Right now, it is possible two folios are contiguous in swap slots
but they don't belong to one memcg. In this case, even we return
a large nr, we can't really batch free all slots.
Reported-by: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
Reported-by: Chris Li <chrisl@xxxxxxxxxx>
Signed-off-by: Barry Song <v-songbaohua@xxxxxxxx>
---
mm/internal.h | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/mm/internal.h b/mm/internal.h
index adbf8c88c9df..d1f1e221212d 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -15,6 +15,7 @@
#include <linux/rmap.h>
#include <linux/swap.h>
#include <linux/swapops.h>
+#include <linux/swap_cgroup.h>
#include <linux/tracepoint-defs.h>
/* Internal core VMA manipulation functions. */
@@ -275,18 +276,22 @@ static inline int swap_pte_batch(pte_t *start_ptep, int max_nr, pte_t pte)
{
pte_t expected_pte = pte_next_swp_offset(pte);
const pte_t *end_ptep = start_ptep + max_nr;
+ swp_entry_t entry = pte_to_swp_entry(pte);
pte_t *ptep = start_ptep + 1;
+ unsigned short cgroup_id;
VM_WARN_ON(max_nr < 1);
VM_WARN_ON(!is_swap_pte(pte));
- VM_WARN_ON(non_swap_entry(pte_to_swp_entry(pte)));
+ VM_WARN_ON(non_swap_entry(entry));
+ cgroup_id = lookup_swap_cgroup_id(entry);
while (ptep < end_ptep) {
pte = ptep_get(ptep);
if (!pte_same(pte, expected_pte))
break;
-
+ if (lookup_swap_cgroup_id(pte_to_swp_entry(pte)) != cgroup_id)
+ break;
expected_pte = pte_next_swp_offset(expected_pte);
ptep++;
}
--
2.34.1
> Chris
>
> >
> > Â Â Â Â /*
> > Â Â Â Â Â * Short-circuit the below loop if none of the entries had their
> > --
> > 2.34.1
> >
Thanks
Barry
