From owner-freebsd-current@freebsd.org Fri Oct 30 23:50:39 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 638BE45EC13 for ; Fri, 30 Oct 2020 23:50:39 +0000 (UTC) (envelope-from cy.schubert@cschubert.com) Received: from smtp-out-no.shaw.ca (smtp-out-no.shaw.ca [64.59.134.12]) (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 4CNJwG5R2rz4d0m for ; Fri, 30 Oct 2020 23:50:38 +0000 (UTC) (envelope-from cy.schubert@cschubert.com) Received: from spqr.komquats.com ([70.67.229.168]) by shaw.ca with ESMTPA id YeAEkPfmWtdldYeAFknxB8; Fri, 30 Oct 2020 17:50:37 -0600 X-Authority-Analysis: v=2.4 cv=INe8tijG c=1 sm=1 tr=0 ts=5f9ca6cd a=7AlCcx2GqMg+lh9P3BclKA==:117 a=7AlCcx2GqMg+lh9P3BclKA==:17 a=xqWC_Br6kY4A:10 a=kj9zAlcOel0A:10 a=afefHYAZSVUA:10 a=KawIFhhbAAAA:8 a=YxBL1-UpAAAA:8 a=6I5d2MoRAAAA:8 a=EkcXrb_YAAAA:8 a=Oqed5r7jc3Zl1anTDEAA: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 7F027DF9; Fri, 30 Oct 2020 16:50:32 -0700 (PDT) Received: from slippy (localhost [127.0.0.1]) by slippy.cwsent.com (8.16.1/8.16.1) with ESMTP id 09UNoVcM033686; Fri, 30 Oct 2020 16:50:31 -0700 (PDT) (envelope-from Cy.Schubert@cschubert.com) Message-Id: <202010302350.09UNoVcM033686@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: <20201030233138.GD34923@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> <202010302300.09UN0t4A032372@slippy.cwsent.com> <20201030233138.GD34923@zxy.spb.ru> Comments: In-reply-to Slawa Olhovchenkov message dated "Sat, 31 Oct 2020 02:31:38 +0300." Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Fri, 30 Oct 2020 16:50:31 -0700 X-CMAE-Envelope: MS4xfGl5ShOSkmVbV3UTYLT70uYPr2GMfiRlmeuGqN/bXhGzTaCPMglRmf769488SjH1/s+MND+8Med0bfZOJOjRfCfp6wuih2lH8RQVAPCjz+qJS2NaLAPm sgKH0IkF0CyZt15vTlvJ6KjXCYjsKjKNJFUBXpbsGIDWNo5rKrdDF2VFa73raQYPUwXXaVRvHr/rWbMQP3QaH0r4q6wW/vF7b6NBUwjIMOlUHV/z/JoWIm99 M3iSiJk272HZ64dNoVACShJ1su2iMoHVTd3/XXe+YZA= X-Rspamd-Queue-Id: 4CNJwG5R2rz4d0m X-Spamd-Bar: / X-Spamd-Result: default: False [-0.25 / 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)[]; RWL_MAILSPIKE_GOOD(0.00)[64.59.134.12:from]; 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(-0.87)[-0.867]; REPLYTO_EQ_FROM(0.00)[]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[4]; NEURAL_SPAM_SHORT(0.35)[0.350]; NEURAL_HAM_LONG(-1.04)[-1.035]; 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)[64.59.134.12:from]; TO_MATCH_ENVRCPT_SOME(0.00)[]; R_SPF_NA(0.00)[no SPF record]; 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 23:50:39 -0000 In message <20201030233138.GD34923@zxy.spb.ru>, Slawa Olhovchenkov writes: > On Fri, Oct 30, 2020 at 04:00:55PM -0700, Cy Schubert wrote: > > > > > > 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. > > Is ZoL ARC hit rate rise from FreeBSD ARC hit rate? We don't know that. You should be able to find out by running some tests that would populate your ARC and run the test again. I see that my -DNO_CLEAN buildworlds run faster, when I run them a second or third time after making a minor edit, than they did before. Thus I assume it uses memory more efficiently. By default it stores more metadata in ARC, 75% instead of IIRC 25% by default. Getting back to your original question. A more efficient ARC would exercise your memory more intensely because you are replacing disk reads with memory reads. And as I said before the old ZFS "found" weak RAM on three separate occasions in three different machines over the last ten years. You're advised to replace the marginal memory. -- 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.