Huang Ying <ying.huang@xxxxxxxxx> writes:
> 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.
Reviewed-by: Alistair Popple <apopple@xxxxxxxxxx>
> 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) {
