Hi
On 6/19/2023 7:07 PM, Kefeng Wang wrote:
Directly use a folio instead of page_folio() when page successfully
isolated (hugepage and movable page) and after folio_get_nontail_page(),
which removes several calls to compound_head().
Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
---
v2:
- update comments and use node_stat_mod_folio, per Matthew Wilcox
- add missed PageLRU conversion and rebase on next-20230619
mm/compaction.c | 84 ++++++++++++++++++++++++++-----------------------
1 file changed, 44 insertions(+), 40 deletions(-)
diff --git a/mm/compaction.c b/mm/compaction.c
index 6149a2d324be..0334eefe4bfa 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -795,6 +795,7 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
struct lruvec *lruvec;
unsigned long flags = 0;
struct lruvec *locked = NULL;
+ struct folio *folio = NULL;
struct page *page = NULL, *valid_page = NULL;
struct address_space *mapping;
unsigned long start_pfn = low_pfn;
@@ -891,7 +892,7 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
if (!valid_page && pageblock_aligned(low_pfn)) {
if (!isolation_suitable(cc, page)) {
low_pfn = end_pfn;
- page = NULL;
+ folio = NULL;
goto isolate_abort;
}
valid_page = page;
@@ -923,7 +924,8 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
* Hugepage was successfully isolated and placed
* on the cc->migratepages list.
*/
- low_pfn += compound_nr(page) - 1;
+ folio = page_folio(page);
+ low_pfn += folio_nr_pages(folio) - 1;
goto isolate_success_no_list;
}
@@ -991,8 +993,10 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
locked = NULL;
}
- if (isolate_movable_page(page, mode))
+ if (isolate_movable_page(page, mode)) {
+ folio = page_folio(page);
goto isolate_success;
+ }
}
goto isolate_fail;
@@ -1003,7 +1007,8 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
* sure the page is not being freed elsewhere -- the
* page release code relies on it.
*/
- if (unlikely(!get_page_unless_zero(page)))
+ folio = folio_get_nontail_page(page);
I'm just curious, how can you make sure the 'page' is not a tail page?
Since the validation is lockless.
