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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 44EB5C433E0 for ; Mon, 25 May 2020 14:57:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 23CDF20890 for ; Mon, 25 May 2020 14:57:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404045AbgEYO47 (ORCPT ); Mon, 25 May 2020 10:56:59 -0400 Received: from mail-pl1-f194.google.com ([209.85.214.194]:39214 "EHLO mail-pl1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404031AbgEYO46 (ORCPT ); Mon, 25 May 2020 10:56:58 -0400 Received: by mail-pl1-f194.google.com with SMTP id x18so6456735pll.6; Mon, 25 May 2020 07:56:58 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:autocrypt :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=GSeJgzuS0GkUO6N4+8ogkUKTdXsBLtVqabwwiImp2S8=; b=oq3coC4jkhtNyyYeCTx+TNmmWoiYcNTdBGClCB3F05f0tLSu9jANtUjTaqKMFuv3vv 4qGN94WMZpgmNNv6cDZbuRmecb7/V7j3qvVjvjDJ8SePHXFf4MBW3pdy2fD86BjmUrxU 3ZAj4GJ2rI0UcJP93HGLxUDdt062Fb4nkTunTsnpSOkhm9BHia/FmXrvosMlgxUvV8/A EiFD5dCuyX1mOivDbBqSEp6JEgjtg6DpzLGhGDkg+fjSMt19E+rqfftg1t7CO8rIcck6 HH9XYTXCOcCAgghAGrGVeU/hF2KFJtaZaOU9jkTwcyZ9NjWhun59dEreTIhR+rpYlG/r yXpQ== X-Gm-Message-State: AOAM530fuqVo1VTJD8pDaIwKE2deFDtt7EqKY0GzNGojZJoVymv9RAQs JyNaIYAYePBpmDuoG0pTFy0= X-Google-Smtp-Source: ABdhPJwZ/vs3v7MT7XANjdmm69IbXqeYAMZns5n/UGzbtqQHE2TqeH5PKsQe3K1u5pc0vEdzKqx4aA== X-Received: by 2002:a17:90a:7087:: with SMTP id g7mr21975421pjk.70.1590418617729; Mon, 25 May 2020 07:56:57 -0700 (PDT) Received: from ?IPv6:2601:647:4000:d7:2590:9462:ff8a:101f? ([2601:647:4000:d7:2590:9462:ff8a:101f]) by smtp.gmail.com with ESMTPSA id o18sm137417pjp.4.2020.05.25.07.56.55 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 25 May 2020 07:56:56 -0700 (PDT) Subject: Re: Another approach of UFSHPB To: daejun7.park@samsung.com, yongmyung lee , Avri Altman , "James E . J . Bottomley" , "Martin K . Petersen" , "linux-scsi@vger.kernel.org" , "linux-kernel@vger.kernel.org" Cc: ALIM AKHTAR , "asutoshd@codeaurora.org" , Zang Leigang , Avi Shchislowski , Bean Huo , "cang@codeaurora.org" , "stanley.chu@mediatek.com" , MOHAMMED RAFIQ KAMAL BASHA , Sang-yoon Oh , Jinyoung CHOI , Adel Choi , BoRam Shin , Sung-Jun Park References: <835c57b9-f792-2460-c3cc-667031969d63@acm.org> <1589538614-24048-1-git-send-email-avri.altman@wdc.com> <231786897.01589928601376.JavaMail.epsvc@epcpadp1> <231786897.01590385382061.JavaMail.epsvc@epcpadp2> From: Bart Van Assche Autocrypt: addr=bvanassche@acm.org; prefer-encrypt=mutual; keydata= mQENBFSOu4oBCADcRWxVUvkkvRmmwTwIjIJvZOu6wNm+dz5AF4z0FHW2KNZL3oheO3P8UZWr LQOrCfRcK8e/sIs2Y2D3Lg/SL7qqbMehGEYcJptu6mKkywBfoYbtBkVoJ/jQsi2H0vBiiCOy fmxMHIPcYxaJdXxrOG2UO4B60Y/BzE6OrPDT44w4cZA9DH5xialliWU447Bts8TJNa3lZKS1 AvW1ZklbvJfAJJAwzDih35LxU2fcWbmhPa7EO2DCv/LM1B10GBB/oQB5kvlq4aA2PSIWkqz4 3SI5kCPSsygD6wKnbRsvNn2mIACva6VHdm62A7xel5dJRfpQjXj2snd1F/YNoNc66UUTABEB AAG0JEJhcnQgVmFuIEFzc2NoZSA8YnZhbmFzc2NoZUBhY20ub3JnPokBOQQTAQIAIwUCVI67 igIbAwcLCQgHAwIBBhUIAgkKCwQWAgMBAh4BAheAAAoJEHFcPTXFzhAJ8QkH/1AdXblKL65M Y1Zk1bYKnkAb4a98LxCPm/pJBilvci6boefwlBDZ2NZuuYWYgyrehMB5H+q+Kq4P0IBbTqTa jTPAANn62A6jwJ0FnCn6YaM9TZQjM1F7LoDX3v+oAkaoXuq0dQ4hnxQNu792bi6QyVdZUvKc macVFVgfK9n04mL7RzjO3f+X4midKt/s+G+IPr4DGlrq+WH27eDbpUR3aYRk8EgbgGKvQFdD CEBFJi+5ZKOArmJVBSk21RHDpqyz6Vit3rjep7c1SN8s7NhVi9cjkKmMDM7KYhXkWc10lKx2 RTkFI30rkDm4U+JpdAd2+tP3tjGf9AyGGinpzE2XY1K5AQ0EVI67igEIAKiSyd0nECrgz+H5 PcFDGYQpGDMTl8MOPCKw/F3diXPuj2eql4xSbAdbUCJzk2ETif5s3twT2ER8cUTEVOaCEUY3 eOiaFgQ+nGLx4BXqqGewikPJCe+UBjFnH1m2/IFn4T9jPZkV8xlkKmDUqMK5EV9n3eQLkn5g lco+FepTtmbkSCCjd91EfThVbNYpVQ5ZjdBCXN66CKyJDMJ85HVr5rmXG/nqriTh6cv1l1Js T7AFvvPjUPknS6d+BETMhTkbGzoyS+sywEsQAgA+BMCxBH4LvUmHYhpS+W6CiZ3ZMxjO8Hgc ++w1mLeRUvda3i4/U8wDT3SWuHcB3DWlcppECLkAEQEAAYkBHwQYAQIACQUCVI67igIbDAAK CRBxXD01xc4QCZ4dB/0QrnEasxjM0PGeXK5hcZMT9Eo998alUfn5XU0RQDYdwp6/kMEXMdmT oH0F0xB3SQ8WVSXA9rrc4EBvZruWQ+5/zjVrhhfUAx12CzL4oQ9Ro2k45daYaonKTANYG22y //x8dLe2Fv1By4SKGhmzwH87uXxbTJAUxiWIi1np0z3/RDnoVyfmfbbL1DY7zf2hYXLLzsJR mSsED/1nlJ9Oq5fALdNEPgDyPUerqHxcmIub+pF0AzJoYHK5punqpqfGmqPbjxrJLPJfHVKy goMj5DlBMoYqEgpbwdUYkH6QdizJJCur4icy8GUNbisFYABeoJ91pnD4IGei3MTdvINSZI5e Message-ID: <6eec7c64-d4c1-c76e-5c14-7904a8792275@acm.org> Date: Mon, 25 May 2020 07:56:54 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: <231786897.01590385382061.JavaMail.epsvc@epcpadp2> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020-05-24 22:40, Daejun Park wrote: > The HPB driver is close to the UFS core function, but it is not essential > for operating UFS device. With reference to this article > (https://lwn.net/Articles/645810/), we implemented extended UFS-feature > as bus model. Because the HPB driver consumes the user's main memory, it should > support bind / unbind functionality as needed. We implemented the HPB driver > can be unbind / unload on runtime. I do not agree that the bus model is the best choice for freeing cache memory if it is no longer needed. A shrinker is probably a much better choice because the callback functions in a shrinker get invoked when a system is under memory pressure. See also register_shrinker(), unregister_shrinker() and struct shrinker in include/linux/shrinker.h. >> Should these parameters be per module or per UFS device? > > I think it is necessary to take parameters for each module. > This is because each extended UFS-feature module has different functions > and may require different parameters. My question was a rhetorical question. Please choose per device parameters when appropriate instead of module parameters. Thanks, Bart.