From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de ([195.135.220.15]:36307 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755942AbbKCTPn (ORCPT ); Tue, 3 Nov 2015 14:15:43 -0500 Date: Tue, 3 Nov 2015 11:15:42 -0800 From: Mark Fasheh To: Stefan Priebe Cc: Qu Wenruo , "linux-btrfs@vger.kernel.org" , jbacik@fb.com, Chris Mason Subject: Re: Regression in: [PATCH 4/4] btrfs: qgroup: account shared subtree during snapshot delete Message-ID: <20151103191542.GD15575@wotan.suse.de> Reply-To: Mark Fasheh References: <56367AE8.9030509@profihost.ag> <5636BDA0.4020200@cn.fujitsu.com> <5636F89E.3010806@profihost.ag> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <5636F89E.3010806@profihost.ag> Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Mon, Nov 02, 2015 at 06:46:06AM +0100, Stefan Priebe wrote: > Am 02.11.2015 um 02:34 schrieb Qu Wenruo: > > > > > >Stefan Priebe wrote on 2015/11/01 21:49 +0100: > >>Hi, > >> > >>this one: http://www.spinics.net/lists/linux-btrfs/msg47377.html > >> > >>adds a regression to my test systems with very large disks (30tb and > >>50tb). > >> > >>btrfs balance is super slow afterwards while heavily making use of cp > >>--reflink=always on big files (200gb - 500gb). > >> > >>Sorry didn't know how to correctly reply to that "old" message. > >> > >>Greets, > >>Stefan > >>-- > >>To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > >>the body of a message to majordomo@vger.kernel.org > >>More majordomo info at http://vger.kernel.org/majordomo-info.html > > > >Thanks for the testing. > > > >Are you using qgroup or just doing normal balance with qgroup disabled? > > just doing normal balance with qgroup disabled. Then that patch is very unlikely to be your actual problem as it won't be doing anything (ok some kmalloc/free of a very tiny object) since qgroups are disabled. Also, btrfs had working subtree accounting in that code for the last N releases (doing the same exact thing) and it only changed for the one release that Qu's rework was in (which lazily tore it out). --Mark -- Mark Fasheh