On Tue 13-06-17 11:25:02, Liam R. Howlett wrote: > * Michal Hocko <mhocko@xxxxxxxx> [170613 01:42]: > > On Mon 12-06-17 21:35:17, Liam R. Howlett wrote: > > [...] > > > Understood. Again, I appreciate all the time you have taken on my > > > patch and explaining your points. I will look at this again as you > > > have suggested. > > > > One way to go forward might be to check the size of the per node pool > > and warn if it grows over a certain threshold of the available memory > > on that node. I do not have a good idea what would be that threshold, > > though. It will certainly depend on workloads. I can also imagine that > > somebody might want to dedicate the full numa node for hugetlb pages > > and still be OK so take this suggestion with some reserve. It is hard > > to protect against misconfigurations in general but maybe you will find > > some way here. > > I thought about an upper threshold of memory and discussed it > internally, but came to the same conclusion; it may be desired and > there's no safe bet beyond warning if the user requests over 100% of the > memory. In the case of requesting over 100% of the memory, we could > warn the user and specify what was allocated. Would it be reasonable to > warn on both boot and through sysfs of such requests? I'm concerned > that this is yet another too-targeted approach. No, I think 100% is just too targeted. As I've said already said, a good enough treshold might be hard to get right but filling up more than 90% of memory with hugetlb pages will just bite you unless you know what you are doing. And if so you can safely ignore such a warning... -- Michal Hocko SUSE Labs -- 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>
