Re: [PATCH -V3 4/5] swap: remove get/put_swap_device() in __swap_duplicate()

David Hildenbrand
2023-05-31T07:47:35Z

On 29.05.23 08:13, Huang Ying wrote:
> __swap_duplicate() is called by
>
> - swap_shmem_alloc(): the folio in swap cache is locked.
>
> - copy_nonpresent_pte() -> swap_duplicate() and try_to_unmap_one() ->
> swap_duplicate(): the page table lock is held.
>
> - __read_swap_cache_async() -> swapcache_prepare(): enclosed with
> get/put_swap_device() in __read_swap_cache_async() already.
>
> So, it's safe to remove get/put_swap_device() in __swap_duplicate().
>
> Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
> Reviewed-by: Yosry Ahmed <yosryahmed@google.com>
> Cc: David Hildenbrand <david@redhat.com>
> Cc: Hugh Dickins <hughd@google.com>
> Cc: Johannes Weiner <hannes@cmpxchg.org>
> Cc: Matthew Wilcox <willy@infradead.org>
> Cc: Michal Hocko <mhocko@suse.com>
> Cc: Minchan Kim <minchan@kernel.org>
> Cc: Tim Chen <tim.c.chen@linux.intel.com>
> Cc: Yang Shi <shy828301@gmail.com>
> Cc: Yu Zhao <yuzhao@google.com>
> Cc: Chris Li <chrisl@kernel.org>
> ---

Reviewed-by: David Hildenbrand <david@redhat.com>

--
Thanks,

David / dhildenb