idle(folio))
+ folio_clear_idle_flag(folio);
}
-EXPORT_SYMBOL(mark_page_accessed);
+EXPORT_SYMBOL(folio_mark_accessed);

/**
* lru_cache_add - add a page to a page list
--
2.30.2