[jdk17u-dev] Integrated: 8307348: Parallelize heap walk for ObjectCount(AfterGC) JFR event collection

[Aleksey Shipilev]

On Thu, 15 Jun 2023 09:19:12 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

> Improves ObjectCount JFR events that take considerable time at GC pause. While the event is still heavy, the parallelization helps to avoid unnecessarily large stalls. 
> 
> The backport is not clean, because there are number of contextual differences: `WorkGang`, `WithUpdatedActiveWorkers` and other renames did not happen yet. I had to massage the patch to fit 17u better.
> 
> Additional testing:
>  - [x] Linux x86_64 fastdebug `jdk/jfr serviceability/sa`
>  - [x] Linux x86_64 fastdebug `tier1 tier2 tier3`
>  - [x] Linux AArch64 fastdebug `tier1 tier2 tier3`

This pull request has now been integrated.

Changeset: fc08b730
Author:    Aleksey Shipilev <shade at openjdk.org>
URL:       https://git.openjdk.org/jdk17u-dev/commit/fc08b730142dcde39291be8044dfa667b98363ad
Stats:     41 lines in 9 files changed: 10 ins; 10 del; 21 mod

8307348: Parallelize heap walk for ObjectCount(AfterGC) JFR event collection

Reviewed-by: ogillespie, phh
Backport-of: 540c706bbcbb809ae1304aac4f2a16a5e83cb458

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PR: https://git.openjdk.org/jdk17u-dev/pull/1441