Re: [PATCH] mm/page_vma_mapped: guard check_pmd() with CONFIG_TRANSPARENT_HUGEPAGE

[Wei Yang <richard.weiyang@gmail.com>]

+cc Balbir

On Wed, Jun 24, 2026 at 09:59:43PM -0700, Andrew Morton wrote:
>On Thu, 25 Jun 2026 03:46:29 +0000 Wei Yang <richard.weiyang@gmail.com> wrote:
>
>> >Sashiko had an off-topic complaint about the surrounding code:
>> >	https://lore.kernel.org/oe-kbuild-all/202606240042.ffPsEXVc-lkp@intel.com/
>> 
>> I see this robot reply, but not see the Sashiko comment.
>> 
>> How can I view Sashiko's commnet?
>
>oop sorry.
>
>You can go to https://sashiko.dev/ and search for the email subject. 
>
>Or append your Message-ID to "https://sashiko.dev/#/patchset":
>
>	https://sashiko.dev/#/patchset/20260624082359.2869-1-richard.weiyang@gmail.com
>

Got it, thansk

This one mentioned two things:

  a. page_vma_mapped_walk() return without check
  b. whether __split_huge_pmd_locked() would split device-private pmd

For a., it is being fixing at [1].

For b., to be honest I am not 100% for sure. If a device-private pmd could be
file backed, then this looks like a bug.

Balbir,

Would you mind taking a look at the second comment raised by Sashiko?

[1]: https://lore.kernel.org/linux-mm/20260624065353.1622-1-richard.weiyang@gmail.com/

-- 
Wei Yang
Help you, Help me