-XX:+PrintClassHistogram Does a FullGC even with CMS enabled and -XX:+ExplicitGCInvokesConcurrent ?

[Matt Miller]

Hi All,

It seems to me that even with 7 (Tested both u45 and u51)  the title 
holds true.
I would expect with ConcMarkSweep enabled, and 
ExplicitGCInvokesConcurrent that -XX:+PrintClassHistogram would NOT do a 
FullGC, but instead start a CMS cycle.
I thought maybe this was addressed by 
http://bugs.java.com/view_bug.do?bug_id=6797870

But I suppose this is not correct?

Is there a bug to fix PrintClassHistogram when using CMS?
Perhaps I am just not finding the correct bug number?

And of course even -XX:+DisableExplicitGC does not help...

Example:
jconsole -J-Xloggc:/Users/mmiller/gc.log -J-XX:+UseConcMarkSweepGC 
-J-XX:+PrintGCDetails -J-XX:+ExplicitGCInvokesConcurrent 
-J-XX:+PrintClassHistogram &
[1] 10759
$ kill -3 10759
$ cat gc.log

<output snipped>

19.169: [Full GC19.169: [CMS: 5620K->6303K(7776K), 0.0338410 secs] 
6950K->6303K(10208K), [CMS Perm : 13492K->13487K(21248K)], 0.0340110 
secs] [Times: user=0.04 sys=0.00, real=0.03 secs]

  num     #instances         #bytes  class name
----------------------------------------------

<snip>


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.openjdk.java.net/pipermail/hotspot-gc-use/attachments/20140402/33e45967/attachment.html>