Maybe it is about the safe points? In a conventional generational gc every thread has its own nursery (plus semi-space for copying collection), so you can colle

Maybe it is about the safe points? In a conventional generational gc every thread has its own nursery (plus semi-space for copying collection), so you can collect one thread's garbage without stopping any other thread (so data threads share must not be allocated in the nursery). > So, for this test with eight threads, on my 8-core Ryzen 7 7840U laptop, the nursery is 16MB including the copy reserve, which happens to be the same size as the L3 on this CPU. Sounds way too small. Speed of copying collection is proportional to the number of survivors and with only 16 mb you risk having lots of false survivors.