RFR: JDK-8281274: deal with ActiveProcessorCount in os::Linux::print_container_info

[Severin Gehwolf]

On Fri, 4 Feb 2022 17:52:10 GMT, Severin Gehwolf <sgehwolf at openjdk.org> wrote:

>> The function os::Linux::print_container_info outputs memory- and cpu-related container information (when running in a containerized environment).
>> However in the case of active processor count , it currently just outputs the info from OSContainer::active_processor_count without  looking at  ActiveProcessorCount that can be set to overwrite the OSContainer::active_processor_count() - information. This should be improved.
>
> src/hotspot/os/linux/os_linux.cpp line 2178:
> 
>> 2176:   if (i > 0) {
>> 2177:     if (ActiveProcessorCount > 0) {
>> 2178:       st->print_cr("%d, but overwritten by flag ActiveProcessorCount: %d",
> 
> This will print the same number (processor count) twice. I'd suggest to only add a blurb like `" overridden by -XX:ActiveProcessorCount"` in case the flag is set and not print the blurb otherwise.

Asserting the new output in the jtreg test would be good to have too.

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PR: https://git.openjdk.java.net/jdk/pull/7354