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b=aF9n1T7DCVy1Hkc5fpzdyVCBZZhkp+kaL1rI5Ax02PcKOU7ga0DmKNtwfAjAGiEyi 84PLNj2H4A12vPsVja9NqV1Ngi2fbkDIrRANB9RVOeG9yhBrMQRoIHrEpykGSN8qQN y07CpYsQGEw4US40Tg2OK7L6HVCSBswDv8zueXLMSOK7tlS6QO6fzhXHsWzYdO0z34 NKVCtVmAc5mOHWoELEpZgZhVc2kT38sdXZCbVGmAdLona1awLOkcL6gdcWkbyUDLVb YMkmx7LTrTPKrXGRDhGoGuEI/czhR4WOKJvNqci5gTwhFJfJlKAk8B/NANIMtsqkAt rUG98FonuYKEQ== Message-ID: Date: Sun, 31 May 2026 21:49:02 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: Process (was Re: [PATCH mm-hotfixes-unstable v18 00/14] khugepaged: add mTHP) collapse support To: "Vlastimil Babka (SUSE)" , Lorenzo Stoakes Cc: Nico Pache , akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, liam@infradead.org, mhocko@suse.com, rppt@kernel.org, vbabka@suse.cz, willy@infradead.org References: <20260522150009.121603-1-npache@redhat.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzS5EYXZpZCBIaWxk ZW5icmFuZCAoQ3VycmVudCkgPGRhdmlkQGtlcm5lbC5vcmc+wsGQBBMBCAA6AhsDBQkmWAik AgsJBBUKCQgCFgICHgUCF4AWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaYJt/AIZAQAKCRBN 3hD3AP+DWriiD/9BLGEKG+N8L2AXhikJg6YmXom9ytRwPqDgpHpVg2xdhopoWdMRXjzOrIKD g4LSnFaKneQD0hZhoArEeamG5tyo32xoRsPwkbpIzL0OKSZ8G6mVbFGpjmyDLQCAxteXCLXz ZI0VbsuJKelYnKcXWOIndOrNRvE5eoOfTt2XfBnAapxMYY2IsV+qaUXlO63GgfIOg8RBaj7x 3NxkI3rV0SHhI4GU9K6jCvGghxeS1QX6L/XI9mfAYaIwGy5B68kF26piAVYv/QZDEVIpo3t7 /fjSpxKT8plJH6rhhR0epy8dWRHk3qT5tk2P85twasdloWtkMZ7FsCJRKWscm1BLpsDn6EQ4 jeMHECiY9kGKKi8dQpv3FRyo2QApZ49NNDbwcR0ZndK0XFo15iH708H5Qja/8TuXCwnPWAcJ DQoNIDFyaxe26Rx3ZwUkRALa3iPcVjE0//TrQ4KnFf+lMBSrS33xDDBfevW9+Dk6IISmDH1R HFq2jpkN+FX/PE8eVhV68B2DsAPZ5rUwyCKUXPTJ/irrCCmAAb5Jpv11S7hUSpqtM/6oVESC 3z/7CzrVtRODzLtNgV4r5EI+wAv/3PgJLlMwgJM90Fb3CB2IgbxhjvmB1WNdvXACVydx55V7 LPPKodSTF29rlnQAf9HLgCphuuSrrPn5VQDaYZl4N/7zc2wcWM7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Stat-Signature: thjqpf7ru9j7q11wkxkp766oo9nat6ch X-Rspamd-Queue-Id: 38BF614000A X-Rspamd-Server: rspam07 X-Rspam-User: X-HE-Tag: 1780256946-146614 X-HE-Meta: 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 QHpr0nho y3QH+0++zK1NwFK/xX9Ae0ba0cwu8Nu3xgp2r9HI7KqKzygO/UK9Pxj24/8azvx/xjYwmgt0NMEBmPOlN9sD4az5xbaxyKH/2t+Z6mOB/C+odkKkCSZBzhun+kH9gn6havauiGqxDrBLBOupxwMOEv56ceGRx4Q5Fyeax7K7lZCgUZUqhbv/rSeUA9QwaPiCoSRt6LeaE3WuNUruwPS2FKP7kKKODc07DH0IdbzIdp2CmfpnU9JsFQQbUwnatz+3Utmhy Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: > >> and have people >> base work against that? > > This I'm not so sure how it would work. Assuming we have submaintainers with > their trees and branches, the final "stable branch" is merged from those. > But it's not a good base for work targeting the same merge window, as that > work would likely go to one of those submaintainer trees. But then it can't > be based on the result of merge of all submaintainer trees. That could only > work for patches targetting the next cycle (after the stable branch becomes > part of rc1). > > So either patches can be based on rc1 and applied as topic branches in a > submaintainer tree and then merged, or if they really depend on something > already in a submaintainer tree, then based on the respective topic branch > that's part of it. Right, most patches can be sent against the "stable branch", but cherry-picked on a submaintainers branch / topic tree. > >> This would be 'source of truth' and what we eventually send to Linus. > > Yes. > >> In that world, the maintainers perform conflict resolution, but with git rerere >> we need only do this once. > > I think the conflicts would arise from merging the submaintainers' branches > to the mm-next tree, and if they get updated and the merges are recreated > (like linux-next works) git rerere avoids resolving the same conflicts again. > > Hm like Andrew said, this needs a diagram indeed :) It's one of the first things we'll discuss in the upcoming meetings ... I want to talk to some other folks (in particular, TIP and KVM) to understand how they are handling that. Hopefully I'll find some time after my inbox calmed down a bit ... jeez, 1500 mails in one week if my eyes didn't betray me. -- Cheers, David