On Fri, 20 Sep 2024 18:11:51 GMT, Robert Toyonaga <d...@openjdk.org> wrote:
>> ### Summary >> This PR just replaces `ThreadCritical` with a lock specific to NMT. >> `ThreadCritical` is a big lock and is unnecessary for the purposes of NMT. >> I've implemented the new lock with a semaphore so that it can be used early >> before VM init. There is also the possibility of adding assertions in >> places we expect NMT to have synchronization. I haven't added assertions yet >> in many places because some code paths such as the (NMT tests) don't lock >> yet. I think it makes sense to close any gaps in locking in another PR in >> which I can also add more assertions. >> >> Testing: >> - hotspot_nmt >> - gtest:VirtualSpace >> - tier1 > > Robert Toyonaga has updated the pull request incrementally with one > additional commit since the last revision: > > Inherit from ConditionalMutexLocker. Use current_or_null_safe instead of > current_or_null. src/hotspot/share/runtime/mutexLocker.cpp line 139: > 137: Mutex* NMTQuery_lock = nullptr; > 138: Mutex* NMTCompilationCostHistory_lock = nullptr; > 139: Mutex* NMT_lock = nullptr; Sorry just noticed the other NMT locks. I think we need a more descriptive name than just plain NMT_lock so the usage is more clear. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/20852#discussion_r1770657123
