Who hates the *Ratio parameters?

[Tony Printezis]

John,

The GC erconomics do largely do that. However, a lot of users still do 
manualy tuning to get the last oz of performance they can get...

Tony

John Pampuch wrote:
> Tony-
>
> In the grand scheme of things though, it would be better if we could 
> figure these out automatically and not need the parameter at all.
>
> -John
>
> Tony Printezis wrote:
>> Paul,
>>
>> Paul Hohensee wrote:
>>   
>>> I would.  I'd use "SurvivorPercent" though, not "SurvivorPerc".  The 
>>> latter
>>> sounds like a bonus you get for surviving. :)
>>>     
>> I was trying to be a be concise, but sure Percent is fine.
>>   
>>> Or maybe just add "SurvivorSize" and "MaxSurvivorSize", like we have
>>> "NewSize" and "MaxNewSize".  That'd be exact, unlike either a percent
>>> or a ratio.
>>>     
>> Well, the problem with using specific sizes is that, if you resize your 
>> young gen (in this case), the survivor size will also have to change. 
>> Maybe, using percentages will handle that case a bit better (even though 
>> I can think of some cases when you want to fix the survivor size but 
>> maybe vary the eden size).
>>   
>>> btw, we seem to use the term "Ratio" to mean both a genuine ratio _and_ a
>>> percent.  E.g., "SurvivorRatio" is a genuine ratio, but 
>>> "MinHeapFreeRatio"
>>> is a percent.
>>>     
>> Yep. Unfortunately, we cannot change the meaning of MinHeapFreeRatio (to 
>> keep backwards compatibility). So, maybe, it'd be best to introduce a 
>> new parameter, say MinHeapFreePercent, with the same semantics as 
>> MinHeapFreeRatio, as a way to start migrating users to the correct one.
>>
>> Tony
>>   
>>> Tony Printezis wrote:
>>>     
>>>> Hi all,
>>>>
>>>> I personally don't like the *Ratio parameters (e.g., 
>>>> -XX:SurvivorRatio=<N>) as I don't think they are very intuitive to 
>>>> set. I've heard the same from a few customers too. Would most people 
>>>> prefer parameters based on percentages (e.g., -XX:SurvivorPerc=<N>, 
>>>> where 0 <= <N> <= 100) instead?
>>>>
>>>> Tony
>>>>
>>>>   
>>>>       
>>
>>   

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