RFR: 8365633: Incorrect info is reported on hybrid CPU [v2]

[Vladimir Kozlov]

On Thu, 21 Aug 2025 06:26:43 GMT, Yasumasa Suenaga <ysuenaga at openjdk.org> wrote:

>>> > `(14 threads)` is just as wrong as it implies 1 processor/core with 14 threads.
>>> 
>>> I don't think so because I think it does not contain neither "per core", thus it implies "total number of threads is 14".
>>> 
>>> However I don't stick to show number of threads on hybrid CPU because the user can refer data sheet from processor model name. I think it can be changed to nothing to show or "14 threads per processor" for clarification. Which do you like?
>> 
>> I prefer nothing - thanks. "threads" is generally understood to be a sub-unit of "cores" which are a sub-unit of "processors", which might be a sub-unit of "sockets".
>
> I removed number of threads information on hybrid CPU. @dholmes-ora Can you review?  
> We can get following strings on hybrid CPU after this change:
> 
> 
> CPU: total 14 (initial active 14)  family 6 model 181 stepping 0 microcode 0xffffffff, cx8, cmov, fxsr, ht, mmx, 3dnowpref, sse, sse2, sse3, ssse3, sse4.1, sse4.2, popcnt, lzcnt, tsc, tscinvbit, avx, avx2, aes, erms, clmul, bmi1, bmi2, adx, sha, fma, vzeroupper, clflush, clflushopt, clwb, hv, serialize, rdtscp, rdpid, fsrm, gfni, f16c, cet_ibt, cet_ss, hybrid
> CPU Model and flags from /proc/cpuinfo:
> model name      : Intel(R) Core(TM) Ultra 5 225U

@YaSuenag  Is it possible to find from CPUID or OS calls the information about hybrid CPU configuration?

"( 2 P cores, 8 E cores, 2 LP cores)" in you case.  I would prefer if for hybrid CPU we print that info instead of "(7 cores per cpu, 2 threads per core) ".

It is important information when we debug issue on such CPUs.

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PR Comment: https://git.openjdk.org/jdk/pull/26808#issuecomment-3211088436