RFR: 8311248: Refactor CodeCache::initialize_heaps to simplify adding new CodeCache segments [v6]

[Evgeny Astigeevich]

On Fri, 2 Feb 2024 09:33:31 GMT, Boris Ulasevich <bulasevich at openjdk.org> wrote:

>> These changes clean up the logic and the code of allocating codecache segments and add more testing of it, to open a door for further optimization of code cache segmentation.  The goal was to keep the behavior as close to the existing behavior as possible, even if it's not quite logical.
>> 
>> Also, these changes better account for alignment - PrintFlagsFinal shows the final aligned segment sizes, and the segments fill the ReservedCodeCacheSize without gaps caused by alignment.
>
> Boris Ulasevich has updated the pull request incrementally with one additional commit since the last revision:
> 
>   set_size_of_unset_code_heap

src/hotspot/share/code/codeCache.cpp line 202:

> 200: static void report_cache_size_error(const CodeHeapInfo& non_nmethod, const CodeHeapInfo& profiled,
> 201:                                     const CodeHeapInfo& non_profiled, size_t cache_size) {
> 202:   size_t total = non_nmethod.size;

You have already calculated the total, why not to reuse it?
Also add an assert: `assert(total != ReservedCodeCacheSize, "Should be invoked to report an error")`

src/hotspot/share/code/codeCache.cpp line 220:

> 218:   }
> 219:   else {
> 220:     message.append(" is not equal to ReservedCodeCacheSize (" SIZE_FORMAT "K).", cache_size/K);

The correct message is " is less than ...". We call the function when they are not equal.

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PR Review Comment: https://git.openjdk.org/jdk/pull/17244#discussion_r1491748816
PR Review Comment: https://git.openjdk.org/jdk/pull/17244#discussion_r1491750222