From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cn.fujitsu.com ([222.73.24.84]:62300 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751893Ab1K2CXf (ORCPT ); Mon, 28 Nov 2011 21:23:35 -0500 Message-ID: <4ED44297.8080503@cn.fujitsu.com> Date: Tue, 29 Nov 2011 10:25:27 +0800 From: Li Zefan MIME-Version: 1.0 To: Alexandre Oliva CC: linux-btrfs@vger.kernel.org Subject: Re: [PATCH 00/20] Here's my current btrfs patchset References: In-Reply-To: Content-Type: text/plain; charset=UTF-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: Alexandre Oliva wrote: > The first 11 patches are relatively simple fixes or improvements that > I suppose go could make it even in 3.2 (02 is particularly essential > to avoid progressive performance degradation and metadata space waste > in the default clustered allocation strategy). > I think 02 (especially!) and 04 are good candidates for 3.2, and others are all improvements to me, that can wait until next merge window. > Patch 12 and its complement 15, and also 19, are debugging aids that > helped me track down the problem fixed in 02. > > Patch 13 is a revised version of the larger-clusters patch I posted > before, that adds a microoptimization to the bitmap computations to > the earlier version. > > Patches 14 to 20 are probably not suitable for inclusion, and are > provided only for reference, although I'm still undecided on 16: it > seems to me to make sense to stick to the ordered list and index > instead of jumping to the current cluster's block group, but it may > also make sense performance-wise to start at the current cluster and > advance from there. We still do that, as long as we find a cluster > to begin with, but I'm yet to double check on the race that causes > multiple subsequent releases/creation of clusters under heavy load. > I'm sure I saw it, and I no longer do, but now I'm no longer sure > whether this is the patch that fixed it, or about the details of how > we came about that scenario. > > Patches 14, 17, 18 and 20 were posted before, and I'm probably dropping > them from future patchsets unless I find them to be still useful. >