RFR: 8348647: CDS dumping commits 3GB when large pages are used

Mon Jan 27 14:35:57 UTC 2025

On Fri, 24 Jan 2025 13:34:18 GMT, Stefan Karlsson <stefank at openjdk.org> wrote:

> CDS inadvertently commits large pages when dumping and -XX:+UseLargePages is used. The fix is simply to use the memory reservation API that doesn't try to allocate large pages.
> 
> FWIW, I think that we should change the overloads so that the simplest overloaded function reserves memory without large pages.
> 
> I verified manually by looking at /proc/meminfo that we're not using large pages for the symbols after this change.

lgtm. 

I remember this being an unexpected issue when we tried to increase the concurrency on our large page testing.

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Marked as reviewed by aboldtch (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/23299#pullrequestreview-2575607026