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=-0.7 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 DA309C4360F for ; Sat, 30 Mar 2019 13:24:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A7BAE218A3 for ; Sat, 30 Mar 2019 13:24:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=gmx.net header.i=@gmx.net header.b="WfzyCiBu" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730834AbfC3NYt (ORCPT ); Sat, 30 Mar 2019 09:24:49 -0400 Received: from mout.gmx.net ([212.227.17.20]:34997 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730784AbfC3NYs (ORCPT ); Sat, 30 Mar 2019 09:24:48 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1553952286; bh=7jAQ2ntaEiZKUx/MFS+mD/vyhysD5QJAA1ODp3daJCs=; h=X-UI-Sender-Class:Subject:To:Cc:References:From:Date:In-Reply-To; b=WfzyCiBuaajriHvCVPt8oVk/PjdTFRBoHqlfLQHczqdTDCBD8bm1pCnMzX2WpR0mN DM9xwQ0aEqWo31YZdQ6f8D4uFq7yeKQX1Pz6BcohS245u3bHQArRgIpTXz4fBMn29N r7GsibodXlSJDZzBXJOvrXddv7yiYqr+RInSOkf4= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from [0.0.0.0] ([210.140.77.29]) by mail.gmx.com (mrgmx101 [212.227.17.174]) with ESMTPSA (Nemesis) id 0Mhdex-1hMXvT2RSl-00MufA; Sat, 30 Mar 2019 14:24:46 +0100 Subject: Re: Is it possible that certain physical disk doesn't implement flush correctly? To: Supercilious Dude Cc: "linux-btrfs@vger.kernel.org" , Linux FS Devel , linux-block@vger.kernel.org References: <16edb2d0-ee41-908f-e0bf-5c27160ccff7@gmx.com> <948a62d3-aa3e-418e-00df-d73d4dbfb5a6@gmx.com> From: Qu Wenruo Openpgp: preference=signencrypt Autocrypt: addr=quwenruo.btrfs@gmx.com; prefer-encrypt=mutual; keydata= mQENBFnVga8BCACyhFP3ExcTIuB73jDIBA/vSoYcTyysFQzPvez64TUSCv1SgXEByR7fju3o 8RfaWuHCnkkea5luuTZMqfgTXrun2dqNVYDNOV6RIVrc4YuG20yhC1epnV55fJCThqij0MRL 1NxPKXIlEdHvN0Kov3CtWA+R1iNN0RCeVun7rmOrrjBK573aWC5sgP7YsBOLK79H3tmUtz6b 9Imuj0ZyEsa76Xg9PX9Hn2myKj1hfWGS+5og9Va4hrwQC8ipjXik6NKR5GDV+hOZkktU81G5 gkQtGB9jOAYRs86QG/b7PtIlbd3+pppT0gaS+wvwMs8cuNG+Pu6KO1oC4jgdseFLu7NpABEB AAG0IlF1IFdlbnJ1byA8cXV3ZW5ydW8uYnRyZnNAZ214LmNvbT6JAVQEEwEIAD4CGwMFCwkI BwIGFQgJCgsCBBYCAwECHgECF4AWIQQt33LlpaVbqJ2qQuHCPZHzoSX+qAUCWdWCnQUJCWYC bgAKCRDCPZHzoSX+qAR8B/94VAsSNygx1C6dhb1u1Wp1Jr/lfO7QIOK/nf1PF0VpYjTQ2au8 ihf/RApTna31sVjBx3jzlmpy+lDoPdXwbI3Czx1PwDbdhAAjdRbvBmwM6cUWyqD+zjVm4RTG rFTPi3E7828YJ71Vpda2qghOYdnC45xCcjmHh8FwReLzsV2A6FtXsvd87bq6Iw2axOHVUax2 FGSbardMsHrya1dC2jF2R6n0uxaIc1bWGweYsq0LXvLcvjWH+zDgzYCUB0cfb+6Ib/ipSCYp 3i8BevMsTs62MOBmKz7til6Zdz0kkqDdSNOq8LgWGLOwUTqBh71+lqN2XBpTDu1eLZaNbxSI ilaVuQENBFnVga8BCACqU+th4Esy/c8BnvliFAjAfpzhI1wH76FD1MJPmAhA3DnX5JDORcga CbPEwhLj1xlwTgpeT+QfDmGJ5B5BlrrQFZVE1fChEjiJvyiSAO4yQPkrPVYTI7Xj34FnscPj /IrRUUka68MlHxPtFnAHr25VIuOS41lmYKYNwPNLRz9Ik6DmeTG3WJO2BQRNvXA0pXrJH1fN GSsRb+pKEKHKtL1803x71zQxCwLh+zLP1iXHVM5j8gX9zqupigQR/Cel2XPS44zWcDW8r7B0 q1eW4Jrv0x19p4P923voqn+joIAostyNTUjCeSrUdKth9jcdlam9X2DziA/DHDFfS5eq4fEv ABEBAAGJATwEGAEIACYWIQQt33LlpaVbqJ2qQuHCPZHzoSX+qAUCWdWBrwIbDAUJA8JnAAAK CRDCPZHzoSX+qA3xB/4zS8zYh3Cbm3FllKz7+RKBw/ETBibFSKedQkbJzRlZhBc+XRwF61mi f0SXSdqKMbM1a98fEg8H5kV6GTo62BzvynVrf/FyT+zWbIVEuuZttMk2gWLIvbmWNyrQnzPl mnjK4AEvZGIt1pk+3+N/CMEfAZH5Aqnp0PaoytRZ/1vtMXNgMxlfNnb96giC3KMR6U0E+siA 4V7biIoyNoaN33t8m5FwEwd2FQDG9dAXWhG13zcm9gnk63BN3wyCQR+X5+jsfBaS4dvNzvQv h8Uq/YGjCoV1ofKYh3WKMY8avjq25nlrhzD/Nto9jHp8niwr21K//pXVA81R2qaXqGbql+zo Message-ID: <4f5586f7-aef1-4e2a-2aee-5d040c023c68@gmx.com> Date: Sat, 30 Mar 2019 21:24:37 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.5.3 MIME-Version: 1.0 In-Reply-To: Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="1izgcv07X0IHw74ZdVylyyyauGPsuYK6H" X-Provags-ID: V03:K1:mPgpHA1nBKVX94uaDMwy2FN+EoGE2mNBG9yLu2uYhX/AoZfxjlh 3PD+4gB2gN3lYxKZKGy8hj9hWopGMsTuIYeYjEQUdJ/JZhoD3u8fBpW9ykeOiDTYh9re9JG Zd/+GRecO4gOdO8Xgtx7E9r0D8yrhvH6cH8FgK+Xpry7CKDR/TStYKF5ye90SDW8Os862Eh 1NHRdfJmMrE621w7jGbwg== X-UI-Out-Filterresults: notjunk:1;V03:K0:Zr3OMGTNwCw=:GHLpU5Y0XQMlENamVV1xHm 8iJWpdEVytdKEg25A0c0qHQNVfFt4WP/vzgbyQjPLPkQpWa5W4D7X+55TvdeIt0RxvItj88fo X1D2zweycvhB9Wpco4u9Vdk1kfz+2NjwfdCYhDp7HPGGV3yLYNwzGaTowYDJyuYRZNrg0QqWx plKCKkfclqsB67sUBdDm8nuhWMBkaxPmThpyoyA1067vAC7NJKXVrCCc3KZwvJ1ROyot4qKZp wzWFf2L8lpl3vK5ubVjBhDUZUD4ZSPdfyGTKXYb/mhOvAVlGOYD0xeRGR2TF3WD/qvihseeCF 25FChoedMNVEOL413ziV+ByHZzqUMEOgPjPKNzCnrPnjSuAEfTRXnPfYJZjH9iBoIxgu0PRJI vXpWAnK5u4709LtFhGhAfLoQvOYgBdWeVY4l8DLDdL26v3BYKkymYEU4gaXOzKY2ML8mXPaoO MrY/FcSk0wQ6oKRJ7qpeGVcNa5FNB1JklMe+e3HC+EPocd6WRepoRXX9+Wl3ehxeBEnbVMiJ2 VG3dSmqHQzmwLPwOSLfvwklR4yzM0NxJfVsABNnAzQ9557LPhFvYA/RHcTAr0zXp/NuTHZvrg b90ep0CbX6kinrqxhUMrpEMK1H6BNBDXe4FY+T8t0RavXwewfKMgCxydYghNG8BTp97z4IJUt vIxS3M2LQaVQz+MKe+e3lb/nPwAnCA1QNuVhcuPGUcov6FkOV6P6Ng8xM9tFVvmr/T1w6JRN5 A78zDEUQeKAE/WAgDPwzA3YGzo8BDyxaao2NWhgYI6KLPOY9lca0rGiCRxq5u6RIUYbu4KfWV eha/sbkCPb8ByJj7h7EUFBDW9lU2Zlj+FdAj07OeMxgGbwu1HJc+WEHBwtuDa7W5mZ4viyVEm NHNkw4No9/l2l6Vk71Tr7OiZI0CHa8HGgNRDaeCvwunuUpmkKzUSHD+N1KR90/ Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --1izgcv07X0IHw74ZdVylyyyauGPsuYK6H Content-Type: multipart/mixed; boundary="NOQREzQziCX4ex6yG6MXBEfUFCWyZDAzy"; protected-headers="v1" From: Qu Wenruo To: Supercilious Dude Cc: "linux-btrfs@vger.kernel.org" , Linux FS Devel , linux-block@vger.kernel.org Message-ID: <4f5586f7-aef1-4e2a-2aee-5d040c023c68@gmx.com> Subject: Re: Is it possible that certain physical disk doesn't implement flush correctly? References: <16edb2d0-ee41-908f-e0bf-5c27160ccff7@gmx.com> <948a62d3-aa3e-418e-00df-d73d4dbfb5a6@gmx.com> In-Reply-To: --NOQREzQziCX4ex6yG6MXBEfUFCWyZDAzy Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 2019/3/30 =E4=B8=8B=E5=8D=889:14, Supercilious Dude wrote: > On Sat, 30 Mar 2019 at 13:09, Qu Wenruo wrote:= >> >> If controller is doing so, it must have its own power or at least fini= sh >> flush when controller writes to its fast cache. >> >=20 > The controller has its own battery backup to power the DRAM cache, as > well as flash storage to dump it onto in the exceedingly unlikely > event that the battery gets depleted. >=20 >> For cache case, if we have enough data, we could still find some clue = on >> the flush execution time. >> >> Despite that, for that enterprise level usage, it's OK. >> >> But for consumer level storage, I'm not sure, especially for HDDs, and= >> maybe NVMe devices. >> >=20 > How do you distinguish who is a who? Am I an enterprise or a consumer? Easy, price. :P To be honest, I don't really care about that fancy use case. It's the vendor doing its work, and if something wrong happened, customer will yell at them. I'm more interesting in the consumer level situation. Thanks, Qu >=20 > Regards >=20 --NOQREzQziCX4ex6yG6MXBEfUFCWyZDAzy-- --1izgcv07X0IHw74ZdVylyyyauGPsuYK6H Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEELd9y5aWlW6idqkLhwj2R86El/qgFAlyfbhUACgkQwj2R86El /qjeEgf/ZKJdbW0sr5a0x7OgTCMpD+BaJRstiSWEDAtPBo0d1Re7fyrV6dMw7IKR dL8ha2KgZl8F9CHOXwyo9XArMkcroEYiikguw+lzl+gHMbva+k7pwCcTPzH1B6Y5 uRxZwsaWTSFsUTEpLmrhu9Qt2wNLqIzAc7s5r91Jv17Y7po2r5W8CF6sbRaVliAH Bw2geCsg5aIF6596WDBNJaaFDIw3zEBk90BvOydmWGpc50opvWj06JSVLy4wIt/f 88uuBgJbvhdHaSwzfc64Ak7lXobAfNACNSRfG4XGqktjI++LyAnrfqmajcXNBMbE Kz9Q17nNE2kBy3Va6xpzXAm3L4kemA== =saC3 -----END PGP SIGNATURE----- --1izgcv07X0IHw74ZdVylyyyauGPsuYK6H--