On 2022/3/7 10:00, Huang, Ying wrote:
> Miaohe Lin <linmiaohe@xxxxxxxxxx> writes:
>
>> When mapping_locked is true, TTU_RMAP_LOCKED is always set to ttu. We can
>> check ttu instead so mapping_locked can be removed. And ttu is either 0
>> or TTU_RMAP_LOCKED now. Change '|=' to '=' to reflect this.
>>
>> Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
>> ---
>> mm/migrate.c | 6 ++----
>> 1 file changed, 2 insertions(+), 4 deletions(-)
>>
>> diff --git a/mm/migrate.c b/mm/migrate.c
>> index 42e3a944f35c..50bc62d85eaf 100644
>> --- a/mm/migrate.c
>> +++ b/mm/migrate.c
>> @@ -1230,7 +1230,6 @@ static int unmap_and_move_huge_page(new_page_t get_new_page,
>> goto put_anon;
>>
>> if (page_mapped(hpage)) {
>> - bool mapping_locked = false;
>> enum ttu_flags ttu = 0;
>>
>> if (!PageAnon(hpage)) {
>> @@ -1244,14 +1243,13 @@ static int unmap_and_move_huge_page(new_page_t get_new_page,
>> if (unlikely(!mapping))
>> goto unlock_put_anon;
>>
>> - mapping_locked = true;
>> - ttu |= TTU_RMAP_LOCKED;
>> + ttu = TTU_RMAP_LOCKED;
>> }
>>
>> try_to_migrate(src, ttu);
>> page_was_mapped = 1;
>>
>> - if (mapping_locked)
>> + if (ttu & TTU_RMAP_LOCKED)
>> i_mmap_unlock_write(mapping);
>> }
>
> I think this is a code style issue. The original code looks more
> readable for me.
>
I think "ttu |= TTU_RMAP_LOCKED;" is the product of the code changing.
And (ttu & TTU_RMAP_LOCKED) can do the right thing as mapping_locked
while removing the page_was_mapped. But if you insist on this, I will
drop this patch.
Thanks.
> Best Regards,
> Huang, Ying
>
> .
>
