Re: [PATCH v3 0/3] Fix CONT-PTE/PMD size hugetlb issue when unmapping or migrating

From: Andrew Morton
Date: Tue May 10 2022 - 00:07:58 EST


On Tue, 10 May 2022 11:45:57 +0800 Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx> wrote:

> Hi,
>
> Now migrating a hugetlb page or unmapping a poisoned hugetlb page, we'll
> use ptep_clear_flush() and set_pte_at() to nuke the page table entry
> and remap it, and this is incorrect for CONT-PTE or CONT-PMD size hugetlb
> page,

It would be helpful to describe why it's wrong. Something like "should
use huge_ptep_clear_flush() and huge_ptep_clear_flush() for this
purpose"?

> which will cause potential data consistent issue. This patch set
> will change to use hugetlb related APIs to fix this issue, please find
> details in each patch. Thanks.

Is a cc:stable needed here? And are we able to identify a target for a
Fixes: tag?