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 D2585C433FE for ; Mon, 7 Dec 2020 12:21:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A2237233A0 for ; Mon, 7 Dec 2020 12:21:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727182AbgLGMVF (ORCPT ); Mon, 7 Dec 2020 07:21:05 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:23641 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726817AbgLGMVF (ORCPT ); Mon, 7 Dec 2020 07:21:05 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1607343579; 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=Itvlqd0kxvScpcIk5b9oFbJP3emazAwFYL5MTR3etUM=; b=LlZiIGlu50Rhg+aqxUj1BLJW+i/QpbpW73vMrMimR4xj0j2VrBINDucg70rCGVFHOk6ecU G/qtsogj+sGax3qeiku8828fbpa4sYCEeUWffnUQs5KkFiRZkXDqpv+Ib8ZwB//eDvejTy ME94B5tfNSKQcfrGMswucAXxJesMO2I= 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-541-rKIvg7AJOtuzNUgkU0omkw-1; Mon, 07 Dec 2020 07:19:35 -0500 X-MC-Unique: rKIvg7AJOtuzNUgkU0omkw-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 A23B8107ACE4; Mon, 7 Dec 2020 12:19:31 +0000 (UTC) Received: from [10.36.114.33] (ovpn-114-33.ams2.redhat.com [10.36.114.33]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3FFE35D6AB; Mon, 7 Dec 2020 12:19:26 +0000 (UTC) Subject: Re: [PATCH v7 03/15] mm/hugetlb: Introduce a new config HUGETLB_PAGE_FREE_VMEMMAP To: Muchun Song , corbet@lwn.net, mike.kravetz@oracle.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, viro@zeniv.linux.org.uk, akpm@linux-foundation.org, paulmck@kernel.org, mchehab+huawei@kernel.org, pawan.kumar.gupta@linux.intel.com, rdunlap@infradead.org, oneukum@suse.com, anshuman.khandual@arm.com, jroedel@suse.de, almasrymina@google.com, rientjes@google.com, willy@infradead.org, osalvador@suse.de, mhocko@suse.com, song.bao.hua@hisilicon.com Cc: duanxiongchun@bytedance.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org References: <20201130151838.11208-1-songmuchun@bytedance.com> <20201130151838.11208-4-songmuchun@bytedance.com> From: David Hildenbrand Organization: Red Hat GmbH Message-ID: <2ec1d360-c8c8-eb7b-2afe-b75ee61cfcea@redhat.com> Date: Mon, 7 Dec 2020 13:19:25 +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: <20201130151838.11208-4-songmuchun@bytedance.com> 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 30.11.20 16:18, Muchun Song wrote: > The purpose of introducing HUGETLB_PAGE_FREE_VMEMMAP is to configure > whether to enable the feature of freeing unused vmemmap associated > with HugeTLB pages. And this is just for dependency check. Now only > support x86. x86 - i386 and x86-64? (I assume the latter only ;) ) > > Signed-off-by: Muchun Song > --- > arch/x86/mm/init_64.c | 2 +- > fs/Kconfig | 14 ++++++++++++++ > 2 files changed, 15 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c > index 0a45f062826e..0435bee2e172 100644 > --- a/arch/x86/mm/init_64.c > +++ b/arch/x86/mm/init_64.c > @@ -1225,7 +1225,7 @@ static struct kcore_list kcore_vsyscall; > > static void __init register_page_bootmem_info(void) > { > -#ifdef CONFIG_NUMA > +#if defined(CONFIG_NUMA) || defined(CONFIG_HUGETLB_PAGE_FREE_VMEMMAP) > int i; > Why does this hunk belong into this patch? Looks like this should go into another patch. > for_each_online_node(i) > diff --git a/fs/Kconfig b/fs/Kconfig > index 976e8b9033c4..4961dd488444 100644 > --- a/fs/Kconfig > +++ b/fs/Kconfig > @@ -245,6 +245,20 @@ config HUGETLBFS > config HUGETLB_PAGE > def_bool HUGETLBFS > > +config HUGETLB_PAGE_FREE_VMEMMAP > + def_bool HUGETLB_PAGE > + depends on X86 > + depends on SPARSEMEM_VMEMMAP > + depends on HAVE_BOOTMEM_INFO_NODE > + help > + When using HUGETLB_PAGE_FREE_VMEMMAP, the system can save up some > + memory from pre-allocated HugeTLB pages when they are not used. > + 6 pages per 2MB HugeTLB page and 4094 per 1GB HugeTLB page. Calculations only apply to 4k base pages, no? (maybe generalize this a bit or mention 4k base pages - I'm pretty sure we'll see the "depends on X86" part fairly soon if this goes upstream) -- Thanks, David / dhildenb