Flag in JDK 7uXX to allow visibility into code cache usage?

[Kirk Pepperdine]

Hi Ramki,

My little VisualVM plugin MemoryPoolViewer was motivated by a need to see the occupancy and size of the code cache. I think it would be helpful if the compilation threads reported on pool maintenance as the GC threads do.

Regards,
Kirk

On 2013-11-04, at 6:17 PM, Srinivas Ramakrishna <ysr1729 at gmail.com> wrote:

> 
> We recently had a situation when code cache flushing, when the code cache was nearly full, caused a large drop
> in performance. It would be nice if there were a product flag (also in 7uXX) by which one could get
> a read of the code cache size on a periodic basis. It might be great, for instance, if this value were
> printed, say at each GC.
> 
> I understand that there is an Mbean that can be read to determine this value, but I was looking for
> something like a JVM flag that allows this to be printed to a log file on a periodic basis, say at each GC (or even eacn
> major gc cycle). In 7uXX at least there seem to be far too few means to track the usage of the code
> cache.
> 
> thanks for anything that can be done in this area, wrt visibility (in 7uXX :-)
> -- ramki