From owner-freebsd-current@FreeBSD.ORG Mon Apr 6 20:18:26 2015 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 7AC24CC for ; Mon, 6 Apr 2015 20:18:26 +0000 (UTC) Received: from bigwig.baldwin.cx (bigwig.baldwin.cx [IPv6:2001:470:1f11:75::1]) (using TLSv1 with cipher DHE-RSA-CAMELLIA256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 53032EA8 for ; Mon, 6 Apr 2015 20:18:26 +0000 (UTC) Received: from ralph.baldwin.cx (pool-173-54-116-245.nwrknj.fios.verizon.net [173.54.116.245]) by bigwig.baldwin.cx (Postfix) with ESMTPSA id 6CAADB946; Mon, 6 Apr 2015 16:18:25 -0400 (EDT) From: John Baldwin To: freebsd-current@freebsd.org Subject: Re: Is a high witness refcount indicative of a missing unlock? Date: Mon, 06 Apr 2015 16:09:03 -0400 Message-ID: <238127021.hvy73srvVG@ralph.baldwin.cx> User-Agent: KMail/4.14.2 (FreeBSD/10.1-STABLE; KDE/4.14.2; amd64; ; ) In-Reply-To: <1117D087-AD76-4A87-8798-AB5526BECF3A@odin-corporation.com> References: <1117D087-AD76-4A87-8798-AB5526BECF3A@odin-corporation.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.2.7 (bigwig.baldwin.cx); Mon, 06 Apr 2015 16:18:25 -0400 (EDT) Cc: Lars X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 06 Apr 2015 20:18:26 -0000 On Sunday, March 29, 2015 02:29:42 PM Lars wrote: > Hi, > I am poking around for a cause for my repeating deadlock issues on my= system based on r 279869. ddb show witness show the =E2=80=9Cvnode int= erlock=E2=80=9D and the =E2=80=9Czfs=E2=80=9D locks both with reference= counts over 200K. Obviously they are related, and there is a find runn= ing (all the filesystems on this machine are zfs ( minus the specialty = ones like devfs). >=20 > I don=E2=80=99t see any other withness entry with reference counts ev= en in the ballpark of these two, so does this indicate that we have a v= node/zfs path were we don=E2=80=99t unlock? The ref count just means that the locks exist (so you have 200k ZFS vno= des), not that the locks are currently held. The reference count on the witn= ess object is bumped when a lock is created that uses that witness object a= nd released when the lock is destroyed. --=20 John Baldwin