From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S965521AbbBQL4s (ORCPT <rfc822;w@1wt.eu>);
	Tue, 17 Feb 2015 06:56:48 -0500
Received: from www.linutronix.de ([62.245.132.108]:43391 "EHLO
	Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S965047AbbBQL4p (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Tue, 17 Feb 2015 06:56:45 -0500
Date: Tue, 17 Feb 2015 12:56:41 +0100
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>, LKML <linux-kernel@vger.kernel.org>,
        linux-rt-users <linux-rt-users@vger.kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>, Carsten Emde <C.Emde@osadl.org>,
        John Kacur <jkacur@redhat.com>, Clark Williams <williams@redhat.com>
Subject: Re: 3.14.23-rt20 - fs,btrfs: fix rt deadlock on extent_buffer->lock
Message-ID: <20150217115641.GI26177@linutronix.de>
References: <20141031170326.1491a63f@gandalf.local.home>
 <1414910967.5380.81.camel@marge.simpson.net>
 <1414913478.5380.114.camel@marge.simpson.net>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
In-Reply-To: <1414913478.5380.114.camel@marge.simpson.net>
X-Key-Id: 97C4700B
X-Key-Fingerprint: 09E2 D1F3 9A3A FF13 C3D3  961C 0688 1C1E 97C4 700B
User-Agent: Mutt/1.5.21 (2010-09-15)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

* Mike Galbraith | 2014-11-02 08:31:18 [+0100]:

>--- a/fs/btrfs/ctree.c
>+++ b/fs/btrfs/ctree.c
>@@ -80,7 +80,7 @@ noinline void btrfs_clear_path_blocking(
> {
> 	int i;
> 
>-#ifdef CONFIG_DEBUG_LOCK_ALLOC
>+#if (defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_PREEMPT_RT_BASE))
> 	/* lockdep really cares that we take all of these spinlocks
> 	 * in the right order.  If any of the locks in the path are not
> 	 * currently blocking, it is going to complain.  So, make really

This is gone since commit f82c458 ("btrfs: fix lockups from
btrfs_clear_path_blocking")

>@@ -107,7 +107,7 @@ noinline void btrfs_clear_path_blocking(
> 		}
> 	}
> 
>-#ifdef CONFIG_DEBUG_LOCK_ALLOC
>+#if (defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_PREEMPT_RT_BASE))
> 	if (held)
> 		btrfs_clear_lock_blocking_rw(held, held_rw);
> #endif
>--- a/fs/btrfs/extent-tree.c
>+++ b/fs/btrfs/extent-tree.c
>@@ -6938,14 +6938,6 @@ use_block_rsv(struct btrfs_trans_handle
> 		goto again;
> 	}
> 
>-	if (btrfs_test_opt(root, ENOSPC_DEBUG)) {
>-		static DEFINE_RATELIMIT_STATE(_rs,
>-				DEFAULT_RATELIMIT_INTERVAL * 10,
>-				/*DEFAULT_RATELIMIT_BURST*/ 1);
>-		if (__ratelimit(&_rs))
>-			WARN(1, KERN_DEBUG
>-				"BTRFS: block rsv returned %d\n", ret);
>-	}
> try_reserve:
> 	ret = reserve_metadata_bytes(root, block_rsv, blocksize,
> 				     BTRFS_RESERVE_NO_FLUSH);
>
and this look like just a warning with enabled debug that is supressed.
May I drop this patch?

Sebastian