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

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Message-ID: <b27b8bc4-8730-4ce8-bf39-0ca8459feecc@gmail.com>
Date: Sun, 18 Jan 2026 22:10:50 +0800
From: Alex Shi <seakeel@...il.com>
To: "David Hildenbrand (Red Hat)" <david@...nel.org>,
 Matthew Wilcox <willy@...radead.org>
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Subject: Re: [PATCH] mm/pgtable: convert pgtable_t to ptdesc pointer

On 2026/1/18 18:51, David Hildenbrand (Red Hat) wrote:
> 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;
> 

Got it. Thanks a lot for the explanation!