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 61308C982FA for ; Tue, 22 Sep 2026 15:04:08 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 6AAA66B009D; Tue, 22 Sep 2026 11:04:07 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 65BDE6B009E; Tue, 22 Sep 2026 11:04:07 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 549DD6B00A1; Tue, 22 Sep 2026 11:04:07 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 324F06B009D for ; Tue, 22 Sep 2026 11:04:07 -0400 (EDT) Received: from smtpin15.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay06.hostedemail.com (Postfix) with ESMTP id BFF59A670F for ; Tue, 22 Sep 2026 15:04:06 +0000 (UTC) X-FDA: 85241718492.15.AA279FB Received: from mta1.migadu.com (out-39.mta1.migadu.com [95.215.58.39]) by imf21.hostedemail.com (Postfix) with ESMTP id 7859C1C0003 for ; Tue, 22 Sep 2026 15:04:04 +0000 (UTC) Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=Teu4L1D6; spf=pass (imf21.hostedemail.com: domain of usama.arif@linux.dev designates 95.215.58.39 as permitted sender) smtp.mailfrom=usama.arif@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1790089444; 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=un5kxF2Be0qSZZ2fJVvIy7S7fFkrTBjmPHWE9HhI63U=; b=kaZ/BRczLIWy9FNgxELpVn8ymhd9Yl9hWpZ1QhaP5Eiv49KIOwbwX/HgWTGawmJkMdQ5Vu 9eqhM+DoyYNrevzJqbk5HhsW0y6s4RnKqmkpEV1muV96VyYPs1z/8F4c/R1tQ3V+fizOrV g4TyLX0hwiPbCnscSlXnimUrMpv2iIg= ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1790089444; b=Ox1hs96RRJ37WzbvcxGsCLVgwJs5KwGcvZ/Emga72gev6czDvFYgVOOxNDkFb2684wzDt2 Fdd4niJ8Yw61j9fiKpWfEhO/B+ejOQsaKWW+rMcTo86raYAuYrv3gkMihWIXlM8dLRTVY5 nrzx1Fo3D6JMsKhuzLDNP4M0qKy55z0= ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=Teu4L1D6; spf=pass (imf21.hostedemail.com: domain of usama.arif@linux.dev designates 95.215.58.39 as permitted sender) smtp.mailfrom=usama.arif@linux.dev; dmarc=pass (policy=none) header.from=linux.dev X-Envelope-To: linux-mm@kvack.org DKIM-Signature: a=rsa-sha256; bh=y+LCUdEE09122n2Tb/Z0cY6K/0y14n1YrOrFxuwwzs4=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1790089443; v=1; x=1790694243; b=Teu4L1D6KPXdg4JlVg4TkEg0rMIvLZ70JP/YisX9QG+hn42tg+BkITgA3qqgnagTlPDoOyDg qf4ssTHcPGcEsbHWjrx74snP44XIbcjlm57sQhytZiAh3vkjZudYZ+os2D2zP7JrXo/rPKKvSiz WvKPGIvAOrdHPprQe6AJqvl8= X-Envelope-To: linux-mm@kvack.org Received: by smtp.migadu.com with ESMTPS id 56074787bb66b1d3; Tue, 22 Sep 2026 15:04:02 +0000 X-Mizu-Trace-ID: 56074787bb66b1d3 X-Migadu-Flow: FLOW_OUT Message-ID: <1fe0f6d0-1d99-45f6-bc3b-7e78dc6047f8@linux.dev> Date: Tue, 22 Sep 2026 16:03:55 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RESEND v7 02/29] arm64: mm: add PMD swap-exclusive helpers To: "David Hildenbrand (Arm)" , 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, Nico Pache , "Liam R. Howlett" , ryan.roberts@arm.com, Vlastimil Babka , lance.yang@linux.dev, linux-kernel@vger.kernel.org, nphamcs@gmail.com, shikemeng@huaweicloud.com, yosry@kernel.org, qi.zheng@linux.dev, luizcap@redhat.com, kernel-team@meta.com, Catalin Marinas , Will Deacon References: <20260914122950.3283997-1-usama.arif@linux.dev> <20260914122950.3283997-3-usama.arif@linux.dev> <35e42ccc-df8f-4703-b10d-f7c96b263e98@kernel.org> <93e71e27-86d7-4853-bbd2-756ac137a925@linux.dev> <64b10ef4-428c-47dc-a97c-59ba178a9044@kernel.org> Content-Language: en-US From: Usama Arif In-Reply-To: <64b10ef4-428c-47dc-a97c-59ba178a9044@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspam-User: X-Stat-Signature: ojx3jxi4hh9zftn3pn7h6e95ezdwrgdn X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 7859C1C0003 X-HE-Tag: 1790089444-302430 X-HE-Meta: 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 3jvPk1w0 60PHL6ttSoQrEnZu5q2Lcm/ImGPUJd4L2VKayI4czxt6214IirWsm3rJtZmsehAJuug92h3AqBBh1Vop4ic3fnbCtgTW4JWpSw5haoJyS0TqkITsG9GKeuxk2j2H2yyudyjIBdMNGCrN39ZpEzJTnpcge9SBc9kX92GaovHFyqaEVwWy+Vw9RyNPK6z6vZTM5t+cwDJqQIOh1YeFA3You+6GNZ7NKANkjOePiNQLCokoU/B9GNV3hq5a6mx8oyesHqPE17fwbd0pnYMP+fm4raJN0cT+TNvBsfrrGAbb6aa4AqgLFY8TB97UWhsQ/T1gzoPjdDje7lw8A9PAK0Gy6D4Xk9tuu64e9xR0KLT2OJNjGc8Y= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 22/09/2026 15:45, David Hildenbrand (Arm) wrote: > On 9/22/26 14:34, Usama Arif wrote: >> >> >> On 18/09/2026 22:11, David Hildenbrand (Arm) wrote: >>> On 9/14/26 14:27, Usama Arif wrote: >>>> A later patch keeps a PMD-mapped anonymous THP mapped by a PMD across the >>>> swap round-trip, so PG_anon_exclusive now has to survive in a swap PMD and >>>> not just in a swap PTE. >>>> >>>> arm64 encodes a swap PMD exactly like a swap PTE, so the new helpers wrap >>>> the PTE ones and reuse PTE_SWP_EXCLUSIVE. >>>> >>>> Cc: Catalin Marinas >>>> Cc: Will Deacon >>>> Signed-off-by: Usama Arif >>>> --- >>>> arch/arm64/include/asm/pgtable.h | 6 ++++++ >>>> 1 file changed, 6 insertions(+) >>>> >>>> diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h >>>> index e89ec5f4787b4..d3f53a601aed3 100644 >>>> --- a/arch/arm64/include/asm/pgtable.h >>>> +++ b/arch/arm64/include/asm/pgtable.h >>>> @@ -599,6 +599,12 @@ static inline int pmd_protnone(pmd_t pmd) >>>> #define pmd_swp_clear_uffd(pmd) \ >>>> pte_pmd(pte_swp_clear_uffd(pmd_pte(pmd))) >>>> #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_WP */ >>>> +#ifdef CONFIG_ARCH_HAS_PMD_SOFTLEAVES >>>> +#define pmd_swp_exclusive(pmd) pte_swp_exclusive(pmd_pte(pmd)) >>>> +#define pmd_swp_mkexclusive(pmd) pte_pmd(pte_swp_mkexclusive(pmd_pte(pmd))) >>>> +#define pmd_swp_clear_exclusive(pmd) \ >>>> + pte_pmd(pte_swp_clear_exclusive(pmd_pte(pmd))) >>>> +#endif >>> >>> Why do we #ifdef that here, but not the uffd-wp swp PMD helper? >>> >> >> uffd-wp is gated on CONFIG_HAVE_ARCH_USERFAULTFD_WP. >> >> If I removed the CONFIG_ARCH_HAS_PMD_SOFTLEAVES guards above, when THP=n, arm64 >> will use the generic macro which is wrong. >> >> I tried building uffd-wp swp with just ARCH_HAS_PMD_SOFTLEAVES guard and I got >> the build error >> >> mm/page_table_check.c:232:20: error: implicit declaration of >> function 'pmd_swp_uffd' >> >> we will probably need a separate patch like: >> >> #ifdef CONFIG_ARCH_HAS_PMD_SOFTLEAVES >> static inline bool pmd_softleaf_uffd(pmd_t pmd) >> { >> return pmd_swp_uffd(pmd); >> } >> #else >> static inline bool pmd_softleaf_uffd(pmd_t pmd) >> { >> return false; >> } >> #endif >> >> >> to avoid the above build error. > > Just to explain where I am coming from: for all these patches I took a look how > the other pmd_swp_* functions where handled (and separated from the pte_swp_* > variants). Nothing earth shattering, was mostly looking for keeping things > consistent within these architecture codes. > Makes sense, this is how I wrote the functions as well, just looking at the existing functions.