JFR sampling question

[Erik Gahlin]

Hi Thomas,

I don’t know what the event is called, but you can look at the configuration files and the period setting for the event.

https://github.com/openjdk/jdk/tree/master/src/jdk.jfr/share/conf/jfr

Erik

> On 4 Nov 2020, at 13:07, Thomas Stüfe <thomas.stuefe at gmail.com> wrote:
> 
> Hi,
> 
> I am currently reworking the Metaspace information shown in JMC, which is
> outdated after JEP387.
> 
> How often is this information sampled? How expensive can the sampling code
> get?
> 
> For example, post-JEP387, the metachunk freelists contain committed as well
> as uncommitted areas. While it may be interesting to know how much area is
> committed, that would require walking the freelists, which could get
> expensive.
> 
> Thanks, Thomas