[lworld] RFR: 8369437: [lworld] Split multiple @run statements in compiler tests into separate @test blocks

[Christian Hagedorn]

On Wed, 15 Oct 2025 06:56:37 GMT, Christian Hagedorn <chagedorn at openjdk.org> wrote:

> This patch splits jtreg tests with multiple `@run` statements in one `@test` block into different blocks. This allows jtreg to do better parallelization.
> 
> I walked through all `compiler/valhalla/inlinetypes` tests. Whenever we had 3 or more `@run` statements in a single `@test` block, I compared the test with execution times on Mach5, mainly tier1. If the test needed more time to execute, I split the block into separate blocks. Otherwise, I left them untouched (we can repeat this process if necessary when we see some more opportunities). Note: I did not change anything else in the tests themselves like loop iterations etc.
> 
> #### Changes
> - Split into separate `@test` blocks.
> - Added packages where we missed them for consistency.
> - Changed `othervm/main` into `main` when there was no flag passed (could be left-over from runs that had `-XX:+EnableValhalla` before).
> - Introduced ids for the different `@test` blocks.
> 
> #### Test Execution Time
> Since I changed quite a lot of tests and there is no simple way to run tier1-4 only with `compiler/valhalla/inlinetypes` tests without also running them with flag combos that they normally do not run, I ran it once through these tiers separately. There were no timeouts reported anymore after the timeout factor change back to 4 in Valhalla. Here are the results for the total machine times compared to the last CI run `jdk-26-valhalla+1-83` (could of course have some variance but the numbers are just an indication):
> 
> |  | lworld | lworld + patch | improvement |
> |-----|----------|----------|----------|
> | tier1 | 1d 00h 45m 31s |  14h 37m 43s |  ~ - 10 h |
> | tier2 | 1d 06h 16m 54s | 1d 02h 50m 17s | ~ - 3h 30min |
> | tier3 | 2d 19h 08m 57s | 2d 15h 25m 58s | ~ - 3h 45min |
> | tier4 | 2d 12h 13m 12s | 2d 01h 28m 00s | ~ - 10h 45min |
> 
> We can see quite some improvements by simply doing that. Note that [JDK-8369530](https://bugs.openjdk.org/browse/JDK-8369530) explores improvement opportunities for the actual testing code.
> 
> Thanks,
> Christian

Thanks Tobias for your review!

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PR Comment: https://git.openjdk.org/valhalla/pull/1681#issuecomment-3405436440