[PATCH v14 023/138] mm/swap: Add folio_rotate_reclaimable()

Matthew Wilcox (Oracle)
2021-07-15T03:57:41Z

Convert rotate_reclaimable_page() to folio_rotate_reclaimable(). This
eliminates all five of the calls to compound_head() in this function,
saving 75 bytes at the cost of adding 15 bytes to its one caller,
end_page_writeback(). We also save 36 bytes from pagevec_move_tail_fn()
due to using folios there. Net 96 bytes savings.

Also move its declaration to mm/internal.h as it's only used by filemap.c.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
include/linux/swap.h | 1 -
mm/filemap.c | 3 ++-
mm/internal.h | 1 +
mm/page_io.c | 4 ++--
mm/swap.c | 30 ++++++++++++++++--------------
5 files changed, 21 insertions(+), 18 deletions(-)

diff --git a/include/linux/swap.h b/include/linux/swap.h
index 3d3d85354026..8394716a002b 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -371,7 +371,6 @@ extern void lru_add_drain(void);
extern void lru_add_drain_cpu(int cpu);
extern void lru_add_drain_cpu_zone(struct zone *zone);
extern void lru_add_drain_all(void);
-extern void rotate_reclaimable_page(struct page *page);
extern void deactivate_file_page(struct page *page);
extern void deactivate_page(struct page *page);
extern void mark_page_lazyfree(struct page *page);
diff --git a/mm/filemap.c b/mm/filemap.c
index fb6398a532e5..4ce2b22b64f8 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1529,8 +1529,9 @@ void end_page_writeback(struct page *page)
* ever page writeback.
*/
if (PageReclaim(page)) {
+ struct folio *folio = page_folio(page);
ClearPageReclaim(page);
- rotate_reclaimable_page(page);
+ folio_rotate_reclaimable(folio);
}

/*
diff --git a/mm/internal.h b/mm/internal.h
index 31ff935b2547..1a8851b73031 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -35,6 +35,7 @@
void page_writeback_init(void);

vm_fault_t do_swap_page(struct vm_fault *vmf);
+void folio_rotate_reclaimable(struct folio *folio);

void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
unsigned long floor, unsigned long ceiling);
diff --git a/mm/page_io.c b/mm/page_io.c
index c493ce9ebcf5..d597bc6e6e45 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -38,7 +38,7 @@ void end_swap_bio_write(struct bio *bio)
* Also print a dire warning that things will go BAD (tm)
* very quickly.
*
- * Also clear PG_reclaim to avoid rotate_reclaimable_page()
+ * Also clear PG_reclaim to avoid folio_rotate_reclaimable()
*/
set_page_dirty(page);
pr_alert_ratelimited("Write-error on swap-device (%u:%u:%llu)\n",
@@ -317,7 +317,7 @@ int __swap_writepage(struct page *page, struct writeback_control *wbc,
* temporary failure if the system has limited
* memory for allocating transmit buffers.
* Mark the page dirty and avoid
- * rotate_reclaimable_page but rate-limit the
+ * folio_rotate_reclaimable but rate-limit the
* messages but do not flag PageError like
* the normal direct-to-bio case as it could
* be temporary.
diff --git a/mm/swap.c b/mm/swap.c
index 19600430e536..095a5ec6f986 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -228,11 +228,13 @@ static void pagevec_lru_move_fn(struct pagevec *pvec,

static void pagevec_move_tail_fn(struct page *page, struct lruvec *lruvec)
{
- if (!PageUnevictable(page)) {
- del_page_from_lru_list(page, lruvec);
- ClearPageActive(page);
- add_page_to_lru_list_tail(page, lruvec);
- __count_vm_events(PGROTATED, thp_nr_pages(page));
+ struct folio *folio = page_folio(page);
+
+ if (!folio_test_unevictable(folio)) {
+ lruvec_del_folio(lruvec, folio);
+ folio_clear_active(folio);
+ lruvec_add_folio_tail(lruvec, folio);
+ __count_vm_events(PGROTATED, folio_nr_pages(folio));
}
}

@@ -249,23 +251,23 @@ static bool pagevec_add_and_need_flush(struct pagevec *pvec, struct page *page)
}

/*
- * Writeback is about to end against a page which has been marked for immediate
- * reclaim. If it still appears to be reclaimable, move it to the tail of the
- * inactive list.
+ * Writeback is about to end against a folio which has been marked for
+ * immediate reclaim. If it still appears to be reclaimable, move it
+ * to the tail of the inactive list.
*
- * rotate_reclaimable_page() must disable IRQs, to prevent nasty races.
+ * folio_rotate_reclaimable() must disable IRQs, to prevent nasty races.
*/
-void rotate_reclaimable_page(struct page *page)
+void folio_rotate_reclaimable(struct folio *folio)
{
- if (!PageLocked(page) && !PageDirty(page) &&
- !PageUnevictable(page) && PageLRU(page)) {
+ if (!folio_test_locked(folio) && !folio_test_dirty(folio) &&
+ !folio_test_unevictable(folio) && folio_test_lru(folio)) {
struct pagevec *pvec;
unsigned long flags;

- get_page(page);
+ folio_get(folio);
local_lock_irqsave(&lru_rotate.lock, flags);
pvec = this_cpu_ptr(&lru_rotate.pvec);
- if (pagevec_add_and_need_flush(pvec, page))
+ if (pagevec_add_and_need_flush(pvec, &folio->page))
pagevec_lru_move_fn(pvec, pagevec_move_tail_fn);
local_unlock_irqrestore(&lru_rotate.lock, flags);
}
--
2.30.2