From owner-freebsd-fs@FreeBSD.ORG Wed Aug 17 13:52:38 2011 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 34F6E106564A for ; Wed, 17 Aug 2011 13:52:37 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from mail.zoral.com.ua (mx0.zoral.com.ua [91.193.166.200]) by mx1.freebsd.org (Postfix) with ESMTP id 6BCFF8FC0A for ; Wed, 17 Aug 2011 13:52:36 +0000 (UTC) Received: from deviant.kiev.zoral.com.ua (root@deviant.kiev.zoral.com.ua [10.1.1.148]) by mail.zoral.com.ua (8.14.2/8.14.2) with ESMTP id p7HDqVXv042198 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Wed, 17 Aug 2011 16:52:31 +0300 (EEST) (envelope-from kostikbel@gmail.com) Received: from deviant.kiev.zoral.com.ua (kostik@localhost [127.0.0.1]) by deviant.kiev.zoral.com.ua (8.14.4/8.14.4) with ESMTP id p7HDqUSG091356; Wed, 17 Aug 2011 16:52:30 +0300 (EEST) (envelope-from kostikbel@gmail.com) Received: (from kostik@localhost) by deviant.kiev.zoral.com.ua (8.14.4/8.14.4/Submit) id p7HDqUU3091354; Wed, 17 Aug 2011 16:52:30 +0300 (EEST) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: deviant.kiev.zoral.com.ua: kostik set sender to kostikbel@gmail.com using -f Date: Wed, 17 Aug 2011 16:52:30 +0300 From: Kostik Belousov To: Rick Macklem Message-ID: <20110817135230.GW17489@deviant.kiev.zoral.com.ua> References: <20110817012806.GA29555@icarus.home.lan> <1313769356.247298.1313586915280.JavaMail.root@erie.cs.uoguelph.ca> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="DTWYra+TaQJg/4dl" Content-Disposition: inline In-Reply-To: <1313769356.247298.1313586915280.JavaMail.root@erie.cs.uoguelph.ca> User-Agent: Mutt/1.4.2.3i X-Virus-Scanned: clamav-milter 0.95.2 at skuns.kiev.zoral.com.ua X-Virus-Status: Clean X-Spam-Status: No, score=-3.3 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00, DNS_FROM_OPENWHOIS autolearn=no version=3.2.5 X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on skuns.kiev.zoral.com.ua Cc: freebsd-fs@freebsd.org, onwahe@gmail.com Subject: Re: NFS calculation of max commit size 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: Wed, 17 Aug 2011 13:52:38 -0000 --DTWYra+TaQJg/4dl Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Aug 17, 2011 at 09:15:15AM -0400, Rick Macklem wrote: >=20 > I think that any fraction of hibufspace should be sufficient to avoid > the deadlock. Also, since the buffer cache code doesn't use vnode locking > these days, I'm not even sure if write backs are blocked by the wrire > vnode op in progress. (ie. I'm not sure the deadlock it originally fixed > would still happen without it.) bufdaemon definitely acquires vnode lock when flushing dirty buffer, this was a problem on its own. I think you refer to the nfsiod operation. There is another op that is performed without holding the vnode lock consistently from (old)nfs code, namely, truncation. It would be useful to fix this. Please see r188386. --DTWYra+TaQJg/4dl Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (FreeBSD) iEYEARECAAYFAk5Lx54ACgkQC3+MBN1Mb4irygCgntPbEsHt+JVa1uL9BfJzv4Lz EBkAoORNKVitJTHM8xVseUyPQvSzpi1N =FgyM -----END PGP SIGNATURE----- --DTWYra+TaQJg/4dl--