RFR: 8293210: G1: Remove redundant check in G1FreeHumongousRegionClosure

[Kim Barrett]

On Thu, 1 Sep 2022 11:17:27 GMT, Albert Mingkun Yang <ayang at openjdk.org> wrote:

> Simple change of removing unnecessary code.
> 
> Test: hotspot_gc

src/hotspot/share/gc/g1/g1CollectedHeap.inline.hpp line 236:

> 234: 
> 235: inline bool G1CollectedHeap::is_humongous_reclaim_candidate(uint region) {
> 236:   assert(_hrm.at(region)->is_starts_humongous(), "Must start a humongous object");

I think I like the semantic requirement that this only be applied to starts-humongous regions.  Unless there is some future change that needs this removal (and not just because of the change to G1FreeHumongousRegionClosure::do_heap_region that I don't like), then I'd prefer it stay.

src/hotspot/share/gc/g1/g1YoungGCPostEvacuateTasks.cpp line 187:

> 185:     if (!r->is_starts_humongous()) {
> 186:       return false;
> 187:     }

I think this check is a fast-path to quickly filter out definitely uninteresting regions, which will be nearly all of them.  I'm not convinced it should be removed.

-------------

PR: https://git.openjdk.org/jdk/pull/10119