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=-13.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 41956C433DB for ; Fri, 26 Feb 2021 12:05:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 03A1C64ED2 for ; Fri, 26 Feb 2021 12:05:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229999AbhBZMFi (ORCPT ); Fri, 26 Feb 2021 07:05:38 -0500 Received: from mx2.suse.de ([195.135.220.15]:51364 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229482AbhBZMFg (ORCPT ); Fri, 26 Feb 2021 07:05:36 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 87B88AB8C; Fri, 26 Feb 2021 12:04:54 +0000 (UTC) Date: Fri, 26 Feb 2021 13:04:51 +0100 From: Oscar Salvador To: David Hildenbrand Cc: Andrew Morton , Michal Hocko , VlastimilBabkavbabka@suse.cz, pasha.tatashin@soleen.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Anshuman Khandual Subject: Re: [PATCH v2 6/7] x86/Kconfig: Introduce ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE Message-ID: <20210226120451.GA3661@localhost.localdomain> References: <20210209133854.17399-1-osalvador@suse.de> <20210209133854.17399-7-osalvador@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 25, 2021 at 07:29:07PM +0100, David Hildenbrand wrote: > On 09.02.21 14:38, Oscar Salvador wrote: > > Enable x86_64 platform to use the MHP_MEMMAP_ON_MEMORY feature. > > > > Signed-off-by: Oscar Salvador > > --- > > arch/x86/Kconfig | 4 ++++ > > 1 file changed, 4 insertions(+) > > > > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > > index 72663de8b04c..81046b7adb10 100644 > > --- a/arch/x86/Kconfig > > +++ b/arch/x86/Kconfig > > @@ -2440,6 +2440,10 @@ config ARCH_ENABLE_MEMORY_HOTREMOVE > > def_bool y > > depends on MEMORY_HOTPLUG > > +config ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE > > + def_bool y > > + depends on X86_64 && MEMORY_HOTPLUG && SPARSEMEM_VMEMMAP_ENABLE > > It depends on SPARSEMEM_VMEMMAP, no? > > I think we could have > > SPARSEMEM_VMEMMAP_ENABLE=y > and > SPARSEMEM_VMEMMAP=n > > on manually tuned configs. I do not think this can happen: from mm/Kconfig: config SPARSEMEM_VMEMMAP_ENABLE bool config SPARSEMEM_VMEMMAP bool "Sparse Memory virtual memmap" depends on SPARSEMEM && SPARSEMEM_VMEMMAP_ENABLE default y help SPARSEMEM_VMEMMAP uses a virtually mapped memmap to optimise pfn_to_page and page_to_pfn operations. This is the most efficient option when sufficient kernel resources are available and from arch/x86/Kconfig: config ARCH_SPARSEMEM_ENABLE def_bool y depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD select SPARSEMEM_STATIC if X86_32 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 So, if I read this correctly, for SPARSEMEM_VMEMMAP to be true, SPARSEMEM_VMEMMAP_ENABLE needs to be true as well. Am I missing something? -- Oscar Salvador SUSE L3