8186248 - Allow more flexibility in selecting Heap % of available RAM

[Bob Vandette]

> On Aug 22, 2017, at 3:50 PM, White, Derek <Derek.White at cavium.com> wrote:
> 
> Hi Bob,
> 
> Do you want to add the old flags to the special_jvm_flags list, to get "deprecated" warnings? Or will that come later after CCC-like approval?
> 

Lets see what others in the VM runtime team have to say about deprecation.

I added Deprecation to the old flag descriptions but there are some hotspot
jtreg tests that use the old flags and I don’t think we want warnings to come out
while running these tests.

If I cause the warnings, then I’ll need to change all uses of these old flags in these
tests as well.  I was expecting to do that in the next release.  Perhaps I can 
use deprecated_in(11).

Bob.


> - Derek
> 
>> -----Original Message-----
>> From: hotspot-runtime-dev [mailto:hotspot-runtime-dev-
>> bounces at openjdk.java.net] On Behalf Of Bob Vandette
>> Sent: Tuesday, August 22, 2017 2:22 PM
>> To: hotspot-runtime-dev at openjdk.java.net runtime <hotspot-runtime-
>> dev at openjdk.java.net>; hotspot-gc-dev at openjdk.java.net
>> Subject: RFR: 8186248 - Allow more flexibility in selecting Heap % of available
>> RAM
>> 
>> Please review the updated webrev which adds new VM flags to allow for the
>> manual selection of Heap size based on a percentage of total available
>> memory.
>> 
>> This version deprecates the existing fractional options and allows the new %
>> based flags to override.
>> 
>> http://cr.openjdk.java.net/~bobv/8186248/webrev.01/
>> <http://cr.openjdk.java.net/~bobv/8186248/webrev.01/>
>> 
>> Bob.
>> 
>> 
>>> On Aug 17, 2017, at 12:36 AM, David Holmes <David.Holmes at oracle.com>
>> wrote:
>>> 
>>> On 17/08/2017 1:29 PM, Bob Vandette wrote:
>>>> I saw that but wasn't sure it needed the added flexibility since its probably
>> ok that initial sizes are 50% or less.
>>> 
>>> I'd go for consistency.
>>> 
>>> Also now you will need to guard against values < 1, I think.
>>> 
>>> There may be an option checking test that will need updating as well.
>>> 
>>> Cheers,
>>> David
>>> 
>>>> Bob.
>>>>> On Aug 16, 2017, at 5:04 PM, David Holmes <david.holmes at oracle.com>
>> wrote:
>>>>> 
>>>>> Hi Bob,
>>>>> 
>>>>>> On 17/08/2017 3:32 AM, Bob Vandette wrote:
>>>>>> Please review this simple two line fix which allows more
>>>>>> flexibility in selecting the % of system RAM to be used by the Heap.  This
>> just changes two int variables to doubles.
>>>>>> RFE:
>>>>>> https://bugs.openjdk.java.net/browse/JDK-8186248
>>>>>> <https://bugs.openjdk.java.net/browse/JDK-8186248>
>>>>>> Webrev:
>>>>>> http://cr.openjdk.java.net/~bobv/8186248
>>>>>> <http://cr.openjdk.java.net/~bobv/8186248>
>>>>> 
>>>>> Wouldn't you also want/need to change the type of InitialRAMFraction?
>>>>> 
>>>>> Note: jdk10/hs is currently closed to changes as we prepare to push up
>> to jdk10/jdk10.
>>>>> 
>>>>> Thanks,
>>>>> David
>>>>> 
>>>>>> Bob.
>