[Beowulf] milan and rhel7

[Kilian Cavalotti]

On Wed, Jun 29, 2022 at 3:54 AM Mikhail Kuzminsky <kus at free.net> wrote:
> Yes, RHEL requires upgrading to 8.3 or later to work with EPYC 7003
> https://access.redhat.com/articles/5899941. Officially CentOS 7
> doesn't support this hardware either.

And yet, Red Hat silently backports Milan-specific bits to 7.9 kernels, like:
- Rudimentary support for AMD Milan - Call init_amd_zn() om Family 19h
processors (BZ#2019218)
in kernel-3.10.0-1160.53.1 (https://access.redhat.com/errata/RHSA-2022:0063)

So yes, in practice, el7 distributions run perfectly fine on Milan
CPUs. You won't have complete support for things like EDAC, but as far
as booting and running the kernel, it works fine:

# uname -r
3.10.0-1160.53.1.el7.x86_64

# lscpu -y
Architecture:          x86_64
CPU op-mode(s):        32-bit, 64-bit
Byte Order:            Little Endian
CPU(s):                32
On-line CPU(s) list:   0-31
Thread(s) per core:    1
Core(s) per socket:    32
Socket(s):             1
NUMA node(s):          2
Vendor ID:             AuthenticAMD
CPU family:            25
Model:                 1
Model name:            AMD EPYC 7543 32-Core Processor
Stepping:              1
CPU MHz:               2794.847
BogoMIPS:              5589.69
Virtualization:        AMD-V
L1d cache:             32K
L1i cache:             32K
L2 cache:              512K
L3 cache:              32768K
NUMA node0 CPU(s):     0-15
NUMA node1 CPU(s):     16-31
Flags:                 fpu vme de pse tsc msr pae mce cx8 apic sep
mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx
mmxext fxsr_opt pdpe1gb rdtscp lm constant_tsc art rep_good nopl
nonstop_tsc extd_apicid aperfmperf eagerfpu pni pclmulqdq monitor
ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt aes xsave avx
f16c rdrand lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a
misalignsse 3dnowprefetch osvw ibs skinit wdt tce topoext perfctr_core
perfctr_nb bpext perfctr_l2 cpb cat_l3 cdp_l3 invpcid_single hw_pstate
sme retpoline_amd ssbd ibrs ibpb stibp vmmcall fsgsbase bmi1 avx2 smep
bmi2 invpcid cqm rdt_a rdseed adx smap clflushopt clwb sha_ni xsaveopt
xsavec xgetbv1 cqm_llc cqm_occup_llc cqm_mbm_total cqm_mbm_local
clzero irperf xsaveerptr arat npt lbrv svm_lock nrip_save tsc_scale
vmcb_clean flushbyasid decodeassists pausefilter pfthreshold
v_vmsave_vmload vgif umip pku ospke vaes vpclmulqdq overflow_recov
succor smca

Cheers,
-- 
Kilian