Unexpected heap growth in gctest if no parallel marker

[ivmai]

Source: master (67090a1)
Build: https://github.com/ivmai/bdwgc/actions/runs/8890197137/job/24409845525
Config: ubuntu-latest native thr:true rwlock:true redir:false gcdeb:false munmap:true paramark:false thrlocal:true dll:false
Occurrence: sometimes
Output (gctest):
``
Final heap size is 1048576 bytes
Unexpected heap growth - collector may be broken (heapsize: 269492224, expected: 159383552)

[ivmai]

Source: master (2ea2415)
Host: x86_64-linux
Build: https://github.com/ivmai/bdwgc/actions/runs/11861573652/job/33059211062
Command: zig build -Dtarget=native -DBUILD_SHARED_LIBS=false -Dbuild_cord=true -Ddisable_handle_fork=false -Denable_cplusplus=true -Denable_gc_assertions=true -Denable_gc_debug=false -Denable_large_config=false -Denable_munmap=false -Denable_parallel_mark=false -Denable_redirect_malloc=false -Denable_rwlock=true -Denable_thread_local_alloc=true -Denable_threads=true -Denable_werror test
Output (gctest):

Running on LINUX/X86_64 target
Supported VDBs: manual soft mprotect
Switched to incremental mode
Reading dirty bits from /proc
Completed 6 tests (concurrently)
Allocated 11792350 collectable objects
Test failed
Allocated 1224 uncollectable objects
Allocated 720438 atomic objects
Reallocated 36 objects
Garbage collection after fork is tested too
Finalized 13253/13253 objects - finalization is probably OK
Total number of bytes allocated is 1160237664
Total memory use by allocated blocks is 1273856 bytes
Final heap size is 164982784 bytes
Unexpected heap growth - collector may be broken (heapsize: 164982784, expected: 159383552)