From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0b-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BC3F83DB62B; Wed, 29 Jul 2026 10:19:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.163.158.5 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785320383; cv=none; b=tTr/qx5flGvUhuWkYSp0rprUulXZtzpudAVZ6IEG6FfBsfbtDjm7qfz7hAO3EeXQAElEJUl53xzX63k/JtohfXF3Et4F5BUebuGaT0Jqru+pFRTf0arUY1JuZLn5Vye/GNrdyws8iDah7f/Mqb0moSylLO70U3sc8CguJEBVfOY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785320383; c=relaxed/simple; bh=sePxyCJHuzEGyx2LqXN3a8pwxTYqAvr8Ds0lIwLelXU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=HmUtzlKD+VwvxKnQ6Hsl3jzbaQm4aX+MioVZ8EeYbSCREnYa0SYI6LJTua5mBDOGqfpmErcZ6uZrTv3zUhFQLDTPV2UsQA4lk7cMekCi8iNZAXUX1l/Cos7LZoz0FIdUZF8mqXFJpMHRACyOB1NJI88Qy2LfhEhqx+KKsKAim/A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com; spf=pass smtp.mailfrom=linux.ibm.com; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b=FE0GRe0O; arc=none smtp.client-ip=148.163.158.5 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b="FE0GRe0O" Received: from pps.filterd (m0353725.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 66T7mVIS3510234; Wed, 29 Jul 2026 10:13:24 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc :content-type:date:from:in-reply-to:message-id:mime-version :references:subject:to; s=pp1; bh=20PLe0W5WCIDnL84N1zaO+HLc/2Flu i3NV1Ycbs9FQE=; b=FE0GRe0Ogg0GxdOaqXto7RlECSlIgi6U4FPECF0W06Wbwd M7AONk2CWa7g6JpJI2ObBumRdUA1swYmrWpTmd7Yhg8jwPbDZPgtdHdki7lJdXyx a5ku0VmqhUWIT7fE2R31EKwMjGZ2WPjK8OmL/dgfnk9UoMkRCYyUVAcgLhPRPvN0 kLIPDOKCSIvgAGARWTb1EH2yPFCJ8AUOWyTqPNEJnE/lDGlRVk3V4VuWQqKVkVwv H1IG3I44nBqMpAKFAi/QqfRPlQYTmOhtD2sUL446yWQE95juDDEVE2tYcHYUFzYi 2UV21GPh0m5G/vyMvB1cyXeyKTzcyGbuTrgbPIEQ== Received: from ppma13.dal12v.mail.ibm.com (dd.9e.1632.ip4.static.sl-reverse.com [50.22.158.221]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 4fmv0ns9wk-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 29 Jul 2026 10:13:24 +0000 (GMT) Received: from pps.filterd (ppma13.dal12v.mail.ibm.com [127.0.0.1]) by ppma13.dal12v.mail.ibm.com (8.18.1.7/8.18.1.7) with ESMTP id 66T9uISf001554; Wed, 29 Jul 2026 10:13:23 GMT Received: from smtprelay06.fra02v.mail.ibm.com ([9.218.2.230]) by ppma13.dal12v.mail.ibm.com (PPS) with ESMTPS id 4fn9pge0sk-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 29 Jul 2026 10:13:22 +0000 (GMT) Received: from smtpav04.fra02v.mail.ibm.com (smtpav04.fra02v.mail.ibm.com [10.20.54.103]) by smtprelay06.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 66TADL8529688252 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 29 Jul 2026 10:13:21 GMT Received: from smtpav04.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id E576B20063; Wed, 29 Jul 2026 10:13:20 +0000 (GMT) Received: from smtpav04.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 75E452005A; Wed, 29 Jul 2026 10:13:19 +0000 (GMT) Received: from li-008a6a4c-3549-11b2-a85c-c5cc2836eea2.ibm.com (unknown [9.224.92.206]) by smtpav04.fra02v.mail.ibm.com (Postfix) with ESMTPS; Wed, 29 Jul 2026 10:13:19 +0000 (GMT) Date: Wed, 29 Jul 2026 12:13:18 +0200 From: Alexander Gordeev To: "David Hildenbrand (Arm)" Cc: Muhammad Usama Anjum , Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , Tvrtko Ursulin , David Airlie , Simona Vetter , Dimitri Sivanich , Arnd Bergmann , Greg Kroah-Hartman , "James E.J. Bottomley" , Helge Deller , Juergen Gross , Stefano Stabellini , Muchun Song , Oscar Salvador , Andrew Morton , "Liam R. Howlett" , Lorenzo Stoakes , Will Deacon , "Aneesh Kumar K.V" , Nick Piggin , Peter Zijlstra , Andrey Ryabinin , Pasha Tatashin , Chris Li , Kairui Song , Uladzislau Rezki , Steven Rostedt , Masami Hiramatsu , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Eduard Zingerman , Kumar Kartikeya Dwivedi , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , SJ Park , "Matthew Wilcox (Oracle)" , Jan Kara , Jason Gunthorpe , Leon Romanovsky , Miaohe Lin , Dennis Zhou , Tejun Heo , Christoph Lameter , Mike Rapoport , Johannes Weiner , ziy@nvidia.com, pfalcato@suse.de, ryan.roberts@arm.com, linux-kernel@vger.kernel.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-parisc@vger.kernel.org, xen-devel@lists.xenproject.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, kasan-dev@googlegroups.com, linux-trace-kernel@vger.kernel.org, bpf@vger.kernel.org, linux-perf-users@vger.kernel.org, damon@lists.linux.dev Subject: Re: [PATCH RFC 00/11] mm: distinguish PTE table storage from PTE values Message-ID: <7813b5fe-e767-442c-a356-afc1a5c567ad-agordeev@linux.ibm.com> References: <20260727164715.2866609-1-usama.anjum@arm.com> <2c19247e-bee6-45f4-a353-2fcc60db26e6@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2c19247e-bee6-45f4-a353-2fcc60db26e6@kernel.org> X-TM-AS-GCONF: 00 X-Proofpoint-Spam-Info: AW1haW4tMjYwNzI5MDA4MCBTYWx0ZWRfX5gvztvTGa1TS cVvs9sLHjmDvl0pv/qnDx3AnLV3WD1PhcS6rWZcrYanN4eoy1jfYhO0/byBUN7m85v7yOdOHFEd jkwp4KNx5XSDCb91frhZzFZIHZypXvU= X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwNzI5MDA4MCBTYWx0ZWRfX1UTcCITLhsoM WVmB1D9GH0QMtrIKGHgL7p0GW+jxunYYOgpbX+DXyGN5j53LZmEz/XAfzXnJVoe6iYvkeEMQ0zl U72YvirOw6n7XecUaLxufeDZ3k7zUoWhwsOzzDr2PnO5B+rHRlQanyNs10kmLyGk0SbO5yjhmsl X/wsvmN7W20tzA/W6s+/Go/LRPoLITRcA0wiEE2RX3SL5wjJQy6dbIfOKXB23C7J+7CUDxsv1hH 2UL0d8RcWDG1m2MOfvzdP1DDLgoJ5qa4fNMDY3Dujfh/q4BEQ3LxkwjYYEZLquYPNzSt8jlE0CR W0NplSr/y92efigHBaNWZE689G10/Vfvu4jsCRV1WwdOJDDLrJCdFPCcT3EXgYundIBLpChodfB V3DgSeKuQKYmWhytTg7Qp/bafc3JxPNb2dXgROBBI3XlcwL1Fe7vq5FAcDbVZ+iHosYceQA6qsM opbeSLXsz6GP+frEBNA== X-Authority-Analysis: v=2.4 cv=b5WCJNGx c=1 sm=1 tr=0 ts=6a69d244 cx=c_pps a=AfN7/Ok6k8XGzOShvHwTGQ==:117 a=AfN7/Ok6k8XGzOShvHwTGQ==:17 a=kj9zAlcOel0A:10 a=RAioF0-LDSMA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=V8glGbnc2Ofi9Qvn3v5h:22 a=17MMwBHFoGJDYN7e9MwA:9 a=CjuIK1q_8ugA:10 X-Proofpoint-GUID: 83X-ft2oRkMXo03OQPgEqsBuw75g_R7Y X-Proofpoint-ORIG-GUID: 83X-ft2oRkMXo03OQPgEqsBuw75g_R7Y X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.134,FMLib:17.12.100.49 definitions=2026-07-29_03,2026-07-28_02,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 spamscore=0 adultscore=0 malwarescore=0 impostorscore=0 bulkscore=0 phishscore=0 suspectscore=0 clxscore=1011 lowpriorityscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2606150000 definitions=main-2607290080 On Tue, Jul 28, 2026 at 09:26:06PM +0200, David Hildenbrand (Arm) wrote: > > The generic definition aliases hw_pte_t to pte_t, so this series preserves > > the representation and behaviour of every architecture. ptep_get() keeps > > its existing READ_ONCE() semantics and converts the stored element through > > __pte_from_hw(). An architecture can later define a distinct hw_pte_t and > > convert its PTE interfaces to make the distinction compiler-enforced. > > Architecture PTE implementations and most architecture code are > > deliberately left for those later opt-in conversions. ... > Do you have a pointer at the arm64 part, so people can get a feeling for how an > actual hw_pte_t implementation can look like. May be we need the generic hw_pte_t implementation as { pte_t pte; } right away? Also, can you envision a case when sizeof(pte_t) != sizeof(hw_pte_t)? If not, the compile-time check is worth adding. > -- > Cheers, > > David Thanks!