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[142.162.112.119]) by smtp.gmail.com with ESMTPSA id af79cd13be357-8c37f51b732sm1696908185a.25.2026.01.13.07.08.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 13 Jan 2026 07:08:29 -0800 (PST) Received: from jgg by wakko with local (Exim 4.97) (envelope-from ) id 1vfg0S-00000003udw-1o8a; Tue, 13 Jan 2026 11:08:28 -0400 Date: Tue, 13 Jan 2026 11:08:28 -0400 From: Jason Gunthorpe To: Mostafa Saleh Cc: "David Hildenbrand (Red Hat)" , linux-mm@kvack.org, iommu@lists.linux.dev, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, corbet@lwn.net, joro@8bytes.org, will@kernel.org, robin.murphy@arm.com, akpm@linux-foundation.org, vbabka@suse.cz, surenb@google.com, mhocko@suse.com, jackmanb@google.com, hannes@cmpxchg.org, ziy@nvidia.com, lorenzo.stoakes@oracle.com, Liam.Howlett@oracle.com, rppt@kernel.org, xiaqinxin@huawei.com, baolu.lu@linux.intel.com, rdunlap@infradead.org, Samiullah Khawaja Subject: Re: [PATCH v6 3/4] iommu: debug-pagealloc: Track IOMMU pages Message-ID: <20260113150828.GP745888@ziepe.ca> References: <20260109195111.GQ545276@ziepe.ca> <20260112133256.GB745888@ziepe.ca> <20260112135208.GD745888@ziepe.ca> <746f5adb-1d91-4ca2-8ae0-a2d171203b66@kernel.org> <482f2f36-e906-492a-a80c-987bf7359d83@kernel.org> Precedence: bulk X-Mailing-List: iommu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Tue, Jan 13, 2026 at 10:49:28AM +0000, Mostafa Saleh wrote: > Would you have a problem if we added a new function in page_ext > "page_ext_from_phys()" as Jason suggested? Given the hidden complexity that David just pointed out I think this is essential to encapsulate it in a function. The function must be able to accept any phys_addr_t and safely returns NULL if page_ext cannot be used for some reason. Jason