mm: free folios in a batch in shrink_folio_list()
Use free_unref_page_batch() to free the folios. This may increase the
number of IPIs from calling try_to_unmap_flush() more often, but that's
going to be very workload-dependent. It may even reduce the number of
IPIs as we now batch-free large folios instead of freeing them one at a
time.
Link: https://lkml.kernel.org/r/20240227174254.710559-12-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff --git a/mm/vmscan.c b/mm/vmscan.c
index dcfbe61..144879d 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1006,14 +1006,15 @@ static unsigned int shrink_folio_list(struct list_head *folio_list,
struct pglist_data *pgdat, struct scan_control *sc,
struct reclaim_stat *stat, bool ignore_references)
{
+ struct folio_batch free_folios;
LIST_HEAD(ret_folios);
- LIST_HEAD(free_folios);
LIST_HEAD(demote_folios);
unsigned int nr_reclaimed = 0;
unsigned int pgactivate = 0;
bool do_demote_pass;
struct swap_iocb *plug = NULL;
+ folio_batch_init(&free_folios);
memset(stat, 0, sizeof(*stat));
cond_resched();
do_demote_pass = can_demote(pgdat->node_id, sc);
@@ -1412,14 +1413,11 @@ static unsigned int shrink_folio_list(struct list_head *folio_list,
*/
nr_reclaimed += nr_pages;
- /*
- * Is there need to periodically free_folio_list? It would
- * appear not as the counts should be low
- */
- if (unlikely(folio_test_large(folio)))
- destroy_large_folio(folio);
- else
- list_add(&folio->lru, &free_folios);
+ if (folio_batch_add(&free_folios, folio) == 0) {
+ mem_cgroup_uncharge_folios(&free_folios);
+ try_to_unmap_flush();
+ free_unref_folios(&free_folios);
+ }
continue;
activate_locked_split:
@@ -1483,9 +1481,9 @@ static unsigned int shrink_folio_list(struct list_head *folio_list,
pgactivate = stat->nr_activate[0] + stat->nr_activate[1];
- mem_cgroup_uncharge_list(&free_folios);
+ mem_cgroup_uncharge_folios(&free_folios);
try_to_unmap_flush();
- free_unref_page_list(&free_folios);
+ free_unref_folios(&free_folios);
list_splice(&ret_folios, folio_list);
count_vm_events(PGACTIVATE, pgactivate);
