Re: [PATCH] mm/migrate: make migrate_pages_batch() stats consistent.

[Zi Yan <ziy@nvidia.com>]

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On 19 Jun 2024, at 3:25, Huang, Ying wrote:

> Zi Yan <zi.yan@sent.com> writes:
>
>> From: Zi Yan <ziy@nvidia.com>
>>
>> As Ying pointed out in [1], stats->nr_thp_failed needs to be updated to
>> avoid stats inconsistency between MIGRATE_SYNC and MIGRATE_ASYNC when
>> calling migrate_pages_batch().

Because if not, when migrate_pages_batch() is called via
migrate_pages(MIGRATE_ASYNC), nr_thp_failed will not be increased and
when migrate_pages_batch() is called via migrate_pages(MIGRATE_SYNC*),
nr_thp_failed will be increase in migrate_pages_sync() by
stats->nr_thp_failed += astats.nr_thp_split.

>>
>> [1] https://lore.kernel.org/linux-mm/87msnq7key.fsf@yhuang6-desk2.ccr.corp.intel.com/
>
> IMHO, we shouldn't ask people to use link to understand the patch
> description or commit message.  If so, we can make the link less
> outstanding and maybe add more words about the issue.

I summarized your explanation from the link. You think the summary is not
enough? I can add more text. Let me know if the above text looks
good to you, then I can resend the patch. Thanks.

--
Best Regards,
Yan, Zi

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