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=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 C8173C2BA19 for ; Fri, 24 Apr 2020 00:34:13 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 87B5220724 for ; Fri, 24 Apr 2020 00:34:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="KdEgONvP" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 87B5220724 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 39C6F8E0005; Thu, 23 Apr 2020 20:34:13 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 34DE78E0003; Thu, 23 Apr 2020 20:34:13 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 263B78E0005; Thu, 23 Apr 2020 20:34:13 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0094.hostedemail.com [216.40.44.94]) by kanga.kvack.org (Postfix) with ESMTP id 07AA88E0003 for ; Thu, 23 Apr 2020 20:34:13 -0400 (EDT) Received: from smtpin27.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id C12AD5841 for ; Fri, 24 Apr 2020 00:34:12 +0000 (UTC) X-FDA: 76740876744.27.tiger19_41d4d61d90d06 X-HE-Tag: tiger19_41d4d61d90d06 X-Filterd-Recvd-Size: 5851 Received: from us-smtp-delivery-1.mimecast.com (us-smtp-2.mimecast.com [207.211.31.81]) by imf47.hostedemail.com (Postfix) with ESMTP for ; Fri, 24 Apr 2020 00:34:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1587688451; 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: in-reply-to:in-reply-to:references:references; bh=n2dWJbdFmIc0aMZ8wHTt5vQhPaXxDdsL9ipp25mLNTI=; b=KdEgONvPhf2zQD4Q1oLX8Ely0LBgNy0lS2p8q13iySOytEW/mNJpWisq+dGCigKsbJy9Xt cxgpfTckjoV58f/Wxxz5HJj8SE5UfXksovh8zrsviVhbiqTiYbSQvG0GeK9XebBT6TMs0q CMoiN9EFU71/wJ078VeHCYoDXCnYtpg= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-101-PdLkUA6CP7mzy-z_Ga33bw-1; Thu, 23 Apr 2020 20:34:09 -0400 X-MC-Unique: PdLkUA6CP7mzy-z_Ga33bw-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 087DD800D24; Fri, 24 Apr 2020 00:34:03 +0000 (UTC) Received: from localhost (ovpn-12-92.pek2.redhat.com [10.72.12.92]) by smtp.corp.redhat.com (Postfix) with ESMTPS id ACFBF1C957; Fri, 24 Apr 2020 00:33:58 +0000 (UTC) Date: Fri, 24 Apr 2020 08:33:56 +0800 From: Baoquan He To: Mike Rapoport Cc: linux-kernel@vger.kernel.org, Andrew Morton , Brian Cain , Catalin Marinas , "David S. Miller" , Geert Uytterhoeven , Greentime Hu , Greg Ungerer , Guan Xuetao , Guo Ren , Heiko Carstens , Helge Deller , Hoan Tran , "James E.J. Bottomley" , Jonathan Corbet , Ley Foon Tan , Mark Salter , Matt Turner , Max Filippov , Michael Ellerman , Michal Hocko , Michal Simek , Nick Hu , Paul Walmsley , Richard Weinberger , Rich Felker , Russell King , Stafford Horne , Thomas Bogendoerfer , Tony Luck , Vineet Gupta , x86@kernel.org, Yoshinori Sato , linux-alpha@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-c6x-dev@linux-c6x.org, linux-csky@vger.kernel.org, linux-doc@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-ia64@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-mm@kvack.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-um@lists.infradead.org, linux-xtensa@linux-xtensa.org, openrisc@lists.librecores.org, sparclinux@vger.kernel.org, uclinux-h8-devel@lists.sourceforge.jp, Mike Rapoport Subject: Re: [PATCH 17/21] mm: free_area_init: allow defining max_zone_pfn in descending order Message-ID: <20200424003356.GA10119@MiWiFi-R3L-srv> References: <20200412194859.12663-1-rppt@kernel.org> <20200412194859.12663-18-rppt@kernel.org> <20200423025311.GZ4247@MiWiFi-R3L-srv> <20200423025720.GA4247@MiWiFi-R3L-srv> <20200423055559.GF14260@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200423055559.GF14260@kernel.org> User-Agent: Mutt/1.10.1 (2018-07-13) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 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: On 04/23/20 at 08:55am, Mike Rapoport wrote: > On Thu, Apr 23, 2020 at 10:57:20AM +0800, Baoquan He wrote: > > On 04/23/20 at 10:53am, Baoquan He wrote: > > > On 04/12/20 at 10:48pm, Mike Rapoport wrote: > > > > From: Mike Rapoport > > > > > > > > Some architectures (e.g. ARC) have the ZONE_HIGHMEM zone below the > > > > ZONE_NORMAL. Allowing free_area_init() parse max_zone_pfn array even it is > > > > sorted in descending order allows using free_area_init() on such > > > > architectures. > > > > > > > > Add top -> down traversal of max_zone_pfn array in free_area_init() and use > > > > the latter in ARC node/zone initialization. > > > > > > Or maybe leave ARC as is. The change in this patchset doesn't impact > > > ARC's handling about zone initialization, leaving it as is can reduce > > > the complication in implementation of free_area_init(), which is a > > > common function. So I personally don't see a strong motivation to have > > > this patch. > > > > OK, seems this patch is prepared to simplify free_area_init_node(), so > > take back what I said at above. > > > > Then this looks necessary, even though it introduces special case into > > common function free_area_init(). > > The idea is to have a single free_area_init() for all architectures > without keeping two completely different ways of calculating the zone > extents. > Another thing, is that with this we could eventually switch ARC from > DISCONTIGMEM. Yeah, I think uniting them into a single free_area_init() is a great idea. Even though I had been through this patchset, when looked into each of them, still may forget the detail in later patch :)