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]) by smtp.lore.kernel.org (Postfix) with ESMTP id 23332D637A3 for ; Wed, 13 Nov 2024 17:56:44 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 80EDE6B00AB; Wed, 13 Nov 2024 12:56:43 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 7985C6B00AC; Wed, 13 Nov 2024 12:56:43 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5EA5F6B00AD; Wed, 13 Nov 2024 12:56:43 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 3E3D36B00AB for ; Wed, 13 Nov 2024 12:56:43 -0500 (EST) Received: from smtpin21.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id E0597ABCDA for ; Wed, 13 Nov 2024 17:56:42 +0000 (UTC) X-FDA: 82781825658.21.2C1A32B Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf02.hostedemail.com (Postfix) with ESMTP id 153F680006 for ; Wed, 13 Nov 2024 17:55:18 +0000 (UTC) Authentication-Results: imf02.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=QRLtBdCL; dmarc=pass (policy=none) header.from=redhat.com; spf=pass (imf02.hostedemail.com: domain of peterx@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=peterx@redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1731520471; a=rsa-sha256; cv=none; b=3e7HucsGhUbR1+3Y2/aydjKffrIMXEPO1ngNqyrGVAbTf7yITxcF6X9tITBy4KThhyuzwB FfKEBLoG6HkEF/gaAyg0QIBFVWjOXK3/NCMcuOobJMOTyTLAR2em9NYQUrdOaRrAx4U4k+ SL9tlqvDkydZBLCAnqPO7CBIuZEwEaY= ARC-Authentication-Results: i=1; imf02.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=QRLtBdCL; dmarc=pass (policy=none) header.from=redhat.com; spf=pass (imf02.hostedemail.com: domain of peterx@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=peterx@redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1731520471; 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=ED4P6NsWli087xm4vi4x4cRp52cJJf0X5FBYEB8bznw=; b=DYs138+baNahfcD1Rqvd0veWPxQrSS8/oltvpRQfvpgnmf73D/exGavz2oRW8BaJ5JACsG fop/zHMqxzyOTtBLBQVDZZ3RK99FpkSsWajNc5HuXY9H9ZXUu3qcg5rRyCE1qKIr5doDLL FDFYnbZjTdFBz3PXr88UawLjWzT7D2U= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1731520598; h=from:from: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; bh=ED4P6NsWli087xm4vi4x4cRp52cJJf0X5FBYEB8bznw=; b=QRLtBdCLk3VtxjSISMiFffRUAYt3eYyPBz1WoHgH02Vh9dYeusXzPT6fa/LlX+zBelrmb6 LXsSMgDqsfyvlFJLBK5VOs2tuM0wGaPE/sAn1CTZdBmQ84eEJnx+bvP4OFcX1cFvUf3HFm a656vwtEBqxekoAXGFFjlDpIHQFUWoY= Received: from mail-oi1-f198.google.com (mail-oi1-f198.google.com [209.85.167.198]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-284-WlU7u62lOXSxNheiwFOdOg-1; Wed, 13 Nov 2024 12:56:37 -0500 X-MC-Unique: WlU7u62lOXSxNheiwFOdOg-1 X-Mimecast-MFC-AGG-ID: WlU7u62lOXSxNheiwFOdOg Received: by mail-oi1-f198.google.com with SMTP id 5614622812f47-3e7a1f72eadso3430585b6e.3 for ; Wed, 13 Nov 2024 09:56:36 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1731520596; x=1732125396; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=ED4P6NsWli087xm4vi4x4cRp52cJJf0X5FBYEB8bznw=; b=VUzcWGmiuSms47TxYMq6kVkKykwZ/YoL5tkfDofNsaJM9WTY/2TUrPY4beLpBqNaqd iKU8CNCFA+T6gsIauwyHXZMPFXpzfjDBJQ4Wxk4At1GsbWNjSFXppX7nYsbcUlL3z+sO Zq66+to4jtq2rr6vfYK1xf6Skj/uhcPkhnVoRqVu0NNbmthgrq1lpQWk+IqiIyt8RR8A fKBTQkzi/n18iyY7KY7ap8bHnxNHeNF5gSfU/EBnuZzFDkT6SHm21ZsmoIeHcWs7e8Wh 2tNVYDlXAVrqtmSsmEwhThKo2ywH6VEnAfZevT+dIZY3oWW0xW3YVB1sxj9cpHaUE6Pp +rVA== X-Forwarded-Encrypted: i=1; AJvYcCW17o8nCWQbTRj3Ha+RTaEr/kPWIlJEIcawBJcjSZakoU4e8NkwIMXhZCaAU+smaURA9yXT6kkYvQ==@kvack.org X-Gm-Message-State: AOJu0YxFsDyxhVNX6PdtqF04syKRdpdjvjIQT5c1c6D8kFHBjxkSuTBq 6tVyoehU+ED0+DmS84M8kJlrZ5nmU5UGRqSoAjSluLGEbs/InvSTTHICDWsmiTh+fhaS3T3uZbC qy/tqNDBxmzw2R3LbSmLLmPKD4lXbohsDU8gkh8tGopoihsLI X-Received: by 2002:a05:6808:210b:b0:3e5:fc09:7f51 with SMTP id 5614622812f47-3e7b0a6ecb1mr3667584b6e.9.1731520596156; Wed, 13 Nov 2024 09:56:36 -0800 (PST) X-Google-Smtp-Source: AGHT+IH4VBL0HBnl2w17tqrXf/BlWXKTcO2I1zi+/iAk9osNVNVd0ENy5K0Fn0z3PGUlANNI5aIeog== X-Received: by 2002:a05:6808:210b:b0:3e5:fc09:7f51 with SMTP id 5614622812f47-3e7b0a6ecb1mr3667559b6e.9.1731520595819; Wed, 13 Nov 2024 09:56:35 -0800 (PST) Received: from x1n (pool-99-254-114-190.cpe.net.cable.rogers.com. [99.254.114.190]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-6d3cf934d85sm24269446d6.33.2024.11.13.09.56.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 13 Nov 2024 09:56:34 -0800 (PST) Date: Wed, 13 Nov 2024 12:56:31 -0500 From: Peter Xu To: David Hildenbrand Cc: Jann Horn , linux-kernel@vger.kernel.org, linux-mm@kvack.org, "Kirill A . Shutemov" , Nicholas Piggin , Matthew Wilcox , Andrew Morton , James Houghton , Huang Ying , "Aneesh Kumar K . V" , Vlastimil Babka , Rick P Edgecombe , Hugh Dickins , Borislav Petkov , Christophe Leroy , Michael Ellerman , Rik van Riel , Dan Williams , Mel Gorman , x86@kernel.org, Ingo Molnar , linuxppc-dev@lists.ozlabs.org, Dave Hansen , Dave Jiang , Oscar Salvador , Thomas Gleixner Subject: Re: [PATCH v5 0/7] mm/mprotect: Fix dax puds Message-ID: References: <20240812181225.1360970-1-peterx@redhat.com> <07ba2a86-f22b-43aa-a542-f1a182656b63@redhat.com> MIME-Version: 1.0 In-Reply-To: <07ba2a86-f22b-43aa-a542-f1a182656b63@redhat.com> X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: r5p30iqd1zQ52DYVsdm--MxIoIzVbdX4DUVI0WyRpQ8_1731520596 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 153F680006 X-Stat-Signature: iaeiawsxkcjhunisek9jkc8umh11m8eh X-Rspam-User: X-Rspamd-Server: rspam05 X-HE-Tag: 1731520518-456205 X-HE-Meta: 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 3x+Fj895 pdsOjw2FuASqdWoGhQhI+vw4O/VhrxxwW/1UER+HlRvtrXLJ55Ys152JdkZsBigZqInt4KE9wjdAXr0/481ZoogWmVeJdT5Fnn07T1E1ZuRGSqeoOhdAPLwFqHdePuJkvKxJGNKgU0QKPcFXHTHYvGODTPR8S7k8tRUCN86WWxYiZKtrF+o+12GG12Za26E+jG133jcKv+/tHa6IOiXVKlKIOXoqfnATAN7tx2AkbMqn9zmX0i6+o1H/TD9iL5LsYRmd8zz74hJOWROimuWddQ2f++M316VVCf+vfZS6NzeSfg9nFsKM59SBvZNb8JipuoeRgYHZbIzRjj+IEC+pEdV2ii+tZsMgofqoPiXN2qcFfNaNIWvnSuDiBEuNflmhcFFyYbvOwIQ4tadDlcT88Dgn31uHveBHz5FYhtDTPntGW21I= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, Nov 13, 2024 at 05:42:15PM +0100, David Hildenbrand wrote: > On 13.11.24 17:39, Peter Xu wrote: > > On Mon, Nov 11, 2024 at 10:20:59PM +0100, Jann Horn wrote: > > > On Mon, Aug 12, 2024 at 8:12 PM Peter Xu wrote: > > > > Dax supports pud pages for a while, but mprotect on puds was missing since > > > > the start. This series tries to fix that by providing pud handling in > > > > mprotect(). The goal is to add more types of pud mappings like hugetlb or > > > > pfnmaps. This series paves way for it by fixing known pud entries. > > > > > > Do people actually use hardware where they can use PUD THP mappings > > > for DAX? I thought that was just some esoteric feature that isn't > > > actually usable on almost any system. > > > Was I wrong about that? > > > > I did run it with a qemu emulated nvdimm device. Though in reality I've no > > idea on how many people are using it.. > > I wonder if we still have to support it ... or could disable it+rip it out. Note that in my previous email, I also mentioned mremap() for PMD on dax too. If that's a real problem, it won't be fixed even if dropping dax PUD support. And we definitely want to understand whether there're still users on pud dax to consider dropping anything.. it could still be that both mprotect() and mremap() are not yet used in the current use cases. Thanks, -- Peter Xu