It looks like this failure requires using madvise() with MADV_HWPOISON (which requires root) and MADV_PAGEOUT, and the stack trace is in deep in the an mm codepath: madvise_cold_or_pageout_pte_range+0x1cac/0x2800 reclaim_pages+0x393/0x560 reclaim_folio_list+0xe2/0x4c0 shrink_folio_list+0x44f/0x3d90 unmap_poisoned_folio+0x130/0x500 try_to_unmap+0x12f/0x140 rmap_walk+0x16b/0x1f0 ... The bisected commit is the one which enables using large folios, so while it's possible that this due to ext4 doing something not quite right when using large folios, it's also posible that this might be a bug in the folio/mm code paths. Does this reproduce on other file systems, such as XFS? - Ted