Date: Fri, 26 Apr 2019 20:53:36 +0000 From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 237590] powerpc64 PowerMac11,2 and 7,2 context, -r330614 and later (including -r345758): "ofwdump -ap" crashes the system, unable to sleep cpus; probable -r330610 "cause" Message-ID: <bug-237590-227@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D237590 Bug ID: 237590 Summary: powerpc64 PowerMac11,2 and 7,2 context, -r330614 and later (including -r345758): "ofwdump -ap" crashes the system, unable to sleep cpus; probable -r330610 "cause" Product: Base System Version: CURRENT Hardware: powerpc OS: Any Status: New Severity: Affects Some People Priority: --- Component: kern Assignee: bugs@FreeBSD.org Reporter: marklmi26-fbsd@yahoo.com The biggest issue may be the inability to sufficiently sleep CPUs on powerpc64 in general, with ofwdump on old PowerMac G5's just being a good way to test that. This was originally observed on head -r345758. But "bisecting" based on: https://artifact.ci.freebsd.org/snapshot/head/r* I found that for the likes of "ofwdump -ap > /dev/null" : -r330572: does not crash the system (or program). -r330614: crashes the system: timeout trying to sleep cpus. There are no other https://artifact.ci.freebsd.org/snapshot/head/r* between -r330572 and -r330614 with powerpc64 present. So I stopped at this range. Turns out that between those two versions is: Revision 330610 . . . Modified Wed Mar 7 17:08:07 2018 UTC . . . by nwhitehorn=20 . . . Move the powerpc64 direct map base address from zero to high memory. This accomplishes a few things: - Makes NULL an invalid address in the kernel, which is useful for catching bugs. . . . (It may be that -r330610 exposed another problem that was accidentally avoided before that.) So far it appears likely that every bootable/usable build from -r330610 on crashes for the likes of "ofwdump -ap" when openfirmware is used live and, so, the cpus need to avoid multi-threading the openfirmware use. (So, for PowerMacs, when booted without usefdt mode for sufficiently recent builds). I've not seen the problem with 32-bit powerpc FreeBSD on old PowerMacs, including when used to boot the same machines. Only powerpc64 FreeBSD. The only powerpc64 test contexts that I have access to sometimes are old G5 PowerMacs: 2-socket/2-core-each PowerMac11,2 and 2-socket/1-core-each PowerMac7,2. So I've no direct evidence for any other powerpc64 context. --=20 You are receiving this mail because: You are the assignee for the bug.=
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