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b=kZYLGiz8XKSmI+FIu8i76ktaY6BJPhmezuife5zN6x8SqWXB6n28hCH+ws9jcVaN5 P+Dc8Nyvnk0T10K+QDLHfktnn/e9iBR1HC7H2opBXLSnsAAjI63S0Eo9IzOyA7CnbG q3HrxQ/XayzJaziKlOhBUH0fkAhzCE8DTBPlZZE7r12VG9JVncydOWXpOsVh2dN/ZI aXgMDUJOTxKKjKxiYHgw43YQRghaqn7Bmy/R+oluTiROhRJRtlTwpTw4AoqLy+KteW 50yA0nZIE+DxzYQRGy3xkjNlwJW+DMsIYt2/eK2z4kGSzyA01q1+m+UxJlkn0GOpgk e/NGGwJtFX6qw== Message-ID: <65433d1e-95ca-4434-828e-8f381d3384b1@kernel.org> Date: Mon, 24 Aug 2026 13:47:54 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH 03/57] mm/collapse: add collapse.h for the shared collapse state To: Kiryl Shutsemau Cc: akpm@linux-foundation.org, ljs@kernel.org, nico.pache@linux.dev, baolin.wang@linux.alibaba.com, baohua@kernel.org, dev.jain@arm.com, hughd@google.com, lance.yang@linux.dev, liam@infradead.org, mhocko@suse.com, rppt@kernel.org, ryan.roberts@arm.com, shuah@kernel.org, surenb@google.com, usama.arif@linux.dev, vbabka@kernel.org, ziy@nvidia.com, usama.anjum@arm.com, agordeev@linux.ibm.com, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, jannh@google.com, willy@infradead.org, pfalcato@suse.de, rostedt@goodmis.org, mhiramat@kernel.org, linux-trace-kernel@vger.kernel.org, bpf@vger.kernel.org References: <20260816224609.308019-1-kirill@shutemov.name> <20260816224609.308019-4-kirill@shutemov.name> <3113ac8b-c1ce-4577-9e93-449b70818918@kernel.org> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: A4C2B4000A X-Stat-Signature: 1hctdb8g1itgjeudxziy5uymbjzoppq6 X-Rspam-User: X-HE-Tag: 1787572085-472791 X-HE-Meta: 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 6Ju/dU3q bal94Eg/yqcQDL9Sf3y06xjHVk5F+4jHUU6g7p+Zv9rBf6tHK8f1F8+ZNHjzrWGAOjRyh0q3A/nW4FxhY/xnVNCTT5CeeDat3wjoFvDaxUxRYA21KOHdQQ0/skLc2Izc8+gdSOzDGXaShwHoja6eYHsnM4CElS8vnqzX+CD7hrn5/7DioJC8OcQkG/t3tLQqZYMALLjzWVQPApeDeSIUkaQS8Zzj7FxTAovs909nEtMJPRJWFIkeHvtZgiWNgtn1fPp4rULcn9j1hfNZW1Dj5sO1aWSHyXdXQxLOk Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 8/20/26 13:11, Kiryl Shutsemau wrote: > On Wed, Aug 19, 2026 at 04:19:41PM +0200, David Hildenbrand (Arm) wrote: >> On 8/17/26 00:45, Kiryl Shutsemau wrote: >>> From: "Kiryl Shutsemau (Meta)" >>> >>> Preparation for building the new collapse engine in its own file. The >>> engine and khugepaged.c need to agree on what a collapse result is and >>> what state a scan carries. >>> >>> Move enum scan_result and struct collapse_control into a new >>> mm/collapse.h. >>> >>> No functional change intended. >>> >>> Assisted-by: Claude-Code:claude-opus-5 >>> Signed-off-by: Kiryl Shutsemau (Meta) >>> --- >> >> BTW, I'm wondering whether it would result in less churn (independent of the >> other changes) to >> >> a) Rename mm/khugeapged.c to mm/collapse.c >> >> b) Move stuff into mm/collapse.h that a new ... >> >> c) mm/khugapegd.c will need. > > I went for a clean collapse.c on purpose: the engine is new code, and a > new file keeps it readable while both mechanisms are in the tree, with 28 > as a plain delete from khugepaged.c. > > Your shape is less churn, though, and it keeps blame: 29-35 move about > 1700 lines as add-and-delete today, and most of that would stay put, with > only the daemon -- mm_slot, the scan loop, sysfs -- extracted into a new > khugepaged.c. > > If you prefer it that way, I can give it a try for v2. > > The rename has to open the series, so it will collide with anything in > flight that touches khugepaged.c. > Kiryl, I have to ask, are you using AI to write your replies? -- Cheers, David