>From 0595acbd688b60ff7b2821a073c0fe857a4ae0ee Mon Sep 17 00:00:00 2001 From: Peter Xu Date: Tue, 21 Feb 2023 16:43:44 -0500 Subject: [PATCH] mm/khugepaged: alloc_charge_hpage() take care of mem charge errors If memory charge failed, instead of returning the hpage but with an error, allow the function to cleanup the folio properly, which is normally what a function should do in this case - either return successfully, or return with no side effect of partial runs with an indicated error. This will also avoid the caller calling mem_cgroup_uncharge() unnecessarily with either anon or shmem path (even if it's safe to do so). Cc: Johannes Weiner Cc: Yang Shi Cc: David Stevens Signed-off-by: Peter Xu --- mm/khugepaged.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 8dbc39896811..941d1c7ea910 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -1063,12 +1063,19 @@ static int alloc_charge_hpage(struct page **hpage, struct mm_struct *mm, gfp_t gfp = (cc->is_khugepaged ? alloc_hugepage_khugepaged_gfpmask() : GFP_TRANSHUGE); int node = hpage_collapse_find_target_node(cc); + struct folio *folio; if (!hpage_collapse_alloc_page(hpage, gfp, node, &cc->alloc_nmask)) return SCAN_ALLOC_HUGE_PAGE_FAIL; - if (unlikely(mem_cgroup_charge(page_folio(*hpage), mm, gfp))) + + folio = page_folio(*hpage); + if (unlikely(mem_cgroup_charge(folio, mm, gfp))) { + folio_put(folio); + *hpage = NULL; return SCAN_CGROUP_CHARGE_FAIL; + } count_memcg_page_event(*hpage, THP_COLLAPSE_ALLOC); + return SCAN_SUCCEED; } -- 2.39.1