From owner-freebsd-hackers@freebsd.org Mon Nov 21 13:45:11 2016 Return-Path: <owner-freebsd-hackers@freebsd.org> Delivered-To: freebsd-hackers@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 7A1B1C4C223 for <freebsd-hackers@mailman.ysv.freebsd.org>; Mon, 21 Nov 2016 13:45:11 +0000 (UTC) (envelope-from Volker.Lendecke@SerNet.DE) Received: from mail.SerNet.de (mail.SerNet.de [193.175.80.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 44714274 for <freebsd-hackers@freebsd.org>; Mon, 21 Nov 2016 13:45:10 +0000 (UTC) (envelope-from Volker.Lendecke@SerNet.DE) Received: from intern.SerNet.DE by mail.SerNet.DE with esmtps (Exim 4.84_2 #1) for freebsd-hackers@freebsd.org id 1c8oks-0004g8-Cs; Mon, 21 Nov 2016 14:35:30 +0100 Received: by intern.sernet.de id 1c8oks-0004Gl-AH; Mon, 21 Nov 2016 14:35:30 +0100 Date: Mon, 21 Nov 2016 14:35:28 +0100 From: Volker Lendecke <Volker.Lendecke@SerNet.DE> To: freebsd-hackers@freebsd.org Subject: process shared mutexes? Message-ID: <20161121133528.GA30947@sernet.de> Reply-To: Volker.Lendecke@SerNet.DE MIME-Version: 1.0 User-Agent: Mutt/1.5.23 (2014-03-12) Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Content-Filtered-By: Mailman/MimeDel 2.1.23 X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Technical Discussions relating to FreeBSD <freebsd-hackers.freebsd.org> List-Unsubscribe: <https://lists.freebsd.org/mailman/options/freebsd-hackers>, <mailto:freebsd-hackers-request@freebsd.org?subject=unsubscribe> List-Archive: <http://lists.freebsd.org/pipermail/freebsd-hackers/> List-Post: <mailto:freebsd-hackers@freebsd.org> List-Help: <mailto:freebsd-hackers-request@freebsd.org?subject=help> List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/freebsd-hackers>, <mailto:freebsd-hackers-request@freebsd.org?subject=subscribe> X-List-Received-Date: Mon, 21 Nov 2016 13:45:11 -0000 Hello! For Samba's tdb I'm trying to get process shared robust mutexes to work. However, tdb has a usage pattern that seems to confuse FreeBSD 11 (32-bit x86 if that matters). The attached program fails in the final pthread_mutex_lock call. If I comment out the call to ptr = mmap(NULL, 0xb0, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0x1000); it works. FWIW, tdb uses robust shared mutexes on Linux successfully for a while now. I haven't tried Solaris yet, the only other platform I know about that has them. What am I doing wrong? Thanks, Volker