Re: [PATCH 0/2] don't use mapcount() to check large folio sharing

Yin, Fengwei
2023-08-02T12:43:47Z

Hi Andrew,

On 7/29/2023 1:24 AM, Andrew Morton wrote:
> On Sat, 29 Jul 2023 00:13:54 +0800 Yin Fengwei <fengwei.yin@intel.com> wrote:
>
>> In madvise_cold_or_pageout_pte_range() and madvise_free_pte_range(),
>> folio_mapcount() is used to check whether the folio is shared. But it's
>> not correct as folio_mapcount() returns total mapcount of large folio.
>>
>> Use folio_estimated_sharers() here as the estimated number is enough.
>
> What are the user-visible runtime effects of these changes?
>
> (and please try to avoid using the same Subject: for different patches)
>

Can you hold on these patches to mm-unstable? I think we need to wait for
David's work on folio_maybe_mapped_shared() and redo the fix base on that.
Thanks and sorry for the noise.

Regards
Yin, Fengwei