CMS: "premature" minor GCs w/ ParNew

[Srinivas Ramakrishna]

Does it happen with a specific application?

You might want to print the gc cause and see. It could be related to
allocating very large objects (arrays). +PrintGCDetails and
+PrintHeapAtGC would provide additional data (but probably not the
cause, although that may have changed in more recent builds (JDK
8/hs25+? have lost track..)

-- ramki

On Wed, May 15, 2013 at 8:05 AM, Vladimir Ivanov
<vladimir.x.ivanov at oracle.com> wrote:
> Hi,
>
> I see minor GCs occurring when young gen occupancy is very low, e.g.:
> [ParNew: 8446K->7381K(943744K), 0.0274200 secs]
>
> Does anybody know what provokes such "premature" GCs?
>
> There's no CMS concurrent cycle running or any other interesting GC events
> occurred around that moment - just a sequence of minor GCs with such
> outlier.
>
> Such premature minor GCs occur on a regular basis.
>
> JDK version: 6u37, 64-Bit Server VM (20.12-b01, mixed mode)
>
> Best regards,
> Vladimir Ivanov