在 2023/5/9 上午10:20, Huang Ying 写道:
Previously, in migrate_pages_batch we need to track whether the source
folio is large/THP before splitting. So is_large is used to cache
folio_test_large() result. Now, we don't need that variable any more
because we don't count retrying and failure of large folios (only
counting that of THP folios). So, in this patch, is_large is removed
to simplify the code.
This is just code cleanup, no functionality changes are expected.
Signed-off-by: "Huang, Ying" <ying.huang@xxxxxxxxx>
Cc: Xin Hao <xhao@xxxxxxxxxxxxxxxxx>
Cc: Zi Yan <ziy@xxxxxxxxxx>
Cc: Yang Shi <shy828301@xxxxxxxxx>
Cc: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Cc: Oscar Salvador <osalvador@xxxxxxx>
Cc: Alistair Popple <apopple@xxxxxxxxxx>
---
mm/migrate.c | 11 ++---------
1 file changed, 2 insertions(+), 9 deletions(-)
diff --git a/mm/migrate.c b/mm/migrate.c
index 10709aed76d3..2ac927a82bbc 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1618,7 +1618,6 @@ static int migrate_pages_batch(struct list_head *from, new_page_t get_new_page,
int nr_failed = 0;
int nr_retry_pages = 0;
int pass = 0;
- bool is_large = false;
bool is_thp = false;
struct folio *folio, *folio2, *dst = NULL, *dst2;
int rc, rc_saved = 0, nr_pages;
@@ -1635,13 +1634,7 @@ static int migrate_pages_batch(struct list_head *from, new_page_t get_new_page,
nr_retry_pages = 0;
list_for_each_entry_safe(folio, folio2, from, lru) {
- /*
- * Large folio statistics is based on the source large
- * folio. Capture required information that might get
- * lost during migration.
- */
- is_large = folio_test_large(folio);
- is_thp = is_large && folio_test_pmd_mappable(folio);
+ is_thp = folio_test_large(folio) && folio_test_pmd_mappable(folio);
nr_pages = folio_nr_pages(folio);
cond_resched();
@@ -1688,7 +1681,7 @@ static int migrate_pages_batch(struct list_head *from, new_page_t get_new_page,
nr_failed++;
stats->nr_thp_failed += is_thp;
/* Large folio NUMA faulting doesn't split to retry. */
- if (is_large && !nosplit) {
+ if (folio_test_large(folio) && !nosplit) {
int ret = try_split_folio(folio, split_folios);
if (!ret) {
LGTM.
Reviewed-by: Xin Hao <xhao@xxxxxxxxxxxxxxxxx>
