RFR(S): 8010738: G1: Output for full GCs with +PrintGCDetails should contain perm gen size/meta data change info
Jon Masamitsu
jon.masamitsu at oracle.com
Wed May 8 17:24:52 UTC 2013
John,
http://cr.openjdk.java.net/~johnc/8010738/webrev.0/src/share/vm/gc_implementation/g1/g1CollectorPolicy.hpp.udiff.html
> + size_t _meta_bytes_before_gc; // Metaspace occupancy before GC
_metaspace_bytes_before_gc, please?
Rest looks good.
Jon
On 5/6/2013 3:23 PM, John Cuthbertson wrote:
> Hi Everyone,
>
> Can I get a couple of volunteers review these fairly straight forward
> changes? The webrev can be found at:
> http://cr.openjdk.java.net/~johnc/8010738/webrev.0/.
>
> Summary:
> At sustaining engineering's request I've added the change information
> about the metadata space to the detailed heap output for full GCs:
>
>> 4.896: [Full GC (Allocation Failure) 512M->343M(512M), 4.3640117 secs]
>> [Eden: 0.0B(25.0M)->0.0B(97.0M) Survivors: 0.0B->0.0B Heap:
>> 512.0M(512.0M)->343.3M(512.0M)], [Metaspace: 1611K->2433K(6448K)]
>> [Times: user=5.13 sys=0.15, real=4.36 secs]
>
> The information that gets printed mirrors that of the other
> collectors. Here's parallel GC:
>
>> 33.245: [Full GC (Ergonomics) [PSYoungGen: 133632K->3423K(144640K)]
>> [ParOldGen: 348158K->348158K(348160K)] 481790K->351581K(492800K),
>> [Metaspace: 1612K->2433K(6448K)], 2.5788089 secs] [Times: user=9.96
>> sys=0.00, real=2.58 secs]
>
> The information that's printed is the amount of metaspace used before
> the GC, the capacity, and the amount of reserved space.
>
> The changes should be straight forward when this is backported to hs24
> - namely replacing the call to MetaspaceAux::print_metaspace_change()
> to perm_gen()->print_heap_change().
>
> Most of the changes are the result of renaming some of the fields in
> G1CollectorPolicy and the local variables in
> G1CollectorPolicy::print_detailed_heap_transition().
>
> The included regression test just spawns a child java process to run a
> very simple system GC test program with G1 and +PrintGCDetails. The
> output of the spawned process is checked for "Metaspace".
>
> Thanks,
>
> JohnC
More information about the hotspot-gc-dev
mailing list