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=-7.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,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 8C4BAC4361B for ; Wed, 9 Dec 2020 09:42:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3339D23B7D for ; Wed, 9 Dec 2020 09:42:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728819AbgLIJlr (ORCPT ); Wed, 9 Dec 2020 04:41:47 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:43530 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726247AbgLIJlq (ORCPT ); Wed, 9 Dec 2020 04:41:46 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1607506820; 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=sgyJMwSASjTecZOGvZIf8VWeLeZrfxFjHje5O8XyFg4=; b=IV3Y80ncQoFHCOwAlIlxITON8IgJIQ+wOAWQnAxG+OGr63VgG30YUl12jnYf/onNoV40Fa /jbNyZQbAoDZrlt+dPG4RyPreG88VcFcHXQkgom/hgBUNmZzltcMFGEBU8XmuAKNfW9Ua5 MjCjDkRVVWta06Ih5XsPhT45nrLJ75M= 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-591-yMXEqtdzP4uOn4f_1jyWWg-1; Wed, 09 Dec 2020 04:40:16 -0500 X-MC-Unique: yMXEqtdzP4uOn4f_1jyWWg-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 0D0AD192D799; Wed, 9 Dec 2020 09:40:15 +0000 (UTC) Received: from [10.36.114.167] (ovpn-114-167.ams2.redhat.com [10.36.114.167]) by smtp.corp.redhat.com (Postfix) with ESMTP id D07585D6D5; Wed, 9 Dec 2020 09:40:13 +0000 (UTC) Subject: Re: [RFC PATCH v3 1/4] mm,memory_hotplug: Add mhp_supports_memmap_on_memory To: Oscar Salvador Cc: mhocko@kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, vbabka@suse.cz, pasha.tatashin@soleen.com References: <20201201115158.22638-1-osalvador@suse.de> <20201201115158.22638-2-osalvador@suse.de> <20201209093608.GA30590@linux> From: David Hildenbrand Organization: Red Hat GmbH Message-ID: <5809e56e-363b-abe4-7b95-08768c6a4b32@redhat.com> Date: Wed, 9 Dec 2020 10:40:13 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.4.0 MIME-Version: 1.0 In-Reply-To: <20201209093608.GA30590@linux> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09.12.20 10:36, Oscar Salvador wrote: > On Wed, Dec 02, 2020 at 10:36:54AM +0100, David Hildenbrand wrote: >> Instead of adding these arch callbacks, what about a config option >> >> ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE >> >> that gets selected by the archs with CONFIG_SPARSEMEM_VMEMMAP ? >> >> The mhp_supports_memmap_on_memory() becomes even more trivial. > > I think that would not be enough. > E.g: s390x supports CONFIG_SPARSEMEM_VMEMMAP but it does not support > altmap (and maybe other arches I did not check too). > That is why I was careful in choosing the ones that a) supports > CONFIG_SPARSEMEM_VMEMMAP and b) support altmap Sorry if I was unclear, s390x will simply not set ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE. -- Thanks, David / dhildenb