From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754951Ab2GNNiW (ORCPT ); Sat, 14 Jul 2012 09:38:22 -0400 Received: from mailout-de.gmx.net ([213.165.64.23]:53423 "HELO mailout-de.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1753275Ab2GNNiU (ORCPT ); Sat, 14 Jul 2012 09:38:20 -0400 X-Authenticated: #14349625 X-Provags-ID: V01U2FsdGVkX18NyWEeMSINDdpGEm6flFhhx+ngI3J9jtQJ7QRjYn ItgjeMD0vX+PVq Message-ID: <1342273096.7368.57.camel@marge.simpson.net> Subject: Re: 3.4.4-rt13: btrfs + xfstests 006 = BOOM.. and a bonus rt_mutex deadlock report for absolutely free! From: Mike Galbraith To: Chris Mason Cc: "linux-rt-users@vger.kernel.org" , LKML , linux-fsdevel , Thomas Gleixner , Steven Rostedt Date: Sat, 14 Jul 2012 15:38:16 +0200 In-Reply-To: <20120713125043.GH30128@shiny> References: <1342072060.7338.102.camel@marge.simpson.net> <20120713125043.GH30128@shiny> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3 Content-Transfer-Encoding: 7bit Mime-Version: 1.0 X-Y-GMX-Trusted: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2012-07-13 at 08:50 -0400, Chris Mason wrote: > There is also a chunk of code in btrfs_clear_path_blocking that makes > sure to strictly honor top down locking order during the conversion. It > only does this when lockdep is enabled because in non-RT kernels we > don't need to worry about it. For RT we'll want to enable that as well. Hm, _seems_ that alone is enough prevent deadlock. Throughput really sucks though. The other bits of my stab bump throughput for dbench 128 from ~200 mb/s to ~360 mb/s (appears it's the paranoid trylock loops). ext3 does 775 mb/s with the same kernel. Or, dbench 8 on ext3 gives ~1800 mb/s and ~480 mb/s btrfs. Not exactly wonderful. Hohum, guess I'll wait and see what your patch looks like. I bet it'll work a lot better than mine does :) -Mike