By Clifford Click, from ~20 years of experience with just Hotspot. Some hard earned knowledge, like: • GC requires SP (& usually PC) for stack roots • Har

By Clifford Click, from ~20 years of experience with just Hotspot. Some hard earned knowledge, like: • GC requires SP (& usually PC) for stack roots • Hard to find the SP+PC of remote thread ─ Common problem of OS's ─ ! Very surprising to me, until I tried it ! ─ Fails (w/low frequency) on many “robust” OSes! ─ Caught in page fault handler, nested in tlb handler, nested in stack overflow handler nested in .... Ouch!