RFR: 8378675: PPC64: increase instruction cache line size [v2]

[David Briemann]

On Thu, 26 Feb 2026 08:41:41 GMT, Richard Reingruber <rrich at openjdk.org> wrote:

>> David Briemann has updated the pull request incrementally with two additional commits since the last revision:
>> 
>>  - add comments that explain getconf behavior
>>  - update copyright headers
>
> src/hotspot/os/linux/os_linux.cpp line 5389:
> 
>> 5387:   int size = sysconf(_SC_LEVEL1_DCACHE_LINESIZE);
>> 5388:   // On some Linuxes this is not available, then return DEFAULT_CACHE_LINE_SIZE.
>> 5389:   return (size == 0) ? DEFAULT_CACHE_LINE_SIZE : size;
> 
> Suggestion:
> 
>   return (size <= 0) ? DEFAULT_CACHE_LINE_SIZE : size;
> 
> The man page says that sysconf returns -1 on error (e.g. if the queried name is unknown).

Interesting. We saw a 0 returned on some Linux. But the `<= 0` check will catch all cases. I will change it.

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PR Review Comment: https://git.openjdk.org/jdk/pull/29918#discussion_r2858265277