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=-8.2 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 9B365C2BB1D for ; Sat, 14 Mar 2020 00:18:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6F3C92074C for ; Sat, 14 Mar 2020 00:18:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=gmx.net header.i=@gmx.net header.b="R57fBkXQ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727680AbgCNASq (ORCPT ); Fri, 13 Mar 2020 20:18:46 -0400 Received: from mout.gmx.net ([212.227.15.19]:41825 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726853AbgCNASq (ORCPT ); Fri, 13 Mar 2020 20:18:46 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1584145121; bh=l3rsTurRWmWdwaxBOFrCRCMIydRDRHZD1Jh58Bi3xHk=; h=X-UI-Sender-Class:Subject:To:References:From:Date:In-Reply-To; b=R57fBkXQ1HQ55jIFBZHEfjnvwduRaSeBQGEWG3Pj+7HekV0BPF6dzzE1KblN7+BMK 1LgYPs7e19RJCGP8impVrq1VSlVsa33Nk3LLBL8Ug6MzQmVWO01xt+ZK7zGFoRFu0B rN1GKx/UgHGn+zTEisTVclixz1XC3EpFSffNJSa4= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from [0.0.0.0] ([149.28.201.231]) by mail.gmx.com (mrgmx004 [212.227.17.184]) with ESMTPSA (Nemesis) id 1MQvCv-1izWcS45Dz-00NyBn; Sat, 14 Mar 2020 01:18:41 +0100 Subject: Re: [PATCH 1/2] btrfs: do not use READA for running delayed refs To: Josef Bacik , linux-btrfs@vger.kernel.org, kernel-team@fb.com References: <20200313210954.148686-1-josef@toxicpanda.com> <20200313210954.148686-2-josef@toxicpanda.com> From: Qu Wenruo Autocrypt: addr=quwenruo.btrfs@gmx.com; prefer-encrypt=mutual; keydata= mQENBFnVga8BCACyhFP3ExcTIuB73jDIBA/vSoYcTyysFQzPvez64TUSCv1SgXEByR7fju3o 8RfaWuHCnkkea5luuTZMqfgTXrun2dqNVYDNOV6RIVrc4YuG20yhC1epnV55fJCThqij0MRL 1NxPKXIlEdHvN0Kov3CtWA+R1iNN0RCeVun7rmOrrjBK573aWC5sgP7YsBOLK79H3tmUtz6b 9Imuj0ZyEsa76Xg9PX9Hn2myKj1hfWGS+5og9Va4hrwQC8ipjXik6NKR5GDV+hOZkktU81G5 gkQtGB9jOAYRs86QG/b7PtIlbd3+pppT0gaS+wvwMs8cuNG+Pu6KO1oC4jgdseFLu7NpABEB AAG0IlF1IFdlbnJ1byA8cXV3ZW5ydW8uYnRyZnNAZ214LmNvbT6JAU4EEwEIADgCGwMFCwkI BwIGFQgJCgsCBBYCAwECHgECF4AWIQQt33LlpaVbqJ2qQuHCPZHzoSX+qAUCXZw1oQAKCRDC PZHzoSX+qCY6CACd+mWu3okGwRKXju6bou+7VkqCaHTdyXwWFTsr+/0ly5nUdDtT3yEVggPJ 3VP70wjlrxUjNjFb6iIvGYxiPOrop1NGwGYvQktgRhaIhALG6rPoSSAhGNjwGVRw0km0PlIN D29BTj/lYEk+jVM1YL0QLgAE1AI3krihg/lp/fQT53wLhR8YZIF8ETXbClQG1vJ0cllPuEEv efKxRyiTSjB+PsozSvYWhXsPeJ+KKjFen7ebE5reQTPFzSHctCdPnoR/4jSPlnTlnEvLeqcD ZTuKfQe1gWrPeevQzgCtgBF/WjIOeJs41klnYzC3DymuQlmFubss0jShLOW8eSOOWhLRuQEN BFnVga8BCACqU+th4Esy/c8BnvliFAjAfpzhI1wH76FD1MJPmAhA3DnX5JDORcgaCbPEwhLj 1xlwTgpeT+QfDmGJ5B5BlrrQFZVE1fChEjiJvyiSAO4yQPkrPVYTI7Xj34FnscPj/IrRUUka 68MlHxPtFnAHr25VIuOS41lmYKYNwPNLRz9Ik6DmeTG3WJO2BQRNvXA0pXrJH1fNGSsRb+pK EKHKtL1803x71zQxCwLh+zLP1iXHVM5j8gX9zqupigQR/Cel2XPS44zWcDW8r7B0q1eW4Jrv 0x19p4P923voqn+joIAostyNTUjCeSrUdKth9jcdlam9X2DziA/DHDFfS5eq4fEvABEBAAGJ ATwEGAEIACYCGwwWIQQt33LlpaVbqJ2qQuHCPZHzoSX+qAUCXZw1rgUJCWpOfwAKCRDCPZHz oSX+qFcEB/95cs8cM1OQdE/GgOfCGxwgckMeWyzOR7bkAWW0lDVp2hpgJuxBW/gyfmtBnUai fnggx3EE3ev8HTysZU9q0h+TJwwJKGv6sUc8qcTGFDtavnnl+r6xDUY7A6GvXEsSoCEEynby 72byGeSovfq/4AWGNPBG1L61Exl+gbqfvbECP3ziXnob009+z9I4qXodHSYINfAkZkA523JG ap12LndJeLk3gfWNZfXEWyGnuciRGbqESkhIRav8ootsCIops/SqXm0/k+Kcl4gGUO/iD/T5 oagaDh0QtOd8RWSMwLxwn8uIhpH84Q4X1LadJ5NCgGa6xPP5qqRuiC+9gZqbq4Nj Message-ID: <4b7a21f7-5676-c0e6-6e5a-75cb3fdcc377@gmx.com> Date: Sat, 14 Mar 2020 08:18:36 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: <20200313210954.148686-2-josef@toxicpanda.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="azDDdxoxfaYKiAUxpw4jhN2cZCMMuy2Ad" X-Provags-ID: V03:K1:qlisU75095Z6po+H6DmVDszeutuhzz3MJOoPY37X9WFIQMil3T9 wfO3/ov0vg7Dc71R0S16D4G9azHOGsX2DAHAaRPRTMPp7e+ROqjURgkOgVYzcqx51BR6klb 4IR7dSdC1ByOX/H42baLQmG2IMM9GmrnmfD1UVfqLjkwi5QdGQvWxecUiip+XWxA+kp9BVF 7quXO4WHTehpWBfRMpa8A== X-UI-Out-Filterresults: notjunk:1;V03:K0:zipKpmvcHT8=:IPwu5XWfOpaF3pEUrjv3ij 5R6RBZ86Ld4UP9zzjmi09sOL2zVi5WBaeKs9WK9GquaV6UmORg0zWeEARa30R5lBC2FaeeSDC 0GRcg+D6DXF8otKi+6frAQogdVWyuMfuqj47cstF7qACNunI99sLUO4/MCUadGMHotA9GS24S B9tE8lF/Ix78uWH/pCd+wgTXaik4H0CKnApW9bk0mNEofoWWXixn3a468opCBdXZGluTyjwr8 9aAv2rls5FNsa/K10NVl0x+88zxmEKRKsxldhM1hqQRwULnO7320tz04mgEd9JR3H8DK7hqwI SpKdr/N1Ig8mMyFyDvkoPXoz/o6z804LXOS9vO0OkQFLUSidggc8MxBw4TR+H3TZ4HP9hF/CH pbM7BDQvibs2o6rCsHKjIC447FOZ1mD87x8Pttp5eJ1NulMstFYmQ0DIXXBcFGzE1VZ14a0h3 OagKlWSvajTer6I5O4uBQsj96RELEzPojEd1rczFv9jrK+XVXitl6dvXOPop3Z5iyqKxp/mwq qXqch3cW1xlvUQRItyzoPrqGQiVUqvSjJPCewdjuE21dQqya13JGCp4lWKisFnSWcXsIbq60H KEo4T7KblqPH9o9MVDCgR4J6SauADuPxFqtu71JuUTck2G0q8h0cTZrO99ATwu/2awwhYB+uZ V+PDGsaD+C6dUf4GJPE0kfZxNyrZDuqjREgOfHfuJkUG8vU8Fgx4T0QiGhDn272DYJtpUlRSo rc4gHhq51FC5CN6SdyIrlZp4Zj4Vm20AQbonMl7XgzfBeDD5xnKzOmGouC7+hMMvnuwKQCXFh J5yqwLvJN4vGQydNuYMWjWtgaGXRXAviqeDqKdiIuduQ0cDJ1LNsrALtt+d8Tv6NDRWd478hT 3NeOf/o8VsCiY2Nk2qmFWXgYwz1UDDNmjlPkcUp6eqfY7oG0dMVqh5MVIPdvq+LXwPigYLGel araE3WMEBnHFnpG/SKTDB94UMP7ZkaXoFjhUdYCJnRWQCuWg2eEDZJbrWL/hPoQUarvvT0vBv 1UDrO0NSExloRhpDddivjupnHi/4geYMN4oiSWxstZM1Rz48KIwbeoHXs8phSADXNnbyAeMgm +KaTE0Y1JLSdy2QLfxqM5meG6tIsFAUFOKnvGyiZoaj3smTHgAvWiUMjEVIs4ODMlAnGohfqH yubOov9bT+odicigFJB12AcYfVIY8LrUZF/2IDRz9vcGYOTw4j6pULSBj1GMWsb0e6yAyvNqb +burbEIUz9esCekK5 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --azDDdxoxfaYKiAUxpw4jhN2cZCMMuy2Ad Content-Type: multipart/mixed; boundary="Q1R4NMqOEMGxzlYvluspbDwpLFetRSrTr" --Q1R4NMqOEMGxzlYvluspbDwpLFetRSrTr Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 2020/3/14 =E4=B8=8A=E5=8D=885:09, Josef Bacik wrote: > READA will generate a lot of extra reads for adjacent nodes, but when > running delayed refs we have no idea if the next ref is going to be > adjacent or not, so this potentially just generates a lot of extra IO. > To make matters worse each ref is truly just looking for one item, it > doesn't generally search forward, so we simply don't need it here. >=20 > Signed-off-by: Josef Bacik Reviewed-by: Qu Wenruo Thanks, Qu > --- > fs/btrfs/extent-tree.c | 4 ---- > 1 file changed, 4 deletions(-) >=20 > diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c > index a24ef1cef9fa..8e5b49baad98 100644 > --- a/fs/btrfs/extent-tree.c > +++ b/fs/btrfs/extent-tree.c > @@ -1469,7 +1469,6 @@ static int __btrfs_inc_extent_ref(struct btrfs_tr= ans_handle *trans, > if (!path) > return -ENOMEM; > =20 > - path->reada =3D READA_FORWARD; > path->leave_spinning =3D 1; > /* this will setup the path even if it fails to insert the back ref *= / > ret =3D insert_inline_extent_backref(trans, path, bytenr, num_bytes, > @@ -1494,7 +1493,6 @@ static int __btrfs_inc_extent_ref(struct btrfs_tr= ans_handle *trans, > btrfs_mark_buffer_dirty(leaf); > btrfs_release_path(path); > =20 > - path->reada =3D READA_FORWARD; > path->leave_spinning =3D 1; > /* now insert the actual backref */ > ret =3D insert_extent_backref(trans, path, bytenr, parent, root_objec= tid, > @@ -1604,7 +1602,6 @@ static int run_delayed_extent_op(struct btrfs_tra= ns_handle *trans, > } > =20 > again: > - path->reada =3D READA_FORWARD; > path->leave_spinning =3D 1; > ret =3D btrfs_search_slot(trans, fs_info->extent_root, &key, path, 0,= 1); > if (ret < 0) { > @@ -2999,7 +2996,6 @@ static int __btrfs_free_extent(struct btrfs_trans= _handle *trans, > if (!path) > return -ENOMEM; > =20 > - path->reada =3D READA_FORWARD; > path->leave_spinning =3D 1; 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