RFR: 8366082: Improve queue size computation in CPU-time sampler [v2]

[Jaroslav Bachorik]

On Mon, 25 Aug 2025 14:29:08 GMT, Johannes Bechberger <jbechberger at openjdk.org> wrote:

>> Improve the sample queue size computation for the CPU-time sampler by increasing the size dynamically when needed, but keeping the default size small.
>
> Johannes Bechberger has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Add queue locking on thread termination

src/hotspot/share/jfr/periodic/sampling/jfrCPUTimeThreadSampler.cpp line 185:

> 183:     }
> 184:     if (factor > 1) {
> 185:       u4 new_capacity = capacity * factor > CPU_TIME_QUEUE_MAX_CAPACITY ? CPU_TIME_QUEUE_MAX_CAPACITY : capacity * factor;

NIT: Could use the MAX2 macro - no real functionality change, though.

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PR Review Comment: https://git.openjdk.org/jdk/pull/26926#discussion_r2315328833