I purchased a new server based on the Supermicro AS-8125GS-TNHR. It has two EPYC 9654 processors. Each processor has 96 cores and 192 hyperthreads. Thus the system as a whole has 192 cores and 384 hyperthreads. I run Debian stable bookworm. When first installed, it ran kernel 6.1.0.12. That kernel found all 384 "CPUs". All were reported in /proc/cpuinfo. I subsequently did an apt upgrade which upgraded to 6.1.0.13. Upon boot, dmesg -lerr reports:
root@poto:~# dmesg -lerr [ 11.080833] smpboot: do_boot_cpu failed(-1) to wakeup CPU#192 Further, /proc/cpuinfo is missing processor 192. I subsequently installed 6.4.0-0-deb12.2-amd64 from bookwork backports. The issue still occurs. If I boot 6.1.0.12 I do not get the issue. There are other reasons I cannot run 6.1.0.12 that I will describe in a different bug report. Jeff (http: //engineering.purdue.edu/~qobi)