RFR(XS): 8191943: [TESTBUG] docker/TestCPUAwareness fails on machine with 2 CPUs

[Bob Vandette]

> On Nov 29, 2017, at 4:10 PM, mikhailo <mikhailo.seledtsov at oracle.com> wrote:
> 
> Hi Bob,
> 
> The failure was caused by invoking this test case:
> 
>     testCpuShares(4096, 4);
>     The test case sets --cpu-shares to 4096, expects active processor count to be 4; ==> actual APC is 2.

Ahh, that makes sense.  I thought docker was complaining due to the arguments being passed going
beyond the available cpus.  

> 
> Command:
> 
>     docker run --tty=true --rm --cpu-shares=4096 jdk-internal:test-cpu /jdk/bin/java -Xlog:os+container=trace -version
> 
> Detailed log is attached at:
> 
> https://bugs.openjdk.java.net/secure/attachment/73820/test-case-failure-cpu-shares-4096.txt
> 
> 
> Once I saw this issue, I decided to put limits on other test cases based on the number of processors available on a machine, just to be on a safe side.
> 
> Perhaps a better approach here is to change the expected APC inside the testCpuShares() to be no greater than max number of available processors?

Yes, the selection algorithm returns the smallest number of computed shares, quotas or active processors.  Using this approach, you’d actually be validating the algorithm more precisely.

Bob.


> 
> 
> Misha
> 
> 
> 
> 
> 
> 
> On 11/29/2017 06:02 AM, Bob Vandette wrote:
>> Misha,
>> 
>> Which specific subtest failed on a 2 cpu system?
>> 
>> I don’t see any subtests that should have failed.  You should be able
>> to pass any quota, period and share value to docker independent of the
>> number of CPUs.  testCpus and testAPCCombo don’t try to test more than 2 cpus.
>> 
>> I’m ok with the change but just wondering why the guards are necessary.
>> 
>> Bob.
>> 
>>> On Nov 28, 2017, at 7:50 PM, mikhailo <mikhailo.seledtsov at oracle.com> wrote:
>>> 
>>> Could you, please, review this simple fix? It limits test cases in TestCPUAwareness.java
>>> based on the number of processors available.
>>> 
>>>     JBS: https://bugs.openjdk.java.net/browse/JDK-8191943
>>>     Webrev: http://cr.openjdk.java.net/~mseledtsov/8191943.00/
>>>     Testing:
>>>         1. Locally: exercised the affected test locally on Linux-x64
>>>         2. Exercised the affected test on 2 processor machine
>>>         3. Exercise the affected test via automated distributed test system
>>>            In progress
>>> 
>>> Misha
>>> 
>