From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Wed, 04 Jun 2014 19:22:29 +0200 (CEST) Received: from mail-ie0-f173.google.com ([209.85.223.173]:42822 "EHLO mail-ie0-f173.google.com" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S6854780AbaFDRWZsNwnU (ORCPT ); Wed, 4 Jun 2014 19:22:25 +0200 Received: by mail-ie0-f173.google.com with SMTP id lx4so7605606iec.18 for ; Wed, 04 Jun 2014 10:22:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; bh=gwIy/zP3LhbH+XHkPBggKDnb03hCsLlAPZ1gR+Xmqgk=; b=GwDog7aLmGxCvMHgPuivnxFAhqWFhTpdmiXZYh+tm/BKorgnGnQgke1spVbvkUKbM4 VfBqWrXULByaHpOJBg6oJTip3nCoX3aLTCDzvfcag6rA3WoHNV42GxmzmPQJ6DXyfRnW Ngwp8kP5Q6XesqLTeIIfMp7C8bcqGWFzPwVWwBGyIi8GdW+Qz2tHf0uR/ZkKMjxnVA3G SLf9tYxvIBVkEMolwaHv1T8Sf2JWnu3CQ+N9CWOr9rOgNfSg+VbTgi50J3AQG6AIo+aJ XCSYjez/+kJaIEj5N1K1WYs6LSIQopjw/hOHzx24kIxZES+QpUuQQ+GygWVo1JCI3csb DCGQ== X-Received: by 10.50.28.51 with SMTP id y19mr9371385igg.5.1401902539479; Wed, 04 Jun 2014 10:22:19 -0700 (PDT) Received: from dl.caveonetworks.com (64.2.3.195.ptr.us.xo.net. [64.2.3.195]) by mx.google.com with ESMTPSA id ql7sm46395963igc.19.2014.06.04.10.22.17 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Wed, 04 Jun 2014 10:22:18 -0700 (PDT) Message-ID: <538F55C9.7090905@gmail.com> Date: Wed, 04 Jun 2014 10:22:17 -0700 From: David Daney User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130625 Thunderbird/17.0.7 MIME-Version: 1.0 To: Ralf Baechle CC: Huacai Chen , John Crispin , "Steven J. Hill" , Aurelien Jarno , linux-mips@linux-mips.org, Fuxin Zhang , Zhangjin Wu Subject: Re: [PATCH V2 4/8] MIPS: Add NUMA support for Loongson-3 References: <1397348662-22502-1-git-send-email-chenhc@lemote.com> <1397348662-22502-5-git-send-email-chenhc@lemote.com> <20140603224739.GU17197@linux-mips.org> <538E5EA8.8010907@gmail.com> <20140604064601.GU5157@linux-mips.org> In-Reply-To: <20140604064601.GU5157@linux-mips.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 40434 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: ddaney.cavm@gmail.com Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips On 06/03/2014 11:46 PM, Ralf Baechle wrote: > > A more important value which I haven't noticed the Looongson patches to > modify is SECTION_SIZE_BITS in : > > #if defined(CONFIG_MIPS_HUGE_TLB_SUPPORT) && defined(CONFIG_PAGE_SIZE_64KB) > # define SECTION_SIZE_BITS 29 > #else > # define SECTION_SIZE_BITS 28 > #endif > > Don't ask me why its definition depends on MIPS_HUGE_TLB_SUPPORT and > PAGE_SIZE_64KB - the value describes the larges chunk of contiguous > memory (that is for example memory per node) and that doesn't depend > on these CONFIG_* symbols. > I think I can answer that. We do the same thing for OCTEON I think. IIRC, with SPARSEMEM, you cannot allocate high order pages that span multiple sections. Therefore you have to have the sections be at least as large as a huge page. in the case of CONFIG_PAGE_SIZE_64KB, the huge pages are 512MB which doesn't fit in 28 bits. David. > Ralf > >