| From: Johannes Weiner <hannes@cmpxchg.org> |
| Subject: mm: page_alloc: batch vmstat updates in expand() |
| Date: Wed, 27 Mar 2024 15:01:11 -0400 |
| |
| expand() currently updates vmstat for every subpage. This is unnecessary, |
| since they're all of the same zone and migratetype. |
| |
| Count added pages locally, then do a single vmstat update. |
| |
| Link: https://lkml.kernel.org/r/20240327190111.GC7597@cmpxchg.org |
| Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> |
| Suggested-by: Vlastimil Babka <vbabka@suse.cz> |
| Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
| --- |
| |
| mm/page_alloc.c | 5 ++++- |
| 1 file changed, 4 insertions(+), 1 deletion(-) |
| |
| --- a/mm/page_alloc.c~mm-page_alloc-batch-vmstat-updates-in-expand |
| +++ a/mm/page_alloc.c |
| @@ -1335,6 +1335,7 @@ static inline void expand(struct zone *z |
| int low, int high, int migratetype) |
| { |
| unsigned long size = 1 << high; |
| + unsigned long nr_added = 0; |
| |
| while (high > low) { |
| high--; |
| @@ -1350,9 +1351,11 @@ static inline void expand(struct zone *z |
| if (set_page_guard(zone, &page[size], high)) |
| continue; |
| |
| - add_to_free_list(&page[size], zone, high, migratetype, false); |
| + __add_to_free_list(&page[size], zone, high, migratetype, false); |
| set_buddy_order(&page[size], high); |
| + nr_added += size; |
| } |
| + account_freepages(zone, nr_added, migratetype); |
| } |
| |
| static void check_new_page_bad(struct page *page) |
| _ |
