>>> Failing on ENOMEM is a questionable thing. I haven't seen that happening >>> wildly but if it is a case then I wouldn't be opposed. >>> >>>> You mentioned memory pressure, if our host is under memory pressure we >>>> can easily trigger running into an endless loop there, because we >>>> basically ignore -ENOMEM e.g. when we cannot get a page to migrate some >>>> memory to be offlined. I assume this is the case here. >>>> do_migrate_range() could be the bad boy if it keeps failing forever and >>>> we keep retrying. >> >> I've seen quite some issues while playing with virtio-mem, but didn't >> have the time to look into the details. Still on my long list of things >> to look into. > > Memory hotplug is really far away from being optimal and robust. This > has always been the case. Issues used to be workaround by retry limits > etc. If we ever want to make it more robust we have to bite a bullet and > actually chase all the issues that might be basically anywhere and fix > them. This is just a nature of a pony that memory hotplug is. > Yes I agree, no more workarounds. -- Thanks, David / dhildenb
