> Am 02.09.2020 um 11:53 schrieb Vlastimil Babka <vbabka@xxxxxxx>: > > On 8/28/20 6:47 PM, Pavel Tatashin wrote: >> There appears to be another problem that is related to the >> cgroup_mutex -> mem_hotplug_lock deadlock described above. >> >> In the original deadlock that I described, the workaround is to >> replace crash dump from piping to Linux traditional save to files >> method. However, after trying this workaround, I still observed >> hardware watchdog resets during machine shutdown. >> >> The new problem occurs for the following reason: upon shutdown systemd >> calls a service that hot-removes memory, and if hot-removing fails for > > Why is that hotremove even needed if we're shutting down? Are there any > (virtualization?) platforms where it makes some difference over plain > shutdown/restart? If all it‘s doing is offlining random memory that sounds unnecessary and dangerous. Any pointers to this service so we can figure out what it‘s doing and why? (Arch? Hypervisor?)