Proposal: Clarifying the CSR rules for dealing with various kinds of -XX flags for hotspot

[David Holmes]

Hi Joe,

On 24/02/2018 9:53 AM, Joseph D. Darcy wrote:
> Hello,
> 
> Catching up on email, I think the general thrust of the proposal is 
> reasonable, but I have a few questions and comments.
> 
> First, what is the full space of kinds of builds, product XOR debug?

First distinction is product vs development

Development can then be: fastdebug (aka debug), slowdebug, or optimized 
(the exact definition of which I can't recall but this is a build 
variation we are removing anyway).

> What syntactic conventions, if any, distinguish all these kinds of 
> flags? Are product and manageable "-X" and all the others "-XX"? (I've 
> previously suggested in jest that a "-XXX" prefix be used for less 
> wholesome options.)

There are no syntactic distinctions - these are all -XX flags, 
regardless of whether product or development, experimental etc. That is 
the long standing convention for hotspot specific flags.

> If so, rather than reading of the general CSR guidelines and concluding 
> "[the guidelines] places all [HotSpot] -XX options into the same CSR 
> basket," an alternative observation might be the HotSpot naming 
> conventions choose to put multiple distinct kinds of options into the 
> same small namespace. 

We only have one namespace for hotspot options.

> Do options commonly move between categories as 
> part of their lifecycle (e.g. experimental -> product, etc.)?

Not commonly. An experimental flag may become product if the 
experimental feature is adopted - that would of course have a CSR 
request at that point. Sometimes a product flag can be reclassified as 
develop, or vice-versa - both of which would again require CSR requests 
as they involve a product flag. Most commonly flags stay in their 
initial category.

Thanks,
David

> Thanks,
> 
> -Joe
> 
> On 2/20/2018 11:27 PM, David Holmes wrote:
>> Dear CSR Group Members,
>>
>> On behalf of the Hotspot team within Oracle, I would like to submit 
>> this proposal regarding the CSR process for dealing with various -XX 
>> Hotspot flags.
>>
>> If this is acceptable then we would like to see this clearly 
>> documented on the OpenJDK site in a suitable location (and referenced 
>> from both Hotspot wiki and CSR wiki).
>>
>> Thank you.
>> David
>> ------
>