Re: [PATCH v3 1/2] mm: migration: fix the FOLL_GET failure on following huge page

[Huang, Ying]

"Wang, Haiyue" <haiyue.wang@xxxxxxxxx> writes:

>> -----Original Message-----
>> From: Wang, Haiyue
>> Sent: Monday, August 15, 2022 10:11
>> To: Huang, Ying <ying.huang@xxxxxxxxx>
>> Cc: linux-mm@xxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; akpm@xxxxxxxxxxxxxxxxxxxx; david@xxxxxxxxxx;
>> linmiaohe@xxxxxxxxxx; songmuchun@xxxxxxxxxxxxx; naoya.horiguchi@xxxxxxxxx; alex.sierra@xxxxxxx
>> Subject: RE: [PATCH v3 1/2] mm: migration: fix the FOLL_GET failure on following huge page
>>
>> > -----Original Message-----
>> > From: Huang, Ying <ying.huang@xxxxxxxxx>
>> > Sent: Monday, August 15, 2022 09:59
>> > To: Wang, Haiyue <haiyue.wang@xxxxxxxxx>
>> > Cc: linux-mm@xxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; akpm@xxxxxxxxxxxxxxxxxxxx; david@xxxxxxxxxx;
>> > linmiaohe@xxxxxxxxxx; songmuchun@xxxxxxxxxxxxx; naoya.horiguchi@xxxxxxxxx; alex.sierra@xxxxxxx
>> > Subject: Re: [PATCH v3 1/2] mm: migration: fix the FOLL_GET failure on following huge page
>> >
>> > Haiyue Wang <haiyue.wang@xxxxxxxxx> writes:
>> >
>
>
>> >
>> > > This is an temporary solution to mitigate the racing fix.
>> >
>> > Why is it "racing fix"?  This isn't a race condition fix.
>>
>> The 'Fixes' commit is about race condition fix.
>>
>> How about " his is an temporary solution to mitigate the side effect
>> Of the race condition fix"
>
> Try to add more words to make things clean:
>
> "This is an temporary solution to mitigate the side effect of the race
> condition fix by calling follow_page() with FOLL_GET set."

Looks good to me.  Thanks!

Best Regards,
Huang, Ying

>>
>> >
>> > Best Regards,
>> > Huang, Ying
>> >
>> > > After supporting follow huge page by FOLL_GET is done, this fix can be
>> > > reverted safely.
>> > >
>> > > Fixes: 4cd614841c06 ("mm: migration: fix possible do_pages_stat_array racing with memory offline")
>> > > Signed-off-by: Haiyue Wang <haiyue.wang@xxxxxxxxx>
>> >
>> > [snip]