RFR (S): 8006088: Incompatible heap size flags accepted by VM

[Jesper Wilhelmsson]

Looks good,
Ship it!
/Jesper

Thomas Schatzl skrev 26/4/13 2:05 PM:
> Hi all,
>
> On Thu, 2013-04-18 at 10:57 -0700, John Cuthbertson wrote:
>> Hi Thomas,
>>
>> [...]
>>
>> Ship it.
>>
>> JohnC
>
>    I still need another reviewer to actually ship this :)
>
> It would also help to have this cleanup for CR-7057939 and CR-8012591.
>
> Thanks,
>    Thomas
>
> On Thu, 2013-04-18 at 10:57 -0700, John Cuthbertson wrote:
>> Hi Thomas,
>>
>> Thanks for the resonse. Inline...
>>
>> On 4/17/2013 12:23 AM, Thomas Schatzl wrote:
>>> Hi,
>>>
>>>     I had the same concerns about inconsistencies with -Xms and
>>> -XX:InitialHeapSize, but -Xms is (apparently) defined to set both
>>> minimum and initial heap size.
>>> I already raised that issue in an earlier discussion.
>>
>> OK. I don't have a problem with it. It just looked 'odd'.
>>>
>>> If you have an official source that states that -Xms only sets minimum
>>> or initial heap size, I will gladly change this. I could not find
>>> anything; actually the documentation (java -X) for -Xms states only that it sets the initial heap size.
>>>
>>> The observations below result from this definition.
>>>
>>> On Mon, 2013-04-15 at 16:29 -0700, John Cuthbertson wrote:
>>>> Hi Thomas,
>>>>
>>>> Why do we treat:
>>>>
>>>> java -Xms8M  -XX:InitialHeapSize=4M...
>>>>
>>>> as an error while accepting:
>>> Because -Xms sets minimum heap size to 8M, and if you then set initial
>>> heap size to 4M there is a conflict in the general condition that
>>> minimum <= initial <= max.
>>>
>>>> java -XX:InitialHeapSize=4M -Xms8M...
>>>>
>>>> It looks inconsistent. In both cases the user has asked for an initial
>>>> heap size less than his requested minimum.
>>> As mentioned, -Xms unfortunately seems to be defined to set both initial
>>> and minimum heap size. So there is no conflict.
>>
>> You're correct. I've looked at the contents of the Xusage.txt file for a
>> couple of really ancient jdks and it says that it sets the initial size.
>>
>>
>>>> In collectorPolicy.cpp, can the code on lines 79-80 and 83-84 be
>>>> coalesced into a single line for each? This would make the setting of
>>>> Initial and Min consistent with the code that sets Max on line 87.
>>>>
>>> Done.
>>>
>>> See http://cr.openjdk.java.net/~tschatzl/8006088/webrev.7/ for the new
>>> webrev.
>>>
>>> In addition to this change I fixed the headers of the jprt test cases to
>>> avoid some issues with jtreg. Namely precompile the used classes and
>>> install the whitebox api class into the boot class path.
>>
>> Thanks. collectorPolicy.cpp looks much cleaner.
>>
>> Ship it.
>>
>> JohnC
>
>