RFR 8078555(M): GC: implement ranges (optionally constraints) for those flags that have them missing

[Jon Masamitsu]

Sangheon,

A general question.  A constraint function such as

   49 static Flag::Error ParallelGCThreadsAndCMSWorkQueueDrainThreshold(uint threads, uintx threshold, bool verbose) {
   50   // CMSWorkQueueDrainThreshold is verified to be less than max_juint
   51   if (UseConcMarkSweepGC && (threads > (uint)(max_jint / (uint)threshold))) {
   52     CommandLineError::print(verbose,
   53                             "ParallelGCThreads (" UINT32_FORMAT ") or CMSWorkQueueDrainThreshold ("
   54                             UINTX_FORMAT ") is too large\n",
   55                             threads, threshold);
   56     return Flag::VIOLATES_CONSTRAINT;
   57   }
   58   return Flag::SUCCESS;
   59 }

takes parameters that should only be ParallelGCThreads for "threads" and
only CMSWorkQueueDrainThreshold for "threshold".  Is that right?

Jon


On 08/26/2015 11:51 AM, sangheon.kim wrote:
> Hi Derek,
>
> Thank you for looking at this!
>
> On 08/26/2015 10:59 AM, Derek White wrote:
>> Hi Sangheon,
>>
>> I haven't reviewed the actual ranges and constraints yet, but one 
>> thing you might want to consider:
>>
>> For the test cases, you may want synchronize the GC specified to 
>> ProcessBuilder with the "@requires gc=" tags. This prevents the test 
>> harness from running G1 tests when the test harness is trying to run 
>> CMS test, etc, and also avoids potential confusing test failures.
>>
>>  @requires vm.gc=="G1" | vm.gc=="null"
>>  (or specify Parallel GC as needed).
> Thank you for the explanation.
> I didn't know about this.
>
> So it seems like vm.gc=="null" means not specifying vm option.
>
>>
>> This is for:
>> TestG1ConcMarkStepDurationMillis.java (G1)
>> TestObjectTenuringFlags.java (Parallel)
>> TestInitialTenuringThreshold.java (Parallel)
>> TestG1HeapRegionSize.java (G1)
> Okay, I will add these tags at next webrev.
>
> Thanks,
> Sangheon
>
>
>>
>>  - Derek
>>
>> On 8/24/15 5:33 PM, sangheon.kim wrote:
>>> Hi Kim,
>>>
>>> On 08/24/2015 02:16 PM, Kim Barrett wrote:
>>>> On Aug 24, 2015, at 3:06 PM, sangheon.kim <sangheon.kim at oracle.com> 
>>>> wrote:
>>>>> Hi Kim,
>>>>>
>>>>> Here's webrev.03 which includes your comment for MarkStackSize 
>>>>> constraint function.
>>>>>
>>>>> http://cr.openjdk.java.net/~sangheki/8078555/webrev.03
>>>>> http://cr.openjdk.java.net/~sangheki/8078555/webrev.03_to_02/
>>>>>
>>>>> And all your comments will be managed by 
>>>>> https://bugs.openjdk.java.net/browse/JDK-8134348 .
>>>> If the value of MarkStackSizeMax were changed later, there's nothing
>>>> to verify MarkStackSize is still smaller.  [This is related to my
>>>> earlier comment about constraints between options being tested twice
>>>> and failures reported twice.]  Do we care in this case?
>>> If your concern is something like
>>> -XX:MarkStackSize=128 -XX:MarkStackSizeMax=100.
>>> Yes, in this case the order is important as ranges and constraint 
>>> functions are verified by its order.
>>> MarkStackSizeMax will be verified first(its range) and MarkStackSize 
>>> will be compared with verified MarkStackSizeMax.
>>>
>>> And as I said your original concern is current limitation.
>>> If we set CMSOldPLABMin and CMSOldPLABMax together with invalid 
>>> values (e.g. CMSOldPLABMin=100, CMSOldPLABMax=50),
>>> they will print out 2 failure messages.
>>>
>>> Thanks,
>>> Sangheon
>>>
>>>>
>>>> Other than that, looks good.
>>>>
>>>
>>
>