XPost: linux.debian.bugs.dist, linux.kernel 
 From: tglx@linutronix.de 
  
 On Wed, Sep 24 2025 at 19:20, Thorsten Sperber wrote: 
 > [Mi Sep 24 14:10:21 2025] NMI: IOCK error (debug interrupt?) for reason 71 
 on CPU 0. 
 > [Mi Sep 24 14:10:21 2025] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 
 6.12.43+deb13-amd64 #1€€ Debian 6.12.43-1 
 > [Mi Sep 24 14:10:21 2025] Hardware name: HP ProLiant MicroServer Gen8, BIOS 
 J06 04/04/2019 
 > [Mi Sep 24 14:10:21 2025] RIP: 0010:intel_idle+0x55/0x90 
 > [Mi Sep 24 14:10:21 2025] Code: 2d 5c 8c 40 00 eb 47 cc cc cc 48 89 f0 0f 
 1f 
 00 31 c9 48 89 ca 0f 01 c8 48 8b 06 a8 08 75 0b b9 01 00 00 00 4c 89 c0 0f 
 01 
 c9  80 66 02 df f0 83 44 24 fc 00 48 8b 06 a8 08 74 0b 65 81 25 a6 
 > [Mi Sep 24 14:10:21 2025] RSP: 0018:ffffffff9d203e38 EFLAGS: 00000046 
 > [Mi Sep 24 14:10:21 2025] RAX: 0000000000000001 RBX: 0000000000000002 RCX: 
 0000000000000001 
  
 That's a MWAIT(C1 Substate 1). Hmmm... 
  
 > # cat /proc/cmdline 
 > BOOT_IMAGE=/vmlinuz-6.1.0-40-amd64 root=/dev/mapper/thecube--vg-root ro 
 quiet intel_iommu=off intel_idle.max_cstate=2 
 > 
 > # cat /sys/devices/system/cpu/cpuidle/current_driver 
 > intel_idle 
 > 
 > # ls -l /sys/devices/system/cpu/cpu0/cpuidle/ 
 > insgesamt 0 
 > drwxr-xr-x 2 root root 0 24. Sep 19:14 state0 
 > drwxr-xr-x 3 root root 0 24. Sep 19:14 state1 
 > drwxr-xr-x 3 root root 0 24. Sep 19:14 state2 
 > 
 > # cat /sys/devices/system/cpu/cpu0/cpuidle/state*/name 
 > POLL 
 > C1 
 > C1E 
  
 What's the output for the above on 6.12? 
  
 --- SoupGate-Win32 v1.05 
  * Origin: you cannot sedate... all the things you hate (1:229/2)