RFR: 8198668: MemoryPoolMBean/isUsageThresholdExceeded/isexceeded001/TestDescription.java still failing [v3]

[Serguei Spitsyn]

On Thu, 30 Jun 2022 20:54:15 GMT, Kevin Walls <kevinw at openjdk.org> wrote:

>> Test has been problemlisted for a long time due to intermittent failures.
>> 
>> This is a difficult test as it tries to monitor usage thresholds on Memory Pools which are outside its control.
>> Not just Java heap pools, where the allocation it makes may or may not affect a particuclar pool, but non-heap pools such as CodeHeap and Metadata, where other activity in the VM can affect their usage and surprise the test.
>> 
>> The test iterates JMX memory pools where thresholds are supported, sets a threshold one byte higher than current usage, and makes an allocation.  This only makes sense on Java heap pools.  It is tempting to skip non-heap pools, but this test can still give a sanity test about threshold behaviour.  That is actually its main purpose, as the allocation is unlikely to affect the pool being tested.
>> 
>> With the changes here, I'm seeing the test and all its variations pass reliably, i.e. 50 iterations in each tested platform.
>> 
>> Skip testing a non-heap memory pool, e.g. CodeHeap, if it is hitting the threshold while we test, because that means it is changing outside our control.  Also re-test isExceeded on failure, as fetching the usage and isExceeded is a race.
>> 
>> Logging of more pool stats to better understand failures.
>
> Kevin Walls has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains three commits:
> 
>  - Merge remote-tracking branch 'upstream/master' into 8198668_MBean_threshold_test
>  - Show log output
>  - 8198668: MemoryPoolMBean/isUsageThresholdExceeded/isexceeded001/TestDescription.java still failing

Looks good to me.
I've posted a couple of minor questions/comments.
Thanks,
Serguei

test/hotspot/jtreg/vmTestbase/nsk/monitoring/MemoryPoolMBean/isUsageThresholdExceeded/isexceeded001.java line 116:

> 114:             }
> 115: 
> 116:             // If used value is less than threshold, then isUsageThresholdExceeded()

Nit: Replace(?): "If used value" => "If peak used value"

test/hotspot/jtreg/vmTestbase/nsk/monitoring/MemoryPoolMBean/isUsageThresholdExceeded/isexceeded001.java line 130:

> 128:                 }
> 129:             } else
> 130:             // If used value is greater or equal than threshold, then

Nit: Replace(?): "If used value" => "If peak used value"

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

Marked as reviewed by sspitsyn (Reviewer).

PR: https://git.openjdk.org/jdk/pull/9309