RFR: 8337493: [JVMCI] Number of libgraal threads might be too low

[Doug Simon]

On Tue, 1 Oct 2024 08:33:49 GMT, Raphael Mosaner <duke at openjdk.org> wrote:

> The `-XX:JVMCINativeLibraryThreadFraction` flag defines the ratio between JVMCI threads and C1 threads.
> With a default value of 0.33 the number of JVMCI threads is significantly smaller than the number of C2 threads would be.
> 
> This can lead to unexpected warmup behavior with `-XX:+UseJVMCICompiler`. This PR changes the default value of `-XX:JVMCINativeLibraryThreadFraction` to yield the same number of JVMCI threads as C2 threads.

LGTM.

-------------

Marked as reviewed by dnsimon (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/21279#pullrequestreview-2339514983