Since commit 7ae88534cdd9 ("mm: move mem_cgroup_uncharge out of
__page_cache_release()"), the mem_cgroup will be uncharged when hpage is
freed. Uncharge mem_cgroup here is harmless but it looks confusing and
buggy: if mem_cgroup charge failed, we will call mem_cgroup_uncharge()
uncorrectly in error path because hpage is not IS_ERR_OR_NULL().
Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
---
mm/khugepaged.c | 4 ----
1 file changed, 4 deletions(-)
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index e886a8618c33..68579cdbdc9b 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -1211,8 +1211,6 @@ static void collapse_huge_page(struct mm_struct *mm,
out_up_write:
mmap_write_unlock(mm);
out_nolock:
- if (!IS_ERR_OR_NULL(*hpage))
- mem_cgroup_uncharge(*hpage);
trace_mm_collapse_huge_page(mm, isolated, result);
return;
out:
@@ -1968,8 +1966,6 @@ static void collapse_file(struct mm_struct *mm,
unlock_page(new_page);
out:
VM_BUG_ON(!list_empty(&pagelist));
- if (!IS_ERR_OR_NULL(*hpage))
- mem_cgroup_uncharge(*hpage);
/* TODO: tracepoints */
}
--
2.19.1
