From owner-freebsd-stable@freebsd.org Sun Sep 13 21:39:14 2020 Return-Path: Delivered-To: freebsd-stable@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 8CA5D3E9DC3 for ; Sun, 13 Sep 2020 21:39:14 +0000 (UTC) (envelope-from freebsd-stable@lists.invis.net) Received: from mail.invis.net (mail.invis.net [5.152.219.147]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 4BqNDK146Wz3ZZY for ; Sun, 13 Sep 2020 21:39:12 +0000 (UTC) (envelope-from freebsd-stable@lists.invis.net) Received: (qmail 36230 invoked by uid 89); 13 Sep 2020 21:30:35 -0000 Received: from unknown (HELO xenon.internal.invis.net) (no-reply@invis.net@84.9.150.199) by smtp.mail.cassiterite.invis.net with SMTP; 13 Sep 2020 21:30:35 -0000 Subject: Re: Cannot find announcement that min supported i386 CPU is now i686 To: freebsd-stable@freebsd.org References: <4460db23-9a29-7972-1b41-74585764a5d7@lists.invis.net> <20200831205136.GA15141@elch.exwg.net> <2986c4ef-6e73-50f9-215e-20e8a9793434@lists.invis.net> <6bd2c4f6-5ce1-5a0d-14b3-71831a0443f4@grosbein.net> From: Charles Lecklider Message-ID: <934c2a63-d3b0-dafb-08cf-8572bb313d03@lists.invis.net> Date: Sun, 13 Sep 2020 22:30:34 +0100 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: <6bd2c4f6-5ce1-5a0d-14b3-71831a0443f4@grosbein.net> Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 4BqNDK146Wz3ZZY X-Spamd-Bar: +++ X-Spamd-Result: default: False [3.28 / 15.00]; RCVD_TLS_LAST(0.00)[]; ARC_NA(0.00)[]; MID_RHS_MATCH_FROM(0.00)[]; FROM_HAS_DN(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; NEURAL_SPAM_SHORT(0.17)[0.170]; MIME_GOOD(-0.10)[text/plain]; TO_DN_NONE(0.00)[]; NEURAL_SPAM_MEDIUM(0.47)[0.467]; RCPT_COUNT_ONE(0.00)[1]; NEURAL_SPAM_LONG(0.74)[0.740]; R_SPF_NA(0.00)[no SPF record]; DMARC_POLICY_REJECT(2.00)[lists.invis.net : No valid SPF, No valid DKIM,reject]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:20860, ipnet:5.152.192.0/19, country:GB]; RCVD_COUNT_TWO(0.00)[2]; MAILMAN_DEST(0.00)[freebsd-stable] X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.33 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 13 Sep 2020 21:39:14 -0000 On 2020-09-01 03:20, Eugene Grosbein wrote: > CPU: Geode(TM) Integrated Processor by AMD PCS (499.91-MHz 586-class CPU) > Origin="AuthenticAMD" Id=0x5a2 Family=0x5 Model=0xa Stepping=2 > Features=0x88a93d > AMD Features=0xc0400000 > > Of course, its NanoBSD image is built with CPUTYPE=i586 as well as installed packages. You've got CMOV so you'll be fine with 11.4-RELEASE, whereas I don't: CPU: Pentium/P55C (232.68-MHz 586-class CPU) Origin="GenuineIntel" Id=0x543 Family=0x5 Model=0x4 Stepping=3 Features=0x8003bf Getting 11.4 to work has been a *major* undertaking: Setting CPUTYPE in `make.conf` doesn't set -march for the kernel build tools, so while you can compile world and kernel for i386, you can't actually link it to create a working kernel on a real i586 (I found that out with `/usr/obj` and `/usr/src` mounted over NFS). clang is hypersensitive to command line arguments - if you just fiddle with CFLAGS etc you'll get a duplicate -O2 and/or -march and that results in a kernel/world that can't build itself (ZFS wedges). You must set NO_CPU_CFLAGS= and then each of CFLAGS/CXXFLAGS/COPTFLAGS. Don't try -Os or -Oz (which really do help on a real i586) - ZFS will wedge quickly. 11.4 i386 doesn't honour `vfs.zfs.arc_max` in any meaningful way resulting in one of the `find`s in periodic security wedging ZFS. By ZFS wedging I mean something gets stuck on zio->i having eaten all of kmem (I presume - on the real i586 I expect ~200M in ARC would do that and that's what `top` shows) and that's it for the machine - it doesn't panic, but there's no more disk IO either. This also happens in VirtualBox with 4GB RAM, so it's not a hardware problem. To get 11.4 to behave itself (and it's only been 72 hours so still early days) I've had to set: options KSTACK_PAGES=4 and kern.maxvnode="1024" vm.kmem_size="330M" vm.kmem_size_max="330M" vfs.zfs.arc_max="125M" vfs.zfs.arc_meta_limit="16M" I had to set kmem for 11.3 but not the rest. TL;DR: I'd avoid 11.4 i386 as it doesn't appear to have been tested on i486/i586 at all. Unfortunately I'm not sure 12 is an option yet either - 12.0 chokes on my SiI3124 SATA controllers, and I've yet to compile 12.1 to test (RELEASE has the same problem as 11.4). -C