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=-7.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS, 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 36531C43331 for ; Tue, 31 Mar 2020 04:04:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 089B22072D for ; Tue, 31 Mar 2020 04:04:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725860AbgCaEEm convert rfc822-to-8bit (ORCPT ); Tue, 31 Mar 2020 00:04:42 -0400 Received: from james.kirk.hungrycats.org ([174.142.39.145]:36846 "EHLO james.kirk.hungrycats.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725535AbgCaEEm (ORCPT ); Tue, 31 Mar 2020 00:04:42 -0400 Received: by james.kirk.hungrycats.org (Postfix, from userid 1002) id 0F107642BDC; Tue, 31 Mar 2020 00:04:40 -0400 (EDT) Date: Tue, 31 Mar 2020 00:04:40 -0400 From: Zygo Blaxell To: Chris Murphy Cc: Brad Templeton <4brad@templetons.com>, Btrfs BTRFS Subject: Re: btrfs-transacti hangs system for several seconds every few minutes Message-ID: <20200331040440.GH2693@hungrycats.org> References: <7c0a1398-322f-400a-abe4-dfea98fd46e1@templetons.com> <20200328212021.GA13306@hungrycats.org> <7778ece0-67d4-8d1c-b773-35f07d81dcbe@templetons.com> <20200329064216.GB13306@hungrycats.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: 8BIT In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Mon, Mar 30, 2020 at 04:14:46PM -0600, Chris Murphy wrote: > On Sun, Mar 29, 2020 at 12:42 AM Zygo Blaxell > wrote: > > > > 90 seconds sounds about right for the block group scan when mounting on > > a 10TB filesystem. There's a feature called block group tree in kernel > > 5.5 that helps with that: it lays out block group items on disk closer > > together so they can be read in milliseconds. This is an on-disk format > > change, so once you enable that feature, you wouldn't be able to mount > > the filesystem on an older kernel. This can be a problem if your > > sound drivers have regressions. You might want to wait a few kernel > > releases to be sure you don't need to downgrade. > > I'm not seeing anything about block group tree in btrfs/super.c. > > There is block_group_cache_tree but I'm not seeing anything about it > in 'man 5 btrfs' using btrfs-progs 5.4, or in the devel branch. > > So I'm not sure what mount option or btrfstune option this would be, > seems to be automatic? > https://github.com/kdave/btrfs-progs/commit/2eaf862f46b3ccb6b7248a0417ebf7096bc93b80 Sorry, my mistake...it was in one of the misc-next branches, but seems to have been dropped. Maybe not finished yet? > > -- > Chris Murphy >