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 6B3EFC433EF for ; Wed, 13 Apr 2022 09:15:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234345AbiDMJSO (ORCPT ); Wed, 13 Apr 2022 05:18:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56948 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234324AbiDMJSM (ORCPT ); Wed, 13 Apr 2022 05:18:12 -0400 Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4D34A245B6; Wed, 13 Apr 2022 02:15:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1649841351; x=1681377351; h=date:from:to:cc:subject:message-id:reply-to:references: mime-version:in-reply-to; bh=Qyg9qkfEOmRnd7ecWKODTY6fNCX00KNJAm/6F+S5OvQ=; b=I8ypfzxbm0qwuSXuFG30iRhXH9mb0FjfoKFFb/P3h0hxXkAWUKgsUU9P Jfi9yb+ddRDoH5iZ3QnhFkHB9Uz3zzYxETClclLkGdUF2/6QzFXpjxTZL glOtAp9hTQ3C/cnMaKnMup0faGNBjbG25qU/KDFC/yhfDswniV1D2hlDm OI4nxbp7vW/7iQmk4DkGTbmejeeRpvKCdwgiLGHeaVcC82SLInFiXoG98 4XaGa1yZ+tA0mjriZzJk10W88znaXn4bP7lFIfRhUmYvoflZN1RMfYsmW u5qgqOoMd0WwqaJsam7d/JO3Cvrmv1tcFCR3wEpT435we3DXKyEc6wiea g==; X-IronPort-AV: E=McAfee;i="6400,9594,10315"; a="260213830" X-IronPort-AV: E=Sophos;i="5.90,256,1643702400"; d="scan'208";a="260213830" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Apr 2022 02:15:51 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.90,256,1643702400"; d="scan'208";a="700175232" Received: from chaop.bj.intel.com (HELO localhost) ([10.240.192.101]) by fmsmga001.fm.intel.com with ESMTP; 13 Apr 2022 02:15:43 -0700 Date: Wed, 13 Apr 2022 17:15:33 +0800 From: Chao Peng To: "Kirill A. Shutemov" 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: <20220413091533.GC10041@chaop.bj.intel.com> Reply-To: Chao Peng 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> <20220412192821.xliop57sblvjx4t4@box.shutemov.name> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220412192821.xliop57sblvjx4t4@box.shutemov.name> User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 12, 2022 at 10:28:21PM +0300, Kirill A. Shutemov wrote: > 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? Yes. > 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. OK, thanks. Chao > > -- > Kirill A. Shutemov