RFR: 8357662: applications/runthese/RunThese8H.java Crash: 'Failed to uncommit metaspace'

[Coleen Phillimore]

On Tue, 10 Jun 2025 12:25:01 GMT, Coleen Phillimore <coleenp at openjdk.org> wrote:

> Make the fatal error a log warning and return. The metaspace commit accounting is done after this return.  Tested with this always returning here, and it seems okay.  Tested with this change tier 1-4 and 8.

I don't see any evidence of a bug filed to examine whether uncommit failures should always/never/sometimes be a fatal error.  As the code is now, it's up to the caller, which is a situation that could go badly wrong if the caller guesses wrong.  I'd rather it always be a fatal error inside our os code that does uncommit in the cases that would corrupt memory.  If that's the case.
This metaspace uncommit is a case that seems like it could fail and the memory simply isn't returned as we'd wished.  Who knows whether memory is corrupted here or not.  I'd like the OS layer of code to tell me that.

Not really sure what to do about this other than close it as WNF.

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PR Comment: https://git.openjdk.org/jdk/pull/25720#issuecomment-2977532489