RFR [XS]: 8229370: make jdk/jfr/event/runtime/TestNetworkUtilizationEvent.java more stable

[Baesken, Matthias]

Hi David ,   I could  add some  optional  UL logging  to see   what happens.

Maybe the  OS counters   that are fetched by   os_perf    are not that reliable on some  kernels .  


Best regards, Matthias



> 
> Hi Matthias,
> 
> On 28/08/2019 10:02 pm, Baesken, Matthias wrote:
> > Hi David,   thanks for reaching out to the net folks.
> >
> > I use now the  stream of InetAddresses   from
> NetworkInterface.networkInterfaces().flatMap(NetworkInterface::inetAddr
> esses)  ;
> >
> > However on the machine  where  I noticed the issue ,   I still have to do a
> couple of retries .
> > Just one  send to the stream of InetAddresses   from
> NetworkInterface.networkInterfaces().flatMap(NetworkInterface::inetAddr
> esses)    does not always give
> >    the expected result ☹ .
> 
> That doesn't make sense to me, if one of the interfaces is the real
> network interface and we write to the real IP address. I think we need
> to add some diagnostics to see exactly which interface and IP address we
> are writing to, and then see what each interface reports on the read
> back of the data.
> 
> Thanks,
> David
> 
> > New webrev :
> >
> > http://cr.openjdk.java.net/~mbaesken/webrevs/8229370.2/
> >
> >
> > Thanks, Matthias
> >