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Sun, 18 Jan 2026 06:11:25 -0800 (PST) Message-ID: Date: Sun, 18 Jan 2026 22:10:50 +0800 Precedence: bulk X-Mailing-List: linux-sh@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mm/pgtable: convert pgtable_t to ptdesc pointer To: "David Hildenbrand (Red Hat)" , Matthew Wilcox Cc: Mike Rapoport , alexs@kernel.org, Richard Henderson , Matt Turner , Magnus Lindholm , Vineet Gupta , Russell King , Will Deacon , "Aneesh Kumar K.V" , Andrew Morton , Nick Piggin , Peter Zijlstra , Catalin Marinas , Guo Ren , Brian Cain , Huacai Chen , WANG Xuerui , Geert Uytterhoeven , Michal Simek , Thomas Bogendoerfer , Dinh Nguyen , Jonas Bonn , Stefan Kristiansson , Stafford Horne , "James E.J. Bottomley" , Helge Deller , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Yoshinori Sato , Rich Felker , John Paul Adrian Glaubitz , Richard Weinberger , Anton Ivanov , Johannes Berg , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" , "H. Peter Anvin" , Andy Lutomirski , Chris Zankel , Max Filippov , Arnd Bergmann , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Suren Baghdasaryan , Michal Hocko , "open list:ALPHA PORT" , open list , "open list:SYNOPSYS ARC ARCHITECTURE" , "moderated list:ARM PORT" , "open list:MMU GATHER AND TLB INVALIDATION" , "open list:MMU GATHER AND TLB INVALIDATION" , "open list:C-SKY ARCHITECTURE" , "open list:QUALCOMM HEXAGON ARCHITECTURE" , "open list:LOONGARCH" , "open list:M68K ARCHITECTURE" , "open list:MIPS" , "open list:OPENRISC ARCHITECTURE" , "open list:PARISC ARCHITECTURE" , "open list:RISC-V ARCHITECTURE" , "open list:SUPERH" , "open list:USER-MODE LINUX (UML)" References: <20260107064642.15771-1-alexs@kernel.org> <080e493a-e4f1-4c97-a3e1-f76f126b5213@gmail.com> <1d110134-89ab-474b-bca6-cfbfd4b5057f@gmail.com> <85a0be43-3598-435d-a50e-9403b7e963f7@gmail.com> <4fd1610b-acc5-4c17-a227-4d63272d3718@kernel.org> Content-Language: en-US From: Alex Shi In-Reply-To: <4fd1610b-acc5-4c17-a227-4d63272d3718@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit 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!