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(p200300cbc7076e00ff02ec7aded5ec1e.dip0.t-ipconnect.de. [2003:cb:c707:6e00:ff02:ec7a:ded5:ec1e]) by smtp.gmail.com with ESMTPSA id r10-20020a05600c458a00b003d35acb0fd7sm2093683wmo.34.2023.01.05.02.47.20 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 05 Jan 2023 02:47:21 -0800 (PST) Message-ID: <60f06008-dea5-a08e-edec-fc4aec76dfb5@redhat.com> Date: Thu, 5 Jan 2023 11:47:20 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.6.0 Subject: Re: [PATCH 00/46] Based on latest mm-unstable (85b44c25cd1e). To: James Houghton , Mike Kravetz , Muchun Song , Peter Xu Cc: David Rientjes , Axel Rasmussen , Mina Almasry , Zach O'Keefe , Manish Mishra , Naoya Horiguchi , "Dr . David Alan Gilbert" , "Matthew Wilcox (Oracle)" , Vlastimil Babka , Baolin Wang , Miaohe Lin , Yang Shi , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20230105101844.1893104-1-jthoughton@google.com> From: David Hildenbrand Organization: Red Hat In-Reply-To: <20230105101844.1893104-1-jthoughton@google.com> X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 463DC160006 X-Stat-Signature: hf8xthuuc7a9mwqfidstryk8s3r9ym6a X-Rspam-User: X-HE-Tag: 1672915646-794592 X-HE-Meta: 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 mBITL5pv UoIx0oLYgAh2FGqv3tUyyyPXaZOGJFNVjS7ZLzr98kXng2BnzQzRxmvZ5HuAaC+/lzK49vIQIenhjZEpi/y15/jBfGLN2HLTFwsk24eBKEuvsWQZSLNiywVHi8JBUjvZ9BkTMztiPyOZDIjI= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 05.01.23 11:17, James Houghton wrote: > This series introduces the concept of HugeTLB high-granularity mapping > (HGM). This series teaches HugeTLB how to map HugeTLB pages at > high-granularity, similar to how THPs can be PTE-mapped. > > Support for HGM in this series is for MAP_SHARED VMAs on x86 only. Other > architectures and (some) support for MAP_PRIVATE will come later. Why even care about the complexity of COW-sharable anon pages? TBH, I'd just limit this to MAP_SHARED and call it a day. Sure, we can come up with use cases for everything (snapshotting VMs using fork while also support optimized postcopy), but I think this would need some real justification for the added complexity and possible (likely!) issues. -- Thanks, David / dhildenb