On Fri, Aug 12, 2016 at 03:21:41PM +0200, Oleg Nesterov wrote: > Whats really interesting is that I still fail to understand do we really > need this hack, iiuc you are not sure too, and Michael didn't bother to > explain why a bogus zero from anon memory is worse than other problems > caused by SIGKKILL from oom-kill.c. vhost thread will die, but vcpu thread is going on. If it's memory is corrupted because vhost read 0 and uses that as an array index, it can do things like corrupt the disk, so it can't be restarted. But I really wish we didn't need this special-casing. Can't PTEs be made invalid on oom instead of pointing them at the zero page? And then won't memory accesses trigger pagefaults instead of returning 0? That would make regular copy_from_user machinery do the right thing, making vhost stop running as appropriate. -- MST -- 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>