support IUnit of Allocation Rate

[Marcus Hirt]

Hi Xin Liu,

JFR already has compound units:
https://github.com/openjdk/jdk/blob/master/src/hotspot/share/jfr/metadata/metadata.xml

  <XmlContentType name="bytes-per-second"
annotation="jdk.jfr.DataAmount(BYTES), jdk.jfr.Frequency" />
  <XmlContentType name="bits-per-second"
annotation="jdk.jfr.DataAmount(BITS), jdk.jfr.Frequency" />

I think adding special cases is likely not the right way forward.

Kind regards,
Marcus


On Tue, Mar 29, 2022 at 1:37 AM Liu, Xin <xxinliu at amazon.com> wrote:

> hi, Marcus,
>
> Yes, I am looking for a general approach to combine two units and get a
> compound unit. Is there any other scenarios besides B/s.
>
> Or we treat B/s as a special case. I look up wikipedia, maybe it's not
> an appalling hack to create a unit called "data-rate"
> https://en.wikipedia.org/wiki/Data-rate_units. It has a clear
> definition, symbol and scales.
>
> I plan to create a map in UnitLookup. it maps MEMORY to MEMORY/s. does
> it sound reasonable?
>
> thanks,
> --lx
>
> On 3/28/22 5:19 AM, Marcus Hirt wrote:
> > *CAUTION*: This email originated from outside of the organization. Do
> > not click links or open attachments unless you can confirm the sender
> > and know the content is safe.
> >
> >
> > Hi Xin Liu,
> >
> > Fixing this properly is probably a bit bigger. We'd probably want to
> > have a compound unit and add support for compound units in a general way.
> >
> > Kind regards,
> > Marcus
> >
> > On Mon, Mar 28, 2022 at 8:37 AM Liu, Xin <xxinliu at amazon.com
> > <mailto:xxinliu at amazon.com>> wrote:
> >
> >     Hi, Developers,
> >
> >     I am new for the codebase of Java mission control. I would like to
> add
> >     allocation Rate in Summary page(JMC-7301).
> >
> >     I manage to extend aggregators ALLOC_INSIDE_TLAB_SUM and
> >     ALLOC_OUTSIDE_TLAB_SUM. The duration is known from
> >     TlabPage::visibleRange.
> >
> >     The biggest challenge is to align with the new unit. IUnit of
> Allocation
> >     Rate is B/s. I haven't found similar IUnit like that. Is there a way
> to
> >     derive B/s from Memory?
> >
> >     To display the correct unit of allocation rate, I create a new
> >     LinearKindOfQuantity "memory bandwidth". The only difference of it
> from
> >     memory is that its atom unit is B/s.
> >
> >     Here is my attempt. sorry it looks awful. Any suggest to make it more
> >     elegant?
> >
> >
> https://github.com/navyxliu/jmc/commit/b3cd19b1b6bb5cb93241b4dbb8086a6305fe4023#diff-d740b28fe16b17f85bf34790e5afc60eb0d2f39d7827f894184713430d74131bR793
> >     <
> https://github.com/navyxliu/jmc/commit/b3cd19b1b6bb5cb93241b4dbb8086a6305fe4023#diff-d740b28fe16b17f85bf34790e5afc60eb0d2f39d7827f894184713430d74131bR793
> >
> >
> >
> >     thanks,
> >     --lx
> >
> >
> >
> >
> >