Hi all, we have been struggling with an issue in the bdwgc project (garbage collector) on P9 systems for a while [1]. There were some test failing on P9, but not on P8 or other platforms (x86, s390x, aarch64). Recently the upstream developer has found out there is likely a problem in the kernel memory mgmt [2], there is a reproduction scenario included. I have rechecked the original code on P9 with hash MMU and it worked. Thus I believe there is a problem in the radix MMU code on Power, where it behaves differently. My testing was using Fedora, which means recent kernels up to 6.4-rc1.
[1] https://github.com/ivmai/bdwgc/issues/479 [2] https://github.com/ivmai/bdwgc/issues/479#issuecomment-1535274481 Thanks, Dan
