On 1/04/2016 15:54, David Crayford wrote:
Good luck with that mate! I've had conversations with the authors of JZOS about
RecordReader and it uses all the tricks bar going down to EXCPs. There are also
smarts to mitigate JNI overhead. If you write your own JNI code it won't be
zIIP eligible?
Have you measured RecordReader against an assembler program doing nothing more
than reading a file? I did that once and it was close.
Yes, the Java program used a little more than double the CPU of the
Assembler program reading 8GB of SMF data - but more than half was on
zIIP so there was actually less CP time. I need to do some tests to work
out how that varies with different quantities of data i.e. how much is
the startup of the JVM.
How close was close when you measured it?
I would prefer to use JZOS and avoid doing my own JNI. I did play around
with JNI and got maybe a 5% total reduction over RecordReader, but the
time on CP was much greater. I have some other improvements to do in my
own code first but might revisit it later.
Regards
Andrew Rowley
--
Andrew Rowley
Black Hill Software
+61 413 302 386
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