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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 83D14C433F5 for ; Tue, 12 Apr 2022 19:27:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1355924AbiDLT3U (ORCPT ); Tue, 12 Apr 2022 15:29:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58266 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352096AbiDLT3M (ORCPT ); Tue, 12 Apr 2022 15:29:12 -0400 Received: from mail-lj1-x22f.google.com (mail-lj1-x22f.google.com [IPv6:2a00:1450:4864:20::22f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E103948E76 for ; Tue, 12 Apr 2022 12:26:51 -0700 (PDT) Received: by mail-lj1-x22f.google.com with SMTP id 15so10523294ljw.8 for ; Tue, 12 Apr 2022 12:26:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=shutemov-name.20210112.gappssmtp.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=uhp2gyxJXafqQhufiyepsQB0fVUjcBdyLXTovCl6zhk=; b=5r3BqAvHHqrB2sxGTnYHVAS69nI4KU7prcQCYLC+0giVYjXTuDzbhcWunmrmixMgiI l6KAoj+O6vndDV8nCt3/S5YfZKl20CFaNrJbcc41X99anlIpoxpW/y7x7Y1M8Moxl+/V 1/swlz2HX63Q+NBEhUfmJQEpWAJDocdiEL2YUckMfpe3C8nZcla3i0xFsf7D/9DkQ9ru eAJG41WiqDv83Av6IuPIHFgdRnfdlNyaK+rskTFa67tR2m82ZCspiqGtd/RBP6s+qYm3 8gfkf6bS7/JwsfLxy6EmCDw65cudX7DLbyf2e7vFavB5H90QMXcKGJMnj7FuirippGU7 eNJQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=uhp2gyxJXafqQhufiyepsQB0fVUjcBdyLXTovCl6zhk=; b=M4CVNCAAjgUcRjFPUh13eDsAu5XQoRpGyMa7FSMZe7/TNPR2+pK4tl52NS4ht5Bn4A AlN5rQFPHCn/VulLwogyS2uh69cDlf2RPz7EjzmQpfYxM/IlNhaeuR5SjVGiBH9AiqMY PHFD1XSLjFVr9T1vOvsq65IOx9Isp5Pikx0qQr8EaOF9Vl5KfT/iK2wy3N48BcV0YwGS WiuXEknwaJHJP4sdfcp+355n7clpFJDMppc87JEfERD6OgJvymyNfJo4dBtFLOxDcIAc UgoExyx4T4mjwjFH3AxUYxH/vR3LZ3JcNdXi30sUo7kjz2Y1zDMEO00Oc5CQBu91glAy 2s4g== X-Gm-Message-State: AOAM533MAG7rOku8VvSYT6AOxMm7xe74UrE330omR1+gr9kHpzB1NuyY eUK0+ddnZSr097YWzcaFBjLF8A== X-Google-Smtp-Source: ABdhPJzNqQFsr22ki1Pj8rD15MClx6e4/Y9XgiO6Rr06pMklFiRq4YmMNE+KUcyBNh7zLIW+Z44IOA== X-Received: by 2002:a05:651c:1a09:b0:24a:c7df:339c with SMTP id by9-20020a05651c1a0900b0024ac7df339cmr25219403ljb.298.1649791610046; Tue, 12 Apr 2022 12:26:50 -0700 (PDT) Received: from box.localdomain ([86.57.175.117]) by smtp.gmail.com with ESMTPSA id h19-20020a056512055300b0046bb9a59e13sm309392lfl.56.2022.04.12.12.26.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 12 Apr 2022 12:26:49 -0700 (PDT) Received: by box.localdomain (Postfix, from userid 1000) id 72EEB1030D2; Tue, 12 Apr 2022 22:28:21 +0300 (+03) Date: Tue, 12 Apr 2022 22:28:21 +0300 From: "Kirill A. Shutemov" To: Chao Peng Cc: Sean Christopherson , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org, qemu-devel@nongnu.org, Paolo Bonzini , Jonathan Corbet , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H . Peter Anvin" , Hugh Dickins , Jeff Layton , "J . Bruce Fields" , Andrew Morton , Mike Rapoport , Steven Price , "Maciej S . Szmigiero" , Vlastimil Babka , Vishal Annapurve , Yu Zhang , "Kirill A . Shutemov" , luto@kernel.org, jun.nakajima@intel.com, dave.hansen@intel.com, ak@linux.intel.com, david@redhat.com Subject: Re: [PATCH v5 04/13] mm/shmem: Restrict MFD_INACCESSIBLE memory against RLIMIT_MEMLOCK Message-ID: <20220412192821.xliop57sblvjx4t4@box.shutemov.name> References: <20220310140911.50924-1-chao.p.peng@linux.intel.com> <20220310140911.50924-5-chao.p.peng@linux.intel.com> <20220411153233.54ljmi7zgqovhgsn@box.shutemov.name> <20220412133925.GG8013@chaop.bj.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220412133925.GG8013@chaop.bj.intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 12, 2022 at 09:39:25PM +0800, Chao Peng wrote: > On Mon, Apr 11, 2022 at 06:32:33PM +0300, Kirill A. Shutemov wrote: > > On Thu, Apr 07, 2022 at 04:05:36PM +0000, Sean Christopherson wrote: > > > Hmm, shmem_writepage() already handles SHM_F_INACCESSIBLE by rejecting the swap, so > > > maybe it's just the page migration path that needs to be updated? > > > > My early version prevented migration with -ENOTSUPP for > > address_space_operations::migratepage(). > > > > What's wrong with that approach? > > I previously thought migratepage will not be called since we already > marked the pages as UNMOVABLE, sounds not correct? Do you mean missing __GFP_MOVABLE? I can be wrong, but I don't see that it direclty affects if the page is migratable. It is a hint to page allocator to group unmovable pages to separate page block and impove availablity of higher order pages this way. Page allocator tries to allocate unmovable pages from pages blocks that already have unmovable pages. -- Kirill A. Shutemov