Hi Lin,
On 1/09/2020 12:28 pm, linzang(臧琳) wrote:
Dear All,
May I ask your help to review this change of adding parallel
heap inspection for PSS Heap?
bug: https://bugs.openjdk.java.net/browse/JDK-8252103
webrev:
http://cr.openjdk.java.net/~lzang/jmap-8214535/8252103/webrev.00/
My preliminary measurement shows about ~1x speed up for when
using 4 threads of jmap -histo. (on a 4 core Linux machine, with -xmx8g
and objects takes 1.5GB in heap.)
~1x speed up is not a speed up. What exactly did you mean here?
Thanks,
David
-----
As spaces in youngGen of parallelScvangeHeap is hard to be
divided for parallel iteration, this change just assign different worker
thread to process different space in youngGen, that is, 1 thread to
process whole eden space etc. so this may be one reason that speedup is
not scale with parallel thread number.
BRs,
Lin
