[lworld] RFR: 8369893: [lworld] Split multiple @run statements in runtime tests into separate @test blocks

[Christian Hagedorn]

On Fri, 17 Oct 2025 07:59:24 GMT, Paul Hübner <phubner at openjdk.org> wrote:

> Hi all,
> 
> This PR mirrors the changes made to [the compiler](https://github.com/openjdk/valhalla/pull/1681) `jtreg` testing setup ([issue](https://bugs.openjdk.org/browse/JDK-8369437)).
> 
> **Concretely:**
> * Split multiple (independent) `@run`s into separate `@test` blocks, specifying new IDs where appropriate.
> * Added packages where we missed them for consistency. This excludes places where the test setup does not allow for packages or for tests that are disabled (some of which don't compile, as our model is evolving). 
> * Changed `@run main/othervm` into `@run main` when there was no flag passed.
> 
> **Impact:**
> 
> I compared machine execution time in tiers 1-4 to `jdk-26-valhalla+1-89` (which my changes are based on). 
> 
> | | lworld | lworld + patch | improvement
> -- | -- | -- | -- 
> tier1 | 1d 00h 26m 16s |  1d 00h 13m 20s | ~ - 3 mins
> tier2 | 1d 03h 16m 04s | 1d 01h 24m 05s | ~ -2 hours
> tier3 | 2d 17h 29m 13s | 2d 17h 16m 15s | ~ -13 mins
> tier4 | 2d 11h 32m 26s | 2d 01h 05m 40s | ~ -10 hours
> 
> Overall, the trend shows shorter execution times. (And by extension, probably less electricity usage too :))
> 
> Note that the CI ran a few extra tasks at tiers 2,  (two orders of magnitude less compared to the total number of tasks) than my personal run did. I don't think these will impact the results significantly.
> 
> *Disclaimers: these measurements were run before adding packages and getting rid of a few leftover `main/othervm`, although these should not change the results significantly. Also, this is very ad-hoc "benchmarking," variance is not measured.*

Looks good to me but maybe someone from the runtime team should maybe also have a look.

Thanks for following up with this for the runtime tests and providing some numbers! Looks like there were not that many splitting opportunities as with the compiler tests but they still had quite an impact in tier2 and 4, nice!

test/hotspot/jtreg/runtime/valhalla/inlinetypes/ValueTearing.java line 47:

> 45: /*
> 46:  * @test
> 47:  * @ignore

Just checking: Is there a tracking issue to re-enable this test?

test/hotspot/jtreg/runtime/valhalla/inlinetypes/WrappersOffsetTest.java line 26:

> 24: 
> 25: /*
> 26:  * @test

Optional: You could also add ids here.

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

Marked as reviewed by chagedorn (Committer).

PR Review: https://git.openjdk.org/valhalla/pull/1682#pullrequestreview-3355511841
PR Review Comment: https://git.openjdk.org/valhalla/pull/1682#discussion_r2444209669
PR Review Comment: https://git.openjdk.org/valhalla/pull/1682#discussion_r2444211779