From owner-freebsd-current@freebsd.org Fri Oct 30 20:46:35 2020 Return-Path: Delivered-To: freebsd-current@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 96ABA45B382 for ; Fri, 30 Oct 2020 20:46:35 +0000 (UTC) (envelope-from slw@zxy.spb.ru) Received: from zxy.spb.ru (zxy.spb.ru [195.70.199.98]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 4CNDqt0PvXz4SrV for ; Fri, 30 Oct 2020 20:46:33 +0000 (UTC) (envelope-from slw@zxy.spb.ru) Received: from slw by zxy.spb.ru with local (Exim 4.86 (FreeBSD)) (envelope-from ) id 1kYbHy-000JnH-Sy; Fri, 30 Oct 2020 23:46:22 +0300 Date: Fri, 30 Oct 2020 23:46:22 +0300 From: Slawa Olhovchenkov To: Cy Schubert Cc: qroxana , freebsd-current@freebsd.org Subject: Re: OpenZFS: kldload zfs.ko freezes on i386 4GB memory Message-ID: <20201030204622.GF2033@zxy.spb.ru> References: <202010300313.09U3D0KZ006216@slippy.cwsent.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <202010300313.09U3D0KZ006216@slippy.cwsent.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: slw@zxy.spb.ru X-SA-Exim-Scanned: No (on zxy.spb.ru); SAEximRunCond expanded to false X-Rspamd-Queue-Id: 4CNDqt0PvXz4SrV X-Spamd-Bar: / X-Spamd-Result: default: False [-0.48 / 15.00]; RCVD_TLS_LAST(0.00)[]; ARC_NA(0.00)[]; MID_RHS_MATCH_FROM(0.00)[]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[3]; TO_DN_SOME(0.00)[]; NEURAL_HAM_LONG(-0.74)[-0.742]; MIME_GOOD(-0.10)[text/plain]; DMARC_NA(0.00)[zxy.spb.ru]; AUTH_NA(1.00)[]; NEURAL_SPAM_SHORT(0.23)[0.227]; TO_MATCH_ENVRCPT_SOME(0.00)[]; NEURAL_HAM_MEDIUM(-0.87)[-0.869]; R_SPF_NA(0.00)[no SPF record]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; RCVD_COUNT_TWO(0.00)[2]; ASN(0.00)[asn:5495, ipnet:195.70.192.0/19, country:RU]; MAILMAN_DEST(0.00)[freebsd-current]; FREEMAIL_CC(0.00)[mail.ru,freebsd.org] X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.33 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: Fri, 30 Oct 2020 20:46:35 -0000 On Thu, Oct 29, 2020 at 08:13:00PM -0700, Cy Schubert wrote: > In message , qroxana > writes > : > > > > Hi, > > > > I have an old i386 machine running r364479. After upgrading to > > r367045, running kldload zfs.ko freezes the whole system. > > > > I also tried to replace the 4GB memory with another 2GB one > > and kldload zfs.ko works without freezing the machine. > > ZFS ARC stresses memory. I've found a number of bad RAM chips over the > years using ZFS. > > The OpenZFS upgrade significantly changed how it manages ARC. It's likely > that prior to the OpenZFS upgrade your memory wasn't stressed to the point > of failure. You can try to mask the problem by reducing your RAM clock rate > or or increase one of the other latency settings in your BIOS. However, > again, this only masks an already weak RAM chip. Sounds like performance drop and regression