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

[John Coomes]

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