From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from rin.romanrm.net ([91.121.86.59]:46076 "EHLO rin.romanrm.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750788AbdFHSrk (ORCPT ); Thu, 8 Jun 2017 14:47:40 -0400 Date: Thu, 8 Jun 2017 23:47:37 +0500 From: Roman Mamedov To: Hans van Kranenburg Cc: linux-btrfs Subject: Re: About free space fragmentation, metadata write amplification and (no)ssd Message-ID: <20170608234737.2a1c8db0@natsu> In-Reply-To: <3e8876c3-b8b9-0922-8962-17f6cf38b81d@knorrie.org> References: <5e11b988-05ea-c468-21ef-589c71058436@mendix.com> <3e8876c3-b8b9-0922-8962-17f6cf38b81d@knorrie.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Thu, 8 Jun 2017 19:57:10 +0200 Hans van Kranenburg wrote: > There is an improvement with subvolume delete + nossd that is visible > between 4.7 and 4.9. I don't remember if I asked before, but did you test on 4.4? The two latest longterm series are 4.9 and 4.4. 4.7 should be abandoned and forgotten by now really, certainly not used daily in production, it's not even listed on kernel.org anymore. Also it's possible the 4.7 branch that you test did not receive all the bugfix backports from mainline like the longterm series do. > I have no idea what change between 4.7 and 4.9 is responsible for this, but > it's good. FWIW, this appears to be the big Btrfs change between 4.7 and 4.9 (in 4.8): Btrfs: introduce ticketed enospc infrastructure https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=957780eb2788d8c218d539e19a85653f51a96dc1 -- With respect, Roman