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=-2.5 required=3.0 tests=MAILING_LIST_MULTI,SPF_PASS, USER_AGENT_MUTT autolearn=ham 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 E3314C43381 for ; Thu, 28 Mar 2019 22:44:38 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 8DE4E2075E for ; Thu, 28 Mar 2019 22:44:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8DE4E2075E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 30F3A6B0006; Thu, 28 Mar 2019 18:44:38 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2BE556B0007; Thu, 28 Mar 2019 18:44:38 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1AD816B0008; Thu, 28 Mar 2019 18:44:38 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from mail-pf1-f198.google.com (mail-pf1-f198.google.com [209.85.210.198]) by kanga.kvack.org (Postfix) with ESMTP id CDC2E6B0006 for ; Thu, 28 Mar 2019 18:44:37 -0400 (EDT) Received: by mail-pf1-f198.google.com with SMTP id j10so68413pfn.13 for ; Thu, 28 Mar 2019 15:44:37 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-original-authentication-results:x-gm-message-state:date:from:to :cc:subject:message-id:references:mime-version:content-disposition :in-reply-to:user-agent; bh=hoXTOMqs77/aDHAbNEOXTowKIcFUiYOGUIvRdh/SNQo=; b=RkML3x7rTxIRXVdVRYamSWIvstUuA+xDmfC1nlpo9d0+ki6VGa5vwmGAAmWIAmTqiA 6Dv56DX5cQ4NqR9vdZv3rVqQG0Re6PqzoCfuuFLU4Vv1+m1k1bpyFWolm/2mpGbLVUVT UbRIPPE8NiiAgcbU64Q9jWgWNS0V/o8xHjj4+USug8OI10l6YwS0To8yheR1Vh2YMaHR MjgfyoMoZsYJwEscWfUMu2hooOtbbqtIdqr37wc7pUuEyPPMv1rSTtyt2jyDOXhFLyAt 4WbFwfVzPqcF1hKYW4RjJ7Jx0U/P1HfzEVWLKSulrIZGBv1sTnEoVuQdCfFoAopncKpM zkTw== X-Original-Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning kbusch@kernel.org does not designate 134.134.136.31 as permitted sender) smtp.mailfrom=kbusch@kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=kernel.org X-Gm-Message-State: APjAAAVoApa01g1nCfftITqKaD0JTkvzeZkDvYF+6phSe3Dr5G4pmJ21 ppvwUaPXExA4w+/yy/GB71TEPy2d19jyiuaCD8mmqr+T3//cWM0ejlxNRaWc7RFmKCOHEFFev5n PlRgDjMmSajhE4uZMP5ZfktDoUtehb6qFxt7psm/5YeLZ7eBEzwwwqD8PkTapFjo= X-Received: by 2002:a65:6148:: with SMTP id o8mr1711248pgv.153.1553813077539; Thu, 28 Mar 2019 15:44:37 -0700 (PDT) X-Google-Smtp-Source: APXvYqw9AsE12zx/fU3P8smaHjDDeZSIdb/Unq5OqUF3fDaUj7G2HiglGK37df10lPPmDF3sKTYI X-Received: by 2002:a65:6148:: with SMTP id o8mr1711222pgv.153.1553813076848; Thu, 28 Mar 2019 15:44:36 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1553813076; cv=none; d=google.com; s=arc-20160816; b=mmkAhdiuzd67SbOileFnFs0hLJtEX4i/qm4E3+YAmdokM9ribMrTZM7o38eXuiienS G1EcEFdyOiYdJgMMeS3Hefibvm5aRYeSEKcIyS4hnQ9Cd7cqbQ+9YjNQUnBomm0Fzov4 HueCh5E9dtDEI/Y/Kgwjzml/CKQjNlOmX5lEkk7VNhOCvKGpqqOJ6QRCd+PqeWN/hjrW 0Xc/ihD+4V/Q4NLSotbZOk7LUIBCmWa+xlN8OHsQjd+H6uJ3ckiDapPDG5J9OXsixhVz hbSgTg7t5PDvIEO3uWj9Lsw1c/mvq7xNTvmxfQ69dkTLgrJ7JVSIEVBVune39Cjt0bnO xapw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date; bh=hoXTOMqs77/aDHAbNEOXTowKIcFUiYOGUIvRdh/SNQo=; b=oe5ErXuyFuOUSZ90uuxuNQzdbYGH01eRypyfl4UtI6ysOyzHjRec/8owjrksOnCvpE ZMLb6ZAArZEQqV0Ox5IVnXP5Apn/dDl5Qa7/QC1OM5gfOSMviGFlAtru8bhcnS7GD500 B5QOhCXfqyKQ4EQ+N55jWjW43UU2KNSAGVCpOR/Vijyn2RyE4gfmf/EIbQqeAcaT/KT6 kfagQUWNmRCNxq79/qHxeXKWuchggu7Xi5H2rBopxYFXMtmrVUTzRMkQwJo8v53h9tqh p4xJHd4PRF2KUreMjNuZPdlcyysfoe08emG2u8nRPLV9U0OuaSia78UOiIqtyE5iXcss NTUw== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning kbusch@kernel.org does not designate 134.134.136.31 as permitted sender) smtp.mailfrom=kbusch@kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: from mga06.intel.com (mga06.intel.com. [134.134.136.31]) by mx.google.com with ESMTPS id h125si339509pgc.290.2019.03.28.15.44.36 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 28 Mar 2019 15:44:36 -0700 (PDT) Received-SPF: softfail (google.com: domain of transitioning kbusch@kernel.org does not designate 134.134.136.31 as permitted sender) client-ip=134.134.136.31; Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning kbusch@kernel.org does not designate 134.134.136.31 as permitted sender) smtp.mailfrom=kbusch@kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=kernel.org X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 28 Mar 2019 15:44:36 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,282,1549958400"; d="scan'208";a="126781810" Received: from unknown (HELO localhost.localdomain) ([10.232.112.69]) by orsmga007.jf.intel.com with ESMTP; 28 Mar 2019 15:44:35 -0700 Date: Thu, 28 Mar 2019 16:45:50 -0600 From: Keith Busch To: Yang Shi Cc: "mhocko@suse.com" , "mgorman@techsingularity.net" , "riel@surriel.com" , "hannes@cmpxchg.org" , "akpm@linux-foundation.org" , "Hansen, Dave" , "Busch, Keith" , "Williams, Dan J" , "Wu, Fengguang" , "Du, Fan" , "Huang, Ying" , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 06/10] mm: vmscan: demote anon DRAM pages to PMEM node Message-ID: <20190328224549.GA11100@localhost.localdomain> References: <1553316275-21985-1-git-send-email-yang.shi@linux.alibaba.com> <1553316275-21985-7-git-send-email-yang.shi@linux.alibaba.com> <20190324222040.GE31194@localhost.localdomain> <20190327003541.GE4328@localhost.localdomain> <39d8fb56-df60-9382-9b47-59081d823c3c@linux.alibaba.com> <20190327130822.GD7389@localhost.localdomain> <599849e6-05b6-1e4d-7578-5cf8825963d2@linux.alibaba.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <599849e6-05b6-1e4d-7578-5cf8825963d2@linux.alibaba.com> User-Agent: Mutt/1.9.1 (2017-09-22) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Mar 28, 2019 at 02:59:30PM -0700, Yang Shi wrote: > Yes, it still could fail. I can't tell which way is better for now. I > just thought scanning another round then migrating should be still > faster than swapping off the top of my head. I think it depends on the relative capacities between your primary and migration tiers and how it's used. Applications may allocate and pin directly out of pmem if they wish, so it's not a dedicated fallback memory space like swap.