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 36943E77197 for ; Thu, 9 Jan 2025 12:10:26 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B979A6B0082; Thu, 9 Jan 2025 07:10:25 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id B47A46B0083; Thu, 9 Jan 2025 07:10:25 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A10556B0085; Thu, 9 Jan 2025 07:10:25 -0500 (EST) 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 81A2A6B0082 for ; Thu, 9 Jan 2025 07:10:25 -0500 (EST) Received: from smtpin02.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 3C0131618D2 for ; 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s=arc-20220608; d=hostedemail.com; t=1736424623; a=rsa-sha256; cv=none; b=VWNmPeEYfdsPYS3M+ZiFlQ/eJMOK36OzdkO71bYlZGstK1dYb5W/wNGSR53679dAsakN4i /locsvO27nzyoQkQ8XGVBm1O8E5pJ2Gi2GACaMmu9B4vE65JgiBsRxIRdxQG4xT7Aht4wh KgnjLdklQS4OTk/rG+s/EMAk6eEBz2o= ARC-Authentication-Results: i=1; imf29.hostedemail.com; dkim=none; dmarc=fail reason="SPF not aligned (relaxed), No valid DKIM" header.from=arm.com (policy=none); spf=pass (imf29.hostedemail.com: domain of cmarinas@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=cmarinas@kernel.org Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 68E435C5AA1; Thu, 9 Jan 2025 12:09:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7E6E6C4CED2; Thu, 9 Jan 2025 12:10:19 +0000 (UTC) Date: Thu, 9 Jan 2025 12:10:17 +0000 From: Catalin Marinas To: Zhenhua Huang Cc: Anshuman Khandual , will@kernel.org, ardb@kernel.org, ryan.roberts@arm.com, mark.rutland@arm.com, joey.gouly@arm.com, dave.hansen@linux.intel.com, akpm@linux-foundation.org, chenfeiyang@loongson.cn, chenhuacai@kernel.org, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, quic_tingweiz@quicinc.com, stable@vger.kernel.org Subject: Re: [PATCH v4] arm64: mm: Populate vmemmap/linear at the page level for hotplugged sections Message-ID: References: <20250107074252.1062127-1-quic_zhenhuah@quicinc.com> <169f8006-ff33-48ca-a680-37fe1cf0efe8@quicinc.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <169f8006-ff33-48ca-a680-37fe1cf0efe8@quicinc.com> X-Stat-Signature: tcsxbe9zfyx6444stkzx81boum6k36bn X-Rspamd-Queue-Id: 99EDF120007 X-Rspam-User: X-Rspamd-Server: rspam01 X-HE-Tag: 1736424623-726746 X-HE-Meta: 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 mf20ca82 HVLM+TFQ+gPadM90apLDIFToQN6Y0hlEd4GHh4q3SOlFjxs0tGo/zIvxEdfjoStfretAcpaF07RvkyMMTjstQkZsqs0BRyr5LH0jNAV3Oy2lfuWipJJX0W+7XCkbzW+oyVQvRB3aQIMLoBOPq8y+8bsbCGlO1DvDdnXzgabIzGXclImjwRm8cR74m99nPg4oiSryJWyR7WNkE8as5ty3MKU7lFEsGE5cM7irGxbvNFQGyIIDuoV6CVLCePa4FqWo45Tu+aqtksyHpPQSM7DXx5Os12DOaWM+EUMY4a4pRAtYXgvMhKl0xYuFyW5HX+cbYtxnbYXb7BHoMb6xd7U5zvi/zxXkwj+8oGptO 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 Thu, Jan 09, 2025 at 03:04:48PM +0800, Zhenhua Huang wrote: > On 2025/1/8 18:11, Anshuman Khandual wrote: > > Just wondering why not start with PUD level itself ? Although SUBSECTION_SHIFT > > might never reach the PUD level but this will help keep the flags calculations > > bit simple and ready for all future changes. > > > > I suppose that it's because these are significantly larger than 2M, whereas > Catalin assumed SUBSECTION_SIZE would not increase? > His comment: > "should cover any changes to SUBSECTION_SHIFT making it *smaller* than 2MB. > " Yeah, I was thinking of having fewer code lines. Otherwise the compiler would likely optimise them anyway to a single assignment. -- Catalin