From owner-freebsd-current@freebsd.org Fri Oct 30 23:01:05 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 5453F45DB53 for ; Fri, 30 Oct 2020 23:01:05 +0000 (UTC) (envelope-from cy.schubert@cschubert.com) Received: from smtp-out-so.shaw.ca (smtp-out-so.shaw.ca [64.59.136.139]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "Client", Issuer "CA" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 4CNHq42yDFz4ZnT for ; Fri, 30 Oct 2020 23:01:04 +0000 (UTC) (envelope-from cy.schubert@cschubert.com) Received: from spqr.komquats.com ([70.67.229.168]) by shaw.ca with ESMTPA id YdOEkeiL4RAWfYdOGkdDMk; Fri, 30 Oct 2020 17:01:02 -0600 X-Authority-Analysis: v=2.4 cv=P9aEOgMu c=1 sm=1 tr=0 ts=5f9c9b2e a=7AlCcx2GqMg+lh9P3BclKA==:117 a=7AlCcx2GqMg+lh9P3BclKA==:17 a=xqWC_Br6kY4A:10 a=kj9zAlcOel0A:10 a=afefHYAZSVUA:10 a=KawIFhhbAAAA:8 a=RgBw9RmQAAAA:8 a=YxBL1-UpAAAA:8 a=6I5d2MoRAAAA:8 a=EkcXrb_YAAAA:8 a=sQiMz30JYC253yhkjtMA:9 a=CjuIK1q_8ugA:10 a=sDZbbUVwIjaXAAecbMhh:22 a=Ia-lj3WSrqcvXOmTRaiG:22 a=IjZwj45LgO3ly-622nXo:22 a=LK5xJRSDVpKd5WXXoEvA:22 Received: from slippy.cwsent.com (slippy [IPv6:fc00:1:1:1::5b]) by spqr.komquats.com (Postfix) with ESMTPS id 1DB53D6C; Fri, 30 Oct 2020 16:00:58 -0700 (PDT) Received: from slippy (localhost [127.0.0.1]) by slippy.cwsent.com (8.16.1/8.16.1) with ESMTP id 09UN0t4A032372; Fri, 30 Oct 2020 16:00:57 -0700 (PDT) (envelope-from Cy.Schubert@cschubert.com) Message-Id: <202010302300.09UN0t4A032372@slippy.cwsent.com> X-Mailer: exmh version 2.9.0 11/07/2018 with nmh-1.7.1 Reply-to: Cy Schubert From: Cy Schubert X-os: FreeBSD X-Sender: cy@cwsent.com X-URL: http://www.cschubert.com/ To: Slawa Olhovchenkov cc: Cy Schubert , qroxana , freebsd-current@freebsd.org Subject: Re: OpenZFS: kldload zfs.ko freezes on i386 4GB memory In-reply-to: <20201030224734.GH2033@zxy.spb.ru> References: <202010300313.09U3D0KZ006216@slippy.cwsent.com> <20201030204622.GF2033@zxy.spb.ru> <202010302053.09UKrAXc031272@slippy.cwsent.com> <20201030220809.GG2033@zxy.spb.ru> <202010302234.09UMYA5d032018@slippy.cwsent.com> <20201030224734.GH2033@zxy.spb.ru> Comments: In-reply-to Slawa Olhovchenkov message dated "Sat, 31 Oct 2020 01:47:35 +0300." Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Fri, 30 Oct 2020 16:00:55 -0700 X-CMAE-Envelope: MS4xfIDLNHxxk46TDu8yeQUhC4E6ePaYTKYNZPzR6zXTcwesTvv2lmSXTiRKVPSiauI4rwLiWD0yqJKol+GIpQdf9zsmL0DHik0AiURoby3p6+4hcAlun+Hj K5S0X5oA7VIPtCNnaNKuapSbR92WC4j6syPx8obyIAzha5CQhebN9uHfxRErh1FH0WnATYuBwm4U87PuKzLYOZZle/8QhyyqfxW1ZLmruUT5NZ1WXQ21BMPl RTF9iSmNu8WZSdvr+YnoGHBgCkm4hM1CuSvFOMi5arA= X-Rspamd-Queue-Id: 4CNHq42yDFz4ZnT X-Spamd-Bar: / X-Spamd-Result: default: False [-0.37 / 15.00]; HAS_REPLYTO(0.00)[Cy.Schubert@cschubert.com]; RCVD_VIA_SMTP_AUTH(0.00)[]; TO_DN_SOME(0.00)[]; MV_CASE(0.50)[]; RCVD_COUNT_THREE(0.00)[4]; RECEIVED_SPAMHAUS_PBL(0.00)[70.67.229.168:received]; RCVD_TLS_LAST(0.00)[]; R_DKIM_NA(0.00)[]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:6327, ipnet:64.59.128.0/20, country:CA]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-0.98)[-0.979]; REPLYTO_EQ_FROM(0.00)[]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[4]; NEURAL_SPAM_SHORT(0.39)[0.386]; NEURAL_HAM_LONG(-1.07)[-1.075]; MIME_GOOD(-0.10)[text/plain]; DMARC_NA(0.00)[cschubert.com: no valid DMARC record]; AUTH_NA(1.00)[]; RCVD_IN_DNSWL_LOW(-0.10)[64.59.136.139:from]; TO_MATCH_ENVRCPT_SOME(0.00)[]; R_SPF_NA(0.00)[no SPF record]; RWL_MAILSPIKE_VERYGOOD(0.00)[64.59.136.139:from]; FREEMAIL_CC(0.00)[cschubert.com,mail.ru,freebsd.org]; MAILMAN_DEST(0.00)[freebsd-current] 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 23:01:05 -0000 In message <20201030224734.GH2033@zxy.spb.ru>, Slawa Olhovchenkov writes: > On Fri, Oct 30, 2020 at 03:34:10PM -0700, Cy Schubert wrote: > > > In message <20201030220809.GG2033@zxy.spb.ru>, Slawa Olhovchenkov writes: > > > On Fri, Oct 30, 2020 at 01:53:10PM -0700, Cy Schubert wrote: > > > > > > > In message <20201030204622.GF2033@zxy.spb.ru>, Slawa Olhovchenkov write > s: > > > > > On Thu, Oct 29, 2020 at 08:13:00PM -0700, Cy Schubert wrote: > > > > > > > > > > > In message , qr > oxan > > > a > > > > > > 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 > like > > > ly > > > > > > that prior to the OpenZFS upgrade your memory wasn't stressed to th > e po > > > int > > > > > > of failure. You can try to mask the problem by reducing your RAM cl > ock > > > rate > > > > > > > > > > > or or increase one of the other latency settings in your BIOS. Howe > ver, > > > > > > > > > again, this only masks an already weak RAM chip. > > > > > > > > > > Sounds like performance drop and regression > > > > > > > > How so. Please explain. > > > > > > More stresses memory usually refers to performance penalty. > > > Usually way for better performance is reduce memory access. > > > > The reason filesystems (UFS, ZFS, EXT4, etc.) cache is to avoid disk > > accesses. Nanoseconds vs milliseconds. > > I mean compared ZoL ZFS ARC vs old (BSD/Opensolaris/Illumos) ZFS ARC. > Any reaason to rise ARC hit rate in ZoL case? That's what hit rate is. It's a memory access instead of a disk access. That's what you want. -- Cheers, Cy Schubert FreeBSD UNIX: Web: https://FreeBSD.org NTP: Web: https://nwtime.org The need of the many outweighs the greed of the few.