From owner-freebsd-threads@FreeBSD.ORG Thu Jul 16 17:53:29 2009 Return-Path: Delivered-To: freebsd-threads@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 11BAD1065670 for ; Thu, 16 Jul 2009 17:53:29 +0000 (UTC) (envelope-from asmrookie@gmail.com) Received: from mail-bw0-f208.google.com (mail-bw0-f208.google.com [209.85.218.208]) by mx1.freebsd.org (Postfix) with ESMTP id 8B2B58FC1C for ; Thu, 16 Jul 2009 17:53:28 +0000 (UTC) (envelope-from asmrookie@gmail.com) Received: by bwz4 with SMTP id 4so254180bwz.43 for ; Thu, 16 Jul 2009 10:53:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:sender:received:in-reply-to :references:date:x-google-sender-auth:message-id:subject:from:to:cc :content-type:content-transfer-encoding; bh=n3WxjeGPOcSsQsrsnvnZgMS4J03kvQaQH6Va76XXRaw=; b=iDDy2Gb2dkbUMo9ZIGRDvONfFNvJBRQ9GSLDkPsO7bUqawPTJ0CpJnBGiFISpiWKQz xzBCGlusV0XZMuG/PLwwLZi+AGN2cwTZKc22uNfS65vYJoW8NDaZqWrJsmCLgHI7pv2q Fy/KvaStAPT8k/5vIIx0FwnkHOmTfaGHmPctY= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type :content-transfer-encoding; b=aCXFCd79gpc8pbzZo//jC8pEEv67hEpOSshQXc1lGGXy1IyXiUrRu/BJw8221z48wW aQT/qSzI8EkzGPvfCDVZUVm+LSMgbDaEfzloVyGpm47JStDnwTdzKGy7t9R5N80BYKZJ lBgijekzvLwa7kVkoetd4LOxDAur29TbuUYTg= MIME-Version: 1.0 Sender: asmrookie@gmail.com Received: by 10.223.123.141 with SMTP id p13mr2932far.84.1247766807583; Thu, 16 Jul 2009 10:53:27 -0700 (PDT) In-Reply-To: <6E6A9516-6C69-4E41-803C-FE5F126F402C@desert.net> References: <200907152140.n6FLe42l045879@freefall.freebsd.org> <3bbf2fe10907160526l2f066698qce8a5e77aee6366b@mail.gmail.com> <3bbf2fe10907160548l74de896bka609de7a9a994899@mail.gmail.com> <6E6A9516-6C69-4E41-803C-FE5F126F402C@desert.net> Date: Thu, 16 Jul 2009 19:53:27 +0200 X-Google-Sender-Auth: 35d45401fba492c7 Message-ID: <3bbf2fe10907161053x3b6aa60dneb8dbd5217b4cb03@mail.gmail.com> From: Attilio Rao To: Nick Esborn Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: freebsd-threads@freebsd.org Subject: Re: threads/136345: Recursive read rwlocks in thread A cause deadlock with write lock in thread B X-BeenThere: freebsd-threads@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Threading on FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 16 Jul 2009 17:53:29 -0000 2009/7/16 Nick Esborn : > > > KDB, DDB, SCHED_ULE, and PREEMPTION are already turned on. I will try > FULL_PREEMPTION, INVARIANT_SUPPORT, INVARIANTS, and WITNESS, but when I > first upgraded to 8.0, this server was unable to handle its workload with > the INVARIANTS and WITNESS options turned on. What do you mean with 'unable'? What was happening precisely? > Also, it can take a while for it to become clear that the deadlock has > occurred -- usually our monitoring picks it up when replication falls > behind. So it may be 15-20 minutes after the deadlock that I am able to run > the above db commands. Of course the thread will still be deadlocked. > Hopefully that doesn't reduce the value of the data obtained. It should be still fine. Thanks, Attilio -- Peace can only be achieved by understanding - A. Einstein