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Mon, 24 Aug 2026 08:10:24 -0400 (EDT) Date: Mon, 24 Aug 2026 13:10:23 +0100 From: Kiryl Shutsemau To: "David Hildenbrand (Arm)" 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 Subject: Re: [RFC PATCH 03/57] mm/collapse: add collapse.h for the shared collapse state Message-ID: References: <20260816224609.308019-1-kirill@shutemov.name> <20260816224609.308019-4-kirill@shutemov.name> <3113ac8b-c1ce-4577-9e93-449b70818918@kernel.org> <65433d1e-95ca-4434-828e-8f381d3384b1@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <65433d1e-95ca-4434-828e-8f381d3384b1@kernel.org> X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 55BAD80008 X-Stat-Signature: 3gxh8984tc1fk5anw9c1d5ofunukq7eh X-Rspam-User: X-HE-Tag: 1787573428-248182 X-HE-Meta: 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 lI7+GZxU 4OKJeUeiJXeqMp2rH9vj/CMceAFGhWeMw7kcEz2NanTHXRXHnzgYUDE/0oOFThe00qSc5tpjY7iOvidhmcXlz3hYhNcdhHQn6HFBPue1g4FA5SZpas9iPOuWHGvy3o6NUxPGcPxmG0FgCM21oLhlBry2kxhF5n/WiJSxNGD7k55oTXbifXGmvBnTMLAzqByoDwXydYVW4qHJpflfVbfsxVHUeYZYd8dztc38tzQobWYYuD6lcGzi97I1HKm/X62raiD0Ndv+Tu3P7jcK4JOJuPCjz0F2rCv5fILxCd4n2wJde/ErDSpgSaEH+sG0ikotuSBqNnaI6VO0g8wniZ9fVpT0MLx+1GlT7og/EssdH/+Z5v3XjrXCp4tGpDQmXO80h+u42lnKFm3FhDrzncp6aIB2yInvZl1RwakTPh+sgoyNJOUJiP19M2cEXnGJqjyPahb4a6aWFae2F5lT1itdp/9Ou+g== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Mon, Aug 24, 2026 at 01:47:54PM +0200, David Hildenbrand (Arm) wrote: > 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? Yes. I use it check my claims and fix my grammar. Why? -- Kiryl Shutsemau / Kirill A. Shutemov