Issues running jcstress on multi-core systems

[Aleksey Shipilev]

Well, I still cannot reproduce this.

However, I strengthen the timings a little bit:
  http://hg.openjdk.java.net/code-tools/jcstress/rev/1558a1741344

Does this help?

-Aleksey

On 08/11/2016 05:45 PM, Pavel Punegov wrote:
> I found that we’ve actually had the same issue some time ago. I just
> haven’t remembered it. I’m sorry.
> 
> Here is an issue https://bugs.openjdk.java.net/browse/CODETOOLS-7901764.
> I’m not quite sure if it's still applicable and correct, but it looks
> the same.
> 
> — Thanks,
> Pavel Punegov
> 
>> On 11 Aug 2016, at 02:24, Johnson, Andy <johnsona at cboe.com
>> <mailto:johnsona at cboe.com>> wrote:
>>
>> I set "-time 2000" (the default value is 1000) and actually got more
>> failures (25) than I did with the default setting.  If I run just the
>> interrupt tests ("-t interrupt."), they all pass.  
>>
>> -----Original Message-----
>> From: Aleksey Shipilev [mailto:aleksey.shipilev at gmail.com]
>> Sent: Wednesday, August 10, 2016 3:54 PM
>> To: Johnson, Andy <johnsona at cboe.com <mailto:johnsona at cboe.com>>;
>> 'jcstress-dev at openjdk.java.net <mailto:jcstress-dev at openjdk.java.net>'
>> <jcstress-dev at openjdk.java.net <mailto:jcstress-dev at openjdk.java.net>>
>> Subject: Re: Issues running jcstress on multi-core systems
>>
>> On 08/10/2016 07:41 PM, Johnson, Andy wrote:
>>> I have recently downloaded, built and run jcstress (custom suite only,
>>> for now) on a 24-core Linux server-class system.  I am finding that
>>> several of the "interrupt" tests are failing.  However, I have
>>> discovered that the number of failures seems to be related to the
>>> number of processor cores being used during the test.
>>
>> "interrupt" tests are inherently time-based: they usually wait for
>> timeout. There is a chance that timeout is not enough on busy machines
>> -- while the test tries to assert that the code quits, it runs out of
>> time before quitting, and infra fails it.
>>
>> Now, I realized we have a hard-coded timeout in the tests. Oops.
>> Fixed, now it is derived from the iteration time:
>>  http://hg.openjdk.java.net/code-tools/jcstress/rev/b0c5e26af669
>>
>> So, with an updated jcstress, you may want to try different "-time
>> <msec>" settings and see if it helps. If it does help, we may need to
>> throttle other tests while interrupt tests are executing.
>>
>>> I am using "taskset" to control the number of cores used by java.
>>
>> jcstress harness accepts "-sc <numCPUs>" to artificially limit the
>> number of hardware threads to use.
>>
>> Thanks,
>> -Aleksey
>>
>