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=-8.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 741B2C43381 for ; Wed, 17 Mar 2021 02:46:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4674964FB3 for ; Wed, 17 Mar 2021 02:46:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229876AbhCQCqE (ORCPT ); Tue, 16 Mar 2021 22:46:04 -0400 Received: from m42-10.mailgun.net ([69.72.42.10]:45535 "EHLO m42-10.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229664AbhCQCp6 (ORCPT ); Tue, 16 Mar 2021 22:45:58 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1615949158; h=Message-ID: References: In-Reply-To: Subject: Cc: To: From: Date: Content-Transfer-Encoding: Content-Type: MIME-Version: Sender; bh=PFjLmq26/670K5Odqek2/4v6djpOGMkv0m21GFquOK4=; b=gUjH2s58VNR7Y9QHZS3ocjfKhC13NxLImpJUqARi5IocUnjs8pbIZHfnCJxwhQ5fEhmcNosm zXVInDEWqNGy+mVdQHR3IEaVgEXXANhoShbzEylt0xyL1IdYBBE5kgxCl06kNHq0yM/LFUQD 1eTv5RDQZ2XlOa62swhC6XgWS0Y= X-Mailgun-Sending-Ip: 69.72.42.10 X-Mailgun-Sid: WyI0MWYwYSIsICJsaW51eC1rZXJuZWxAdmdlci5rZXJuZWwub3JnIiwgImJlOWU0YSJd Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n06.prod.us-east-1.postgun.com with SMTP id 60516d586dc1045b7dcdf91a (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Wed, 17 Mar 2021 02:45:44 GMT Sender: cang=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 4F6C9C433C6; Wed, 17 Mar 2021 02:45:43 +0000 (UTC) Received: from mail.codeaurora.org (localhost.localdomain [127.0.0.1]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: cang) by smtp.codeaurora.org (Postfix) with ESMTPSA id 888FFC433CA; Wed, 17 Mar 2021 02:45:40 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Wed, 17 Mar 2021 10:45:40 +0800 From: Can Guo To: daejun7.park@samsung.com Cc: Greg KH , avri.altman@wdc.com, jejb@linux.ibm.com, martin.petersen@oracle.com, asutoshd@codeaurora.org, stanley.chu@mediatek.com, bvanassche@acm.org, huobean@gmail.com, ALIM AKHTAR , linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, JinHwan Park , Javier Gonzalez , SEUNGUK SHIN , Sung-Jun Park , Jinyoung CHOI , BoRam Shin Subject: Re: [PATCH v29 4/4] scsi: ufs: Add HPB 2.0 support In-Reply-To: <20210317014253epcms2p1f45db6a281645282e1540e0070999d73@epcms2p1> References: <2da1c963bd3ff5f682d18a251ed08989@codeaurora.org> <20210315012850epcms2p361447b689e925561c48aa9ca54434eb5@epcms2p3> <20210315013137epcms2p861f06e66be9faff32b6648401778434a@epcms2p8> <20210315070728epcms2p87136c86803afa85a441ead524130245c@epcms2p8> <20210317014253epcms2p1f45db6a281645282e1540e0070999d73@epcms2p1> Message-ID: <79aea8a80c1be2ff7f05683c2f4918ce@codeaurora.org> X-Sender: cang@codeaurora.org User-Agent: Roundcube Webmail/1.3.9 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021-03-17 09:42, Daejun Park wrote: >> On 2021-03-15 15:23, Can Guo wrote: >>> On 2021-03-15 15:07, Daejun Park wrote: >>>>>> This patch supports the HPB 2.0. >>>>>> >>>>>> The HPB 2.0 supports read of varying sizes from 4KB to 512KB. >>>>>> In the case of Read (<= 32KB) is supported as single HPB read. >>>>>> In the case of Read (36KB ~ 512KB) is supported by as a >>>>>> combination >>>>>> of >>>>>> write buffer command and HPB read command to deliver more PPN. >>>>>> The write buffer commands may not be issued immediately due to >>>>>> busy >>>>>> tags. >>>>>> To use HPB read more aggressively, the driver can requeue the >>>>>> write >>>>>> buffer >>>>>> command. The requeue threshold is implemented as timeout and can >>>>>> be >>>>>> modified with requeue_timeout_ms entry in sysfs. >>>>>> >>>>>> Signed-off-by: Daejun Park >>>>>> --- >>>>>> +static struct attribute *hpb_dev_param_attrs[] = { >>>>>> + &dev_attr_requeue_timeout_ms.attr, >>>>>> + NULL, >>>>>> +}; >>>>>> + >>>>>> +struct attribute_group ufs_sysfs_hpb_param_group = { >>>>>> + .name = "hpb_param_sysfs", >>>>>> + .attrs = hpb_dev_param_attrs, >>>>>> +}; >>>>>> + >>>>>> +static int ufshpb_pre_req_mempool_init(struct ufshpb_lu *hpb) >>>>>> +{ >>>>>> + struct ufshpb_req *pre_req = NULL; >>>>>> + int qd = hpb->sdev_ufs_lu->queue_depth / 2; >>>>>> + int i, j; >>>>>> + >>>>>> + INIT_LIST_HEAD(&hpb->lh_pre_req_free); >>>>>> + >>>>>> + hpb->pre_req = kcalloc(qd, sizeof(struct ufshpb_req), >>>>>> GFP_KERNEL); >>>>>> + hpb->throttle_pre_req = qd; >>>>>> + hpb->num_inflight_pre_req = 0; >>>>>> + >>>>>> + if (!hpb->pre_req) >>>>>> + goto release_mem; >>>>>> + >>>>>> + for (i = 0; i < qd; i++) { >>>>>> + pre_req = hpb->pre_req + i; >>>>>> + INIT_LIST_HEAD(&pre_req->list_req); >>>>>> + pre_req->req = NULL; >>>>>> + pre_req->bio = NULL; >>>>> >>>>> Why don't prepare bio as same as wb.m_page? Won't that save more >>>>> time >>>>> for ufshpb_issue_pre_req()? >>>> >>>> It is pre_req pool. So although we prepare bio at this time, it just >>>> only for first pre_req. >>> >>> I meant removing the bio_alloc() in ufshpb_issue_pre_req() and >>> bio_put() >>> in ufshpb_pre_req_compl_fn(). bios, in pre_req's case, just hold a >>> page. >>> So, prepare 16 (if queue depth is 32) bios here, just use them along >>> with >>> wb.m_page and call bio_reset() in ufshpb_pre_req_compl_fn(). Shall it >>> work? >>> >> >> If it works, you can even have the bio_add_pc_page() called here. >> Later >> in >> ufshpb_execute_pre_req(), you don't need to call >> ufshpb_pre_req_add_bio_page(), >> just call ufshpb_prep_entry() once instead - it save many repeated >> steps >> for a >> pre_req, and you don't even need to call bio_reset() in this case, >> since >> for a >> bio, nothing changes after it is binded with a specific page... > > Hi, Can Guo > > I tried the idea that you suggested, but it doesn't work properly. > This optimization should be done next time for enhancement. Can you elaborate please? Any error seen? Per my understanding, in the case for pre_reqs, a bio is no different from a page. Here it can reserve 16 pages for later use, which can be done the same for bios. This is not an enhancement, but a doubt - why not? Unless it is not doable. Thanks, Can Guo. > > Thanks > Daejun > >> Can Guo. >> >>> Thanks, >>> Can Guo. >>> >>>> After use it, it should be prepared bio at issue phase. >>>> >>>> Thanks, >>>> Daejun >>>> >>>>> >>>>> Thanks, >>>>> Can Guo. >>>>> >>>>>> + >>>>>> + pre_req->wb.m_page = alloc_page(GFP_KERNEL | >>>>>> __GFP_ZERO); >>>>>> + if (!pre_req->wb.m_page) { >>>>>> + for (j = 0; j < i; j++) >>>>>> + >>>>>> __free_page(hpb->pre_req[j].wb.m_page); >>>>>> + >>>>>> + goto release_mem; >>>>>> + } >>>>>> + list_add_tail(&pre_req->list_req, >>>>>> &hpb->lh_pre_req_free); >>>>>> + } >>>>>> + >>>>>> + return 0; >>>>>> +release_mem: >>>>>> + kfree(hpb->pre_req); >>>>>> + return -ENOMEM; >>>>>> +} >>>>>> + >>>>> >>>>> >>>>> >> >> >>