diff options
| -rw-r--r-- | mm/vmscan.c | 25 |
1 files changed, 22 insertions, 3 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c index dcd476a66a59..1a59171c6695 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2088,10 +2088,29 @@ keep: nr_reclaimed += demote_folio_list(&demote_folios, pgdat); /* Folios that could not be demoted are still in @demote_folios */ if (!list_empty(&demote_folios)) { - /* Folios which weren't demoted go back on @folio_list for retry: */ + /* Folios which weren't demoted go back on @folio_list */ list_splice_init(&demote_folios, folio_list); - do_demote_pass = false; - goto retry; + + /* + * goto retry to reclaim the undemoted folios in folio_list if + * desired. + * + * Reclaiming directly from top tier nodes is not often desired + * due to it breaking the LRU ordering: in general memory + * should be reclaimed from lower tier nodes and demoted from + * top tier nodes. + * + * However, disabling reclaim from top tier nodes entirely + * would cause ooms in edge scenarios where lower tier memory + * is unreclaimable for whatever reason, eg memory being + * mlocked or too hot to reclaim. We can disable reclaim + * from top tier nodes in proactive reclaim though as that is + * not real memory pressure. + */ + if (!sc->proactive) { + do_demote_pass = false; + goto retry; + } } pgactivate = stat->nr_activate[0] + stat->nr_activate[1]; |