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=-11.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,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 72177C433DB for ; Fri, 8 Jan 2021 23:17:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2713423A79 for ; Fri, 8 Jan 2021 23:17:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726078AbhAHXRP (ORCPT ); Fri, 8 Jan 2021 18:17:15 -0500 Received: from m43-15.mailgun.net ([69.72.43.15]:43387 "EHLO m43-15.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725792AbhAHXRP (ORCPT ); Fri, 8 Jan 2021 18:17:15 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1610147815; h=Content-Transfer-Encoding: MIME-Version: Message-Id: Date: Subject: Cc: To: From: Sender; bh=8k9WBpeIGAP0mLspkxyR4XM/TtoK/2Q8inGNLk6er9g=; b=P9x/Xe0jHwUcu3ni85S+HFO38hYth6byvdZ/EGo7p/wwjNLqA9FVWxb3vuxF6z4u6/L256ps 9x8lN1kupnpmCrb9zPJ+Y2LK6EMFodSzHzoPSAnBgU2N5cikLIRG1aVlHv/FtBo0R45eoF1j p3Gh1a22S37GO8T06/ZlcxfXiwA= X-Mailgun-Sending-Ip: 69.72.43.15 X-Mailgun-Sid: WyI0MWYwYSIsICJsaW51eC1rZXJuZWxAdmdlci5rZXJuZWwub3JnIiwgImJlOWU0YSJd Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n08.prod.us-east-1.postgun.com with SMTP id 5ff8e7c246a6c7cde75592b9 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Fri, 08 Jan 2021 23:16:18 GMT Sender: sudaraja=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 38631C43463; Fri, 8 Jan 2021 23:16:18 +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 4704CC433C6; Fri, 8 Jan 2021 23:16:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 4704CC433C6 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: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, will@kernel.org, anshuman.khandual@arm.com, david@redhat.com Cc: Sudarshan Rajagopalan Subject: [PATCH 0/1] arm64: reduce section size for sparsemem Date: Fri, 8 Jan 2021 15:15:59 -0800 Message-Id: X-Mailer: git-send-email 2.25.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch is the follow-up from the discussions in the thread [1]. Reducing the section size has the merit of reducing wastage of reserved memory for huge memory holes in sparsemem model. Also with smaller section size gives more grunularity and agility for memory hot(un)plugging. This patch tends to use the suggestion from David Hildenbrand in thread [1] to set the least possible SECTION_SIZE_BITS for 4K, 16K and 64K page granule. That is 27 (128MB) for 4K/16K and 29 (512MB) for 64K page granule. [1] https://lore.kernel.org/lkml/cover.1609895500.git.sudaraja@codeaurora.org/T/#m8ee60ae69db5e9eb06ca7999c43828d49ccb9626 Sudarshan Rajagopalan (1): arm64: reduce section size for sparsemem arch/arm64/include/asm/sparsemem.h | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project