RFR: 8222533 - jtreg test jdk/internal/platform/cgroup/TestCgroupMetrics.java fails on SLES12.3 linux ppc64le machine

[David Holmes]

Hi Bob,

This fix seems quite reasonable.

Thanks,
David

On 8/05/2019 6:25 am, Bob Vandette wrote:
> Please review this simple fix for a TestCgroupMetrics.java test failure.
> 
> --- a/src/java.base/linux/classes/jdk/internal/platform/cgroupv1/SubSystem.java
> +++ b/src/java.base/linux/classes/jdk/internal/platform/cgroupv1/SubSystem.java
> @@ -108,7 +108,7 @@
>           try {
>               List<String> lines = Files.readAllLines(Paths.get(subsystem.path(), param));
>               for (String line: lines) {
> -                if (line.contains(match)) {
> +                if (line.startsWith(match)) {
>                       retval = conversion.apply(line);
>                       break;
>                   }
> 
> Under docker we typically only see a single block I/O device so
> the test passed since both lines containing “Total” are the same value.
> 
> 8:16 Read 4452352
> 8:16 Write 0
> 8:16 Sync 0
> 8:16 Async 4452352
> 8:16 Total 4452352
> Total 4452352
> 
> It’s possible and likely that there will be multiple devices causing failures
> since the test and the Metrics API are not examining the same lines.
> 
> 249:0 Read 10477568
> 249:0 Write 294431895552
> 249:0 Sync 17292476416
> 249:0 Async 277149896704
> 249:0 Total 294442373120 <——— The API was returning this
> 8:16 Read 19017216
> 8:16 Write 326780178432
> 8:16 Sync 17398915072
> 8:16 Async 309400280576
> 8:16 Total 326799195648
> 8:0 Read 27092992
> 8:0 Write 31070281728
> 8:0 Sync 10728873984
> 8:0 Async 20368500736
> 8:0 Total 31097374720
> Total 652338943488 <—— Test test was comparing to this
> 
> We are after the line that “startsWith” “Total”.
> 
> Bob.
>