linux-kernel - Re: [PATCH] mm/pgtable: convert pgtable

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Message-ID: <4fd1610b-acc5-4c17-a227-4d63272d3718@kernel.org>
Date: Sun, 18 Jan 2026 11:51:01 +0100
From: "David Hildenbrand (Red Hat)" <david@...nel.org>
To: Alex Shi <seakeel@...il.com>, Matthew Wilcox <willy@...radead.org>
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Subject: Re: [PATCH] mm/pgtable: convert pgtable_t to ptdesc pointer

On 1/18/26 09:13, Alex Shi wrote:
> 
> 
> On 2026/1/8 10:23, Alex Shi wrote:
>>
>>
>> On 2026/1/7 22:48, Matthew Wilcox wrote:
>>> On Wed, Jan 07, 2026 at 05:28:36PM +0800, Alex Shi wrote:
>>>> Right, I will fix this. and sent the 2nd version.
>>> No, the patch is stupid and wrong.  Don't send a v2.  You seem to have a
>>> hairtrigger resend, so I'm trying to prevent a v2 being sent instead of
>>> sending a patient reply.
>>
>> Hi Matthew,
>>
>> I hear you—no v2 will be sent.
>> but sorry for a bit confusing, what's your expected fix? is the too
>> quick resenting? or the direction to alignment pgtable_t with ptdesc is
>> wrong?
> 
> Hi Willy, Do you mind to share the detailed concern for this patch?

I think we recently had a discussion that we should much rather rework 
core code to consistently make pgtable_t a pointer to the start of the 
page table or something like that.

Because the way you change the code just means that we will not be able 
to handle code that fits multiple pages tables into a single page 
(s390x, ppc) consistently.

	arch/s390/include/asm/page.h:typedef pte_t *pgtable_t;

-- 
Cheers

David