linux-6.1.12: WARNING: CPU: 0 PID: 0 at include/linux/cpumask.h:47 prefill_possible_map+0xff/0x145

[Martin MOKREJŠ]

Hi,
  I updated a kernel from 5.15.74 to 6.1.12 on a guest running under KVM. I think enabled to set down the number of CPUs to the amount available during compile time but I just cannot find it in the .config. But now, it issues a warning with a kernel stacktrace.

  Would some friendly soul tell me which option causes that? I have 2 CPU core available inside the rented virtual machine.



[    0.021948] ACPI: HPET id: 0x8086a201 base: 0xfed00000
[    0.021958] TSC deadline timer available
[    0.021974] ------------[ cut here ]------------
[    0.021976] WARNING: CPU: 0 PID: 0 at include/linux/cpumask.h:47 prefill_possible_map+0xff/0x145
[    0.021988] Modules linked in:
[    0.021992] CPU: 0 PID: 0 Comm: swapper Not tainted 6.1.12 #1 3756ce620d8cac9610c90ecbab5f0cff2a1e72f5
[    0.021997] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1.fc27 04/01/2014
[    0.021999] RIP: 0010:prefill_possible_map+0xff/0x145
[    0.022004] Code: 00 e8 d4 64 22 ff 83 3d df 67 c4 ff 00 75 16 39 dd 7e 12 89 ee 31 d2 48 c7 c7 50 4d f7 81 89 dd e8 b5 64 22 ff 83 fd 40 74 02 <0f> 0b b8 00 00 00 00 89 ea 2b 15 97 53 0f 00 89 ee 0f 48 d0 48 c7
[    0.022006] RSP: 0000:ffffffff82203ec0 EFLAGS: 00010083 ORIG_RAX: 0000000000000000
[    0.022010] RAX: 0000000000000001 RBX: 0000000000000040 RCX: 0000000000000001
[    0.022011] RDX: 0000000000000040 RSI: 0000000000000092 RDI: 0000000000000000
[    0.022013] RBP: 0000000000000001 R08: 80000000ffffe03d R09: 612072656d697420
[    0.022015] R10: 6d697420656e696c R11: 6461656420435354 R12: 0000000000000000
[    0.022017] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[    0.022019] FS:  0000000000000000(0000) GS:ffffffff82695000(0000) knlGS:0000000000000000
[    0.022022] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    0.022024] CR2: ffff888002a01000 CR3: 000000000220a000 CR4: 00000000000606b0
[    0.022086] Call Trace:
[    0.022088]  <TASK>
[    0.022091]  ? setup_arch+0x850/0x8fc
[    0.022099]  ? start_kernel+0x64/0x662
[    0.022103]  ? secondary_startup_64_no_verify+0xcd/0xdb
[    0.022109]  </TASK>
[    0.022111] ---[ end trace 0000000000000000 ]---
[    0.022114] smpboot: Allowing 1 CPUs, 0 hotplug CPUs
[    0.022132] [mem 0x80000000-0xfeffbfff] available for PCI devices
[    0.022136] clocksource: refined-jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604462750000 ns
[    0.028128] ------------[ cut here ]------------
[    0.028134] WARNING: CPU: 0 PID: 0 at include/linux/cpumask.h:47 setup_nr_cpu_ids+0x15/0x1c
[    0.028148] Modules linked in:
[    0.028152] CPU: 0 PID: 0 Comm: swapper Tainted: G        W          6.1.12 #1 3756ce620d8cac9610c90ecbab5f0cff2a1e72f5
[    0.028156] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1.fc27 04/01/2014
[    0.028159] RIP: 0010:setup_nr_cpu_ids+0x15/0x1c
[    0.028164] Code: 00 00 00 74 05 e8 26 88 24 ff 31 c0 48 83 c4 18 e9 cb a7 52 ff 48 8b 05 0c 8a c8 ff 48 85 c0 74 09 48 0f bd c0 83 f8 3f 74 02 <0f> 0b e9 af a7 52 ff e8 60 c5 ff ff e8 b3 b2 ff ff 48 c7 c7 b8 44
[    0.028166] RSP: 0000:ffffffff82203f08 EFLAGS: 00010093 ORIG_RAX: 0000000000000000
[    0.028216] RAX: 0000000000000000 RBX: ffff88807ffd4940 RCX: 0000000000000000
[    0.028219] RDX: 0000000000000032 RSI: ffffffff827430c0 RDI: ffff88807ffd4900
[    0.028220] RBP: ffffffff827430c0 R08: ffff88807ffd4900 R09: 0000000000000032
[    0.028222] R10: 0000000000000032 R11: 000000007ffd4940 R12: 0000000000000032
[    0.028224] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[    0.028226] FS:  0000000000000000(0000) GS:ffffffff82695000(0000) knlGS:0000000000000000
[    0.028228] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    0.028230] CR2: ffff888002a01000 CR3: 000000000220a000 CR4: 00000000000606b0
[    0.028236] Call Trace:
[    0.028240]  <TASK>
[    0.028241]  start_kernel+0x1e3/0x662
[    0.028249]  secondary_startup_64_no_verify+0xcd/0xdb
[    0.028256]  </TASK>
[    0.028257] ---[ end trace 0000000000000000 ]---
[    0.028260] setup_percpu: NR_CPUS:64 nr_cpumask_bits:64 nr_cpu_ids:64 nr_node_ids:1
[    0.030597] percpu: Embedded 44 pages/cpu s140904 r8192 d31128 u2097152
[    0.030612] pcpu-alloc: s140904 r8192 d31128 u2097152 alloc=1*2097152
[    0.030617] pcpu-alloc: [0] 0

I can provide the .config off the list.

Thank you,
Martin