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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 28088CD98CC for ; Thu, 11 Jun 2026 12:51:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=9S9SdGtbm1JyTfljX6WLjQs95rf1oKktzDq3rIIBuu0=; b=zUITvHv6hRb+yLMMDbRbeDon4Q MbFR85oiz3aZTppaB2ypTMdeUQZJOOvNqE6C7M1jL178sIFI9EL66j1jmr2+R8vcgvrCBdCDgSKTF J+LhrD8m0mmotzmGwWiYlrntXHmyJR+b3ZhX14Huf8RvS+O775U4j+iYnWxTV7JJWvWKURmUe2tzo A1K739W9eGcnJPgEE76m3HUv+E9YqD+ZcfNyEd5Kuk3X66rR7MJ+UphpmmFVFHUHAFFAiORMDIeDa Rl0G7QqkjlTbA5RQymOlYedFb4rIykvcKMMz5gtqUsgpHl7E7qspxWSRhM0IXj1PllR9cPOWpMqBP TwxH4T4Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wXest-00000009RWS-1Vxq; Thu, 11 Jun 2026 12:51:47 +0000 Received: from out-172.mta1.migadu.com ([2001:41d0:203:375::ac]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wXesq-00000009RVF-3o4I for linux-arm-kernel@lists.infradead.org; Thu, 11 Jun 2026 12:51:46 +0000 Message-ID: <1a547b9b-dd6a-40fb-8669-3bb307eb05e2@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1781182291; 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=9S9SdGtbm1JyTfljX6WLjQs95rf1oKktzDq3rIIBuu0=; b=eesZ0NDn4arZq1eS4Me+sKBxmY7/1zh2Xohy+gcqQwOvoaQoEOYaxTNVbuV3UrqYxOYMgS +wiEuiiDOgD4QpWz/uuqRw3jEL3Lso9r4Qc9VpX9LdZmf0E7EYh7LcKERuNt/hVveKmu5R QXn3GY34ZpXtYuPfbBLNl5hnkucIye0= Date: Thu, 11 Jun 2026 20:50:04 +0800 MIME-Version: 1.0 Subject: Re: [RFC PATCH v2 1/3] mm/huge_memory: make persistent huge zero folio read-only Content-Language: en-US To: "David Hildenbrand (Arm)" Cc: akpm@linux-foundation.org, xueyuan.chen21@gmail.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, x86@kernel.org, catalin.marinas@arm.com, will@kernel.org, tglx@kernel.org, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, hpa@zytor.com, ljs@kernel.org, liam@infradead.org, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, ziy@nvidia.com, baolin.wang@linux.alibaba.com, npache@redhat.com, ryan.roberts@arm.com, dev.jain@arm.com, baohua@kernel.org, yang@os.amperecomputing.com, jannh@google.com, dave.hansen@intel.com References: <8c36a91d-288f-4ffb-b2ec-41e3ef789d72@kernel.org> <20260611115817.59353-1-lance.yang@linux.dev> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Lance Yang In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260611_055145_099275_D537BA59 X-CRM114-Status: GOOD ( 11.10 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 2026/6/11 20:21, David Hildenbrand (Arm) wrote: > On 6/11/26 13:58, Lance Yang wrote: >> >> On Thu, Jun 11, 2026 at 01:28:58PM +0200, David Hildenbrand (Arm) wrote: >>> On 6/10/26 04:15, Lance Yang wrote: >>>> >>>> >>>> Right, this came from the RFC v1 discussion[1]. David preferred a page- >>>> range helper for possible future non-folio callers, not something folio- >>>> only. >>>> >>>> Of course, we could also add a folio wrapper on top of that if needed :) >>> >>> Best to document that as part of the patch description: we don't really expect >>> to have a lot of read-only folios in the near future (zero page is rather >>> special; maybe it won't even be a folio in the future). >> >> Ah, good to know, thanks. Will spell that out in RFC v3. >> >> Maybe something like this? >> >> The huge zero page is pretty special case, and maybe it won't even be a >> folio in the future. Since read-only folios are unlikely to become a >> common thing, a page-range helper is the cleaner fit. > > Right. And if read-only folios in FSes become a real thing, we can always add > infrastructure for that. Got it, that draws the line nicely :P