[PATCH v14 011/138] mm/lru: Add folio LRU functions

Matthew Wilcox (Oracle)
2021-07-15T03:46:32Z

Handle arbitrary-order folios being added to the LRU. By definition,
all pages being added to the LRU were already head or base pages, but
call page_folio() on them anyway to get the type right and avoid the
buried calls to compound_head().

Saves 783 bytes of kernel text; no functions grow.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Yu Zhao <yuzhao@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Howells <dhowells@redhat.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
include/linux/mm_inline.h | 98 ++++++++++++++++++++++------------
include/trace/events/pagemap.h | 2 +-
2 files changed, 65 insertions(+), 35 deletions(-)

diff --git a/include/linux/mm_inline.h b/include/linux/mm_inline.h
index 355ea1ee32bd..ee155d19885e 100644
--- a/include/linux/mm_inline.h
+++ b/include/linux/mm_inline.h
@@ -6,22 +6,27 @@
#include <linux/swap.h>

/**
- * page_is_file_lru - should the page be on a file LRU or anon LRU?
- * @page: the page to test
+ * folio_is_file_lru - should the folio be on a file LRU or anon LRU?
+ * @folio: the folio to test
*
- * Returns 1 if @page is a regular filesystem backed page cache page or a lazily
- * freed anonymous page (e.g. via MADV_FREE). Returns 0 if @page is a normal
- * anonymous page, a tmpfs page or otherwise ram or swap backed page. Used by
- * functions that manipulate the LRU lists, to sort a page onto the right LRU
- * list.
+ * Returns 1 if @folio is a regular filesystem backed page cache folio
+ * or a lazily freed anonymous folio (e.g. via MADV_FREE). Returns 0 if
+ * @folio is a normal anonymous folio, a tmpfs folio or otherwise ram or
+ * swap backed folio. Used by functions that manipulate the LRU lists,
+ * to sort a folio onto the right LRU list.
*
* We would like to get this info without a page flag, but the state
- * needs to survive until the page is last deleted from the LRU, which
+ * needs to survive until the folio is last deleted from the LRU, which
* could be as far down as __page_cache_release.
*/
+static inline int folio_is_file_lru(struct folio *folio)
+{
+ return !folio_test_swapbacked(folio);
+}
+
static inline int page_is_file_lru(struct page *page)
{
- return !PageSwapBacked(page);
+ return folio_is_file_lru(page_folio(page));
}

static __always_inline void update_lru_size(struct lruvec *lruvec,
@@ -39,69 +44,94 @@ static __always_inline void update_lru_size(struct lruvec *lruvec,
}

/**
- * __clear_page_lru_flags - clear page lru flags before releasing a page
- * @page: the page that was on lru and now has a zero reference
+ * __folio_clear_lru_flags - clear page lru flags before releasing a page
+ * @folio: The folio that was on lru and now has a zero reference
*/
-static __always_inline void __clear_page_lru_flags(struct page *page)
+static __always_inline void __folio_clear_lru_flags(struct folio *folio)
{
- VM_BUG_ON_PAGE(!PageLRU(page), page);
+ VM_BUG_ON_FOLIO(!folio_test_lru(folio), folio);

- __ClearPageLRU(page);
+ __folio_clear_lru(folio);

/* this shouldn't happen, so leave the flags to bad_page() */
- if (PageActive(page) && PageUnevictable(page))
+ if (folio_test_active(folio) && folio_test_unevictable(folio))
return;

- __ClearPageActive(page);
- __ClearPageUnevictable(page);
+ __folio_clear_active(folio);
+ __folio_clear_unevictable(folio);
+}
+
+static __always_inline void __clear_page_lru_flags(struct page *page)
+{
+ __folio_clear_lru_flags(page_folio(page));
}

/**
- * page_lru - which LRU list should a page be on?
- * @page: the page to test
+ * folio_lru_list - which LRU list should a folio be on?
+ * @folio: the folio to test
*
- * Returns the LRU list a page should be on, as an index
+ * Returns the LRU list a folio should be on, as an index
* into the array of LRU lists.
*/
-static __always_inline enum lru_list page_lru(struct page *page)
+static __always_inline enum lru_list folio_lru_list(struct folio *folio)
{
enum lru_list lru;

- VM_BUG_ON_PAGE(PageActive(page) && PageUnevictable(page), page);
+ VM_BUG_ON_FOLIO(folio_test_active(folio) && folio_test_unevictable(folio), folio);

- if (PageUnevictable(page))
+ if (folio_test_unevictable(folio))
return LRU_UNEVICTABLE;

- lru = page_is_file_lru(page) ? LRU_INACTIVE_FILE : LRU_INACTIVE_ANON;
- if (PageActive(page))
+ lru = folio_is_file_lru(folio) ? LRU_INACTIVE_FILE : LRU_INACTIVE_ANON;
+ if (folio_test_active(folio))
lru += LRU_ACTIVE;

return lru;
}

+static __always_inline
+void lruvec_add_folio(struct lruvec *lruvec, struct folio *folio)
+{
+ enum lru_list lru = folio_lru_list(folio);
+
+ update_lru_size(lruvec, lru, folio_zonenum(folio),
+ folio_nr_pages(folio));
+ list_add(&folio->lru, &lruvec->lists[lru]);
+}
+
static __always_inline void add_page_to_lru_list(struct page *page,
struct lruvec *lruvec)
{
- enum lru_list lru = page_lru(page);
+ lruvec_add_folio(lruvec, page_folio(page));
+}
+
+static __always_inline
+void lruvec_add_folio_tail(struct lruvec *lruvec, struct folio *folio)
+{
+ enum lru_list lru = folio_lru_list(folio);

- update_lru_size(lruvec, lru, page_zonenum(page), thp_nr_pages(page));
- list_add(&page->lru, &lruvec->lists[lru]);
+ update_lru_size(lruvec, lru, folio_zonenum(folio),
+ folio_nr_pages(folio));
+ list_add_tail(&folio->lru, &lruvec->lists[lru]);
}

static __always_inline void add_page_to_lru_list_tail(struct page *page,
struct lruvec *lruvec)
{
- enum lru_list lru = page_lru(page);
+ lruvec_add_folio_tail(lruvec, page_folio(page));
+}

- update_lru_size(lruvec, lru, page_zonenum(page), thp_nr_pages(page));
- list_add_tail(&page->lru, &lruvec->lists[lru]);
+static __always_inline
+void lruvec_del_folio(struct lruvec *lruvec, struct folio *folio)
+{
+ list_del(&folio->lru);
+ update_lru_size(lruvec, folio_lru_list(folio), folio_zonenum(folio),
+ -folio_nr_pages(folio));
}

static __always_inline void del_page_from_lru_list(struct page *page,
struct lruvec *lruvec)
{
- list_del(&page->lru);
- update_lru_size(lruvec, page_lru(page), page_zonenum(page),
- -thp_nr_pages(page));
+ lruvec_del_folio(lruvec, page_folio(page));
}
#endif
diff --git a/include/trace/events/pagemap.h b/include/trace/events/pagemap.h
index 1d28431e85bd..92ad176210ff 100644
--- a/include/trace/events/pagemap.h
+++ b/include/trace/events/pagemap.h
@@ -41,7 +41,7 @@ TRACE_EVENT(mm_lru_insertion,
TP_fast_assign(
__entry->page = page;
__entry->pfn = page_to_pfn(page);
- __entry->lru = page_lru(page);
+ __entry->lru = folio_lru_list(page_folio(page));
__entry->flags = trace_pagemap_flags(page);
),

--
2.30.2