From owner-freebsd-stable@FreeBSD.ORG Sat Oct 4 15:03:47 2014 Return-Path: Delivered-To: freebsd-stable@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 54BA845B; Sat, 4 Oct 2014 15:03:47 +0000 (UTC) Received: from smtp1.multiplay.co.uk (smtp1.multiplay.co.uk [85.236.96.35]) by mx1.freebsd.org (Postfix) with ESMTP id 171EED8B; Sat, 4 Oct 2014 15:03:46 +0000 (UTC) Received: by smtp1.multiplay.co.uk (Postfix, from userid 65534) id 4A8B420E7089B; Sat, 4 Oct 2014 15:03:46 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.multiplay.co.uk X-Spam-Level: * X-Spam-Status: No, score=1.3 required=8.0 tests=AWL,BAYES_00,DOS_OE_TO_MX, FSL_HELO_NON_FQDN_1,RDNS_DYNAMIC autolearn=no version=3.3.1 Received: from r2d2 (82-69-141-170.dsl.in-addr.zen.co.uk [82.69.141.170]) by smtp1.multiplay.co.uk (Postfix) with ESMTP id 0307020E70899; Sat, 4 Oct 2014 15:03:44 +0000 (UTC) Message-ID: <9E274FD2D44943ED9F9C6057068C8CE0@multiplay.co.uk> From: "Steven Hartland" To: "Glen Barber" References: <20141004024011.GC1199@hub.FreeBSD.org> <64F0D761D09546C7B47DFAA1551500BE@multiplay.co.uk> <20141004031614.GD1199@hub.FreeBSD.org> <6618E7E0B17D41D09DB9B0160C2D4DF1@multiplay.co.uk> Subject: Re: Heads-up: Possible regression between 10.0-RELEASE and 10.1-BETA1 with '/ on ZFS' setup Date: Sat, 4 Oct 2014 16:03:39 +0100 MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=response Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5931 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.6157 Cc: freebsd-stable@FreeBSD.org, FreeBSD Release Engineering Team X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 04 Oct 2014 15:03:47 -0000 ----- Original Message ----- From: "Steven Hartland" > ----- Original Message ----- > From: "Glen Barber" >> On Sat, Oct 04, 2014 at 03:51:39AM +0100, Steven Hartland wrote: >> > > [...] >> > >A possible solution to this is to set kern.kstack_pages=4 via loader(8), >> > >however in my tests (solely in VirtualBox), this has been ineffective. >> > > >> > >> > This has been a known issue on i386 since the switch to Clang see UPDATING: >> > 20121223: >> > After switching to Clang as the default compiler some users of ZFS >> > on i386 systems started to experience stack overflow kernel panics. >> > Please consider using 'options KSTACK_PAGES=4' in such configurations. >> > >> > In my experience your millage may vary but essentially without 4 stack pages >> > all bets are off in terms of stability. >> > >> >> Did you read my email? > > Cleary 4am was too late to be reading emails and my brain didn't ingest the > "has been ineffective" so sorry for that. > > That said setting options KSTACK_PAGES=4 has more reaching effects than > kern.kstack_pages=4 so I wonder if you recompiled the kernel with this > option if you would have any more luck? Oh and just looking at the code kern.kstack_pages is read only so wont have any effect, hence you will definitely need to set the kernel option as per the UPDATING entry. Regards Steve