From owner-freebsd-fs@FreeBSD.ORG  Wed Oct 17 16:39:57 2012
Return-Path: <owner-freebsd-fs@FreeBSD.ORG>
Delivered-To: freebsd-fs@FreeBSD.org
Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52])
 by hub.freebsd.org (Postfix) with ESMTP id 50015356
 for <freebsd-fs@FreeBSD.org>; Wed, 17 Oct 2012 16:39:57 +0000 (UTC)
 (envelope-from avg@FreeBSD.org)
Received: from citadel.icyb.net.ua (citadel.icyb.net.ua [212.40.38.140])
 by mx1.freebsd.org (Postfix) with ESMTP id 906E88FC18
 for <freebsd-fs@FreeBSD.org>; Wed, 17 Oct 2012 16:39:56 +0000 (UTC)
Received: from odyssey.starpoint.kiev.ua (alpha-e.starpoint.kiev.ua
 [212.40.38.101])
 by citadel.icyb.net.ua (8.8.8p3/ICyb-2.3exp) with ESMTP id TAA08041;
 Wed, 17 Oct 2012 19:39:47 +0300 (EEST)
 (envelope-from avg@FreeBSD.org)
Message-ID: <507EDF52.4050705@FreeBSD.org>
Date: Wed, 17 Oct 2012 19:39:46 +0300
From: Andriy Gapon <avg@FreeBSD.org>
User-Agent: Mozilla/5.0 (X11; FreeBSD amd64;
 rv:16.0) Gecko/20121012 Thunderbird/16.0.1
MIME-Version: 1.0
To: Adam Vande More <amvandemore@gmail.com>
Subject: Re: I have a DDB session open to a crashed ZFS server
References: <1350317019.71982.50.camel@btw.pki2.com>
 <201210160844.41042.jhb@freebsd.org> <1350400597.72003.32.camel@btw.pki2.com>
 <201210161215.33369.jhb@freebsd.org> <507D8B69.3090903@FreeBSD.org>
 <alpine.BSF.2.00.1210161139060.22959@btw.pki2.com>
 <0B0CA833-79FA-4C8E-86AC-828E7947FF67@gmail.com>
 <507EC242.1070809@FreeBSD.org>
 <CA+tpaK3EkYKj5Qb-=Pfti5ybVcTPPRK25pf3Jq4tDTixFfwi+A@mail.gmail.com>
In-Reply-To: <CA+tpaK3EkYKj5Qb-=Pfti5ybVcTPPRK25pf3Jq4tDTixFfwi+A@mail.gmail.com>
X-Enigmail-Version: 1.4.5
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Cc: freebsd-fs@FreeBSD.org, dg17@penx.com, Dennis Glatting <dg@pki2.com>
X-BeenThere: freebsd-fs@freebsd.org
X-Mailman-Version: 2.1.14
Precedence: list
List-Id: Filesystems <freebsd-fs.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/freebsd-fs>,
 <mailto:freebsd-fs-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-fs>
List-Post: <mailto:freebsd-fs@freebsd.org>
List-Help: <mailto:freebsd-fs-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-fs>,
 <mailto:freebsd-fs-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 17 Oct 2012 16:39:57 -0000

on 17/10/2012 19:06 Adam Vande More said the following:
> On Wed, Oct 17, 2012 at 9:35 AM, Andriy Gapon <avg@freebsd.org
> <mailto:avg@freebsd.org>> wrote:
> 
>     on 17/10/2012 10:04 Nikolay Denev said the following:
>     > I'm running with the patch from here :
>     http://thread.gmane.org/gmane.os.freebsd.devel.file-systems/16000/focus=16017
>     > And there were no deadlocks since it's applied.
>     > If you're hitting the same issue as I was, this should help.
> 
>     I am going to commit that change soon-ish, if nobody expressly objects to it.
> 
> 
> I imagine you don't have much to do with the release process, but this seems to be
> a rather major bug warranting serious consideration about inserting into the 9_1
> branch prior to final release. 

No, I don't think so.
The bug can only be triggered by running out of KVA space (vm.kmem_map_free
getting too low), and that can be worked around by increasing vm.kmem_size via a
loader tunable.  I hear that a value twice the physical memory size is pretty safe.

-- 
Andriy Gapon