From nobody Sun Apr 14 15:05:56 2024 X-Original-To: freebsd-arm@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4VHYXV0cVbz5Gl6D for ; Sun, 14 Apr 2024 15:06:02 +0000 (UTC) (envelope-from tuexen@freebsd.org) Received: from drew.franken.de (mail-n.franken.de [193.175.24.27]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "*.franken.de", Issuer "Sectigo RSA Domain Validation Secure Server CA" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4VHYXT4Dm1z4H5X for ; Sun, 14 Apr 2024 15:06:01 +0000 (UTC) (envelope-from tuexen@freebsd.org) Authentication-Results: mx1.freebsd.org; none Received: from smtpclient.apple (unknown [IPv6:2a02:8109:1140:c3d:8123:aa6b:606b:f909]) (Authenticated sender: micmac) by drew.franken.de (Postfix) with ESMTPSA id 81827721E2806; Sun, 14 Apr 2024 17:05:57 +0200 (CEST) Content-Type: text/plain; charset=us-ascii List-Id: Porting FreeBSD to ARM processors List-Archive: https://lists.freebsd.org/archives/freebsd-arm List-Help: List-Post: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3774.500.171.1.1\)) Subject: Re: Loading vmm From: tuexen@freebsd.org In-Reply-To: <08796868-9E24-4BFE-AE96-F8B4A7FB6C0A@mit.edu> Date: Sun, 14 Apr 2024 17:05:56 +0200 Cc: freebsd-arm Content-Transfer-Encoding: quoted-printable Message-Id: <987CD248-9FFD-46C2-A801-7C78A009D147@freebsd.org> References: <760D76E5-F2D5-4D0D-9CDC-A42D3335C9DA@freebsd.org> <08796868-9E24-4BFE-AE96-F8B4A7FB6C0A@mit.edu> To: John F Carr X-Mailer: Apple Mail (2.3774.500.171.1.1) X-Spam-Status: No, score=-2.9 required=5.0 tests=ALL_TRUSTED,BAYES_00 autolearn=disabled version=3.4.1 X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on mail-n.franken.de X-Spamd-Bar: ---- X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[]; ASN(0.00)[asn:680, ipnet:193.174.0.0/15, country:DE] X-Rspamd-Queue-Id: 4VHYXT4Dm1z4H5X > On 14. Apr 2024, at 14:17, John F Carr wrote: >=20 > See bug https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D277559. = It was suspected to be specific to the heterogenous Rockchip RK3399 but = perhaps it is more widespread. >=20 > When I first hit the bug there was a 30-50% chance that the first = kldload vmm would hang the system so hard I couldn't even invoke the = debugger with break on a serial console. Later, with no relevant = changes to source code, it would take about 2,000 load/unload pairs to = hang the system. If that 1-in-2000 chance is typical this bug could = affect all systems. Give it a try on your 128 core system: >=20 > # while kldload vmm ; do echo -n . ; kldunload vmm ; done I tried 70000 times on the 128 core system: No problem. On the 32 core system the problem occurs every time I call kldload vmm. Tried 5 times, happened 5 times. =46rom my point of view, the behavior is deterministic on both systems. Best regards Michael >=20 > If anybody can tell me how to debug at the hardware level using JTAG, = I can give it a try on my RockPro64 and see where the kernel is stuck. = I have used hardware level debugging tools, but they were always black = boxes my employer bought with instructions included. >=20 >> On Apr 14, 2024, at 04:50, tuexen@freebsd.org wrote: >>=20 >> Dear all, >>=20 >> using the sources for kernel/world of yesterday running >> kldload vmm >> on a 128 core Ampere system runs just fine: >>=20 >> CPU 0: ARM Neoverse-N1 r3p1 affinity: 18 0 0 >> Cache Type =3D <64 byte D-cacheline,64 byte = I-cacheline,PIPT ICache,64 byte ERG,64 byte CWG,IDC> >> Instruction Set Attributes 0 =3D = >> Instruction Set Attributes 1 =3D >> Instruction Set Attributes 2 =3D <> >> Processor Features 0 =3D = >> Processor Features 1 =3D >> Memory Model Features 0 =3D = >> Memory Model Features 1 =3D >> Memory Model Features 2 =3D >> Debug Features 0 =3D >> Debug Features 1 =3D <> >> Auxiliary Features 0 =3D <> >> Auxiliary Features 1 =3D <> >> AArch32 Instruction Set Attributes 5 =3D = >> AArch32 Media and VFP Features 0 =3D >> AArch32 Media and VFP Features 1 =3D >>=20 >> However, doing the same on a 32 core Ampere system results in >> the system becoming unresponsive. No reaction on the console, >> no message there, no response over the network. >>=20 >> CPU 0: APM eMAG 8180 r3p2 affinity: 0 0 >> Cache Type =3D <64 byte D-cacheline,64 byte = I-cacheline,PIPT ICache,64 byte ERG,64 byte CWG> >> Instruction Set Attributes 0 =3D >> Instruction Set Attributes 1 =3D <> >> Instruction Set Attributes 2 =3D <> >> Processor Features 0 =3D >> Processor Features 1 =3D <> >> Memory Model Features 0 =3D = >> Memory Model Features 1 =3D <8bit VMID> >> Trying to mount root from ufs:/dev/ada0p2 [rw]... >> Memory Model Features 2 =3D <32bit CCIDX,48bit VA> >> Debug Features 0 =3D >> Debug Features 1 =3D <> >> Auxiliary Features 0 =3D <> >> Auxiliary Features 1 =3D <> >> AArch32 Instruction Set Attributes 5 =3D = >> AArch32 Media and VFP Features 0 =3D >> AArch32 Media and VFP Features 1 =3D >>=20 >> Any idea, what is going wrong? >>=20 >> Best regards >> Michael >=20 >=20