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=-17.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 15B7DC433B4 for ; Tue, 20 Apr 2021 16:01:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C30FB613C9 for ; Tue, 20 Apr 2021 16:01:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233072AbhDTQBf (ORCPT ); Tue, 20 Apr 2021 12:01:35 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:33191 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232174AbhDTQBb (ORCPT ); Tue, 20 Apr 2021 12:01:31 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1618934459; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=1VLwDHA1T1kECXFVXDoESN93Xu3CIGiC8uj+j3Bh2ag=; b=L/hZoR2CF/2McZ8FvPDUAEqNRT5CCp+LOOGEQuxok9myXCdn/U6jwYZAYkR39JuzBBsORr 17nF8zjZmDWqu/bmLYjpu2Mc5RCcdFWd/7GzFEkfDKVRSeNuF+nXE2R/AfbhqEWpVIuOpO V7Jz9mxc4fQZa+XqRWPVMQPetgp3yTI= Received: from mail-wm1-f70.google.com (mail-wm1-f70.google.com [209.85.128.70]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-35-Bw8r28LgMV27SwkZkeVQKg-1; Tue, 20 Apr 2021 12:00:57 -0400 X-MC-Unique: Bw8r28LgMV27SwkZkeVQKg-1 Received: by mail-wm1-f70.google.com with SMTP id k26-20020a7bc41a0000b0290125f388fcfbso5838918wmi.9 for ; Tue, 20 Apr 2021 09:00:57 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:organization :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=1VLwDHA1T1kECXFVXDoESN93Xu3CIGiC8uj+j3Bh2ag=; b=CjLAnfUALuMSBZ/W4qCMW/e0r/7gaplFaSBx7wXe6faqMldmIBjnXZW50ereRife4X JIRl0rx0eZpgRuxKRr8ufiiUP2bNvrd0kUf9tbcuvrckwRQBw6Y1pWvWfrcKLJs/gLWD JdhRy9w0pe3bmMeUTYN0K8NUXaPy6HkLS6wQQiWFa/cDE0zk2YRiUtr9jol/nWkDQNv+ eiZNLnRzbnEwBo9LEPrScnKZf3WguksAzZjD6mvnZs7L6z8k4I6UxWCtg9U4Tc/L82d7 y3XStQ3VlMsKXm4pJgYYDhZrv44kUiCCdl7xighGmf4Y2dF+nnGFfyBHatGQI9ms23H+ 4X0A== X-Gm-Message-State: AOAM533JKuQUrIw8vVEP2p26B5Heh1T/B/fOvspdfrdExxelxGtnreu9 R1Z+sNgE+mgz8ooiEzWEnt6V80nSUexgR1h/Ps3OWfag5bVt9IyVd+A9+TJU46PhMIHodSsf4ZB o+95mREhq8xeWEK6H2O6BGFqu X-Received: by 2002:adf:d0cc:: with SMTP id z12mr21739748wrh.18.1618934456651; Tue, 20 Apr 2021 09:00:56 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxr5kh0sjqy8wW7F/IAJRwsgXm3O7rTTKuYEi9XNs0Np8ms/WxZijQLIJublkxDKy/HuPS98A== X-Received: by 2002:adf:d0cc:: with SMTP id z12mr21739705wrh.18.1618934456321; Tue, 20 Apr 2021 09:00:56 -0700 (PDT) Received: from [192.168.3.132] (p4ff2390a.dip0.t-ipconnect.de. [79.242.57.10]) by smtp.gmail.com with ESMTPSA id o4sm9592968wrn.81.2021.04.20.09.00.55 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 20 Apr 2021 09:00:56 -0700 (PDT) Subject: Re: [PATCH v1 4/4] arm64: drop pfn_valid_within() and simplify pfn_valid() To: Mike Rapoport , linux-arm-kernel@lists.infradead.org Cc: Anshuman Khandual , Ard Biesheuvel , Catalin Marinas , Marc Zyngier , Mark Rutland , Mike Rapoport , Will Deacon , kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, linux-mm@kvack.org References: <20210420090925.7457-1-rppt@kernel.org> <20210420090925.7457-5-rppt@kernel.org> From: David Hildenbrand Organization: Red Hat Message-ID: <8e7171e7-a85c-6066-4ab6-d2bc98ec103b@redhat.com> Date: Tue, 20 Apr 2021 18:00:55 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <20210420090925.7457-5-rppt@kernel.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 20.04.21 11:09, Mike Rapoport wrote: > From: Mike Rapoport > > The arm64's version of pfn_valid() differs from the generic because of two > reasons: > > * Parts of the memory map are freed during boot. This makes it necessary to > verify that there is actual physical memory that corresponds to a pfn > which is done by querying memblock. > > * There are NOMAP memory regions. These regions are not mapped in the > linear map and until the previous commit the struct pages representing > these areas had default values. > > As the consequence of absence of the special treatment of NOMAP regions in > the memory map it was necessary to use memblock_is_map_memory() in > pfn_valid() and to have pfn_valid_within() aliased to pfn_valid() so that > generic mm functionality would not treat a NOMAP page as a normal page. > > Since the NOMAP regions are now marked as PageReserved(), pfn walkers and > the rest of core mm will treat them as unusable memory and thus > pfn_valid_within() is no longer required at all and can be disabled by > removing CONFIG_HOLES_IN_ZONE on arm64. > > pfn_valid() can be slightly simplified by replacing > memblock_is_map_memory() with memblock_is_memory(). > > Signed-off-by: Mike Rapoport > --- > arch/arm64/Kconfig | 3 --- > arch/arm64/mm/init.c | 4 ++-- > 2 files changed, 2 insertions(+), 5 deletions(-) > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index e4e1b6550115..58e439046d05 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -1040,9 +1040,6 @@ config NEED_PER_CPU_EMBED_FIRST_CHUNK > def_bool y > depends on NUMA > > -config HOLES_IN_ZONE > - def_bool y > - > source "kernel/Kconfig.hz" > > config ARCH_SPARSEMEM_ENABLE > diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c > index c54e329aca15..370f33765b64 100644 > --- a/arch/arm64/mm/init.c > +++ b/arch/arm64/mm/init.c > @@ -243,7 +243,7 @@ int pfn_valid(unsigned long pfn) > > /* > * ZONE_DEVICE memory does not have the memblock entries. > - * memblock_is_map_memory() check for ZONE_DEVICE based > + * memblock_is_memory() check for ZONE_DEVICE based > * addresses will always fail. Even the normal hotplugged > * memory will never have MEMBLOCK_NOMAP flag set in their > * memblock entries. Skip memblock search for all non early > @@ -254,7 +254,7 @@ int pfn_valid(unsigned long pfn) > return pfn_section_valid(ms, pfn); > } > #endif > - return memblock_is_map_memory(addr); > + return memblock_is_memory(addr); > } > EXPORT_SYMBOL(pfn_valid); > > What are the steps needed to get rid of custom pfn_valid() completely? I'd assume we would have to stop freeing parts of the mem map during boot. How relevant is that for arm64 nowadays, especially with reduced section sizes? -- Thanks, David / dhildenb