On Tue, Jan 26, 2021 at 08:13:11PM +0100, Vlastimil Babka wrote:

On 1/22/21 11:05 PM, Yu Zhao wrote:

quoted

The "enum lru_list" parameter to add_page_to_lru_list() and
add_page_to_lru_list_tail() is redundant in the sense that it can
be extracted from the "struct page" parameter by page_lru().

Okay, however, it means repeated extraction of a value that we already knew. The
result of compilation is rather sad. This is bloat-o-meter on mm/built-in.a
(without CONFIG_DEBUG_VM, btw) between patch 2 and 5:

Thanks for noticing this, Vlastimil. Should I drop the rest of the
series except the first patch?

add/remove: 0/0 grow/shrink: 10/5 up/down: 1837/-60 (1777)
Function                                     old     new   delta
lru_deactivate_file_fn                       932    1368    +436
lru_lazyfree_fn.part                         629     953    +324
check_move_unevictable_pages                1171    1424    +253
__activate_page.part                         735     984    +249
lru_deactivate_fn.part                       593     822    +229
perf_trace_mm_lru_insertion                  458     560    +102
trace_event_raw_event_mm_lru_insertion       412     500     +88
__page_cache_release                         479     558     +79
release_pages                               1430    1499     +69
pagevec_move_tail_fn.part                    761     769      +8
isolate_lru_page                             471     470      -1
__bpf_trace_mm_lru_insertion                   7       5      -2
__traceiter_mm_lru_insertion                  55      47      -8
isolate_migratepages_block                  3200    3185     -15
__pagevec_lru_add_fn                        1092    1058     -34

quoted

A caveat is that we need to make sure PageActive() or
PageUnevictable() is correctly set or cleared before calling
these two functions. And they are indeed.

Link: https://lore.kernel.org/linux-mm/20201207220949.830352-4-yuzhao@google.com/ (local)
Signed-off-by: Yu Zhao <redacted>
---
 include/linux/mm_inline.h |  8 ++++++--
 mm/swap.c                 | 15 +++++++--------
 mm/vmscan.c               |  6 ++----
 3 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/include/linux/mm_inline.h b/include/linux/mm_inline.h
index 2889741f450a..130ba3201d3f 100644
--- a/include/linux/mm_inline.h
+++ b/include/linux/mm_inline.h

@@ -106,15 +106,19 @@ static __always_inline enum lru_list page_lru(struct page *page)
 }
 
 static __always_inline void add_page_to_lru_list(struct page *page,
-				struct lruvec *lruvec, enum lru_list lru)
+				struct lruvec *lruvec)
 {
+	enum lru_list lru = page_lru(page);
+
 	update_lru_size(lruvec, lru, page_zonenum(page), thp_nr_pages(page));
 	list_add(&page->lru, &lruvec->lists[lru]);
 }
 
 static __always_inline void add_page_to_lru_list_tail(struct page *page,
-				struct lruvec *lruvec, enum lru_list lru)
+				struct lruvec *lruvec)
 {
+	enum lru_list lru = page_lru(page);
+
 	update_lru_size(lruvec, lru, page_zonenum(page), thp_nr_pages(page));
 	list_add_tail(&page->lru, &lruvec->lists[lru]);
 }

diff --git a/mm/swap.c b/mm/swap.c
index 490553f3f9ef..4b058ef37add 100644
--- a/mm/swap.c
+++ b/mm/swap.c

@@ -231,7 +231,7 @@ static void pagevec_move_tail_fn(struct page *page, struct lruvec *lruvec)
 	if (!PageUnevictable(page)) {
 		del_page_from_lru_list(page, lruvec, page_lru(page));
 		ClearPageActive(page);
-		add_page_to_lru_list_tail(page, lruvec, page_lru(page));
+		add_page_to_lru_list_tail(page, lruvec);
 		__count_vm_events(PGROTATED, thp_nr_pages(page));
 	}
 }

@@ -313,8 +313,7 @@ static void __activate_page(struct page *page, struct lruvec *lruvec)
 
 		del_page_from_lru_list(page, lruvec, lru);
 		SetPageActive(page);
-		lru += LRU_ACTIVE;
-		add_page_to_lru_list(page, lruvec, lru);
+		add_page_to_lru_list(page, lruvec);
 		trace_mm_lru_activate(page);
 
 		__count_vm_events(PGACTIVATE, nr_pages);

@@ -543,14 +542,14 @@ static void lru_deactivate_file_fn(struct page *page, struct lruvec *lruvec)
 		 * It can make readahead confusing.  But race window
 		 * is _really_ small and  it's non-critical problem.
 		 */
-		add_page_to_lru_list(page, lruvec, lru);
+		add_page_to_lru_list(page, lruvec);
 		SetPageReclaim(page);
 	} else {
 		/*
 		 * The page's writeback ends up during pagevec
 		 * We moves tha page into tail of inactive.
 		 */
-		add_page_to_lru_list_tail(page, lruvec, lru);
+		add_page_to_lru_list_tail(page, lruvec);
 		__count_vm_events(PGROTATED, nr_pages);
 	}
 

@@ -570,7 +569,7 @@ static void lru_deactivate_fn(struct page *page, struct lruvec *lruvec)
 		del_page_from_lru_list(page, lruvec, lru + LRU_ACTIVE);
 		ClearPageActive(page);
 		ClearPageReferenced(page);
-		add_page_to_lru_list(page, lruvec, lru);
+		add_page_to_lru_list(page, lruvec);
 
 		__count_vm_events(PGDEACTIVATE, nr_pages);
 		__count_memcg_events(lruvec_memcg(lruvec), PGDEACTIVATE,

@@ -595,7 +594,7 @@ static void lru_lazyfree_fn(struct page *page, struct lruvec *lruvec)
 		 * anonymous pages
 		 */
 		ClearPageSwapBacked(page);
-		add_page_to_lru_list(page, lruvec, LRU_INACTIVE_FILE);
+		add_page_to_lru_list(page, lruvec);
 
 		__count_vm_events(PGLAZYFREE, nr_pages);
 		__count_memcg_events(lruvec_memcg(lruvec), PGLAZYFREE,

@@ -1005,7 +1004,7 @@ static void __pagevec_lru_add_fn(struct page *page, struct lruvec *lruvec)
 			__count_vm_events(UNEVICTABLE_PGCULLED, nr_pages);
 	}
 
-	add_page_to_lru_list(page, lruvec, lru);
+	add_page_to_lru_list(page, lruvec);
 	trace_mm_lru_insertion(page, lru);
 }
 

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 19875660e8f8..09e4f97488c9 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c

@@ -1867,7 +1867,7 @@ static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec,
 		 * inhibits memcg migration).
 		 */
 		VM_BUG_ON_PAGE(!lruvec_holds_page_lru_lock(page, lruvec), page);
-		add_page_to_lru_list(page, lruvec, page_lru(page));
+		add_page_to_lru_list(page, lruvec);
 		nr_pages = thp_nr_pages(page);
 		nr_moved += nr_pages;
 		if (PageActive(page))

@@ -4282,12 +4282,10 @@ void check_move_unevictable_pages(struct pagevec *pvec)
 
 		lruvec = relock_page_lruvec_irq(page, lruvec);
 		if (page_evictable(page) && PageUnevictable(page)) {
-			enum lru_list lru = page_lru_base_type(page);
-
 			VM_BUG_ON_PAGE(PageActive(page), page);
 			ClearPageUnevictable(page);
 			del_page_from_lru_list(page, lruvec, LRU_UNEVICTABLE);
-			add_page_to_lru_list(page, lruvec, lru);
+			add_page_to_lru_list(page, lruvec);
 			pgrescued += nr_pages;
 		}
 		SetPageLRU(page);