Hi! On Friday, 17 October 2025 at 16:26, Dave Hansen wrote: [...] > That's a fun one.
I'm getting a similar trace on Fedora 42 with kernel-6.17.8: Nov 26 23:25:43 localhost kernel: ------------[ cut here ]------------ Nov 26 23:25:43 localhost kernel: WARNING: CPU: 1 PID: 0 at arch/x86/kernel/cpu/cpuid-deps.c:123 do_clear_cpu_cap+0xdc/0x130 Nov 26 23:25:43 localhost kernel: Modules linked in: Nov 26 23:25:43 localhost kernel: CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.17.8-200.fc42.x86_64 #1 PREEMPT(lazy) Nov 26 23:25:43 localhost kernel: Hardware name: FOXCONN TPS01/TPS01, BIOS 080015 03/23/2010 Nov 26 23:25:43 localhost kernel: RIP: 0010:do_clear_cpu_cap+0xdc/0x130 Nov 26 23:25:43 localhost kernel: Code: 44 24 60 65 48 2b 05 5b 7f 49 03 75 67 48 83 c4 68 5b 5d 41 5c 41 5d c3 cc cc cc cc 8> Nov 26 23:25:43 localhost kernel: RSP: 0000:ffffcb40c00bfdb0 EFLAGS: 00010002 Nov 26 23:25:43 localhost kernel: RAX: 0000000000000000 RBX: ffffcb40c00bfdb0 RCX: 0000000000000000 Nov 26 23:25:43 localhost kernel: RDX: 0000000000000001 RSI: 0000000000000070 RDI: ffffcb40c00bfe10 Nov 26 23:25:43 localhost kernel: RBP: 0000000000000070 R08: 0000000000000000 R09: ffffcb40c00bfc28 Nov 26 23:25:43 localhost kernel: R10: ffffffff90f39a88 R11: 00000000ffffdfff R12: 0000000000000000 Nov 26 23:25:43 localhost kernel: R13: 0000000000000018 R14: 0000000000000000 R15: 0000000000000000 Nov 26 23:25:43 localhost kernel: FS: 0000000000000000(0000) GS:ffff89baab6c7000(0000) knlGS:0000000000000000 Nov 26 23:25:43 localhost kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 Nov 26 23:25:43 localhost kernel: CR2: 0000000000000000 CR3: 0000000019a2c000 CR4: 00000000000006f0 Nov 26 23:25:43 localhost kernel: Call Trace: Nov 26 23:25:43 localhost kernel: <TASK> Nov 26 23:25:43 localhost kernel: early_init_intel.cold+0x47/0x112 Nov 26 23:25:43 localhost kernel: ? cpu_parse_topology+0xa4/0x170 Nov 26 23:25:43 localhost kernel: init_intel+0x26/0x2d0 Nov 26 23:25:43 localhost kernel: identify_cpu+0x193/0x7d0 Nov 26 23:25:43 localhost kernel: identify_secondary_cpu+0x4f/0xb0 Nov 26 23:25:43 localhost kernel: ? lapic_setup_esr+0x4d/0xa0 Nov 26 23:25:43 localhost kernel: start_secondary+0x7a/0x170 Nov 26 23:25:43 localhost kernel: common_startup_64+0x13e/0x141 Nov 26 23:25:43 localhost kernel: </TASK> Nov 26 23:25:43 localhost kernel: ---[ end trace 0000000000000000 ]--- Nov 26 23:25:43 localhost kernel: ------------[ cut here ]------------ Admittedly, the machine is 15 years old. > Could you boot the system on a known good kernel and run this, please? > > rdmsr -a 0x000001a0 > > That'll dump out MSR_IA32_MISC_ENABLE on all the CPUs. # rdmsr -a 0x000001a0 60840488 60840488 60840488 60840489 > When was the last kernel that worked for you? Out of available Fedora kernels, the last one without the WARNING is 6.9.12. > Also, do you have old microcode? I have version 0x107. I think there's no newer one for Atom D510. > Can you dump the beginning of /proc/cpuinfo, please? # head -n 27 /proc/cpuinfo processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 28 model name : Intel(R) Atom(TM) CPU D510 @ 1.66GHz stepping : 10 microcode : 0x107 cpu MHz : 1666.655 cache size : 512 KB physical id : 0 siblings : 4 core id : 0 cpu cores : 2 ... Regards, Dominik -- Fedora https://fedoraproject.org Deep in the human unconscious is a pervasive need for a logical universe that makes sense. But the real universe is always one step beyond logic. -- from "The Sayings of Muad'Dib" by the Princess Irulan
