On Wed, 8 Sep 2021 09:56:21 GMT, Per Liden <pli...@openjdk.org> wrote:
> JDK-8237354 introduced the concept of "foreground work" in WorkGang, as a > special case for use by the HeapDumper. I propose that we remove this code, > since this special use case can be solved without the need for the concept of > "foreground work" in WorkGang. > > As far as I can tell, there's no reason why it must be the VM thread that > takes on the task of writing the header, iterating over roots, etc. So, in > VM_HeapDumper::work(), instead of checking if the current thread is the VM > thread we can just check if the worker_id is non-zero. That way, a single > worker thread will take on the task of writing the header, iterating over > roots, etc, and all other worker threads will continue to call worker_loop(). > > Testing: > - Passed Tier1-3 > - Passed multiple runs of test/hotspot/jtreg/serviceability/dcmd/gc/ > - Manually ran jcmd GC.heap_dump with various GCs enabled Patch updated include the removal of a few asserts, as discussed here: http://mail.openjdk.java.net/pipermail/hotspot-gc-dev/2021-September/036807.html ------------- PR: https://git.openjdk.java.net/jdk/pull/5410
