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=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 7BA14C74A3F for ; Wed, 10 Jul 2019 23:42:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 54A0821530 for ; Wed, 10 Jul 2019 23:42:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=aol.com header.i=@aol.com header.b="NWn4mMA7" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727834AbfGJXmj (ORCPT ); Wed, 10 Jul 2019 19:42:39 -0400 Received: from sonic303-21.consmr.mail.ir2.yahoo.com ([77.238.178.202]:36735 "EHLO sonic303-21.consmr.mail.ir2.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727220AbfGJXmj (ORCPT ); Wed, 10 Jul 2019 19:42:39 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=aol.com; s=a2048; t=1562802156; bh=dk97VOnEirqZGW/C4jJZaUVdSBxy5Zj+0GzwIPvKK30=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From:Subject; b=NWn4mMA7TRvb2AsUI6USWmjL+jWMNY8SqXPCPB0Zmdx1gPg1zll4t29tc1oNPXsyhhe2gwAujgi9pD6oa3djsb/wbjN4www/vlwUFTA7C3i8XhqeFJ71zQgVSClmPa5o3VnSm1VBoGz8tjT8TV0VfcazeSyrajNUNL3fiMTDV7EY7qvFc2dEQ6GZw85WPJ6/zhqS3gNX6Fw2CXHoJNokY+mkwEbKHXO5OvNBMSHVh9JICdDzbmzD7QvKmMEFe1Lt9E3xPZnO+CjluBqHOeBR2lxJIK/MQZ+g+GHaKpz6ZaxJkyDlAYE0UbsAU/JIYgeEYO1cNIESs/Qhd+G3WrHbAg== X-YMail-OSG: E3F8to0VM1lxsh9FADTaRfvpLst1eRzWVhrH9QDugxBepJ04eijm0ZXK2CQjq_z d3J5gTj6JVk93_wRbN4ZvIquLkVgCq0Uac4N2w7NV082cSbr6sz1GBRIofvl0ZSK1C8fKPsWhSV4 bbBvnWiV4Y315tKvAxulQL9klAarfYafa8XGnzJMwqWzRggrM1Pe7yEfAHghy6dYYTOORhEuSDO. A30ELrUL67WOdUbA00HhBanaUN0cyCpc0i65Td.71IZGm6t9qjbO5HMIz2Z.bTAiU0tNi77MSBSA bQs4_VVnQbxhs0m5PCYf8TgqDTUg58oEZTpddrzTrmdoxiFhAWzn42gOwpgIV0pwJL.q9Ta.iBNd 09zxBa.fg98h2zyrjc3VtKef1LbJhMTHzK74zE8swopH7KNyPaXzd6qKgkcwPAdXxJrlJibcEcBc Jbnsel8_iXN0c3ZeCXJgDxKhC4eQPt9MN0TedlzcYR7ezt51Q2lVZaRlyMcx81ikxn1KfhsUSLR7 QDRyQQ4i6rrdgYWYBkB8B_kuxfc8Hv4UQo_Lpc2OnevRCyN0IY2sowUiV0nG5y.cEq7hElf3vq.N 6PQdt7s6CfnFUXqcigYIWc.W.pDTmlcytRc2BLZpJmpsdCuYzJQJ1UiuKkjYyhaPxjZqk4agPLLk FxzV6ODxHtY2y96snE1fb2FMiAnFNQIJjj0qEIAbjENER.hz1ZmziKA7ThVjW3qjKCP85U8Skrt_ 2GU67NHAejgJn9QLLLXQRjcEI0GqXB92cA10lTPWQeMWJPLD5HtBWjoVGR7RaIiJJtIak_iPjN_e skGfkmMPl2M5yYK7vVDjHvIRQyXsdHSJmEBfbJHrzysULmQC7fLoBcrj7dlUH1KMcwRw.4x4R7FW 1QjvII.Bm9rMWUyriE6DO6gHc9kWgdKQnPmtcNE4eZzwaZG0Y1V7kR.1F_dk3VQfjzouhAG.3KfL RMAJ4VYpFuH9Q1J6I744jHTRW.y95iIBwuCrH0eD1FlDVsu4KYB_U5j4dcsyKPGXv4dGGJiJJyH4 p8NrdkQVqS9lMZNMxDDxoms8BAqhHjtwiWYsi0wQxTNg06JjcXnLQzLQkZ30HEfyHv16ZbE1BEnI CfNADe.qah45J5tXIGDCFF7fTh9Mx5Gt9DWnZGl5JQ8UY1fW_K9M1.haRcFzJZ2FNHRYkBQHiMGp hpHXVXvj9a5zybkrdIoM47yocnP7YYgoh6ozLGJOljn5h Received: from sonic.gate.mail.ne1.yahoo.com by sonic303.consmr.mail.ir2.yahoo.com with HTTP; Wed, 10 Jul 2019 23:42:36 +0000 Received: by smtp404.mail.ir2.yahoo.com (Oath Hermes SMTP Server) with ESMTPA ID d9e0da08a84931d992641df66c776383; Wed, 10 Jul 2019 23:42:31 +0000 (UTC) Subject: Re: [RFC PATCH] iomap: generalize IOMAP_INLINE to cover tail-packing case To: =?UTF-8?Q?Andreas_Gr=c3=bcnbacher?= Cc: Chao Yu , Christoph Hellwig , "Darrick J. Wong" , linux-xfs@vger.kernel.org, Linux FS-devel Mailing List , Gao Xiang , chao@kernel.org References: <20190703075502.79782-1-yuchao0@huawei.com> <39944e50-5888-f900-1954-91be2b12ea5b@huawei.com> From: Gao Xiang Message-ID: <1506e523-109d-7253-ee4b-961c4264781d@aol.com> Date: Thu, 11 Jul 2019 07:42:20 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Content-Language: en-US Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org At 2019/7/11 ??????5:50, Andreas Gr??nbacher Wrote: > At this point, can I ask how important this packing mechanism is to > you? I can see a point in implementing inline files, which help > because there tends to be a large number of very small files. But for > not-so-small files, is saving an extra block really worth the trouble, > especially given how cheap storage has become? I would try to answer the above. I think there are several advantages by using tail-end packing inline: 1) It is more cache-friendly. Considering a file "A" accessed by user now or recently, we ?????? tend to (1) get more data about "A" (2) leave more data about "A" according to LRU-like assumption ?????? because it is more likely to be used than the metadata of some other files "X", especially for files whose ?????? tail-end block is relatively small enough (less than a threshold, e.g. < 100B just for example); 2) for directories files, tail-end packing will boost up those traversal performance; 3) I think tail-end packing is a more generic inline, it saves I/Os for generic cases not just to ?????? save the storage space; "is saving an extra block really worth the trouble" I dont understand what exact the trouble is... Thanks, Gao Xiang