From owner-svn-src-head@FreeBSD.ORG Mon Aug 17 21:19:51 2009 Return-Path: Delivered-To: svn-src-head@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 5442F10656C8; Mon, 17 Aug 2009 21:19:51 +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 8E2DD8FC59; Mon, 17 Aug 2009 21:19:50 +0000 (UTC) Received: by mail.garage.freebsd.pl (Postfix, from userid 65534) id 2C7BE45DF4; Mon, 17 Aug 2009 23:19:49 +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 030BF45CAC; Mon, 17 Aug 2009 23:19:43 +0200 (CEST) Date: Mon, 17 Aug 2009 23:19:46 +0200 From: Pawel Jakub Dawidek To: Sam Leffler Message-ID: <20090817211945.GC2298@garage.freebsd.pl> References: <200908170842.n7H8gYo5054777@svn.freebsd.org> <4A8978EC.101@errno.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="zCKi3GIZzVBPywwA" Content-Disposition: inline In-Reply-To: <4A8978EC.101@errno.com> User-Agent: Mutt/1.4.2.3i X-PGP-Key-URL: http://people.freebsd.org/~pjd/pjd.asc X-OS: FreeBSD 8.0-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: svn-src-head@FreeBSD.org, svn-src-all@FreeBSD.org, src-committers@FreeBSD.org Subject: Re: svn commit: r196293 - head/sys/kern X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 17 Aug 2009 21:19:51 -0000 --zCKi3GIZzVBPywwA Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Aug 17, 2009 at 08:36:12AM -0700, Sam Leffler wrote: > Pawel Jakub Dawidek wrote: > >Author: pjd > >Date: Mon Aug 17 08:42:34 2009 > >New Revision: 196293 > >URL: http://svn.freebsd.org/changeset/base/196293 > > > >Log: > > Because taskqueue_run() can drop tq_mutex, we need to check if the > > TQ_FLAGS_ACTIVE flag wasn't removed in the meantime, which means we=20 > > missed a > > wakeup. >=20 > So this would leave a task q thread running? [...] Sleeping infinitely to be precise. > [...] Can you describe the=20 > scenario that demonstrated this problem? Once I moved ZFS from taskq ported from OpenSolaris to wrapper around our taskqueue(9), the deadlock was easy to trigger (I experienced it by testing with fsstress). --=20 Pawel Jakub Dawidek http://www.wheel.pl pjd@FreeBSD.org http://www.FreeBSD.org FreeBSD committer Am I Evil? Yes, I Am! --zCKi3GIZzVBPywwA Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.4 (FreeBSD) iD8DBQFKiclxForvXbEpPzQRAh0LAKCcS7z/9M9nZtLkDizI8IRWCoF08QCg5y2f 423irYfVn6XnBNHBemNhm10= =Vbc5 -----END PGP SIGNATURE----- --zCKi3GIZzVBPywwA--