RFR: 8319795: Static huge pages are not used for CodeCache [v8]

[Evgeny Astigeevich]

On Tue, 19 Dec 2023 16:20:44 GMT, Thomas Stuefe <stuefe at openjdk.org> wrote:

> The new version (which I like, btw) now assumes min_pages=1 if InitialCCS == ReservedCCS.

It is only for the non-segmented CodeCache. Here we explicitly specify to use the segmented CodeCache. As such, we need to split 2G among three code heaps. InitialCCS is tricky in such a case, with the segmented CodeCache, the initial size of a code heap is the min of InitialCCS and the code heap size. We want the 2G segmented CodeCache to have 8 pages at least which is not possible with 1G pages. The number 8 is hard-coded. 

I think calculating the minimum number of pages is not easy for the segmented CodeCache.
We have:
- InitialCodeCacheSize
- ReservedCodeCacheSize
- LargePageSizeInBytes
- NonNMethodCodeHeapSize
- ProfiledCodeHeapSize
- NonProfiledCodeHeapSize

It's too many parameters for users.

A possible configuration: one 1G page for the non-nmethod code heap and the profiled code heap, another 1G page for the non-profiled code heap.

BTW, this is the original first test.

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PR Review Comment: https://git.openjdk.org/jdk/pull/16582#discussion_r1431983598