From owner-freebsd-fs@FreeBSD.ORG Sat Oct 3 00:09:19 2009 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 52CE0106568F for ; Sat, 3 Oct 2009 00:09:19 +0000 (UTC) (envelope-from pjd@garage.freebsd.pl) Received: from mail.garage.freebsd.pl (chello087206049004.chello.pl [87.206.49.4]) by mx1.freebsd.org (Postfix) with ESMTP id 7228C8FC19 for ; Sat, 3 Oct 2009 00:09:17 +0000 (UTC) Received: by mail.garage.freebsd.pl (Postfix, from userid 65534) id 9A90145E93; Sat, 3 Oct 2009 02:09:15 +0200 (CEST) Received: from localhost (chello087206049004.chello.pl [87.206.49.4]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.garage.freebsd.pl (Postfix) with ESMTP id 2BEFA45684; Sat, 3 Oct 2009 02:09:09 +0200 (CEST) Date: Sat, 3 Oct 2009 02:09:09 +0200 From: Pawel Jakub Dawidek To: Artem Belevich Message-ID: <20091003000909.GD1660@garage.freebsd.pl> References: <4AC1E540.9070001@fsn.hu> <4AC5B2C7.2000200@fsn.hu> <20091002184526.GA1660@garage.freebsd.pl> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="Q0rSlbzrZN6k9QnT" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.3i X-PGP-Key-URL: http://people.freebsd.org/~pjd/pjd.asc X-OS: FreeBSD 9.0-CURRENT i386 X-Spam-Checker-Version: SpamAssassin 3.0.4 (2005-06-05) on mail.garage.freebsd.pl X-Spam-Level: X-Spam-Status: No, score=-0.6 required=4.5 tests=BAYES_00,RCVD_IN_SORBS_DUL autolearn=no version=3.0.4 Cc: freebsd-fs@freebsd.org Subject: Re: ARC size constantly shrinks, then ZFS slows down extremely X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 03 Oct 2009 00:09:19 -0000 --Q0rSlbzrZN6k9QnT Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Oct 02, 2009 at 04:38:24PM -0700, Artem Belevich wrote: > With the patch, if vfs.zfs.arc_min is set high enough, the system locks u= p. >=20 > On a box with 8G or RAM I had arc_min=3D6G and arc_max=3D7G. Once ARC grew > to ~5.8G as reported by kstat.zfs.misc.arcstats.size, number of wired > pages grew to ~7400MB and the processes got stuck in 'vmwait' state. I > had to reboot in order to recover. >=20 > On one hand setting arc_min can be considered a pilot error. On the > other, it may be a good idea to allow system to reclaim memory from > ARC even if ARC is smaller than arc_min if the system really really > needs it. The question is how to define "really needs it". >=20 > On a side note, it appears that wired page count tends to be > substantially larger than ARC size. I.e. in my case if ARC size grows > to 6G, wired page count is about 1.5G bigger. Perhaps we should allow > reclaiming memory Before we start debuging pathological cases, could you try the patch with defaul settings? Eventually with vm.kmem_size set to the amount of RAM you have. --=20 Pawel Jakub Dawidek http://www.wheel.pl pjd@FreeBSD.org http://www.FreeBSD.org FreeBSD committer Am I Evil? Yes, I Am! --Q0rSlbzrZN6k9QnT Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.4 (FreeBSD) iD8DBQFKxpYlForvXbEpPzQRAonOAKDraj7ZSbTaC/31Up5xzjDd0HIfLACgpf4m WdRgq+8TSAI2nvZbbQKMg2c= =Ur6x -----END PGP SIGNATURE----- --Q0rSlbzrZN6k9QnT--