diff mbox series

[RFC,03/15] mm: memcontrol: remove the pgdata parameter of mem_cgroup_page_lruvec

Message ID 20210330101531.82752-4-songmuchun@bytedance.com (mailing list archive)
State New, archived
Headers show
Series Use obj_cgroup APIs to charge the LRU pages | expand

Commit Message

Muchun Song March 30, 2021, 10:15 a.m. UTC 
All the callers of mem_cgroup_page_lruvec() just pass page_pgdat(page)
as the 2nd parameter to it (except isolate_migratepages_block()). But
for isolate_migratepages_block(), the page_pgdat(page) is also equal
to the local variable of @pgdat. So mem_cgroup_page_lruvec() do not
need the pgdat parameter. Just remove it to simplify the code.

Signed-off-by: Muchun Song <songmuchun@bytedance.com>
---
 include/linux/memcontrol.h | 10 +++++-----
 mm/compaction.c            |  2 +-
 mm/memcontrol.c            |  9 +++------
 mm/page-writeback.c        |  2 +-
 mm/swap.c                  |  2 +-
 mm/workingset.c            |  2 +-
 6 files changed, 12 insertions(+), 15 deletions(-)

Comments

Johannes Weiner April 2, 2021, 3:22 p.m. UTC | #1 
On Tue, Mar 30, 2021 at 06:15:19PM +0800, Muchun Song wrote:
> All the callers of mem_cgroup_page_lruvec() just pass page_pgdat(page)
> as the 2nd parameter to it (except isolate_migratepages_block()). But
> for isolate_migratepages_block(), the page_pgdat(page) is also equal
> to the local variable of @pgdat. So mem_cgroup_page_lruvec() do not
> need the pgdat parameter. Just remove it to simplify the code.
> 
> Signed-off-by: Muchun Song <songmuchun@bytedance.com>

There is a minor benefit in not doing the page_pgdat() lookup twice.
But I think it only really matters on 32-bit NUMA, where we have more
than one node but not enough space in page->flags to store the nid,
and so page_to_nid() is out-of-line and needs to go through section.

Those setups aren't really around anymore, and certainly don't justify
the hassle (and potential bugs) of the awkward interface.

Acked-by: Johannes Weiner <hannes@cmpxchg.org>
diff mbox series

Patch

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 7fdc92e1983e..a35a22994cf7 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -732,13 +732,12 @@  static inline struct lruvec *mem_cgroup_lruvec(struct mem_cgroup *memcg,
 /**
  * mem_cgroup_page_lruvec - return lruvec for isolating/putting an LRU page
  * @page: the page
- * @pgdat: pgdat of the page
  *
  * This function relies on page->mem_cgroup being stable.
  */
-static inline struct lruvec *mem_cgroup_page_lruvec(struct page *page,
-						struct pglist_data *pgdat)
+static inline struct lruvec *mem_cgroup_page_lruvec(struct page *page)
 {
+	pg_data_t *pgdat = page_pgdat(page);
 	struct mem_cgroup *memcg = page_memcg(page);
 
 	VM_WARN_ON_ONCE_PAGE(!memcg && !mem_cgroup_disabled(), page);
@@ -1232,9 +1231,10 @@  static inline struct lruvec *mem_cgroup_lruvec(struct mem_cgroup *memcg,
 	return &pgdat->__lruvec;
 }
 
-static inline struct lruvec *mem_cgroup_page_lruvec(struct page *page,
-						    struct pglist_data *pgdat)
+static inline struct lruvec *mem_cgroup_page_lruvec(struct page *page)
 {
+	pg_data_t *pgdat = page_pgdat(page);
+
 	return &pgdat->__lruvec;
 }
 
diff --git a/mm/compaction.c b/mm/compaction.c
index e04f4476e68e..8b8fc279766e 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -994,7 +994,7 @@  isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
 		if (!TestClearPageLRU(page))
 			goto isolate_fail_put;
 
-		lruvec = mem_cgroup_page_lruvec(page, pgdat);
+		lruvec = mem_cgroup_page_lruvec(page);
 
 		/* If we already hold the lock, we can skip some rechecking */
 		if (lruvec != locked) {
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 48e4c20bf115..405c9642aac0 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1305,9 +1305,8 @@  void lruvec_memcg_debug(struct lruvec *lruvec, struct page *page)
 struct lruvec *lock_page_lruvec(struct page *page)
 {
 	struct lruvec *lruvec;
-	struct pglist_data *pgdat = page_pgdat(page);
 
-	lruvec = mem_cgroup_page_lruvec(page, pgdat);
+	lruvec = mem_cgroup_page_lruvec(page);
 	spin_lock(&lruvec->lru_lock);
 
 	lruvec_memcg_debug(lruvec, page);
@@ -1318,9 +1317,8 @@  struct lruvec *lock_page_lruvec(struct page *page)
 struct lruvec *lock_page_lruvec_irq(struct page *page)
 {
 	struct lruvec *lruvec;
-	struct pglist_data *pgdat = page_pgdat(page);
 
-	lruvec = mem_cgroup_page_lruvec(page, pgdat);
+	lruvec = mem_cgroup_page_lruvec(page);
 	spin_lock_irq(&lruvec->lru_lock);
 
 	lruvec_memcg_debug(lruvec, page);
@@ -1331,9 +1329,8 @@  struct lruvec *lock_page_lruvec_irq(struct page *page)
 struct lruvec *lock_page_lruvec_irqsave(struct page *page, unsigned long *flags)
 {
 	struct lruvec *lruvec;
-	struct pglist_data *pgdat = page_pgdat(page);
 
-	lruvec = mem_cgroup_page_lruvec(page, pgdat);
+	lruvec = mem_cgroup_page_lruvec(page);
 	spin_lock_irqsave(&lruvec->lru_lock, *flags);
 
 	lruvec_memcg_debug(lruvec, page);
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index eb34d204d4ee..f517e0669924 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -2727,7 +2727,7 @@  int test_clear_page_writeback(struct page *page)
 	int ret;
 
 	memcg = lock_page_memcg(page);
-	lruvec = mem_cgroup_page_lruvec(page, page_pgdat(page));
+	lruvec = mem_cgroup_page_lruvec(page);
 	if (mapping && mapping_use_writeback_tags(mapping)) {
 		struct inode *inode = mapping->host;
 		struct backing_dev_info *bdi = inode_to_bdi(inode);
diff --git a/mm/swap.c b/mm/swap.c
index 31b844d4ed94..af695acb7413 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -300,7 +300,7 @@  void lru_note_cost(struct lruvec *lruvec, bool file, unsigned int nr_pages)
 
 void lru_note_cost_page(struct page *page)
 {
-	lru_note_cost(mem_cgroup_page_lruvec(page, page_pgdat(page)),
+	lru_note_cost(mem_cgroup_page_lruvec(page),
 		      page_is_file_lru(page), thp_nr_pages(page));
 }
 
diff --git a/mm/workingset.c b/mm/workingset.c
index cd39902c1062..1ab5784c9e25 100644
--- a/mm/workingset.c
+++ b/mm/workingset.c
@@ -408,7 +408,7 @@  void workingset_activation(struct page *page)
 	memcg = page_memcg_rcu(page);
 	if (!mem_cgroup_disabled() && !memcg)
 		goto out;
-	lruvec = mem_cgroup_page_lruvec(page, page_pgdat(page));
+	lruvec = mem_cgroup_page_lruvec(page);
 	workingset_age_nonresident(lruvec, thp_nr_pages(page));
 out:
 	rcu_read_unlock();