KOSAKI Motohiro wrote: >>> Have you seen any real world example of this? >> At the unsophisticated end, there are lots of (Fortran) HPC applications >> with very large static array declarations but only "use" a small fraction >> of that. Those users know they only need a small fraction and are happy >> to volunteer small physical memory limits that we (admins/queuing >> systems) can apply. >> >> At the sophisticated end, the use of numerous large memory maps in >> parallel HPC applications to gain visibility into other processes is >> growing. We have processes with VSZ > 400GB just because they have >> 4GB maps into 127 other processes. Their physical page use is of >> the order 2GB. > > Ah, agreed. > Fujitsu HPC user said similar things ago. OK, so this use case is HPC specific. I am not against the swap controller, but overcommit can lead to problems if not controlled - such as OOM kill. The virtual address space limit helps applications fail gracefully rather than swap out excessively or OOM. I suspect there'll be applications that swing both ways. -- Warm Regards, Balbir Singh Linux Technology Center IBM, ISTL _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers
