Invalid ranges for options

[David Holmes]

On 9/06/2016 12:02 AM, Lindenmaier, Goetz wrote:
> Hi David,
>
> I agree there is no obvious lower bound for this. We use this with
> rather big values, though (5 min, several hours) so that a lower bound
> of 100ms would be far from limiting.  And simple test shows that even
> 10ms helps.
>
> If the lower bound is a value that will not work for sure, it makes no
> sense to have it.  Also, it makes no sense to test the bounds without activating
> the freature as TestOptionsWithRanges does.
> So I would remove both, the test and the bounds in this case.

I think I'm misunderstanding the problem. What exactly are you proposing 
should be changed? The range checking of SafepointTimeoutDelay is 
independent of the operation of the safepoint timeout facility. And if 
you turn it on a delay of zero does exactly what I would expect. The 
range tests are primarily for legality not practicality.

David
-----


> Best regards,
>   Goetz.
>
>> -----Original Message-----
>> From: David Holmes [mailto:david.holmes at oracle.com]
>> Sent: Mittwoch, 8. Juni 2016 14:42
>> To: Lindenmaier, Goetz <goetz.lindenmaier at sap.com>; hotspot-runtime-
>> dev at openjdk.java.net
>> Subject: Re: Invalid ranges for options
>>
>> Hi Goetz,
>>
>> On 8/06/2016 8:27 PM, Lindenmaier, Goetz wrote:
>>> Hi,
>>>
>>> As SAP JVM is has some different default settings,
>> TestOptionsWithRanges.java has
>>> detected two problematic ranges:
>>>   java -XX:MaxJNILocalCapacity=1 -
>> Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=1044
>>>   java -XX:+SafepointTimeout -XX:SafepointTimeoutDelay=0
>>
>> I don't see any problem with SafepointTimeoutDelay. If you set it to
>> zero there is no delay and it times out immediately. It may not be
>> useful, but then neither is a value of 1, 2, 3 ...
>>
>> David
>> -----
>>
>>> I think the ranges of MaxJNILocalCapacity and SafepointTimeoutDelay
>> should be fixed.
>>> Should I open a bug for this?
>>>
>>> Best regards,
>>>   Goetz.
>>>
>>>
>>> bin/java  -XX:+SafepointTimeout -XX:SafepointTimeoutDelay=0
>>> # SafepointSynchronize::begin: Timeout detected:
>>> # SafepointSynchronize::begin: Timed out while waiting for threads to stop.
>>> # SafepointSynchronize::begin: Threads which did not reach the safepoint:
>>> # "C1 CompilerThread14" #20 daemon prio=9 os_prio=0
>> tid=0x00007efe7c01f800 nid=0x8784 runnable [0x0000000000000000]
>>>    java.lang.Thread.State: RUNNABLE
>>>    JavaThread state: _thread_in_native
>>>
>>>
>>> bin/java -XX:MaxJNILocalCapacity=1 -
>> Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=1044
>>> JDWP exit error AGENT_ERROR_OUT_OF_MEMORY(188): PushLocalFrame:
>> Unable to push JNI frame [util.c:1559]
>>> FATAL ERROR in native method: JDWP PushLocalFrame: Unable to push JNI
>> frame, jvmtiError=AGENT_ERROR_OUT_OF_MEMORY(188)
>>> Current thread is 34829
>>> Dumping core ...
>>> Abort
>>>