RFR: 8238665: Add JFR event for direct memory statistics

[Erik Gahlin]

Yes, I can sponsor it.

Erik

> On 1 Apr 2020, at 16:43, Alan Bateman <Alan.Bateman at oracle.com> wrote:
> 
> On 31/03/2020 17:22, Denghui Dong wrote:
>> Hi Erik,
>> 
>> IMO, one event type per pool is a better choice, because:
>> 1. easy filtering and configuration as you said, and I don't think there will be too many buffer pool types in the future
>> 2. some buffer pools may have extra fields, e.g. direct memory has max capacity limit.
>> 
>> webrev: http://cr.openjdk.java.net/~ddong/8238665/webrev.05/ <http://cr.openjdk.java.net/~ddong/8238665/webrev.05/>
>> diff with webrev.04: http://cr.openjdk.java.net/~ddong/8238665/v4-v5.diff <http://cr.openjdk.java.net/~ddong/8238665/v4-v5.diff>
>> 
>> 
> This update looks good to me too.
> 
> Erik, are you okay to sponsor this one?
>