From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 21186C43458 for ; Wed, 1 Jul 2026 20:03:37 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A93B96B00A8; Wed, 1 Jul 2026 16:03:34 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A6B2F6B00A9; Wed, 1 Jul 2026 16:03:34 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 95CD86B00AB; Wed, 1 Jul 2026 16:03:34 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id DF9E06B00A8 for ; Wed, 1 Jul 2026 16:03:33 -0400 (EDT) Received: from smtpin07.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 4F6B3C257F for ; Wed, 1 Jul 2026 20:03:33 +0000 (UTC) X-FDA: 84941282706.07.5E9974F Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf29.hostedemail.com (Postfix) with ESMTP id 8B06912000E for ; Wed, 1 Jul 2026 20:03:31 +0000 (UTC) Authentication-Results: imf29.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=imHR64ns; spf=pass (imf29.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1782936211; b=VUs+8A5VpeObYNmsNj95X6aD/8jl7aSQae/DWmq/mApQzMpuKt8dyYV1W/ceBhsGEv7WVx CTfVYTQZo9yPgVwBn0zgWk8CqPCY3n1VkmpKUtC/ww0QNHJQi+BdLJ5Z+N+HKew8Cw8Zez 4wtdnWOf4EX+Y2frLVBqFJtom9SjJ2s= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1782936211; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=6zp09cAbru0LBE7s3fcZYa3/iefpTqvsPd295TfbYY4=; b=A4eFuOjChWyLeZsOpB3mFzzxZ9DrVHW8LRXVULubAJOvhr2K+HHY6Bbb6yyFK4nNB+km4o /1Swx56rJAb2m5xvd/GvkJcMsiaSvkuvyj1tLGNmvXCw1Kk/WK4+LOI2h1r3jJMy4262f9 2GoUBGq/FYrRu1xnNaMtdkTNcBMPIpU= ARC-Authentication-Results: i=1; imf29.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=imHR64ns; spf=pass (imf29.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id E6F786001D; Wed, 1 Jul 2026 20:03:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 317411F000E9; Wed, 1 Jul 2026 20:03:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782936210; bh=6zp09cAbru0LBE7s3fcZYa3/iefpTqvsPd295TfbYY4=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=imHR64nsQ4Ic2E8LNQelQ0fnWppOOkbDz2FDT1MGXSEFI62xLOIFofiq4Zi+6t3Jh Ak7f2+aOZEavQ9BGLAlkbg4L+LEdVbi44UvEN2sgsxd7UvgzYdUvGQTFPFLOnGfG9n SPgazdzQLgJjqgk0ZOcZMuYKKCGBQNw6mcTehwnxQfHT/1ZTdeMZEbx49JvAWtSMab EW/IO5o6eEWhy7yfbhQui8vBWpKCe4Ed19q1QFWEOZxG25daIQDbTQEQCJXsbEUSdo GaxQ9aJnijUNz0PHGIqqb6CP6+jomvwsj91xIJoGWt1WyvN2V9stEJqKra2S13zEon +h2ZeGZ3DGxWQ== Message-ID: Date: Wed, 1 Jul 2026 22:03:21 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 6/6] mm: rename ARCH_ENABLE_THP_MIGRATION to ARCH_SUPPORTS_PMD_SOFTLEAF To: Usama Arif , Andrew Morton , chrisl@kernel.org, kasong@tencent.com, ljs@kernel.org, ziy@nvidia.com, linux-mm@kvack.org Cc: ying.huang@linux.alibaba.com, Baoquan He , willy@infradead.org, youngjun.park@lge.com, hannes@cmpxchg.org, riel@surriel.com, shakeel.butt@linux.dev, alex@ghiti.fr, kas@kernel.org, baohua@kernel.org, dev.jain@arm.com, baolin.wang@linux.alibaba.com, npache@redhat.com, "Liam R. Howlett" , ryan.roberts@arm.com, Vlastimil Babka , lance.yang@linux.dev, linux-kernel@vger.kernel.org, nphamcs@gmail.com, shikemeng@huaweicloud.com, kernel-team@meta.com References: <20260630164143.1595669-1-usama.arif@linux.dev> <20260630164143.1595669-7-usama.arif@linux.dev> 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: <20260630164143.1595669-7-usama.arif@linux.dev> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Stat-Signature: zo7risz6byqrrny13ntuy96njacp1nq5 X-Rspam-User: X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 8B06912000E X-HE-Tag: 1782936211-827852 X-HE-Meta: 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 wd3gDIUU rQXm3AJhKqSoWBFi/62knwXwAjrVlMhKjeYSyZWgF9bwbS5FYtXLO4VH70DHYzzErOIMvPKFi08pYR6Rrg43usWGPcvloDwIGrQ4XavKI+8BUtmSNwO/IEDVlXEXvYp1twapNyDAn1PjGeKvA3ncNDc7o1EF8Z9qCK9NH8MdkzJVmHg3mFXrilqqYT04jfukidRA+R7j7Je3g9naCglLo6jnp+h1L/sVjTkqej/rpLiMfnIhgozkbB9t3PfbGknfwDQqoUIyIpumxUP7arURZcyGXG3sYr5UaedkKExkSuF9GeLbWnyGs2ipY/w== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 6/30/26 18:34, Usama Arif wrote: > CONFIG_ARCH_ENABLE_THP_MIGRATION started life gating just PMD-level > migration entries, but has grown to gate the entire PMD-level softleaf > machinery: migration entries, device-private entries, and soon swap > entries. device-private really relies on migration support. See do_huge_pmd_device_private() where we migrate back to CPU memory. The whole concept is pased on migration. So that's why it currently makes sense. So "has grown to" is not quite accurate. It's a different story with swap entries (that can exist even without migration support). > Rename CONFIG_ARCH_ENABLE_THP_MIGRATION to CONFIG_ARCH_SUPPORTS_PMD > _SOFTLEAF to make this clear. This is a pure rename: the set of > selecting architectures (x86, arm64, s390, riscv, loongarch, and > powerpc on PPC_BOOK3S_64) and the gating semantics are unchanged. Hm, that makes me wonder what it would take to make this all just be implicitly supported by CONFIG_TRANSPARENT_HUGEPAGE. Looks like someone would have the courage to touch stuff like arc, mips and sparc64 (+arm and x86, but that's less of a concern :) ). So yeah, renaming the config option makes sense. The config space is the wild west. We have PGTABLE_HAS_HUGE_LEAVES and stuff like HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD HAVE_ARCH_SOFT_DIRTY ARCH_HAS_GIGANTIC_PAGE ARCH_HAS_PTE_SPECIAL We do have a limited number of "SUPPORTS" (which is longer than HAS), but I would either use ARCH_HAS_PMD_SOFTLEAVES or HAVE_ARCH_PMD_SOFTLEAVES Apart from that LGTM. -- Cheers, David