On Mon, 28 Oct 2024 15:45:31 GMT, Robert Toyonaga <d...@openjdk.org> wrote:
>> src/hotspot/share/runtime/mutexLocker.cpp line 299: >> >>> 297: MUTEX_DEFN(ThreadsSMRDelete_lock , PaddedMonitor, >>> service-2); // Holds ConcurrentHashTableResize_lock >>> 298: MUTEX_DEFN(ThreadIdTableCreate_lock , PaddedMutex , >>> safepoint); >>> 299: MUTEX_DEFN(SharedDecoder_lock , PaddedMutex , >>> service-5); >> >> Why this? Do we print stacks under NMT lock protection? > > Yes I think so. `MemTracker::print_containing_region` first acquires the NMT > lock then the `SharedDecoder_lock` like this: > > `MemTracker::print_containing_region` --> > `PrintRegionWalker::do_allocation_site` --> > `NativeCallStack::print_frame` --> > `Decoder::get_source_info` --> > `Decoder::shared_decoder_lock()` Otherwise `make test TEST=hotspot_nmt` throws a lock rank error when running the test `location_printing_mmap_1`. That test uses `MemTracker::print_containing_region`. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/20852#discussion_r1819316109
