I'm not a GC specialist, but your approach looks reasonable to me.
parallelScavengeHeap.cpp:
"less that 1 workers" -> "less that 1 worker"
psOldGen.cpp:
">=2" -> ">= 2"
"thread_num-2 worker" -> "(thread_num -2) workers"
"cross blocks" -> "crosses blocks"
"that the object start address locates in the related block" -> "that owns the
block within which the object starts"
blocks_iterate_parallel() relies on BLOCK_SIZE being an integral multiple of a
start_array() block (i.e., ObjectStartArray:: block_size). I'd add an assert to
that effect.
The comment on the definition of BLOCK_SIZE is "64 KB", but you're doing
pointer arithmetic in terms of HeapWords, which means the actual byte value is
either 256KB or 512KB for 32- and 64-bit respectively. You could use
const int BLOCK_SIZE = (64 * 1024 / HeapWordSize);
"// There is objects" -> "There are objects"
"reture" -> "return"
", here only focus objects" -> ". Here only focus on objects"
It's a matter of taste, but imo the loop in blocks_iterate_parallel() would be
more clear as
for (HeapWord* p = start; p < end; p += oop(p)->size()) {
cl->do_object(oop(p));
}
psOldGen.hpp:
blocks_iterate_parallel() is pure implementation and I don't see a reference
outside psOldGen.cpp. So, it should be private, not public.
psYoungGen.cpp:
"<=1" -> "<= 1"
Thanks,
Paul
On 9/11/20, 12:29 AM, "hotspot-gc-dev on behalf of Lin Zang"
<hotspot-gc-dev-r...@openjdk.java.net on behalf of lz...@openjdk.java.net>
wrote:
On Sun, 6 Sep 2020 01:13:48 GMT, Lin Zang <lz...@openjdk.org> wrote:
> - Parallel heap iteration support for PSS
> - JBS: https://bugs.openjdk.java.net/browse/JDK-8252103
Dear All,
May I ask your help to review this PR? Thanks!
-Lin
-------------
PR: https://git.openjdk.java.net/jdk/pull/25
