Re: Is the kernel for sun4m SMP capable ?

[Nobuyoshi SATO <nobu-s%iwate-pu.ac.jp@localhost>]

On Tue, 20 Jan 2026 18:11:18 -0800,
Jason Thorpe <thorpej%me.com@localhost> wrote:

>> On Jan 20, 2026, at 5:04 PM, Dennis Clarke <dclarke%blastwave.org@localhost> wrote:
>> 
>> On a dual CPU old Sun SPARCStation 20 it seems to be only using one CPU.
...
> Use GENERIC.MP; looks like the standard GENERIC doesn’t have MULTIPROCESSOR (and other associated options for it) enabled.

From Jan  8 21:53:30 JST, my SPARCstation 20 is working with 2 CPUs
to build entire NetBSD 10.1, in 100% CPU usage. Screen shots:
https://mstdn.nere9.help/@7n2jju/115930828328006686
https://imgs.nere9.help/media_attachments/files/115/930/828/057/954/074/small/1ac953ac93e734f1.png
(It still keep on buiding about two weeks, but my SS20 hanged
in last Sunday because of memory related error. I resumed on
Monday after I have replaced a doubtful memory module.)

If kernel has configured for second cpu like,
options         MULTIPROCESSOR  # include multiprocessor support
cpu*    at mainbus0             # declare additional CPUs
dmesg shows cpu1 and if you have more.
[     1.000000] mainbus0 (root): SUNW,SPARCstation-20: hostid 7271b491
[     1.000000] cpu0 at mainbus0: mid 8: TI,TMS390Z55 @ 75 MHz, on-chip FPU
[     1.000000] cpu0: physical 20K instruction (64 b/l), 16K data (32 b/l), 1024
K external (32 b/l): cache enabled
[     1.000000] cpu1 at mainbus0: mid 10: TI,TMS390Z55 @ 75 MHz, on-chip FPU
[     1.000000] cpu1: physical 20K instruction (64 b/l), 16K data (32 b/l), 1024
K external (32 b/l): cache enabled


Lecturer / Faculty of Software & Info. Sci., Iwate Prefectural Univ., Japan
Nobuyoshi Sato, Ph.D / nobu-s%iwate-pu.ac.jp@localhost / +81-19-694-2612