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

[kirk]

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
>
>
>