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[5.186.124.214]) by smtp.gmail.com with ESMTPSA id b17sm13218700eju.76.2020.12.07.11.24.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 07 Dec 2020 11:24:54 -0800 (PST) From: "Javier =?utf-8?B?R29uesOhbGV6?=" X-Google-Original-From: Javier =?utf-8?B?R29uesOhbGV6?= Date: Mon, 7 Dec 2020 20:24:53 +0100 To: Hannes Reinecke Cc: Christoph Hellwig , SelvaKumar S , linux-nvme@lists.infradead.org, kbusch@kernel.org, axboe@kernel.dk, damien.lemoal@wdc.com, sagi@grimberg.me, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, dm-devel@redhat.com, snitzer@redhat.com, selvajove@gmail.com, nj.shetty@samsung.com, joshi.k@samsung.com, "Martin K. Petersen" , Bart Van Assche , Mikulas Patocka , linux-scsi@vger.kernel.org Subject: Re: [RFC PATCH v2 0/2] add simple copy support Message-ID: <20201207192453.vc6clbdhz73hzs7l@mpHalley> References: <20201204094659.12732-1-selvakuma.s1@samsung.com> <20201207141123.GC31159@lst.de> <01fe46ac-16a5-d4db-f23d-07a03d3935f3@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Disposition: inline In-Reply-To: <01fe46ac-16a5-d4db-f23d-07a03d3935f3@suse.de> Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 07.12.2020 15:56, Hannes Reinecke wrote: >On 12/7/20 3:11 PM, Christoph Hellwig wrote: >>So, I'm really worried about: >> >> a) a good use case. GC in f2fs or btrfs seem like good use cases, as >> does accelating dm-kcopyd. I agree with Damien that lifting dm-kcopyd >> to common code would also be really nice. I'm not 100% sure it should >> be a requirement, but it sure would be nice to have >> I don't think just adding an ioctl is enough of a use case for complex >> kernel infrastructure. >> b) We had a bunch of different attempts at SCSI XCOPY support form IIRC >> Martin, Bart and Mikulas. I think we need to pull them into this >> discussion, and make sure whatever we do covers the SCSI needs. >> >And we shouldn't forget that the main issue which killed all previous >implementations was a missing QoS guarantee. >It's nice to have simply copy, but if the implementation is _slower_ >than doing it by hand from the OS there is very little point in even >attempting to do so. >I can't see any provisions for that in the TPAR, leading me to the >assumption that NVMe simple copy will suffer from the same issue. > >So if we can't address this I guess this attempt will fail, too. Good point. We can share some performance data on how Simple Copy scales in terms of bw / latency and the CPU usage. Do you have anything else in mind? 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=-3.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 6755DC433FE for ; Mon, 7 Dec 2020 19:25:07 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0B22B238A0 for ; Mon, 7 Dec 2020 19:25:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0B22B238A0 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=javigon.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:Date:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Xc6SAfQjthPBDEd2Q4Bp0C5QN+NNtuFDCxonF2d/SuA=; b=z36PL0sk1dhImRrF3jl1antin yU2t+gwtLQtsFgZ8cfShZVBWpfGXWHZJdWSP8EEe8uuxLDH5thQbhkhi3nc2ez+g+BrN1DJt8aNLg aj2K50iETCRTlm2yxs1Q+mptOYejomTPn1h0R3aLQkuu1qhtWR3qaL43gT8BDZShvK+t9j81ZgRdq XWe7mqoGGPJ5tf6zBGQKsKCglXhloP+LyDRvdXQKXXUIGWqS6qS8vfxTxPwDwRWHArhE+8i1cXQAG v6SKBq4gIltH7EQFQ7LjQCNO0skE5E+mOWP7aSe9lA2sRZzlX4JogdyzrAIAFzq7G4BA5PA4k9frB c10yCTZcg==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kmM87-00018s-9r; Mon, 07 Dec 2020 19:25:03 +0000 Received: from mail-ej1-x643.google.com ([2a00:1450:4864:20::643]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kmM84-00017J-Rv for linux-nvme@lists.infradead.org; Mon, 07 Dec 2020 19:25:01 +0000 Received: by mail-ej1-x643.google.com with SMTP id ga15so21158070ejb.4 for ; Mon, 07 Dec 2020 11:24:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=javigon-com.20150623.gappssmtp.com; s=20150623; h=from:date:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=IVD1p2kuvVXrBfr0DQp8uX8UYpU8DuPwPA/j+U9iw7o=; b=BT+NDgyuc4B9FYRdUmCPvz8gjOkn6+mHA6vCDn6QzeHfUUeVlC9fv9qefVr60Fi4o8 N+o33ru5BmuDsrganRp9xPYlw9T4COKiKzJVIiibRWtkGYUeWzfA+vwEjIThXkXCM/Ob v+IduKCrHlR2/fbICCriKjUrIp3nu1m1Yjdr6Q9zzZw8wQ+/MzIoQ+PIjpI2AHX08tNF o79x236sD+eQzaNCTTmeXMydo7bCcfYZv2T91v+5zWh9xA1eXU1ksRhuj/YKDJDQ4LB1 0EJPtboMkRXu+WFzXkzP01egTvP5VfJha5u1lyfPXyF4vmUc1wpvHu9UBb6KiowaNlCa iHoQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:date:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=IVD1p2kuvVXrBfr0DQp8uX8UYpU8DuPwPA/j+U9iw7o=; b=EdApfy9ZvoXmW1rWEukpNF2ky+RN13s3OcXlosdR00vSCZsmI3HoM9Y6fQD2YnvyvQ LZBbwJGXVZDU1i/ARknRolflEhJ+SjL0H486cnJVhzUpru5DS729bRChkyQXw8vD4HI8 EOZtWwV9tqSfLE8dpeJuZcaTVaUyprKukfmYQgnBMg6rBb9HWTFaNzUl7CmpMYvSjTN/ 8XaCswKwoRhf08LYZa4hZ5WWFfrc8EDF58ghlNJo9i9uvrTeF339KZ5KV3ro0cvWyv+t dnGoREsU9L9C2BZNQPY1HVrbKnYXi4UDv0xWYVfIPx+qCkIkfuEzCAr2HVGAKrzgfvcV JTbQ== X-Gm-Message-State: AOAM5314VmNwzPKhG3Jq4Ho/zETv+fgoFHF/nN/BCShVLWyDONzoa0yn +639cdhpXERzF651/AFt47n7eQ== X-Google-Smtp-Source: ABdhPJz9bYSQy3NHjmWx84lzpD6uTWLsBYmyjEhdoYT4EzGm+iefSEkI4OwWBZ212/zNmk1iIBD9rw== X-Received: by 2002:a17:906:b08b:: with SMTP id x11mr20225762ejy.302.1607369095020; Mon, 07 Dec 2020 11:24:55 -0800 (PST) Received: from localhost (5.186.124.214.cgn.fibianet.dk. [5.186.124.214]) by smtp.gmail.com with ESMTPSA id b17sm13218700eju.76.2020.12.07.11.24.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 07 Dec 2020 11:24:54 -0800 (PST) From: "Javier =?utf-8?B?R29uesOhbGV6?=" X-Google-Original-From: Javier =?utf-8?B?R29uesOhbGV6?= Date: Mon, 7 Dec 2020 20:24:53 +0100 To: Hannes Reinecke Subject: Re: [RFC PATCH v2 0/2] add simple copy support Message-ID: <20201207192453.vc6clbdhz73hzs7l@mpHalley> References: <20201204094659.12732-1-selvakuma.s1@samsung.com> <20201207141123.GC31159@lst.de> <01fe46ac-16a5-d4db-f23d-07a03d3935f3@suse.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <01fe46ac-16a5-d4db-f23d-07a03d3935f3@suse.de> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201207_142500_936031_CB5BFF0E X-CRM114-Status: GOOD ( 15.92 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: axboe@kernel.dk, damien.lemoal@wdc.com, SelvaKumar S , sagi@grimberg.me, snitzer@redhat.com, selvajove@gmail.com, linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, nj.shetty@samsung.com, linux-block@vger.kernel.org, dm-devel@redhat.com, Mikulas Patocka , joshi.k@samsung.com, "Martin K. Petersen" , kbusch@kernel.org, linux-scsi@vger.kernel.org, Christoph Hellwig , Bart Van Assche Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On 07.12.2020 15:56, Hannes Reinecke wrote: >On 12/7/20 3:11 PM, Christoph Hellwig wrote: >>So, I'm really worried about: >> >> a) a good use case. GC in f2fs or btrfs seem like good use cases, as >> does accelating dm-kcopyd. I agree with Damien that lifting dm-kcopyd >> to common code would also be really nice. I'm not 100% sure it should >> be a requirement, but it sure would be nice to have >> I don't think just adding an ioctl is enough of a use case for complex >> kernel infrastructure. >> b) We had a bunch of different attempts at SCSI XCOPY support form IIRC >> Martin, Bart and Mikulas. I think we need to pull them into this >> discussion, and make sure whatever we do covers the SCSI needs. >> >And we shouldn't forget that the main issue which killed all previous >implementations was a missing QoS guarantee. >It's nice to have simply copy, but if the implementation is _slower_ >than doing it by hand from the OS there is very little point in even >attempting to do so. >I can't see any provisions for that in the TPAR, leading me to the >assumption that NVMe simple copy will suffer from the same issue. > >So if we can't address this I guess this attempt will fail, too. Good point. We can share some performance data on how Simple Copy scales in terms of bw / latency and the CPU usage. Do you have anything else in mind? _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme 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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 76315C4361B for ; Wed, 9 Dec 2020 09:57:13 +0000 (UTC) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [63.128.21.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C1A3C23433 for ; Wed, 9 Dec 2020 09:57:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C1A3C23433 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=javigon.com Authentication-Results: mail.kernel.org; spf=tempfail smtp.mailfrom=dm-devel-bounces@redhat.com Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-226-hb3mCaY2Plm8591Rk73oUw-1; Wed, 09 Dec 2020 04:57:09 -0500 X-MC-Unique: hb3mCaY2Plm8591Rk73oUw-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 53750809DD6; Wed, 9 Dec 2020 09:57:05 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.21]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 332565C266; Wed, 9 Dec 2020 09:57:05 +0000 (UTC) Received: from lists01.pubmisc.prod.ext.phx2.redhat.com (lists01.pubmisc.prod.ext.phx2.redhat.com [10.5.19.33]) by colo-mx.corp.redhat.com (Postfix) with ESMTP id D21B75002F; Wed, 9 Dec 2020 09:57:04 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) by lists01.pubmisc.prod.ext.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id 0B7JP2ct014526 for ; Mon, 7 Dec 2020 14:25:03 -0500 Received: by smtp.corp.redhat.com (Postfix) id CD6841004059; Mon, 7 Dec 2020 19:25:02 +0000 (UTC) Received: from mimecast-mx02.redhat.com (mimecast04.extmail.prod.ext.rdu2.redhat.com [10.11.55.20]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C89C91112862 for ; Mon, 7 Dec 2020 19:25:00 +0000 (UTC) Received: from us-smtp-1.mimecast.com (us-smtp-delivery-1.mimecast.com [205.139.110.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 7D296100B165 for ; Mon, 7 Dec 2020 19:25:00 +0000 (UTC) Received: from mail-ej1-f67.google.com (mail-ej1-f67.google.com [209.85.218.67]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-324-AHMT8Sk1PNG-OXgA5rlMxA-1; Mon, 07 Dec 2020 14:24:56 -0500 X-MC-Unique: AHMT8Sk1PNG-OXgA5rlMxA-1 Received: by mail-ej1-f67.google.com with SMTP id f23so21174370ejk.2 for ; Mon, 07 Dec 2020 11:24:56 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:date:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=IVD1p2kuvVXrBfr0DQp8uX8UYpU8DuPwPA/j+U9iw7o=; b=j+9t6v3Vz+3KwH56VQKuH6deqe1YLY4fK9nWkj0CSxy5m9NohDlNO6EC6uApMzdodA ldGt1Ci9YytCDBqFvFMuQnsLYHC3ciF59iGvy+bD9G2/yjAlJmphho/PNO4RXFEcnQX1 s524FyhMeVUqZo7UN8gKFB76+op+YzxSwTzj3w/3Vwu8/xXdYtCgX+J6IJeyZy1EBsoR S17bx8YkJ5qT+TX1Edsi8yXV+lIXUPHYQ2+wsSic0Qw1kb/Lv4UO1vk5FW5qE1cLTehV LSXRSzG72moURYE0/uXxMYcRH8y3eXNMPH0cnGAl9xCtSHiBxiw+Ec+K+F70Qm/ue1Yk RxMg== X-Gm-Message-State: AOAM533WOn/sXXNxxmf+7a4LiWQoiU63PgdT0pOPCKBfs/ZBX/dS7zR8 Hs0NpB3bKcAW75NzySicV2eNZQ== X-Google-Smtp-Source: ABdhPJz9bYSQy3NHjmWx84lzpD6uTWLsBYmyjEhdoYT4EzGm+iefSEkI4OwWBZ212/zNmk1iIBD9rw== X-Received: by 2002:a17:906:b08b:: with SMTP id x11mr20225762ejy.302.1607369095020; Mon, 07 Dec 2020 11:24:55 -0800 (PST) Received: from localhost (5.186.124.214.cgn.fibianet.dk. [5.186.124.214]) by smtp.gmail.com with ESMTPSA id b17sm13218700eju.76.2020.12.07.11.24.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 07 Dec 2020 11:24:54 -0800 (PST) From: "Javier =?utf-8?B?R29uesOhbGV6?=" X-Google-Original-From: Javier =?utf-8?B?R29uesOhbGV6?= Date: Mon, 7 Dec 2020 20:24:53 +0100 To: Hannes Reinecke Message-ID: <20201207192453.vc6clbdhz73hzs7l@mpHalley> References: <20201204094659.12732-1-selvakuma.s1@samsung.com> <20201207141123.GC31159@lst.de> <01fe46ac-16a5-d4db-f23d-07a03d3935f3@suse.de> MIME-Version: 1.0 In-Reply-To: <01fe46ac-16a5-d4db-f23d-07a03d3935f3@suse.de> X-Mimecast-Impersonation-Protect: Policy=CLT - Impersonation Protection Definition; Similar Internal Domain=false; Similar Monitored External Domain=false; Custom External Domain=false; Mimecast External Domain=false; Newly Observed Domain=false; Internal User Name=false; Custom Display Name List=false; Reply-to Address Mismatch=false; Targeted Threat Dictionary=false; Mimecast Threat Dictionary=false; Custom Threat Dictionary=false X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 X-loop: dm-devel@redhat.com X-Mailman-Approved-At: Wed, 09 Dec 2020 04:56:16 -0500 Cc: axboe@kernel.dk, damien.lemoal@wdc.com, SelvaKumar S , sagi@grimberg.me, snitzer@redhat.com, selvajove@gmail.com, linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, nj.shetty@samsung.com, linux-block@vger.kernel.org, dm-devel@redhat.com, Mikulas Patocka , joshi.k@samsung.com, "Martin K. Petersen" , kbusch@kernel.org, linux-scsi@vger.kernel.org, Christoph Hellwig , Bart Van Assche Subject: Re: [dm-devel] [RFC PATCH v2 0/2] add simple copy support X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dm-devel-bounces@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Disposition: inline Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" On 07.12.2020 15:56, Hannes Reinecke wrote: >On 12/7/20 3:11 PM, Christoph Hellwig wrote: >>So, I'm really worried about: >> >> a) a good use case. GC in f2fs or btrfs seem like good use cases, as >> does accelating dm-kcopyd. I agree with Damien that lifting dm-kcopyd >> to common code would also be really nice. I'm not 100% sure it should >> be a requirement, but it sure would be nice to have >> I don't think just adding an ioctl is enough of a use case for complex >> kernel infrastructure. >> b) We had a bunch of different attempts at SCSI XCOPY support form IIRC >> Martin, Bart and Mikulas. I think we need to pull them into this >> discussion, and make sure whatever we do covers the SCSI needs. >> >And we shouldn't forget that the main issue which killed all previous >implementations was a missing QoS guarantee. >It's nice to have simply copy, but if the implementation is _slower_ >than doing it by hand from the OS there is very little point in even >attempting to do so. >I can't see any provisions for that in the TPAR, leading me to the >assumption that NVMe simple copy will suffer from the same issue. > >So if we can't address this I guess this attempt will fail, too. Good point. We can share some performance data on how Simple Copy scales in terms of bw / latency and the CPU usage. Do you have anything else in mind? -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel