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Bottomley" , Helge Deller , Juergen Gross , Stefano Stabellini , Muchun Song , Oscar Salvador , Andrew Morton , "Liam R. Howlett" , Lorenzo Stoakes , Will Deacon , "Aneesh Kumar K.V" , Nick Piggin , Peter Zijlstra , Andrey Ryabinin , Pasha Tatashin , Chris Li , Kairui Song , Uladzislau Rezki , Steven Rostedt , Masami Hiramatsu , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Eduard Zingerman , Kumar Kartikeya Dwivedi , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , SJ Park , "Matthew Wilcox (Oracle)" , Jan Kara , Jason Gunthorpe , Leon Romanovsky , Miaohe Lin , Dennis Zhou , Tejun Heo , Christoph Lameter , Mike Rapoport , Johannes Weiner , ziy@nvidia.com, pfalcato@suse.de, ryan.roberts@arm.com, linux-kernel@vger.kernel.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-parisc@vger.kernel.org, xen-devel@lists.xenproject.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, kasan-dev@googlegroups.com, linux-trace-kernel@vger.kernel.org, bpf@vger.kernel.org, linux-perf-users@vger.kernel.org, damon@lists.linux.dev Subject: Re: [PATCH RFC 00/11] mm: distinguish PTE table storage from PTE values To: "David Hildenbrand (Arm)" , Alexander Gordeev References: <20260727164715.2866609-1-usama.anjum@arm.com> <2c19247e-bee6-45f4-a353-2fcc60db26e6@kernel.org> <7813b5fe-e767-442c-a356-afc1a5c567ad-agordeev@linux.ibm.com> <6db0a8c0-b500-4364-be3d-d3a537c61258@kernel.org> <46319967-0338-4532-b953-dbea77084fe3@arm.com> <78a0402d-5436-4aab-a704-90fab56eec50@kernel.org> From: Muhammad Usama Anjum Content-Language: en-US In-Reply-To: <78a0402d-5436-4aab-a704-90fab56eec50@kernel.org> Content-Type: text/plain; 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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: m0BkR8/X+Y/2YSrkkhKTipf4ehePcxOeGjGK/HMkPiYq7x39VpT9pGIXx7YjICzv3dRrqVt9sMng/ogk3QR9JPjPVZDXM1YgsAg+zgKYiY3e4gz87ekXnJD9bP9WANACldnpUqdaa35mxnTBbcd894orNH2g8SrxM9ZAn5W58w1zMGuaVye3TOZ83Oc/wNRno9jPD2BOXdvPD1yNIJUurQJQdrLaoa/ROMQmerFi43w6h1wEFavCUCRR+O/w724YL3ik/wRFKA1t5AkJA1gM/KUrdGpxK+MVxCHrUqKJ2Xf3pJSCGf6YLFYT5FpZ3awy7ih5nFESHUohIjTg1siXNBov8HTzWhXGdNSMXEaNMhXSOIlMbpHMNr09aLmPFt2MmnEVkvuwZE/n9ljUi2FCKQ/93R8Aj8Y2/N9mlIBkVF6PRjyP4qYyg2/llcQJ0hwg X-OriginatorOrg: arm.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 29 Jul 2026 12:22:36.3600 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 9aea7950-6810-4793-59dd-08deed6c1301 X-MS-Exchange-CrossTenant-Id: f34e5979-57d9-4aaa-ad4d-b122a662184d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=f34e5979-57d9-4aaa-ad4d-b122a662184d;Ip=[4.158.2.129];Helo=[outbound-uk1.az.dlp.m.darktrace.com] X-MS-Exchange-CrossTenant-AuthSource: DB1PEPF00039233.eurprd03.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: PAWPR08MB9616 On 29/07/2026 12:52 pm, David Hildenbrand (Arm) wrote: > On 7/29/26 13:33, Muhammad Usama Anjum wrote: >> On 29/07/2026 12:05 pm, David Hildenbrand (Arm) wrote: >>> On 7/29/26 12:13, Alexander Gordeev wrote: >>>> ... >>>> >>>> May be we need the generic hw_pte_t implementation as { pte_t pte; } >>>> right away? >>> >>> Indeed, that makes sense. We just need a way for the architecture to opt-in that >>> it did the conversion. >> Yeah and architecture cannot opt-in until its converted. So we should leave >> it to architecture to define hw_pte_t. > > In the context of this series, we should have something like an > CONFIG_ARCH_HAS_XXX and select the definition based on that. > > So we'd have a generic variant. I'll add CONFIG_ARCH_HAS_XXX config in generic version. I don't understand why generic code would define hw_pte_t if arch optionally opts-in. Are you saying pte_t may have different definition in different arches. But the hw_pte_t would always be structure of pte_t. Hence definition typedef struct { pte_t __pte; }; hw_pte_t; can be moved to the generic code? Moving definition to generic side is fine at this point in time. But if a arch wants to hw_pte_t opaque and don't want the generic code to perform arithmatic (ptep++), it'll not work. -- Thanks, Usama