Yosry Ahmed <yosryahmed@xxxxxxxxxx> writes:
> On Mon, May 22, 2023 at 12:09 AM Huang Ying <ying.huang@xxxxxxxxx> wrote:
>>
>> __swap_count() is called in do_swap_page() only, which encloses the
>> call site with get/put_swap_device() already.
>>
>> Signed-off-by: "Huang, Ying" <ying.huang@xxxxxxxxx>
>> Cc: David Hildenbrand <david@xxxxxxxxxx>
>> Cc: Hugh Dickins <hughd@xxxxxxxxxx>
>> Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
>> Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
>> Cc: Michal Hocko <mhocko@xxxxxxxx>
>> Cc: Minchan Kim <minchan@xxxxxxxxxx>
>> Cc: Tim Chen <tim.c.chen@xxxxxxxxxxxxxxx>
>> Cc: Yang Shi <shy828301@xxxxxxxxx>
>> Cc: Yu Zhao <yuzhao@xxxxxxxxxx>
>> ---
>> mm/swapfile.c | 10 ++--------
>> 1 file changed, 2 insertions(+), 8 deletions(-)
>>
>> diff --git a/mm/swapfile.c b/mm/swapfile.c
>> index 274bbf797480..8419cba9c192 100644
>> --- a/mm/swapfile.c
>> +++ b/mm/swapfile.c
>> @@ -1432,16 +1432,10 @@ void swapcache_free_entries(swp_entry_t *entries, int n)
>>
>
> nit: I would add a comment here that the caller needs get/put_swap_device().
It's default behavior to call get/put_swap_device() in the caller for
all almost all swap functions. I would rather comment the swap
functions needn't to do that, as the comments for
read_swap_cache_async() in [2/5].
> Reviewed-by: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
Thanks!
>> int __swap_count(swp_entry_t entry)
>> {
>> - struct swap_info_struct *si;
>> + struct swap_info_struct *si = swp_swap_info(entry);
>> pgoff_t offset = swp_offset(entry);
>> - int count = 0;
>>
>> - si = get_swap_device(entry);
>> - if (si) {
>> - count = swap_count(si->swap_map[offset]);
>> - put_swap_device(si);
>> - }
>> - return count;
>> + return swap_count(si->swap_map[offset]);
>> }
>>
>> /*
Best Regards,
Huang, Ying
