>> Add debugfs files /sys/kernel/debug/sgx/poison_page_list so that system >> administrators get a list of those pages that have been dropped because >> of poison. > > So, what would a sysadmin do with that detailed information? It's going to be a rare case that there are any poisoned pages on that list (a large enough cluster will have some systems that have uncorrected recoverable errors in SGX EPC memory). Even when there are some poisoned pages, there will only be a few. Systems that have thousands of pages with uncorrected memory errors will surely crash because one of those errors is going to either trigger an error marked as fatal, or the error won’t be recoverable by Linux because it is in kernel memory. A sysadmin might add a script to run during system shutdown (or periodically during run-time) to save the poison page list. Then at startup run: for addr in `cat saved_sgx_poison_page_list` do echo $addr > /sys/devices/system/memory/hard_offline_page done to make poison persistent across reboots. -Tony
