Re: [PATCH v2 1/1] mm: swap: remove duplicate nr_swap_pages decrement in get_swap_page_of_type()

On Sun, Nov 2, 2025 at 4:36 PM Youngjun Park youngjun.park@lge.com wrote:

After commit 4f78252da887, nr_swap_pages is decremented in swap_range_alloc(). Since cluster_alloc_swap_entry() calls swap_range_alloc() internally, the decrement in get_swap_page_of_type() causes double-decrementing.

Remove the duplicate decrement.

Fixes: 4f78252da887 ("mm: swap: move nr_swap_pages counter decrement from folio_alloc_swap() to swap_range_alloc()") Cc: stable@vger.kernel.org # v6.17-rc1 Signed-off-by: Youngjun Park youngjun.park@lge.com Acked-by: Chris Li chrisl@kernel.org Reviewed-by: Barry Song baohua@kernel.org

---

v1 -> v2:

• Collect Acked-by from Chris - thank you!
• Collect Reviewed-by from Barry - thank you!
• Link to v1: https://lore.kernel.org/linux-mm/20251101134158.69908-1-youngjun.park@lge.co...

mm/swapfile.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/mm/swapfile.c b/mm/swapfile.c index 543f303f101d..66a502cd747b 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -2020,10 +2020,8 @@ swp_entry_t get_swap_page_of_type(int type) local_lock(&percpu_swap_cluster.lock); offset = cluster_alloc_swap_entry(si, 0, 1); local_unlock(&percpu_swap_cluster.lock);

•                   if (offset) {
  

•                   if (offset)
                            entry = swp_entry(si->type, offset);
  

•                           atomic_long_dec(&nr_swap_pages);
  

•                   }
            }
            put_swap_device(si);
    }
  

-- 2.34.1

Thanks.

Reviewed-by: Kairui Song kasong@tencent.com