Code review request: 6855834: G1: minimize the output when -XX:+PrintHeapAtGC is set (S)

Tony Printezis Antonios.Printezis at sun.com
Tue Jul 7 08:46:05 PDT 2009


We'll consider it!

kirk wrote:
> Hi All,
>
> can we take this opportunity to come up with a normalized machine 
> readable format? Something that we can start down the road with?
>
> G1 total 24576K used 16950K [0xf2400000, 0xf3c00000, 0xf5400000) 
> region size 1024K, 16 young (16384K), 1 survivor (1024K)
>
> 16384+1024=16408 meaning 24576-16408=8168 for old and perm? 8192 would 
> be 8 old regions.
>
> Regards,
> Kirk
>
> John Coomes wrote:
>> Tony Printezis (Antonios.Printezis at Sun.COM) wrote:
>>  
>>> http://cr.openjdk.java.net/~tonyp/6855834/webrev.0/
>>>
>>> The CR has more information on the new format:
>>>     
>>
>> Haven't reviewed the code yet (sorry), but have some questions.
>>
>> Does G1 have reasonably accurate occupancy info when this info is
>> printed?  If so, it would be nice to have a breakdown of the amount or
>> percentage used in young regions, survivor regions & old regions.
>> That would be closer to the info you get for the other collectors.
>>
>> If not, then I would combine the "region size" line with the one that
>> follows it.  Best shown by example:
>>
>> Change this:
>>
>>  garbage-first heap   total 24576K, used 16950K [0xf2400000, 
>> 0xf3c00000, 0xf5400000)
>>   region size 1024K
>>   young regions 16 / 16384K  survivor regions 0 / 0K
>>
>>
>> To something like this:
>>
>>  garbage-first heap   total 24576K, used 16950K [0xf2400000, 
>> 0xf3c00000, 0xf5400000)
>>   region size 1024K, 16 young (16384K), 1 survivor (1024K)
>>
>> -John
>>
>>
>>   
>

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