Hi Rafael, we have been chasing the following BUG() triggering during the memory hotremove (remove_memory): ret = walk_memory_range(PFN_DOWN(start), PFN_UP(start + size - 1), NULL, check_memblock_offlined_cb); if (ret) BUG(); and it took a while to learn that the issue is caused by /sys/firmware/acpi/hotplug/force_remove being enabled. I was really surprised to see such an option because at least for the memory hotplug it cannot work at all. Memory hotplug fails when the memory is still in use. Even if we do not BUG() here enforcing the hotplug operation will lead to problematic behavior later like crash or a silent memory corruption if the memory gets onlined back and reused by somebody else. I am wondering what was the motivation for introducing this behavior and whether there is a way to disallow it for memory hotplug. Or maybe drop it completely. What would break in such a case? Thanks! -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
