Explicit memcg uncharging is not needed when the memcg accounting has the
same lifespan of the page/folio. That becomes the case for khugepaged
after Yang & Zach's recent rework so the hpage will be allocated for each
collapse rather than being cached.
Cleanup the explicit memcg uncharge in khugepaged failure path and leave
that for put_page().
Suggested-by: Zach O'Keefe <zokeefe@xxxxxxxxxx>
Signed-off-by: Peter Xu <peterx@xxxxxxxxxx>
---
mm/khugepaged.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 941d1c7ea910..dd5a7d9bc593 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -1230,10 +1230,8 @@ static int collapse_huge_page(struct mm_struct *mm, unsigned long address,
out_up_write:
mmap_write_unlock(mm);
out_nolock:
- if (hpage) {
- mem_cgroup_uncharge(page_folio(hpage));
+ if (hpage)
put_page(hpage);
- }
trace_mm_collapse_huge_page(mm, result == SCAN_SUCCEED, result);
return result;
}
@@ -2250,10 +2248,8 @@ static int collapse_file(struct mm_struct *mm, unsigned long addr,
unlock_page(hpage);
out:
VM_BUG_ON(!list_empty(&pagelist));
- if (hpage) {
- mem_cgroup_uncharge(page_folio(hpage));
+ if (hpage)
put_page(hpage);
- }
trace_mm_khugepaged_collapse_file(mm, hpage, index, is_shmem, addr, file, nr, result);
return result;
--
2.39.1
