diff options
Diffstat (limited to 'mm/memcontrol-v1.c')
| -rw-r--r-- | mm/memcontrol-v1.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/mm/memcontrol-v1.c b/mm/memcontrol-v1.c index 81d8819f13cd..f8744f5630bb 100644 --- a/mm/memcontrol-v1.c +++ b/mm/memcontrol-v1.c @@ -848,6 +848,8 @@ static int mem_cgroup_move_account(struct folio *folio, css_get(&to->css); css_put(&from->css); + /* Warning should never happen, so don't worry about refcount non-0 */ + WARN_ON_ONCE(folio_unqueue_deferred_split(folio)); folio->memcg_data = (unsigned long)to; __folio_memcg_unlock(from); @@ -1217,7 +1219,9 @@ static int mem_cgroup_move_charge_pte_range(pmd_t *pmd, enum mc_target_type target_type; union mc_target target; struct folio *folio; + bool tried_split_before = false; +retry_pmd: ptl = pmd_trans_huge_lock(pmd, vma); if (ptl) { if (mc.precharge < HPAGE_PMD_NR) { @@ -1227,6 +1231,27 @@ static int mem_cgroup_move_charge_pte_range(pmd_t *pmd, target_type = get_mctgt_type_thp(vma, addr, *pmd, &target); if (target_type == MC_TARGET_PAGE) { folio = target.folio; + /* + * Deferred split queue locking depends on memcg, + * and unqueue is unsafe unless folio refcount is 0: + * split or skip if on the queue? first try to split. + */ + if (!list_empty(&folio->_deferred_list)) { + spin_unlock(ptl); + if (!tried_split_before) + split_folio(folio); + folio_unlock(folio); + folio_put(folio); + if (tried_split_before) + return 0; + tried_split_before = true; + goto retry_pmd; + } + /* + * So long as that pmd lock is held, the folio cannot + * be racily added to the _deferred_list, because + * __folio_remove_rmap() will find !partially_mapped. + */ if (folio_isolate_lru(folio)) { if (!mem_cgroup_move_account(folio, true, mc.from, mc.to)) { |