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Thu, 15 Oct 2026 04:41:10 +0000 X-Mizu-Trace-ID: 786eab450f251e7c X-Migadu-Flow: FLOW_OUT From: Lance Yang To: kas@kernel.org Cc: akpm@linux-foundation.org, david@kernel.org, ljs@kernel.org, ziy@nvidia.com, baolin.wang@linux.alibaba.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@meta.com, liam@infradead.org, nico.pache@linux.dev, ryan.roberts@arm.com, dev.jain@arm.com, baohua@kernel.org, lance.yang@linux.dev, usama.arif@linux.dev, vbabka@kernel.org, jannh@google.com Subject: Re: [PATCH v5 4/9] mm/collapse: add collapse.h for the collapse interface Date: Thu, 15 Oct 2026 12:41:03 +0800 Message-ID: <20261015044103.58141-1-lance.yang@linux.dev> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20261014171145.3292736-5-kas@kernel.org> References: <20261014171145.3292736-5-kas@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 87C5B40006 X-Rspam-User: X-Stat-Signature: jzhy4p4ojjch1xj17w3kd7fbpmwc8dq6 X-HE-Tag: 1792039271-244210 X-HE-Meta: U2FsdGVkX1+KLX2HXQdgmHcsklh+P2mF7zZvLJctvARyHKYMOgaUuIWB7PBMVs448ogAoq4oKVpLqVyrmlJ2iTKr6zDAOvuYAQpl1K75N4+CUcGsCS3kwe/QD41INSrWk9BSBWmMFvGyvjjQ1dwrHe1atBTX6ZXQka6LOkrfz5mGeh1HOS54INsB+ZT679hSnNrZOtCnQoN5IZjz7uZuzDPTHb/BXD13ERblS09lKQkc1rtBwu3Cei7EMDJ8e5slWCFaZUntOidEt2srTpMF2WR3tyUHgtJuVc1Ae08FeeKeJ+LvB5Ekl9APwzhe+Vso8rDhHDdTtPKLIwbzMAuhjxwd2nE8vwcEE8usTBcAMynK1Z8bHmxUEhZl6/Sgy2NQAljHfVubEk0+ogc/z8qdHUhLisBKebFw0zY6ohXkSLysbEPDqTudlKuE/yb76EWvy1WoNC2Fnhn7d+ElfqAJDBCCIKbZnSRaWuCM5/UDC8B8xgYcw3GbjP7vAUo2OeOac87fHhzKI6+0sRz40xGXFAsxQNRlKvgEwPlkGCdZjzlyMueTTWYCa1MOTmKShpSX/8Bbt/0MFjadpe5YZ70wyWrHU6VWxcfiImC2i4bqfat4xZcgGh/qpRXLnySFSS1bHsYwjdBLaTazKHbKiVRQxm73lvMKPetfEAAOW98kICr9uBYJ2BXz947Z3i70CEa1K129nAgQdB8FLzv34vsDW8fdTOkZJJA/iSXFWAGt9DuvqdS9Pp54lR37deLyiwk4hcjxwPOLP1Oe35MQxmR8XaFoc2sZyjlO38A/7NfRxtAVnkGkMdodbcjepo/0IaMBQJT5q8X3FkgVuXpPRNr7iH5hDc8AXiEuFYxpexAU6AU0d7u2KQXSJ4N5sLJqWvm5js/fle8JGcWDXw+8cRMDoO2nyccxrsRwP9T1ydWrxvdPovH8jD5NxyZGZJo9TzvW7XEzzjDlLdrMV9SRTCg gKgU/v2y Kbh6wI0U015sXo90v8VOcWdZiRWBioMk8K1Zp9WsJhSt7SWpYtnXUMP5Up/JxLP/gYuxqmPZIHJlUHhzQZ668TnwmDeAJcXAJEbielT2B6AOP6XvpsQMsmfz3Itc93nBW5g89puPEmjxfv9L1cHku7kPXDMRERbBfAxwv5ire+XzQOdX9MPxaqesm2ZxUfMZF1N8+i9pLPhFLQc5q5GzTmY6RWL7yxuXPj+amMfod367flYVeVE0i9t9N+b+HLCXTfukxgQVAG+/terv4g1tU8J5RXtnfS0xLZp2J6MIh7jz4g4xpAc+sQCxBaw== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, Oct 14, 2026 at 06:11:37PM +0100, Kiryl Shutsemau (Meta) wrote: >khugepaged.c holds both the users of collapse and the machinery that >performs it. The daemon's scan loop, the sysfs tunables, MADV_COLLAPSE's >entry point and the collapse itself all sit in one file and reach into >each other freely. Nothing marks where a user ends and the engine >begins. > >Start drawing that line. > >Add mm/collapse.h for what the two sides have to agree on: > > - enum scan_result - what the engine hands back; > - struct collapse_control - the state a request carries. > >And two constants move with them: > > - KHUGEPAGED_MAX_PTES_LIMIT -> COLLAPSE_MAX_PTES_LIMIT; > - KHUGEPAGED_MIN_MTHP_ORDER -> COLLAPSE_MIN_MTHP_ORDER. > >Neither is a fact about the daemon, so both lose the KHUGEPAGED_ prefix. > >No functional change. > >Assisted-by: LLM >Acked-by: David Hildenbrand (Arm) >Reviewed-by: Zi Yan >Reviewed-by: Baolin Wang >Signed-off-by: Kiryl Shutsemau (Meta) >--- Reviewed-by: Lance Yang