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=-2.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 CD896C2BA19 for ; Fri, 24 Apr 2020 00:36:16 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 801DE20724 for ; Fri, 24 Apr 2020 00:36:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="ajMWxHXT"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="ajMWxHXT" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 801DE20724 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 497ZwZ2M7lzDr84 for ; Fri, 24 Apr 2020 10:36:14 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=redhat.com (client-ip=207.211.31.81; helo=us-smtp-delivery-1.mimecast.com; envelope-from=bhe@redhat.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=ajMWxHXT; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=ajMWxHXT; dkim-atps=neutral Received: from us-smtp-delivery-1.mimecast.com (us-smtp-1.mimecast.com [207.211.31.81]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 497ZtJ0V9JzDr4M for ; Fri, 24 Apr 2020 10:34:15 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1587688452; 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=ajMWxHXT2w7PK1YNEfcT4u5MfXF7NLTrQHRMfcHeo8VEd65ITKkjgBlIHMhhf/x2yMEFlP 1KY3c1Sg68XtDRtBTnLanl6wH+u/KhpeOFt82XNQVEUVs6HtRR7Iz7c4lVwuJb3LEZaD5x Cw132f/1eJlmbpV50uV9329c4A/Q7fA= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1587688452; 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=ajMWxHXT2w7PK1YNEfcT4u5MfXF7NLTrQHRMfcHeo8VEd65ITKkjgBlIHMhhf/x2yMEFlP 1KY3c1Sg68XtDRtBTnLanl6wH+u/KhpeOFt82XNQVEUVs6HtRR7Iz7c4lVwuJb3LEZaD5x Cw132f/1eJlmbpV50uV9329c4A/Q7fA= 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 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-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Rich Felker , linux-ia64@vger.kernel.org, linux-doc@vger.kernel.org, Catalin Marinas , Heiko Carstens , Michal Hocko , "James E.J. Bottomley" , Max Filippov , Guo Ren , linux-csky@vger.kernel.org, linux-parisc@vger.kernel.org, sparclinux@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-riscv@lists.infradead.org, Greg Ungerer , linux-arch@vger.kernel.org, linux-s390@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-c6x-dev@linux-c6x.org, Brian Cain , Jonathan Corbet , linux-sh@vger.kernel.org, Helge Deller , x86@kernel.org, Russell King , Ley Foon Tan , Mike Rapoport , Geert Uytterhoeven , linux-arm-kernel@lists.infradead.org, Mark Salter , Matt Turner , linux-mips@vger.kernel.org, uclinux-h8-devel@lists.sourceforge.jp, linux-xtensa@linux-xtensa.org, linux-alpha@vger.kernel.org, linux-um@lists.infradead.org, linux-m68k@lists.linux-m68k.org, Tony Luck , Greentime Hu , Paul Walmsley , Stafford Horne , Guan Xuetao , Hoan Tran , Michal Simek , Thomas Bogendoerfer , Yoshinori Sato , Nick Hu , linux-mm@kvack.org, Vineet Gupta , linux-kernel@vger.kernel.org, openrisc@lists.librecores.org, Richard Weinberger , Andrew Morton , linuxppc-dev@lists.ozlabs.org, "David S. Miller" Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" 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 :)