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=-5.2 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 0943FC433E0 for ; Tue, 2 Feb 2021 14:34:58 +0000 (UTC) Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (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 9D1CC64DD6 for ; Tue, 2 Feb 2021 14:34:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9D1CC64DD6 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvdimm-bounces@lists.01.org Received: from ml01.vlan13.01.org (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id 252FC100EA2B2; Tue, 2 Feb 2021 06:34:57 -0800 (PST) Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=63.128.21.124; helo=us-smtp-delivery-124.mimecast.com; envelope-from=david@redhat.com; receiver= Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [63.128.21.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 192A3100EA2B1 for ; Tue, 2 Feb 2021 06:34:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1612276493; 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=DMQGIZBX3ZSdULucq6YnujqHSWIcTSgvTL7Om1Dz16I=; b=TB4f54GA6of7/fhHlL/DuK168L4SCX0eFlv9Nj8+BS15mujoNNh6Zh3wB3ferDM6D4LsUp RzxQbicNJa2cuAV1vIX2jC3Yl57abYxTir8Gadw03l/KFjyRH7KGgjWtMYBNIb+ZwZ/p1A F/GWWPlOnXmMZeSqeqhRJ/9dts0hSrg= 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-464-dkvrsbKJMeCl98dqyoVbLw-1; Tue, 02 Feb 2021 09:34:48 -0500 X-MC-Unique: dkvrsbKJMeCl98dqyoVbLw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 0E886184DBF0; Tue, 2 Feb 2021 14:34:44 +0000 (UTC) Received: from [10.36.114.148] (ovpn-114-148.ams2.redhat.com [10.36.114.148]) by smtp.corp.redhat.com (Postfix) with ESMTP id 505D15D9C6; Tue, 2 Feb 2021 14:34:36 +0000 (UTC) Subject: Re: [PATCH v16 07/11] secretmem: use PMD-size pages to amortize direct map fragmentation To: Michal Hocko References: <73738cda43236b5ac2714e228af362b67a712f5d.camel@linux.ibm.com> <6de6b9f9c2d28eecc494e7db6ffbedc262317e11.camel@linux.ibm.com> <20210202124857.GN242749@kernel.org> <6653288a-dd02-f9de-ef6a-e8d567d71d53@redhat.com> <211f0214-1868-a5be-9428-7acfc3b73993@redhat.com>

From: David Hildenbrand Organization: Red Hat GmbH Message-ID: <95625b83-f7e2-b27a-2b99-d231338047fb@redhat.com> Date: Tue, 2 Feb 2021 15:34:29 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.5.0 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Message-ID-Hash: EORD5PGJMPUQZMHEDHNHUY6R6CKGZCOB X-Message-ID-Hash: EORD5PGJMPUQZMHEDHNHUY6R6CKGZCOB X-MailFrom: david@redhat.com X-Mailman-Rule-Hits: nonmember-moderation X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation CC: Mike Rapoport , James Bottomley , Andrew Morton , Alexander Viro , Andy Lutomirski , Arnd Bergmann , Borislav Petkov , Catalin Marinas , Christopher Lameter , Dave Hansen , Elena Reshetova , "H. Peter Anvin" , Ingo Molnar , "Kirill A. Shutemov" , Matthew Wilcox , Mark Rutland , Mike Rapoport , Michael Kerrisk , Palmer Dabbelt , Paul Walmsley , Peter Zijlstra , Rick Edgecombe , Roman Gushchin , Shakeel Butt , Shuah Khan , Thomas Gleixner , Tycho Ander sen , Will Deacon , linux-api@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-nvdimm@lists.01.org, linux-riscv@lists.infradead.org, x86@kernel.org, Hagen Paul Pfeifer , Palmer Dabbelt X-Mailman-Version: 3.1.1 Precedence: list List-Id: "Linux-nvdimm developer list." Archived-At: List-Archive: List-Help: List-Post: List-Subscribe: List-Unsubscribe: Content-Type: text/plain; charset="us-ascii"; format="flowed" Content-Transfer-Encoding: 7bit On 02.02.21 15:32, Michal Hocko wrote: > On Tue 02-02-21 15:26:20, David Hildenbrand wrote: >> On 02.02.21 15:22, Michal Hocko wrote: >>> On Tue 02-02-21 15:12:21, David Hildenbrand wrote: >>> [...] >>>> I think secretmem behaves much more like longterm GUP right now >>>> ("unmigratable", "lifetime controlled by user space", "cannot go on >>>> CMA/ZONE_MOVABLE"). I'd either want to reasonably well control/limit it or >>>> make it behave more like mlocked pages. >>> >>> I thought I have already asked but I must have forgotten. Is there any >>> actual reason why the memory is not movable? Timing attacks? >> >> I think the reason is simple: no direct map, no copying of memory. > > This is an implementation detail though and not something terribly hard > to add on top later on. I was more worried there would be really > fundamental reason why this is not possible. E.g. security implications. I don't remember all the details. Let's see what Mike thinks regarding migration (e.g., security concerns). -- Thanks, David / dhildenb _______________________________________________ Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org To unsubscribe send an email to linux-nvdimm-leave@lists.01.org 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=-7.8 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 18F9DC433DB for ; Tue, 2 Feb 2021 14:47:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DEAAA64F5C for ; Tue, 2 Feb 2021 14:47:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234631AbhBBOrg (ORCPT ); Tue, 2 Feb 2021 09:47:36 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:47656 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234614AbhBBOgT (ORCPT ); Tue, 2 Feb 2021 09:36:19 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1612276493; 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=DMQGIZBX3ZSdULucq6YnujqHSWIcTSgvTL7Om1Dz16I=; b=TB4f54GA6of7/fhHlL/DuK168L4SCX0eFlv9Nj8+BS15mujoNNh6Zh3wB3ferDM6D4LsUp RzxQbicNJa2cuAV1vIX2jC3Yl57abYxTir8Gadw03l/KFjyRH7KGgjWtMYBNIb+ZwZ/p1A F/GWWPlOnXmMZeSqeqhRJ/9dts0hSrg= 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-464-dkvrsbKJMeCl98dqyoVbLw-1; Tue, 02 Feb 2021 09:34:48 -0500 X-MC-Unique: dkvrsbKJMeCl98dqyoVbLw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 0E886184DBF0; Tue, 2 Feb 2021 14:34:44 +0000 (UTC) Received: from [10.36.114.148] (ovpn-114-148.ams2.redhat.com [10.36.114.148]) by smtp.corp.redhat.com (Postfix) with ESMTP id 505D15D9C6; Tue, 2 Feb 2021 14:34:36 +0000 (UTC) Subject: Re: [PATCH v16 07/11] secretmem: use PMD-size pages to amortize direct map fragmentation To: Michal Hocko Cc: Mike Rapoport , James Bottomley , Andrew Morton , Alexander Viro , Andy Lutomirski , Arnd Bergmann , Borislav Petkov , Catalin Marinas , Christopher Lameter , Dan Williams , Dave Hansen , Elena Reshetova , "H. Peter Anvin" , Ingo Molnar , "Kirill A. Shutemov" , Matthew Wilcox , Mark Rutland , Mike Rapoport , Michael Kerrisk , Palmer Dabbelt , Paul Walmsley , Peter Zijlstra , Rick Edgecombe , Roman Gushchin , Shakeel Butt , Shuah Khan , Thomas Gleixner , Tycho Andersen , Will Deacon , linux-api@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-nvdimm@lists.01.org, linux-riscv@lists.infradead.org, x86@kernel.org, Hagen Paul Pfeifer , Palmer Dabbelt References: <73738cda43236b5ac2714e228af362b67a712f5d.camel@linux.ibm.com> <6de6b9f9c2d28eecc494e7db6ffbedc262317e11.camel@linux.ibm.com> <20210202124857.GN242749@kernel.org> <6653288a-dd02-f9de-ef6a-e8d567d71d53@redhat.com> <211f0214-1868-a5be-9428-7acfc3b73993@redhat.com>

From: David Hildenbrand Organization: Red Hat GmbH Message-ID: <95625b83-f7e2-b27a-2b99-d231338047fb@redhat.com> Date: Tue, 2 Feb 2021 15:34:29 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.5.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02.02.21 15:32, Michal Hocko wrote: > On Tue 02-02-21 15:26:20, David Hildenbrand wrote: >> On 02.02.21 15:22, Michal Hocko wrote: >>> On Tue 02-02-21 15:12:21, David Hildenbrand wrote: >>> [...] >>>> I think secretmem behaves much more like longterm GUP right now >>>> ("unmigratable", "lifetime controlled by user space", "cannot go on >>>> CMA/ZONE_MOVABLE"). I'd either want to reasonably well control/limit it or >>>> make it behave more like mlocked pages. >>> >>> I thought I have already asked but I must have forgotten. Is there any >>> actual reason why the memory is not movable? Timing attacks? >> >> I think the reason is simple: no direct map, no copying of memory. > > This is an implementation detail though and not something terribly hard > to add on top later on. I was more worried there would be really > fundamental reason why this is not possible. E.g. security implications. I don't remember all the details. Let's see what Mike thinks regarding migration (e.g., security concerns). -- Thanks, David / dhildenb 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=-5.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 31226C433DB for ; Tue, 2 Feb 2021 14:35:05 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 D6CE564DDC for ; Tue, 2 Feb 2021 14:35:04 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D6CE564DDC Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=F54Ou54Y3ZDQhtdsmHOOXI8SXW+NGboG2CWEYthGrDQ=; b=AaNB/mMjGw/Y2gtpKh440A6z7 QDL9oE5FhwUc9bBUDJJdehN2paD9n3tHhYdLFohU5ipEvCIYrEuNgRyYFM4yzZsTR1d7vsxnk8GZ1 /B/vFjt4UUDquu13wNkYWyjecFPr02FylMLMI8FL0nsZv4vDzk5NWgF7lGmn3Fa7PXE1p2GqUBCfK f2xL4pzUHgw5yf5O8/DNmpx855sWOkFfjHfJGYE8NcwX8eE+PpdvnZ/MwtyRmRpeHq3ZI0wYv0vwX vfst2E+voQjvKrYQaf1JTeebBJ9QVA/A4Kyz9i1JwDYwwXQE+vj6YiT1+2XmWs5pEahBKOLoJRnkH zbHh4m+Ng==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l6wlc-0001pV-CS; Tue, 02 Feb 2021 14:34:56 +0000 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1l6wlZ-0001o3-BC for linux-riscv@lists.infradead.org; Tue, 02 Feb 2021 14:34:54 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1612276493; 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=DMQGIZBX3ZSdULucq6YnujqHSWIcTSgvTL7Om1Dz16I=; b=TB4f54GA6of7/fhHlL/DuK168L4SCX0eFlv9Nj8+BS15mujoNNh6Zh3wB3ferDM6D4LsUp RzxQbicNJa2cuAV1vIX2jC3Yl57abYxTir8Gadw03l/KFjyRH7KGgjWtMYBNIb+ZwZ/p1A F/GWWPlOnXmMZeSqeqhRJ/9dts0hSrg= 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-464-dkvrsbKJMeCl98dqyoVbLw-1; Tue, 02 Feb 2021 09:34:48 -0500 X-MC-Unique: dkvrsbKJMeCl98dqyoVbLw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 0E886184DBF0; Tue, 2 Feb 2021 14:34:44 +0000 (UTC) Received: from [10.36.114.148] (ovpn-114-148.ams2.redhat.com [10.36.114.148]) by smtp.corp.redhat.com (Postfix) with ESMTP id 505D15D9C6; Tue, 2 Feb 2021 14:34:36 +0000 (UTC) Subject: Re: [PATCH v16 07/11] secretmem: use PMD-size pages to amortize direct map fragmentation To: Michal Hocko References: <73738cda43236b5ac2714e228af362b67a712f5d.camel@linux.ibm.com> <6de6b9f9c2d28eecc494e7db6ffbedc262317e11.camel@linux.ibm.com> <20210202124857.GN242749@kernel.org> <6653288a-dd02-f9de-ef6a-e8d567d71d53@redhat.com> <211f0214-1868-a5be-9428-7acfc3b73993@redhat.com>

From: David Hildenbrand Organization: Red Hat GmbH Message-ID: <95625b83-f7e2-b27a-2b99-d231338047fb@redhat.com> Date: Tue, 2 Feb 2021 15:34:29 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.5.0 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210202_093453_426400_4D72D874 X-CRM114-Status: GOOD ( 18.83 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Peter Zijlstra , Catalin Marinas , Dave Hansen , linux-mm@kvack.org, linux-kselftest@vger.kernel.org, "H. Peter Anvin" , Christopher Lameter , Shuah Khan , Thomas Gleixner , Elena Reshetova , linux-arch@vger.kernel.org, Tycho Andersen , linux-nvdimm@lists.01.org, Will Deacon , x86@kernel.org, Matthew Wilcox , Mike Rapoport , Ingo Molnar , Michael Kerrisk , Palmer Dabbelt , Arnd Bergmann , James Bottomley , Hagen Paul Pfeifer , Borislav Petkov , Alexander Viro , Andy Lutomirski , Paul Walmsley , "Kirill A. Shutemov" , Dan Williams , linux-arm-kernel@lists.infradead.org, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, Palmer Dabbelt , linux-fsdevel@vger.kernel.org, Shakeel Butt , Andrew Morton , Rick Edgecombe , Roman Gushchin , Mike Rapoport Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On 02.02.21 15:32, Michal Hocko wrote: > On Tue 02-02-21 15:26:20, David Hildenbrand wrote: >> On 02.02.21 15:22, Michal Hocko wrote: >>> On Tue 02-02-21 15:12:21, David Hildenbrand wrote: >>> [...] >>>> I think secretmem behaves much more like longterm GUP right now >>>> ("unmigratable", "lifetime controlled by user space", "cannot go on >>>> CMA/ZONE_MOVABLE"). I'd either want to reasonably well control/limit it or >>>> make it behave more like mlocked pages. >>> >>> I thought I have already asked but I must have forgotten. Is there any >>> actual reason why the memory is not movable? Timing attacks? >> >> I think the reason is simple: no direct map, no copying of memory. > > This is an implementation detail though and not something terribly hard > to add on top later on. I was more worried there would be really > fundamental reason why this is not possible. E.g. security implications. I don't remember all the details. Let's see what Mike thinks regarding migration (e.g., security concerns). -- Thanks, David / dhildenb _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv 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=-5.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 49AD6C433E0 for ; Tue, 2 Feb 2021 14:36:06 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 D6DC764F4D for ; Tue, 2 Feb 2021 14:36:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D6DC764F4D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Ab2dY/GEUvhFXmHu6OErDvcGf9pWJgxak1WtowskcXA=; b=S4MuVxJg2G6NSoS2x3OMrpFzo i+3lRnDmIBKdSPniqZQqvn7KuDREmI5Qy2PHkTYG6xOfLW/JCJEPpHZypyv+R1UAk3/Vyd/Qud4YS dR4Zdx/Iqu2OMTsDZZpoANoKTeQR15en04IvCumNL4p1gPr60hz8dkI1T3klPnV/EEy1xaHIdPYG9 NTAz5jzq8TgKd7r0l6WmEFlzGGAhLI+PGAKpqxW3lYVF2qxO7wpF3T98/O8RJMvAOkJe0AyyfFCQQ DQa53dRdJ9CFoQPQt7LtajmNU17mGa0W3uo+scfyxyKpjnYWtNUoRzeCK+gGXXK1G5VAloR6WgWUQ ZTuz9msMw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l6wlf-0001q1-00; Tue, 02 Feb 2021 14:34:59 +0000 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1l6wlZ-0001o4-BE for linux-arm-kernel@lists.infradead.org; Tue, 02 Feb 2021 14:34:56 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1612276493; 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=DMQGIZBX3ZSdULucq6YnujqHSWIcTSgvTL7Om1Dz16I=; b=TB4f54GA6of7/fhHlL/DuK168L4SCX0eFlv9Nj8+BS15mujoNNh6Zh3wB3ferDM6D4LsUp RzxQbicNJa2cuAV1vIX2jC3Yl57abYxTir8Gadw03l/KFjyRH7KGgjWtMYBNIb+ZwZ/p1A F/GWWPlOnXmMZeSqeqhRJ/9dts0hSrg= 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-464-dkvrsbKJMeCl98dqyoVbLw-1; Tue, 02 Feb 2021 09:34:48 -0500 X-MC-Unique: dkvrsbKJMeCl98dqyoVbLw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 0E886184DBF0; Tue, 2 Feb 2021 14:34:44 +0000 (UTC) Received: from [10.36.114.148] (ovpn-114-148.ams2.redhat.com [10.36.114.148]) by smtp.corp.redhat.com (Postfix) with ESMTP id 505D15D9C6; Tue, 2 Feb 2021 14:34:36 +0000 (UTC) Subject: Re: [PATCH v16 07/11] secretmem: use PMD-size pages to amortize direct map fragmentation To: Michal Hocko References: <73738cda43236b5ac2714e228af362b67a712f5d.camel@linux.ibm.com> <6de6b9f9c2d28eecc494e7db6ffbedc262317e11.camel@linux.ibm.com> <20210202124857.GN242749@kernel.org> <6653288a-dd02-f9de-ef6a-e8d567d71d53@redhat.com> <211f0214-1868-a5be-9428-7acfc3b73993@redhat.com>