Re: [RFC] Enhanced Garbage Collection Probe Points

[Mark Wielaard <mark@klomp.org>]

On Thu, 2012-08-02 at 09:10 -0400, Lukas Berk wrote:
> I've been working on adding improved probe point within the garbage
> collection system.  This will allow system administrators using various
> tools to better analyze which garbage collection algorithms are
> effective and java developers to better understand how (often) their
> objects are being collected.
> 
> Specific probe points that I've aimed to include are:
> 
> - G1, concurrent mark sweep, parallel mark sweep, and tenured
>   collections
> 
> - new generation definitions
> 
> - parallel scavenges
> 
> - parallel compaction
> 
> - object 'moves/resizes' between memory addresses
> 
> Please note that the attached patch should be appended to the
> patch/systemtap.patch file.  Any feedback or suggestions would be
> greatly appreciated.

They look interesting, but do you have some example usage for this? My
garbage collector knowledge is very rusty. Just some simple description
when which point would be hit and what interesting data can be
collected/analysed at that time would be nice to put this in context.

Did you happen to talk to the thermostat team? They might give some
feedback on what kind of information they need and whether these probe
points would cover their needs.

Thanks,

Mark