On Wed, Dec 4, 2024 at 5:11 PM Chen Ridong <chenridong@xxxxxxxxxxxxxxx> wrote:
>
> From: Chen Ridong <chenridong@xxxxxxxxxx>
>
> Add find_folios_written_back() helper, which will be called in the
> shrink_inactive_list function in subsequent patch.
This is not about adding a helper but rather extracting a function
that can be used
by both lru_gen and the traditional active/inactive LRU. Making it a
separate patch
may not be ideal, as it isn’t an external function that warrants
special attention.
Combining patch 1 and patch 2 into a single patch creates a more cohesive and
logical flow, making it easier to review.
>
> Signed-off-by: Chen Ridong <chenridong@xxxxxxxxxx>
> ---
> mm/vmscan.c | 73 +++++++++++++++++++++++++++++++----------------------
> 1 file changed, 43 insertions(+), 30 deletions(-)
>
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index 76378bc257e3..af1ff76f83e7 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -283,6 +283,48 @@ static void set_task_reclaim_state(struct task_struct *task,
> task->reclaim_state = rs;
> }
>
> +/**
> + * find_folios_written_back - Find and move the written back folios to a new list.
> + * @list: filios list
> + * @clean: the written back folios list
> + * @skip: whether skip to move the written back folios to clean list.
> + */
> +static inline void find_folios_written_back(struct list_head *list,
> + struct list_head *clean, bool skip)
> +{
> + struct folio *folio;
> + struct folio *next;
> +
> + list_for_each_entry_safe_reverse(folio, next, list, lru) {
> + if (!folio_evictable(folio)) {
> + list_del(&folio->lru);
> + folio_putback_lru(folio);
> + continue;
> + }
> +
> + if (folio_test_reclaim(folio) &&
> + (folio_test_dirty(folio) || folio_test_writeback(folio))) {
> + /* restore LRU_REFS_FLAGS cleared by isolate_folio() */
> + if (lru_gen_enabled() && folio_test_workingset(folio))
> + folio_set_referenced(folio);
> + continue;
> + }
> +
> + if (skip || folio_test_active(folio) || folio_test_referenced(folio) ||
> + folio_mapped(folio) || folio_test_locked(folio) ||
> + folio_test_dirty(folio) || folio_test_writeback(folio)) {
> + /* don't add rejected folios to the oldest generation */
> + if (lru_gen_enabled())
> + set_mask_bits(&folio->flags, LRU_REFS_MASK | LRU_REFS_FLAGS,
> + BIT(PG_active));
> + continue;
> + }
> +
> + /* retry folios that may have missed folio_rotate_reclaimable() */
> + list_move(&folio->lru, clean);
> + }
> +}
> +
> /*
> * flush_reclaim_state(): add pages reclaimed outside of LRU-based reclaim to
> * scan_control->nr_reclaimed.
> @@ -4567,8 +4609,6 @@ static int evict_folios(struct lruvec *lruvec, struct scan_control *sc, int swap
> int reclaimed;
> LIST_HEAD(list);
> LIST_HEAD(clean);
> - struct folio *folio;
> - struct folio *next;
> enum vm_event_item item;
> struct reclaim_stat stat;
> struct lru_gen_mm_walk *walk;
> @@ -4597,34 +4637,7 @@ static int evict_folios(struct lruvec *lruvec, struct scan_control *sc, int swap
> scanned, reclaimed, &stat, sc->priority,
> type ? LRU_INACTIVE_FILE : LRU_INACTIVE_ANON);
>
> - list_for_each_entry_safe_reverse(folio, next, &list, lru) {
> - if (!folio_evictable(folio)) {
> - list_del(&folio->lru);
> - folio_putback_lru(folio);
> - continue;
> - }
> -
> - if (folio_test_reclaim(folio) &&
> - (folio_test_dirty(folio) || folio_test_writeback(folio))) {
> - /* restore LRU_REFS_FLAGS cleared by isolate_folio() */
> - if (folio_test_workingset(folio))
> - folio_set_referenced(folio);
> - continue;
> - }
> -
> - if (skip_retry || folio_test_active(folio) || folio_test_referenced(folio) ||
> - folio_mapped(folio) || folio_test_locked(folio) ||
> - folio_test_dirty(folio) || folio_test_writeback(folio)) {
> - /* don't add rejected folios to the oldest generation */
> - set_mask_bits(&folio->flags, LRU_REFS_MASK | LRU_REFS_FLAGS,
> - BIT(PG_active));
> - continue;
> - }
> -
> - /* retry folios that may have missed folio_rotate_reclaimable() */
> - list_move(&folio->lru, &clean);
> - }
> -
> + find_folios_written_back(&list, &clean, skip_retry);
> spin_lock_irq(&lruvec->lru_lock);
>
> move_folios_to_lru(lruvec, &list);
> --
> 2.34.1
>
Thanks
Barry
