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 X-Spam-Level: X-Spam-Status: No, score=-11.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7FAEFC433DB for ; Wed, 6 Jan 2021 01:28:59 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 11EC422CB9 for ; Wed, 6 Jan 2021 01:28:58 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 11EC422CB9 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 854928D00D4; Tue, 5 Jan 2021 20:28:58 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 7DD6C8D00D1; Tue, 5 Jan 2021 20:28:58 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6A53F8D00D4; Tue, 5 Jan 2021 20:28:58 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0220.hostedemail.com [216.40.44.220]) by kanga.kvack.org (Postfix) with ESMTP id 5204D8D00D1 for ; Tue, 5 Jan 2021 20:28:58 -0500 (EST) Received: from smtpin09.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 11ED6824556B for ; Wed, 6 Jan 2021 01:28:58 +0000 (UTC) X-FDA: 77673616356.09.pot15_490fea9274dd Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin09.hostedemail.com (Postfix) with ESMTP id EA28A180AD811 for ; Wed, 6 Jan 2021 01:28:57 +0000 (UTC) X-HE-Tag: pot15_490fea9274dd X-Filterd-Recvd-Size: 3779 Received: from m43-15.mailgun.net (m43-15.mailgun.net [69.72.43.15]) by imf30.hostedemail.com (Postfix) with ESMTP for ; Wed, 6 Jan 2021 01:28:57 +0000 (UTC) DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1609896537; h=Content-Transfer-Encoding: MIME-Version: Message-Id: Date: Subject: Cc: To: From: Sender; bh=4p4DqJ5urwWJifyBoVvu5TpdqgDgH0bV0rmDfagihD0=; b=ajqducC80iPntFCFU3cd9KYZbQR7x0eqpH+B1pX1BSBnHs/8Z7AoS5MJfjbEbmnEomwRz1it 669h0BIxyYyIg8TgepjpDR58vZlAR24tu457GicLFJ8WVslwmHwpPPXE6aNIQnzjVdouIj03 V+sOAF11723ArFjNF5OtJhfneKg= X-Mailgun-Sending-Ip: 69.72.43.15 X-Mailgun-Sid: WyIwY2Q3OCIsICJsaW51eC1tbUBrdmFjay5vcmciLCAiYmU5ZTRhIl0= Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n09.prod.us-east-1.postgun.com with SMTP id 5ff51258a1d2634b3f7d0b6a (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Wed, 06 Jan 2021 01:28:56 GMT Received: by smtp.codeaurora.org (Postfix, from userid 1001) id EF582C43461; Wed, 6 Jan 2021 01:28:55 +0000 (UTC) Received: from th-lint-014.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: sudaraja) by smtp.codeaurora.org (Postfix) with ESMTPSA id 30F7FC433CA; Wed, 6 Jan 2021 01:28:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 30F7FC433CA Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=fail smtp.mailfrom=sudaraja@codeaurora.org From: Sudarshan Rajagopalan To: akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: Sudarshan Rajagopalan Subject: [PATCH 0/1] arm64: make section size configurable for memory hotplug Date: Tue, 5 Jan 2021 17:28:45 -0800 Message-Id: X-Mailer: git-send-email 2.25.0 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable 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: The section size defines the granularity of memory hotplug. This is curre= ntly hard coded to 1GB on arm64 linux, which defines that the least size of me= mblock that can be hotplugged out is 1GB. Some DDR configurations (especially lo= w RAM and dual-rank DDRs) may have section sizes that are less than 1GB (ex. 51= 2MB, 256MB etc.). Having an option to reduce the memblock size to section size or lower giv= es more granularity of memory hotplug. For example, a system with DDR section siz= e of 512MB and kernel memblock size of 1GB, we would have to remove two segments of = DDR sections in order to hotplug out atleast 1 memblock from kernel POV.=20 Section sizes of DDRs vary based on specs (number of ranks, channels, reg= ions etc.) Making this section size configurable helps users to assign based on the = DDR being used. The default is set to 1GB which is the current memblock size. Sudarshan Rajagopalan (1): arm64: Make section size configurable for memory hotplug arch/arm64/Kconfig | 11 +++++++++++ arch/arm64/include/asm/sparsemem.h | 4 ++++ 2 files changed, 15 insertions(+) --=20 Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project