From owner-freebsd-current@FreeBSD.ORG Mon Mar 2 09:26:53 2009 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id AE340106566C for ; Mon, 2 Mar 2009 09:26:53 +0000 (UTC) (envelope-from ed@hoeg.nl) Received: from palm.hoeg.nl (mx0.hoeg.nl [IPv6:2001:7b8:613:100::211]) by mx1.freebsd.org (Postfix) with ESMTP id 4AA6A8FC12 for ; Mon, 2 Mar 2009 09:26:53 +0000 (UTC) (envelope-from ed@hoeg.nl) Received: by palm.hoeg.nl (Postfix, from userid 1000) id 7BD791CCED; Mon, 2 Mar 2009 10:26:52 +0100 (CET) Date: Mon, 2 Mar 2009 10:26:52 +0100 From: Ed Schouten To: Yuriy Tsibizov Message-ID: <20090302092652.GD19161@hoeg.nl> References: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="wUMz9o/vfMbinXcu" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.19 (2009-01-05) Cc: FreeBSD Current Subject: Re: mutex Giant recursed at /usr/src/sys/kern/tty.c:1222 (via linux_ioctl_termio) X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 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, 02 Mar 2009 09:26:54 -0000 --wUMz9o/vfMbinXcu Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable HI Yuriy, The subject line says enough: the Linuxolator calls into the TTY layer holding Giant. I changed the TTY layer some time ago to never acquire Giant recursively by making /dev/console MPSAFE. It can only happen that drivers pick up Giant recursively before calling into the TTY layer, but this is generally not a problem. The assertion in the code isn't really required. It isn't necessarily bad to recurse on Giant, but looking forward to a Giantless kernel, I think it's not a bad idea to keep it there. Two ways to fix this problem: - Fix the Linuxolator to not require Giant (which I like). - Remove MA_NOTRECURSED from tty_(timed)wait() (which I don't like). Because I'm now rdivacky's mentor, I talk a lot to him anyway. I'll discuss this subject with him. Thanks for reporting this issue. --=20 Ed Schouten WWW: http://80386.nl/ --wUMz9o/vfMbinXcu Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (FreeBSD) iEYEARECAAYFAkmrplwACgkQ52SDGA2eCwV7jwCfZnFeg7ENFt2+cY5a1yTAH6td CF8AnjWr3q9rKB6IqPBvO+rcVCYsTkJo =Aec/ -----END PGP SIGNATURE----- --wUMz9o/vfMbinXcu--